Serum Myoglobin

Anoosh Zafar Gondal; Lisa Foris; Muhammad Zubair; John Richards

Serum Myoglobin

Free Review Questions

Introduction

Myoglobin is a dark red cytoplasmic hemoprotein found only in cardiac myocytes and oxidative skeletal muscle fibers.[1] It belongs to the super globin family of proteins. It comprises a single polypeptide chain of 154 amino acids and a porphyrin ring containing a central ferrous iron molecule. Similar to hemoglobin, myoglobin functions to reversibly bind oxygen and can form oxymyoglobin, carboxy myoglobin, or metmyoglobin.[2] Unlike hemoglobin, however, myoglobin has only one binding site for oxygen, the affinity of which is comparatively very high.[3] As a result, myoglobin can receive oxygen from hemoglobin at the tissue level via the Bohr effect and either store oxygen or deliver it to muscle cells during periods of hypoxia, anoxia, or increased metabolic activity.[4]

Etiology and Epidemiology

Due to its low molecular weight, myoglobin is released quickly following muscle injury; it is the earliest marker of myocardial infarction and rhabdomyolysis.[5] The release of myoglobin from muscles during such conditions is often also associated with the release of lactate dehydrogenase (LDH), creatine kinase, and serum glutamic-pyruvic transaminase, in addition to other enzymes.[6] Secondary complications of rhabdomyolysis include hyperkalemia, hypocalcemia, and acute kidney injury; myoglobin in the urine is toxic to the nephron.[7]

Myoglobinuria in adults is most often encountered in cases of alcohol and drug abuse or trauma; muscle necrosis with subsequent myoglobin release also commonly occurs due to prolonged immobilization or pressure from the weight of the body.[8] Furthermore, excessive physical activity; metabolic disorders; viral infections, such as influenza, HIV, or herpes simplex; toxin-producing bacterial infections; connective tissue disease; seizures; electrical shock injury, including lightning strikes; third-degree burns; venom from a snake or insect bite; certain medications, such as statins or antipsychotics; or prolonged alcohol or drug use, as with heroin, cocaine, or amphetamines all can create an imbalance in muscle energy production and consumption which result in muscle damage and destruction.[9]

Contrastingly, rhabdomyolysis or myoglobinuria in children is often associated with viral myositis, trauma, excessive muscular exertion, drug overdose, seizures, connective tissue disease, or metabolic disorders.[10]

The incidence of myoglobinuria in the United States varies depending on the incidence of traumas or natural disasters. An increased incidence of viral myositis, such as that caused by a regional epidemic, may cause a temporary increase in the incidence of rhabdomyolysis and myoglobinuria.[11] The excessive heat or higher temperatures seen in the summer months or warmer geographic areas may cause heat stroke, especially in those who are more active; malignant hyperthermia or neuroleptic malignant syndrome may additionally increase the incidence of stress or exertion-induced rhabdomyolysis.[12]

Pathophysiology

Under normal conditions, myoglobin circulates in the blood bound to plasma globulins which are maintained between 0 to 0.003 mg/dL.[7] Once serum myoglobin levels reach a level above 0.5 to 1.5 mg/dL, the rate of metabolism, endocytosis, and serum protein binding capacity is overwhelmed, and myoglobin is rapidly excreted in the urine.[13]

Myoglobin release from muscle tissues occurs due to damage to muscle cells and a change in skeletal muscle cell membrane permeability.[14] Damage to muscle cells results in dysregulation of sodium-calcium channel functioning, ultimately elevating intracellular free ionized calcium.[15] This causes a resultant activation of calcium-dependent enzymes, which further metabolize and destroy the muscle cell membrane and allow for the release of intracellular contents, including myoglobin and creatine kinase.[16]

In health, myoglobin is easily filtered by the glomerulus and quickly excreted in the urine. However, large amounts of myoglobin in renal tubules can lead to an interaction of the hemoprotein with Tamm-Horsfall proteins, subsequent precipitation, and tubular obstruction.[17] This process occurs most favorably in conditions where acidic urine is present. In addition, damage to both muscle tissues and kidney epithelial cells promotes the production of reactive oxygen species, which can, in turn, lead to the oxidation of ferrous oxide to ferric oxide, a hydroxyl radical.[18] Myoglobinuria-induced tubular obstruction and oxidative damage can, either alone or in combination, lead to acute kidney injury.[19]

Specimen Requirements and Procedure

The preferred specimen is non-hemolyzed, non-lipemic serum. One study found no significant difference between heparinized plasma and serum, although results from EDTA plasma samples were significantly lower than serum samples.[20] Another study found that different anticoagulants can substantially interfere with myoglobin assays.[21] Each method should be investigated concerning the differences observed between serum and the use of various anticoagulants. Specimens are stable at 4^oC for one week and up to four weeks at −20^oC.[22]

Urine samples should be collected without preservatives and assayed within 24 hours of sample collection. If the test is not performed immediately after sample collection, the urine sample should be kept at 2^oC to 8^oC and centrifuged to remove any debris before the assay.[23] Myoglobin in urine is stable under alkaline conditions (pH 9.0) for many days at 2^oC, −20^oC, and −70^oC; sodium hydroxide can be added if long-term storage is needed.[24]

Diagnostic Tests

The diagnosis of rhabdomyolysis requires a high index of suspicion, given that the classic clinical symptoms may not be present.[7] A definitive diagnosis is often made by elevated serum creatine kinase or urine myoglobin.[25] Liver and renal function may be assessed if complications secondary to rhabdomyolysis are concerning.[26]

