Myoglobin-Serum:
Why Myoglobin - Serum Test?
CLINICAL INFORMATION
Myoglobin is a single polypeptide encoded by the MB gene. Myoglobin is a red cytoplasmic - low molecular weight protein containing heme (it is structurally similar to a subunit of haemoglobin) as a prosthetic group and has one oxygen binding site (myoglobin has a higher affinity for oxygen than haemoglobin). Myoglobin contains a porphyrin ring with an iron at its centre. It carries and serves oxygen intracellularly in the striated muscles - including skeletal muscles (muscles attached to the bones and tendons). The main function is to supply oxygen to the myocytes (cells in the muscles). In severe muscle damage (rhabdomyolysis) like heart attack, the myoglobin is released into the blood after 2 to 3 hours of symptoms. Possible causes of higher myoglobin include low phosphate levels, surgery, certain (viral) infections, poisons, toxins, heavy metal toxicity, burns, high voltage snake venom, thrombosis leading to ischemia, electric shock, inherited hereditary disorders of the muscles (like muscular dystrophy), inborn errors of metabolism, metabolic diseases, progressive muscular disease, strenuous exercise, seizures, crush injury-causing extensive trauma, malignant hyperthermia, hypothyroidism, hyperthyroidism, immobilization and/or coma, medications etc. The symptoms of muscle damage include fever, increased heart rate, nausea, vomiting, abdominal pain, muscle pain, stiffness, cramping, dark brown or reddish urine etc. During muscle injury, the myoglobin in the muscle cells is released into the bloodstream. Kidneys help to excrete myoglobin protein from the blood. Excess myoglobin (the presence of protoxin in myoglobin is toxic) can damage the kidneys and hence myoglobinuria can lead to acute kidney injury (toxic to renal tubular epithelium). Complications include disseminated intravascular coagulation (DIC), Myoglobin being a sensitive marker for tissue injury. Hence myoglobin blood test (in serum) is performed to screen for extensive skeletal muscle damage in the body and/or acute kidney damage from muscle injury (if untreated can lead to kidney failure) eg myositis, rhabdomyolysis, skeletal muscle ischemia etc. This test has been largely replaced by the troponin test. Additional tests include urine immuno-fixation test, CK-MB, cardiac troponin, creatine phosphokinase, ECG, KFT etc. Other tests include CBC, BUN, creatinine, routine electrolytes, calcium, phosphate, uric acid, albumin etc.
General Instructions:
Sample Requirement: Specimen - Blood sample collected from the vein. Test Preparation: None.
NOTE - Sample for specimen collections may vary based on the patient’s condition/cases according to the patient’s presenting complaints/signs or symptoms:
SPECIMEN REQUIREMENT (Special or Rare Cases) - As instructed and guided by Physician / Clinician / Pathologist / as per Laboratory’s requirements, according to procedures and protocols.
This Multi-Specialty Clinical Referral Laboratory RT DIAGNOSTICS provides precise and accurate tests with an extensive range of testing services to the medical centres to help in the diagnosis and identification of pathology in the test specimens for infectious diseases and also to evaluate the function of organ systems of the patient. It prevents further complications and helps to stabilize and restore health to near normalcy at the earliest without delay.
