Fluid for LDH:
Why Fluid for LDH Test?
In General, the enzymes within the cell (cytosol) are impermeable to cell membranes (hence these cellular enzymes cannot enter blood circulation easily) and thus these enzyme activities are very low compared to those within the cell.LDH is also known as ‘lactate dehydrogenase’. This enzyme catalyzes the conversion of lactate to pyruvate.LDH is present in almost every cell in the body- including blood (serum and/or plasma), muscles, brain (CSF sample specimen collected by lumbar puncture also known as a spinal tap), kidneys, liver, lung (eg. empyema), pancreas etc. “Iso-enzymes” are the multiple forms of the same enzyme that differ with physical properties but they have the same function (similar catalytic activity) eg- they have the same substrates (or in other words - They are different variants of the same enzyme having identical functions). Iso-enzymes are of utmost clinical interest since they can be used as molecular markers of tissue damage. The iso-forms of LDH are LDH-1: present in the heart, brain and RBCs, LDH-2: present in the RES – Reticulo-Endothelial System, LDH-3: present in the lungs, LDH-4: present in the kidney, placenta and the pancreas, LDH-5: present in the liver, striated muscles and the brain. LDH test measures the amount of LDH enzyme present in the blood and/or other body fluids. Hence this test looks for signs of damage to the body tissues (eg. Myocardial infarction) and also to know the extent of injuries like in case of heart, liver or kidney diseases. This test is a helpful tool in conditions like hemolytic and/or megaloblastic anaemia, prognosis in cancer treatment etc. The sample specimen is usually an intra-vascular fluid eg. Blood (serum/plasma) and/or body or bio-fluids. Body fluids such as intracellular and extracellular fluids are an accurate source of potential biomarkers as they have their ability to actively exchange certain biological factors between them i.e for example the lymphatic system, tissue interstitial fluid and blood plasma etc. The purpose of body fluids are to deliver nutrients and oxygen to all the cells of the body and remove the end products or toxic substances from the cells that are produced during the metabolism, to eliminate them out of the system by flushing them out of the body as urine, faeces, sweat etc. Other functions of the bio-fluid/body fluids include maintenance of body temperature. When the body temperature increases, the blood circulation to the skin also instantaneously increases thus facilitating the dissipation of heat through sweating etc. Body/Bio-Fluid tests: It includes Peritoneal/Ascitic fluid (in a pathological condition called as Ascites); in peritonitis (inflammation of the lining of inner abdominal wall etc), abnormal or infected Pericardial fluid resulting due to inflammation, infected pleural fluid causing pleural effusion, specimens collected by Bronchial Wash, Drain or aspiration Fluids - Paracentesis, Thoracocentesis, aspiration of bone marrow, aspiration of amniotic fluid, invasive surgical interventions like JP drain , collection of usual sample specimen of intra-vascular fluids like blood (serum and/or plasma), or other specimen of interest like tissue interstitial fluid, trans-cellular fluid, urine, mucus, saliva, sweat, bile fluid, seminal fluid, vaginal fluid, synovial fluid or synovial, nasal fluid, CSF, lymph, tears, phlegm, vomitus, endolymph etc, can provide vital clue in biochemical investigation of certain disorders and/or in pathological conditions (i.e in certain differential diagnosis) to arrive to a conclusive definitive diagnosis and also for prognosis.Significance of LDH on body/Bio-Fluids Test: This test helps to find the cause of fluid build-up eg. Transudate- pleural effusion, pericardial effusion or Exudate – due to high hydrostatic pressure or low oncotic pressure, Injury, inflammation, infections like viral or bacterial meningitis. This test also helps to screen in the diagnosis of bowel infarction, rhabdomyolysis, bone fractures, severe shock, hypoxia etc. Additional tests include Troponin-1 (the diagnosis of infarction has been largely superseded by this test) test. Other tests include other serum levels of skeletal muscle enzymes or proteins that serve as markers in pathological conditions for eg. Creatine kinase, aldolase, myoglobin, troponin, aspartate aminotransferase, carbonic anhydrase CAIII. But in physiological conditions too for example in strenuous exercises – muscle injury mediated by apoptosis may occur triggered by increased oxidative stress and hence other markers may serve as an important tool like thio-barbituric acid- reactive substances, malondialdehyde, sulfhydryl groups, reduced glutathione, oxidized glutathione, super-oxide dismutase, catalase etc.
General Instructions:
Sample Requirement: Specimen - Body Fluid Sample specimen (as directed by the physician or the pathologist after clinical assessment. 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 RTDIAGNOSTICS 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.