Although myoglobin is the first enzyme to be elevated in rhabdomyolysis, levels often return to normal within 24 hours after the onset of symptoms.[27] Serum creatine kinase levels, on the other hand, begin to rise approximately 2 to 12 hours after the onset of symptoms and remain elevated for 7 to 10 days, with levels peaking around three days after the onset of symptoms.[28] Serum creatine kinase is also an important and useful tool for gauging the severity of rhabdomyolysis.[29] Elevated serum creatine kinase suggests a possible delay of clearance from the plasma by the kidneys, indicating complications such as acute kidney damage or injury.[30]

Though myoglobinuria is pathognomonic for rhabdomyolysis, it is important to note that rhabdomyoglobinuria is not always present or visible.[31] The presence of myoglobin in the blood also lacks cardiac specificity due to its concomitant expression in both cardiac and skeletal muscle cells.[32] Therefore, a more specific indicator, such as troponin or creatine kinase, must be measured to confirm a diagnosis of acute myocardial infarction.[33]

Urinalysis should be employed to evaluate for myoglobinuria and assess the presence or severity of renal damage or acute kidney injury.[34] Furthermore, if kidney injury due to rhabdomyolysis is suspected, the serum creatinine level should be assessed; creatinine is often quickly elevated during rhabdomyolysis when compared to other causes of kidney injury. In addition to this, the blood urea nitrogen to creatinine ratio is also generally low.[35]

A thorough history and physical examination are critical to diagnosing rhabdomyolysis, though they are not always helpful in determining the underlying cause.[25] If infectious causes are suspected, one should assess the complete blood count, appropriate cultures, and any additional serologic studies that may help confirm or point toward a diagnosis. Blood chemistries and endocrine assays may be helpful if an underlying endocrine abnormality is suspected.[26] If drugs or toxins are a potential underlying cause, the appropriate screening for toxins should be performed.[36] In patients with repeated instances of rhabdomyolysis, genetic testing, a muscle biopsy, or the forearm ischemic exercise test may reveal an underlying myopathy or metabolic disorder.[28]

Though imaging is not generally indicated in cases of rhabdomyolysis, given that it is a clinical syndrome often diagnosed with supportive laboratory tests, MRI, bone scintigraphy, ultrasound, or CT can be used to demonstrate some changes in muscle tissue.[37] An ECG is necessary to detect cardiac arrhythmias from electrolyte abnormalities due to rhabdomyolysis.[38] An assessment of blood chemistries also may help point towards this, in addition to an arterial blood gas analysis if metabolic acidosis is suspected.[25]

Testing Procedures

Qualitative and semiquantitative immunological methods have been used for the detection of myoglobin.[24] With the simplicity of the agar gel precipitin techniques and the speed of electrophoresis, counter immunoelectrophoresis has been used to detect myoglobin in both serum and urine.[39] It is a qualitative procedure with a sensitivity of only 2 mg/L. Thus, it is unsuitable for detecting acute myocardial infarction (AMI).[40]

A rapid, qualitative latex agglutination test for detecting increased concentrations of myoglobin in serum has been reported.[41] In this test procedure, any interfering rheumatoid factor present in the sample is removed when 50 μL of test serum is mixed with 5 μL of rheumatoid factor absorption medium on a dark slide. About 50 μL of a suspension of latex particles with bound anti-myoglobin antibodies is added and mixed with the serum by gentle tilting for 5 minutes. Agglutination of the particles occurs in the presence of myoglobin. A negative exponential relationship has been found between the time of agglutination and myoglobin concentrations.[42] Myoglobin concentration was considered to be greater than 400 mg/L if agglutination occurred within 1 minute, 150 to 400 mg/L if agglutination time was between 1 and 2 minutes, 80 to 150 mg/L if agglutination time was between 2 and 3 minutes, and less than 80 mg/L (upper limit of reference interval) if more than 3 minutes were required for agglutination.[43]

Red blood cell agglutination techniques are reported to be sensitive in the 50 to 100 mg/L range. A disadvantage of this technique is that some sera containing a high concentration of rheumatoid factor gave positive agglutination reactions.[44] The latex agglutination procedure is, at best semiquantitative and is somewhat subjective, requiring visual observation to establish an endpoint. The sensitivity of the latex test may not be adequate.[45] The advantage of the latex test is its simplicity.[42]

A quantitative microcomplement fixation assay has been developed to detect myoglobin in the serum and urine of patients with acute coronary syndrome or myopathies.[46] This technique is based on consuming a fixed amount of hemolytic complement by myoglobin-antimyoglobin complexes.[47] The amount of myoglobin present in the sample is inversely proportional to the extent of hemolysis of the hemolysin-sensitized sheep cells used as the indicator system.[48] Quantitative microcomplement fixation is an extremely time-consuming and laborious technique.[47]

Currently, the determination of serum myoglobin for diagnosing AMI and other muscle disorders is performed almost exclusively by immunoassay techniques because of their high analytical sensitivity, specificity, precision, and rapid turnaround time.[49] Radioimmunoassay (RIA) procedures have also been described for quantitative measurement of serum myoglobin. However, in clinical laboratories, RIA has largely been replaced by automated 2-site non-isotopic immunoassays.[50] The capture antibody is linked to a bead or paramagnetic particle. The detecting antibody is linked to a tag that can produce a nephelometric, turbidimetric, fluorometric, or chemiluminescence signal.[49] Automated immunoassay analyzers perform a separation between bound and free labels to produce a quantitative result.[51]

Qualitative and quantitative methods for serum myoglobin have also been developed for point-of-care (POC) use.[52] One POC method utilizes a self-calibrating immunoassay system whereby whole blood is separated from plasma that reacts with fluorescent antibody conjugates within a reaction chamber. Following an incubation step, the reaction mixture flows down a detection lane by capillary action. The myoglobin–fluorescent antibody complex is captured by a second antibody in a discrete measuring zone. The intensity of the label (visual or fluorescence) is related to myoglobin concentration. The procedure takes approximately 15 minutes to complete.[53] Since myoglobin measurements are most commonly used in diagnosing and excluding AMI, several POC devices have combined myoglobin with other cardiac markers, such as CK-MB and cardiac troponin, into a single cartridge or slide.[54]

International guidelines such as those from the National Academy of Clinical Biochemistry have suggested that results of cardiac markers should be reported within one hour of blood collection.[55] Other groups, such as the American Heart Association, have suggested an optimal turnaround time of under 30 minutes.[56] These POC devices are designed for use at the patient bedside or emergency department satellite laboratories to produce results that meet these recommended 30- to 60-minute turnaround time goals for reporting test results.[57]

Interfering Factors

The use of collection tubes with separator gels has been reported to both increase and decrease myoglobin results.[21] Bilirubin has been found not to interfere.[58] Rheumatoid factor (RF) has been found to affect results in some assays, with a lack of concordance between concentrations of RF and the magnitude of interference.[49] As with any 2-site immunoassays that use monoclonal antibodies, the presence of human anti-mouse antibodies can potentially cause a false-positive result.[59]

Clinical Significance

Myoglobin is a relatively small globular protein composed of a single polypeptide chain of 154 amino acids and an iron-containing heme prosthetic group identical to that of hemoglobin.[11] It can reversibly bind oxygen molecules and speed up the diffusion of oxygen into skeletal and cardiac muscle cells, where it is present.[1] Myoglobin is an oxygen carrier in the cytoplasm and appears responsible for transporting oxygen from the muscle cell membrane to the mitochondrion.[60] Immunological techniques cannot discriminate between myoglobins from skeletal and cardiac muscles since they are immunologically identical.[46]

Due to its relatively low molecular mass, myoglobin may leak from muscle tissue into the bloodstream due to skeletal or cardiac muscle injury and then show up in the urine.[8] Myoglobinemia and myoglobinuria have been used in the diagnosis of myopathies and cardiomyopathies.[28] A pronounced increase in serum myoglobin is an early quantitative indicator of AMI.[5] It has been reported that myoglobinuria is a more sensitive clinical indicator of AMI than increased activities or concentrations of serum creatine kinase-MB (CK-MB) isoenzyme, especially when blood samples are drawn in the early stage of the disease (e.g., within 3 hours after onset).[61] However, these assays are less specific because no assay can differentiate myocardial from skeletal muscle myoglobin.[62] Increased serum myoglobin concentrations return to normal sooner than total CK and the CK-MB isoenzyme in AMI.[63] The faster elimination of myoglobin from the blood may be advantageous in the assessment of reinfarctions occurring during the period of increased enzyme activities.[64] Recurrent increases in serum myoglobin are thus suggestive of an extension of the original infarction.[65]

Since myoglobin is also present in skeletal muscle and is cleared almost exclusively through glomerular filtration, myoglobin will increase after acute muscle trauma, acute or chronic kidney injury, severe heart failure, prolonged shock, and in patients with myopathies of a variety of causes.[11] Therefore, using serum myoglobin levels to furnish early, quantitative documentation of AMI should be limited to patients who do not have these underlying or associated problems and who are within the first 18 hours of the clinical onset of infarction.

In addition, serum myoglobin levels have been used to evaluate neuromuscular diseases such as muscular dystrophy, muscular atrophy, and polymyositis.[66] Percy et al. reported that the combination of CK, hemopexin, and myoglobin measurements provided significantly better detection of Duchenne muscular dystrophy carriers than when these three tests were used alone or as a combination of CK and hemopexin without myoglobin.[67]

In studies conducted on myopathies in children, serum myoglobin concentrations for subjects 0.6 to 20 years were lower than in adults, so using assays with a high sensitivity of 2 µg/L or less is necessary.[68] Mean myoglobin concentrations of 17.1 and 12.5 µg/L were obtained from 37 males and 29 females, respectively, and were statistically different.

Investigations in children with muscle diseases, however, have been somewhat disappointing. Only 2 out of 14 patients studied had increased serum myoglobin concentrations. The patients evaluated in this study were relatively young, ranging from 0.3 to 16 years of age, and were presumably in the relatively early stages of the disease.[66] This might have contributed to the low rate of hypermyoglobinemia in this group of patients. Edwards et al. also found that measurement of myoglobin offered no advantage over CK for investigating any aspect of Duchenne muscular dystrophy. However, serum myoglobin measurements were helpful in detecting Duchenne muscular dystrophy carriers when used with CK and hemopexin.[69]

Myoglobin measurements are also used for the diagnosis of patients with rhabdomyolysis.[7] The course and clinical presentation of rhabdomyolysis can vary significantly depending on the cause of the muscle injury. Symptoms may be localized to one specific area or diffusely affect the entire body. Complications may occur at varying stages of muscle injury.[26] The classic triad of symptoms associated with rhabdomyolysis includes muscle pain, especially in the shoulders, lower back, or thighs; muscle weakness; and darkened brownish urine or decreased urine output.[25] Approximately 50% of individuals who experience rhabdomyolysis may present asymptomatically.[27]

Other symptoms seen with rhabdomyolysis include nausea, vomiting, abdominal pain, tachycardia, fever or chills, dehydration, confusion, or an altered level of consciousness which may present as a coma.[70] Severe complications due to rhabdomyolysis are more frequently encountered in patients who are dehydrated.[71] Elevated potassium in the blood due to muscle cell damage may result in cardiac arrhythmias or even cardiac arrest and death.[28] Serum uric acid may increase, and metabolic acidosis may occur due to acute kidney injury secondary to myoglobinuria. Kidney injury may lead to elevated creatinine and blood urea nitrogen levels, in addition to an increase in creatinine leaking into the blood from the damaged muscle cells themselves.[30]

Although myoglobin is easily filtered by the glomerulus and rapidly excreted into the urine in health, it is important to recognize the presence and severity of myoglobinuria and intervene as early as possible. Aggressive hydration or alkalinization of urine may facilitate the excretion of myoglobin and prevent acute kidney injury.[72] Myoglobinuria is often associated with darkened, brown, or tea-colored urine and decreased urine output.[8] However, it is essential to distinguish myoglobinuria from hematuria. Where myoglobinuria produces more brownish-colored urine and only a few red blood cells per high-power field on urinalysis, hematuria often will cause reddish urine and many red blood cells on urinalysis.[9] The creatine kinase level will be much higher in patients with myoglobinuria than in those with hematuria.[71]

Quality Control and Lab Safety

For non-waived tests, laboratory regulations require, at the minimum, analysis of at least two levels of control materials once every 24 hours.[73] Laboratories can assay QC samples more frequently to ensure accurate results. Quality control samples should be assayed after calibration or maintenance of an analyzer to verify the correct method performance.[74] To minimize QC when performing tests for which manufacturers’ recommendations are less than those required by the regulatory agency (such as once per month), the labs can develop an individualized quality control plan (IQCP) that involves performing a risk assessment of potential sources of error in all phases of testing and putting in place a QC plan to reduce the likelihood of errors.[75] Westgard multi-rules are used to evaluate the quality control runs. In case of any rule violation, proper corrective and preventive action should be taken before patient testing is performed.[76]

The laboratory must participate in the external quality control or proficiency testing (PT) program because it is a regulatory requirement published by the Centers for Medicare and Medicaid Services (CMS) in the Clinical Laboratory Improvement Amendments (CLIA) regulations.[77] It is helpful to ensure the accuracy and reliability of the laboratory with regard to other laboratories performing the same or comparable assays. Required participation and scored results are monitored by CMS and voluntary accreditation organizations.[78] The PT plan should be included as an aspect of the quality assessment (QA) plan and the overall quality program of the laboratory.[79]

Consider all specimens, control materials, and calibrator materials as potentially infectious. Exercise the normal precautions required for handling all laboratory reagents. Disposal of all waste material should be in accordance with local guidelines.[80] Wear gloves, a lab coat, and safety glasses when handling human blood specimens. Place all plastic tips, sample cups, and gloves that come into contact with blood in a biohazard waste container. Discard all disposable glassware into sharps waste containers.[81] Protect all work surfaces with disposable absorbent bench top paper, discarded into biohazard waste containers weekly or whenever blood contamination occurs. Wipe all work surfaces weekly.[82]

Details

References

[1]

Ordway GA, Garry DJ. Myoglobin: an essential hemoprotein in striated muscle. The Journal of experimental biology. 2004 Sep:207(Pt 20):3441-6 [PubMed PMID: 15339940]

[2]

Hendgen-Cotta UB, Flögel U, Kelm M, Rassaf T. Unmasking the Janus face of myoglobin in health and disease. The Journal of experimental biology. 2010 Aug 15:213(Pt 16):2734-40. doi: 10.1242/jeb.041178. Epub [PubMed PMID: 20675542]

[3]

Kuzmanovska B, Cvetkovska E, Kuzmanovski I, Jankulovski N, Shosholcheva M, Kartalov A, Spirovska T. Rhabdomyolysis in Critically Ill Surgical Patients. Medical archives (Sarajevo, Bosnia and Herzegovina). 2016 Jul 27:70(4):308-310 [PubMed PMID: 27703296]

[4]

Giuliani KTK, Kassianos AJ, Healy H, Gois PHF. Pigment Nephropathy: Novel Insights into Inflammasome-Mediated Pathogenesis. International journal of molecular sciences. 2019 Apr 23:20(8):. doi: 10.3390/ijms20081997. Epub 2019 Apr 23 [PubMed PMID: 31018590]

[5]

Aydin S, Ugur K, Aydin S, Sahin İ, Yardim M. Biomarkers in acute myocardial infarction: current perspectives. Vascular health and risk management. 2019:15():1-10. doi: 10.2147/VHRM.S166157. Epub 2019 Jan 17 [PubMed PMID: 30697054]

Level 3 (low-level) evidence

[6]

Nilsson A, Alkner B, Wetterlöv P, Wetterstad S, Palm L, Schilcher J. Low compartment pressure and myoglobin levels in tibial fractures with suspected acute compartment syndrome. BMC musculoskeletal disorders. 2019 Jan 5:20(1):15. doi: 10.1186/s12891-018-2394-y. Epub 2019 Jan 5 [PubMed PMID: 30611244]

[7]

Cabral BMI, Edding SN, Portocarrero JP, Lerma EV. Rhabdomyolysis. Disease-a-month : DM. 2020 Aug:66(8):101015. doi: 10.1016/j.disamonth.2020.101015. Epub 2020 Jun 10 [PubMed PMID: 32532456]

[8]

David WS. Myoglobinuria. Neurologic clinics. 2000 Feb:18(1):215-43 [PubMed PMID: 10658177]

[9]

Oishi A, Kira J. [Myoglobinuria]. Ryoikibetsu shokogun shirizu. 2001:(35):189-91 [PubMed PMID: 11555907]

[10]

Tein I, DiMauro S, DeVivo DC. Recurrent childhood myoglobinuria. Advances in pediatrics. 1990:37():77-117 [PubMed PMID: 2264536]

Level 3 (low-level) evidence

[11]

Servonnet A, Dubost C, Martin G, Lefrère B, Fontan E, Ceppa F, Delacour H. [Myoglobin: still a useful biomarker in 2017?]. Annales de biologie clinique. 2018 Apr 1:76(2):137-141. doi: 10.1684/abc.2018.1326. Epub [PubMed PMID: 29623882]

[12]

Stopp T, Feichtinger M, Eppel W, Stulnig TM, Husslein P, Göbl C. Pre- and peripartal management of a woman with McArdle disease: a case report. Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology. 2018 Sep:34(9):736-739. doi: 10.1080/09513590.2018.1451507. Epub 2018 Mar 21 [PubMed PMID: 29560763]

Level 2 (mid-level) evidence

[13]

Stanley M, Chippa V, Aeddula NR, Quintanilla Rodriguez BS, Adigun R. Rhabdomyolysis. StatPearls. 2023 Jan:(): [PubMed PMID: 28846335]

[14]

Conley KE, Ordway GA, Richardson RS. Deciphering the mysteries of myoglobin in striated muscle. Acta physiologica Scandinavica. 2000 Apr:168(4):623-34 [PubMed PMID: 10759599]

[15]

Ono-Moore KD, Olfert IM, Rutkowsky JM, Chintapalli SV, Willis BJ, Blackburn ML, Williams DK, O'Reilly J, Tolentino T, Lloyd KCK, Adams SH. Metabolic physiology and skeletal muscle phenotypes in male and female myoglobin knockout mice. American journal of physiology. Endocrinology and metabolism. 2021 Jul 1:321(1):E63-E79. doi: 10.1152/ajpendo.00624.2020. Epub 2021 May 10 [PubMed PMID: 33969704]

[16]

Sylvén C, Jansson E, Böök K. Myoglobin content in human skeletal muscle and myocardium: relation to fibre size and oxidative capacity. Cardiovascular research. 1984 Jul:18(7):443-6 [PubMed PMID: 6744365]

[17]

Rodríguez-Capote K, Balion CM, Hill SA, Cleve R, Yang L, El Sharif A. Utility of urine myoglobin for the prediction of acute renal failure in patients with suspected rhabdomyolysis: a systematic review. Clinical chemistry. 2009 Dec:55(12):2190-7. doi: 10.1373/clinchem.2009.128546. Epub 2009 Oct 1 [PubMed PMID: 19797717]

Level 1 (high-level) evidence

[18]

Moreno JA, Martín-Cleary C, Gutiérrez E, Toldos O, Blanco-Colio LM, Praga M, Ortiz A, Egido J. AKI associated with macroscopic glomerular hematuria: clinical and pathophysiologic consequences. Clinical journal of the American Society of Nephrology : CJASN. 2012 Jan:7(1):175-84. doi: 10.2215/CJN.01970211. Epub 2011 Nov 17 [PubMed PMID: 22096039]

[19]

Martín Cleary C, Moreno JA, Fernández B, Ortiz A, Parra EG, Gracia C, Blanco-Colio LM, Barat A, Egido J. Glomerular haematuria, renal interstitial haemorrhage and acute kidney injury. Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. 2010 Dec:25(12):4103-6. doi: 10.1093/ndt/gfq493. Epub 2010 Aug 13 [PubMed PMID: 20709744]

[20]

Pagani F, Bonetti G, Stefini F, Cuccia C, Panteghini M. Serum and plasma samples for ACS:systems cardiac markers. Clinical chemistry. 2000 Jul:46(7):1020-2 [PubMed PMID: 10894856]

[21]

Zaninotto M, Pagani F, Altinier S, Amboni P, Bonora R, Dolci A, Pergolini P, Vernocchi A, Plebani M, Panteghini M. Multicenter evaluation of five assays for myoglobin determination. Clinical chemistry. 2000 Oct:46(10):1631-7 [PubMed PMID: 11017942]

[22]

Carraro P, Plebani M, Varagnolo MC, Zaninotto M, Rossetti M, Burlina A. A new immunoassay for the measurement of myoglobin in serum. Journal of clinical laboratory analysis. 1994:8(2):70-5 [PubMed PMID: 8189324]

[23]

Wu AH, Laios I, Green S, Gornet TG, Wong SS, Parmley L, Tonnesen AS, Plaisier B, Orlando R. Immunoassays for serum and urine myoglobin: myoglobin clearance assessed as a risk factor for acute renal failure. Clinical chemistry. 1994 May:40(5):796-802 [PubMed PMID: 8174254]

[24]

Loun B, Astles R, Copeland KR, Sedor FA. Adaptation of a quantitative immunoassay for urine myoglobin. Predictor in detecting renal dysfunction. American journal of clinical pathology. 1996 Apr:105(4):479-86 [PubMed PMID: 8604691]

[25]

Gupta A, Thorson P, Penmatsa KR, Gupta P. Rhabdomyolysis: Revisited. The Ulster medical journal. 2021 May:90(2):61-69 [PubMed PMID: 34276082]

[26]

Baeza-Trinidad R. Rhabdomyolysis: A syndrome to be considered. Medicina clinica. 2022 Mar 25:158(6):277-283. doi: 10.1016/j.medcli.2021.09.025. Epub 2021 Dec 3 [PubMed PMID: 34872769]

[27]

Zimmerman JL, Shen MC. Rhabdomyolysis. Chest. 2013 Sep:144(3):1058-1065. doi: 10.1378/chest.12-2016. Epub [PubMed PMID: 24008958]

[28]

Nance JR, Mammen AL. Diagnostic evaluation of rhabdomyolysis. Muscle & nerve. 2015 Jun:51(6):793-810. doi: 10.1002/mus.24606. Epub 2015 Mar 14 [PubMed PMID: 25678154]

[29]

Zutt R, van der Kooi AJ, Linthorst GE, Wanders RJ, de Visser M. Rhabdomyolysis: review of the literature. Neuromuscular disorders : NMD. 2014 Aug:24(8):651-9. doi: 10.1016/j.nmd.2014.05.005. Epub 2014 May 21 [PubMed PMID: 24946698]

[30]

Petejova N, Martinek A. Acute kidney injury due to rhabdomyolysis and renal replacement therapy: a critical review. Critical care (London, England). 2014 May 28:18(3):224. doi: 10.1186/cc13897. Epub 2014 May 28 [PubMed PMID: 25043142]

[31]

Shipley SL, Wrye S. Myoglobinuria. Heart & lung : the journal of critical care. 1976 Nov-Dec:5(6):950-4 [PubMed PMID: 1049218]

[32]

Lindner A, Zierz S. [Rhabdomyolysis and myoglobinuria]. Der Nervenarzt. 2003 Jun:74(6):505-15 [PubMed PMID: 12799789]

[33]

Apple FS, Voss E, Lund L, Preese L, Berger CR, Henry TD. Cardiac troponin, CK-MB and myoglobin for the early detection of acute myocardial infarction and monitoring of reperfusion following thrombolytic therapy. Clinica chimica acta; international journal of clinical chemistry. 1995 Jun 15:237(1-2):59-66 [PubMed PMID: 7664479]

[34]

Schifman RB, Luevano DR. Value and Use of Urinalysis for Myoglobinuria. Archives of pathology & laboratory medicine. 2019 Nov:143(11):1378-1381. doi: 10.5858/arpa.2018-0475-OA. Epub 2019 May 22 [PubMed PMID: 31116043]

[35]

Alavi-Moghaddam M, Safari S, Najafi I, Hosseini M. Accuracy of urine dipstick in the detection of patients at risk for crush-induced rhabdomyolysis and acute kidney injury. European journal of emergency medicine : official journal of the European Society for Emergency Medicine. 2012 Oct:19(5):329-32. doi: 10.1097/MEJ.0b013e32834dd2ef. Epub [PubMed PMID: 22082877]

[36]

Cervellin G, Comelli I, Benatti M, Sanchis-Gomar F, Bassi A, Lippi G. Non-traumatic rhabdomyolysis: Background, laboratory features, and acute clinical management. Clinical biochemistry. 2017 Aug:50(12):656-662. doi: 10.1016/j.clinbiochem.2017.02.016. Epub 2017 Feb 21 [PubMed PMID: 28235546]

[37]

Mian AZ, Saito N, Sakai O. Rhabdomyolysis of the head and neck: computed tomography and magnetic resonance imaging findings. Dento maxillo facial radiology. 2011 Sep:40(6):390-2. doi: 10.1259/dmfr/52800685. Epub [PubMed PMID: 21831980]

[38]

Keltz E, Khan FY, Mann G. Rhabdomyolysis. The role of diagnostic and prognostic factors. Muscles, ligaments and tendons journal. 2013 Oct:3(4):303-12 [PubMed PMID: 24596694]

[39]

Hibrawi H, Garrison FD, Smith HJ. A comparison of various agarose preparations in a counter--immunoelectrophoresis (CIE) system for assaying urinary myoglobin. Journal of immunological methods. 1977:14(1):59-63 [PubMed PMID: 833429]

[40]

Motegi S, Ohki K, Hokari T, Ogawa T, Hiramori K, Sumiyoshi T, Honda T, Kondo M, Kimata S, Hirosawa K. [Serum myoglobin detection by counterimmunoelectrophoresis using a dextran-supplemented agarose plate: method and application to acute myocardial infarction diagnosis (author's transl)]. Rinsho byori. The Japanese journal of clinical pathology. 1978:26(3):235-9 [PubMed PMID: 650953]

[41]

Cloonan JM, Donald TG, Neale C, Wilcken DE. The detection of myoglobin in urine and its application to the diagnosis of myocardial infarction. Pathology. 1976 Oct:8(4):313-20 [PubMed PMID: 1018950]

[42]

Nørregaard-Hansen K, Hangaard J, Nørgaard-Pedersen B. A rapid latex agglutination test for detection of elevated levels of myoglobin in serum and its value in the early diagnosis of acute myocardial infarction. Scandinavian journal of clinical and laboratory investigation. 1984 Apr:44(2):99-103 [PubMed PMID: 6719025]

[43]

Hangaard J, Rasmussen O, Nørregaard-Hansen K, Jørgensen N, Simonsen EE, Nørgaard-Pedersen B. Early diagnosis of acute myocardial infarction with a rapid latex agglutination test for semi-quantitative estimation of serum myoglobin. Acta medica Scandinavica. 1987:221(4):343-8 [PubMed PMID: 3604750]

[44]

Chapelle JP, Heusghem C. Semi-quantitative estimation of serum myoglobin by a rapid latex agglutination method: an emergency screening test for acute myocardial infarction. Clinica chimica acta; international journal of clinical chemistry. 1985 Jan 30:145(2):143-50 [PubMed PMID: 3971587]

[45]

Zhang LH, Zhang NZ, Zhao YQ. [Semi-quantitative estimation of serum myoglobin with rapid reverse passive latex agglutination (RPLA) test and its application in the early diagnosis of acute myocardial infarction]. Zhonghua nei ke za zhi. 1990 May:29(5):280-2, 316 [PubMed PMID: 2242688]

[46]

Kagen LJ. Myoglobin: methods and diagnostic uses. CRC critical reviews in clinical laboratory sciences. 1978:9(4):273-302 [PubMed PMID: 401372]

[47]

Dombrovskiĭ VI, Staroverov II, Rott GM, Poverennyĭ AM, Tsyb AF. [Immunochemical methods of determining myoglobin in blood and urine]. Biulleten' Vsesoiuznogo kardiologicheskogo nauchnogo tsentra AMN SSSR. 1981:4(1):88-94 [PubMed PMID: 7259874]

[48]

Miyoshi K, Saito S, Kawai H, Kondo A, Iwasa M, Hayashi T, Yagita M. Radioimmunoassay for human myoglobin: methods and results in patients with skeletal muscle or myocardial disorders. The Journal of laboratory and clinical medicine. 1978 Sep:92(3):341-52 [PubMed PMID: 681820]

[49]

Matveeva E, Gryczynski Z, Gryczynski I, Malicka J, Lakowicz JR. Myoglobin immunoassay utilizing directional surface plasmon-coupled emission. Analytical chemistry. 2004 Nov 1:76(21):6287-92 [PubMed PMID: 15516120]

[50]

Stone MJ, Willerson JT, Gomez-Sanchez CE, Waterman MR. Radioimmunoassay of myoglobin in human serum. Results in patients with acute myocardial infarction. The Journal of clinical investigation. 1975 Nov:56(5):1334-9 [PubMed PMID: 1184754]

[51]

Matveeva EG, Gryczynski Z, Lakowicz JR. Myoglobin immunoassay based on metal particle-enhanced fluorescence. Journal of immunological methods. 2005 Jul:302(1-2):26-35 [PubMed PMID: 15996681]

[52]

Kottwitz J, Bruno KA, Berg J, Salomon GR, Fairweather D, Elhassan M, Baltensperger N, Kissel CK, Lovrinovic M, Baltensweiler A, Schmied C, Templin C, Lima JAC, Landmesser U, Lüscher TF, Manka R, Heidecker B. Myoglobin for Detection of High-Risk Patients with Acute Myocarditis. Journal of cardiovascular translational research. 2020 Oct:13(5):853-863. doi: 10.1007/s12265-020-09957-8. Epub 2020 Jan 31 [PubMed PMID: 32006209]

[53]

Kim TK, Oh SW, Hong SC, Mok YJ, Choi EY. Point-of-care fluorescence immunoassay for cardiac panel biomarkers. Journal of clinical laboratory analysis. 2014 Nov:28(6):419-27. doi: 10.1002/jcla.21704. Epub 2014 Mar 20 [PubMed PMID: 24652617]

[54]

Hudson MP, Christenson RH, Newby LK, Kaplan AL, Ohman EM. Cardiac markers: point of care testing. Clinica chimica acta; international journal of clinical chemistry. 1999 Jun 30:284(2):223-37 [PubMed PMID: 10451248]

[55]

Zhang X, Fei Y, Wang W, Zhao H, Wang M, Chen B, Zhou J, Wang Z. National survey on turnaround time of clinical biochemistry tests in 738 laboratories in China. Journal of clinical laboratory analysis. 2018 Feb:32(2):. doi: 10.1002/jcla.22251. Epub 2017 May 11 [PubMed PMID: 28493522]

Level 3 (low-level) evidence

[56]

Wlazeł RN, Kasprzak J, Paradowski M. A new generation of biomarkers tests of myocardial necrosis: the real quality a physician can get from the laboratory. Medical science monitor : international medical journal of experimental and clinical research. 2015 Jan 28:21():338-44. doi: 10.12659/MSM.892033. Epub 2015 Jan 28 [PubMed PMID: 25629263]

Level 2 (mid-level) evidence

[57]

Males RG, Stephenson J, Harris P. Cardiac markers and point-of-care testing: a perfect fit. Critical care nursing quarterly. 2001 May:24(1):54-61 [PubMed PMID: 11868696]

[58]

Bakker AJ, Boymans DA, Dijkstra D, Gorgels JP, Lerk R. Rapid determination of serum myoglobin with a routine chemistry analyzer. Clinical chemistry. 1993 Apr:39(4):653-8 [PubMed PMID: 8472361]

[59]

Lippi G, Plebani M. Serum myoglobin immunoassays: obsolete or still clinically useful? Clinical chemistry and laboratory medicine. 2016 Oct 1:54(10):1541-3. doi: 10.1515/cclm-2016-0472. Epub [PubMed PMID: 27341565]

[60]

Berenbrink M. Myoglobin's old and new clothes: from molecular structure to integrated function and evolution. The Journal of experimental biology. 2010 Aug 15:213(Pt 16):2711-2. doi: 10.1242/jeb.048918. Epub [PubMed PMID: 20675539]

[61]

Fan J, Ma J, Xia N, Sun L, Li B, Liu H. Clinical Value of Combined Detection of CK-MB, MYO, cTnI and Plasma NT-proBNP in Diagnosis of Acute Myocardial Infarction. Clinical laboratory. 2017 Mar 1:63(3):427-433. doi: 10.7754/Clin.Lab.2016.160533. Epub [PubMed PMID: 28271683]

[62]

Montague C, Kircher T. Myoglobin in the early evaluation of acute chest pain. American journal of clinical pathology. 1995 Oct:104(4):472-6 [PubMed PMID: 7572801]

[63]

Woo J, Lacbawan FL, Sunheimer R, LeFever D, McCabe JB. Is myoglobin useful in the diagnosis of acute myocardial infarction in the emergency department setting? American journal of clinical pathology. 1995 Jun:103(6):725-9 [PubMed PMID: 7785657]

[64]

Hasić S, Jadrić R, Kiseljaković E, Radovanović J, Winterhalter-Jadrić M. Comparison of creatine kinase activity and myoglobin blood level in acute myocardial infarction patients. Bosnian journal of basic medical sciences. 2006 Feb:6(1):19-23 [PubMed PMID: 16533174]

[65]

Scheffold T, Zehelein J, Müller-Bardorff M, Katus HA. [Monitoring ischemia with new markers]. Zeitschrift fur Kardiologie. 1994:83 Suppl 6():75-82 [PubMed PMID: 7863704]

[66]

Askmark H, Osterman PO, Roxin LE, Venge P. Radioimmunoassay of serum myoglobin in neuromuscular diseases. Journal of neurology, neurosurgery, and psychiatry. 1981 Jan:44(1):68-72 [PubMed PMID: 7205308]

[67]

Percy ME, Pichora GA, Chang LS, Manchester KE, Andrews DF. Serum myoglobin in Duchenne muscular dystrophy carrier detection: a comparison with creatine kinase and hemopexin using logistic discrimination. American journal of medical genetics. 1984 Jun:18(2):279-87 [PubMed PMID: 6465202]

[68]

Olivé M, Engvall M, Ravenscroft G, Cabrera-Serrano M, Jiao H, Bortolotti CA, Pignataro M, Lambrughi M, Jiang H, Forrest ARR, Benseny-Cases N, Hofbauer S, Obinger C, Battistuzzi G, Bellei M, Borsari M, Di Rocco G, Viola HM, Hool LC, Cladera J, Lagerstedt-Robinson K, Xiang F, Wredenberg A, Miralles F, Baiges JJ, Malfatti E, Romero NB, Streichenberger N, Vial C, Claeys KG, Straathof CSM, Goris A, Freyer C, Lammens M, Bassez G, Kere J, Clemente P, Sejersen T, Udd B, Vidal N, Ferrer I, Edström L, Wedell A, Laing NG. Myoglobinopathy is an adult-onset autosomal dominant myopathy with characteristic sarcoplasmic inclusions. Nature communications. 2019 Mar 27:10(1):1396. doi: 10.1038/s41467-019-09111-2. Epub 2019 Mar 27 [PubMed PMID: 30918256]

Level 3 (low-level) evidence

[69]

Edwards RJ, Rodeck CH, Watts DC. The diagnostic value of plasma myoglobin levels in the adult and fetus at-risk for Duchenne muscular dystrophy. Journal of the neurological sciences. 1984 Feb:63(2):173-82 [PubMed PMID: 6707690]

[70]

Bosch X, Poch E, Grau JM. Rhabdomyolysis and acute kidney injury. The New England journal of medicine. 2009 Jul 2:361(1):62-72. doi: 10.1056/NEJMra0801327. Epub [PubMed PMID: 19571284]

[71]

Khan FY. Rhabdomyolysis: a review of the literature. The Netherlands journal of medicine. 2009 Oct:67(9):272-83 [PubMed PMID: 19841484]

[72]

Kamal F, Snook L, Saikumar JH. Rhabdomyolysis-Associated Acute Kidney Injury With Normal Creatine Phosphokinase. The American journal of the medical sciences. 2018 Jan:355(1):84-87. doi: 10.1016/j.amjms.2017.04.014. Epub 2017 Apr 24 [PubMed PMID: 29289268]

[73]

Kearney E. Internal quality control. Methods in molecular biology (Clifton, N.J.). 2013:1065():277-89. doi: 10.1007/978-1-62703-616-0_18. Epub [PubMed PMID: 23996371]

Level 2 (mid-level) evidence

[74]

Kinns H, Pitkin S, Housley D, Freedman DB. Internal quality control: best practice. Journal of clinical pathology. 2013 Dec:66(12):1027-32. doi: 10.1136/jclinpath-2013-201661. Epub 2013 Sep 26 [PubMed PMID: 24072731]

Level 2 (mid-level) evidence

[75]

Bruno LC. IQCP: Guideline and Helpful Tools for Implementation. Laboratory medicine. 2016 Nov:47(4):e42-e46 [PubMed PMID: 27708173]

[76]

Poh DKH, Lim CY, Tan RZ, Markus C, Loh TP. Internal quality control: Moving average algorithms outperform Westgard rules. Clinical biochemistry. 2021 Dec:98():63-69. doi: 10.1016/j.clinbiochem.2021.09.007. Epub 2021 Sep 14 [PubMed PMID: 34534518]

Level 2 (mid-level) evidence

[77]

Prier JE, Sideman L, Yankevitch IJ. Clinical laboratory proficiency testing. Health laboratory science. 1968 Jan:5(1):12-8 [PubMed PMID: 5637121]

[78]

Bartola J. The importance of an effective proficiency testing program to the regulation of clinical laboratories. The view from one state. Archives of pathology & laboratory medicine. 1988 Apr:112(4):368-70 [PubMed PMID: 3128246]

[79]

Abu-Amero KK. Overview of the laboratory accreditation programme of the College of American Pathologists. Eastern Mediterranean health journal = La revue de sante de la Mediterranee orientale = al-Majallah al-sihhiyah li-sharq al-mutawassit. 2002 Jul-Sep:8(4-5):654-63 [PubMed PMID: 15603049]

Level 3 (low-level) evidence

[80]

Cornish NE, Anderson NL, Arambula DG, Arduino MJ, Bryan A, Burton NC, Chen B, Dickson BA, Giri JG, Griffith NK, Pentella MA, Salerno RM, Sandhu P, Snyder JW, Tormey CA, Wagar EA, Weirich EG, Campbell S. Clinical Laboratory Biosafety Gaps: Lessons Learned from Past Outbreaks Reveal a Path to a Safer Future. Clinical microbiology reviews. 2021 Jun 16:34(3):e0012618. doi: 10.1128/CMR.00126-18. Epub 2021 Jun 9 [PubMed PMID: 34105993]

[81]

Chung CL, Bellis KS, Pullman A, O'Connor A, Shultz A. Building Biosafety Capacity in Our Nation's Laboratories. Health security. 2019 Sep/Oct:17(5):353-363. doi: 10.1089/hs.2019.0056. Epub [PubMed PMID: 31593513]

[82]

Pentella MA. Update on Biosafety and Emerging Infections for the Clinical Microbiology Laboratory. Clinics in laboratory medicine. 2020 Dec:40(4):473-482. doi: 10.1016/j.cll.2020.08.005. Epub [PubMed PMID: 33121616]