Clinical Pathology Laboratory

A clinical pathological laboratory is a laboratory where clinical pathological tests are performed to get the necessary information regarding a patient’s health and to confirm a diagnosis^1,2. Confirmation of diagnosis helps doctors in recommending the appropriate preventive measures or treatment for patients. The clinical lab staff includes pathologists, clinical biochemists, medical laboratory scientist, medical lab assistant and phlebotomist¹.

A clinical lab technician deals with two main areas, namely Anatomic Pathology and Clinical Pathology^1,2,. Anatomic Pathology is the examination of physical appearance and microscopic tissue structure. The analysis of biopsies and organs removed during surgery, the collection of cells from brushings of body fluids and autopsies performed to investigate the cause of death are some of the key responsibilities of a lab technician.

Meanwhile, Clinical Pathology deals with the levels of chemical constituents in the blood and body fluids including analysis of blood cells and identification of microorganisms. This particular area also involves managing the blood bank, which comprises of the collection, preparation and use of blood for transfusion procedures.

Clinical Labs are usually divided into two sections which are further subdivided into multiple units^2,3.

• Anatomic Pathology - consists of Histopathology, Cytopathology, and Electron Microscopy.
• Clinical Pathology – includes five sub-sections which are as follows:
  • Clinical Microbiology which involves bacteriology, virology, parasitology, immunology and mycology.
  • Clinical Chemistry including analysis of blood components, toxicology, and endocrinology.
  • Haematology involves automated and manual analysis of blood cells.
  • Reproductive biology consists of semen analysis, sperm bank and technology required for assisted reproduction.
  • Genetics is studied as a part of c ytogenetics which involves testing of bone marrow, genes, and amniotic flood.

Practices

There are variety of tests conducted at clinical laboratories, including but not limited to^2,3

Complete Blood Count commonly known as CBC, is the most widely conducted blood test. CBC measures the type and number of different cells in your blood, which includes red blood cells, white blood cells, and platelets. CBC is used to determine the general health of the patient. CBC helps evaluate symptoms of weakness, fatigue, bruising thereby enabling diagnosis of conditions like anaemia, malaria, typhoid, infections, etc.

Lipid profile is a group of tests that are done to evaluate cardiac risk. Lipid profile also helps to check any risks related to eating habits, diet, stress, exercise and lifestyle-related conditions like obesity. Lipid profile includes the following tests - high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides, very-low-density lipoprotein cholesterol (VLDL-C), total cholesterol, and LDL/HDL ratio.

Renal profile is a series of tests performed to evaluate kidney function. Renal profile includes measuring levels of serum electrolytes like sodium, potassium, chlorine, serum proteins, and blood glucose levels to determine kidney health.

Diabetic profile includes various tests used to diagnose diabetes. Blood glucose levels, HbA1c - average of blood glucose levels over 3 months, urine glucose and ketones in urine are some of the tests conducted in diabetic profile.

Liver profile involves a group of tests which help to evaluate the health of your liver⁴. The liver enzymes, proteins in the blood - albumin and globulin, bilirubin in the blood and prothrombin time, are measured in this test profile. The liver function test helps diagnose liver infections like Hepatitis C, Hepatitis B and cirrhosis, to name a few.

Urine analysis includes tests like urine routine, 24-hour urinary protein, urinary glucose, etc. Urine routine helps determine any urinary infection by evaluating the number of pus cells, epithelial cells, blood, protein, in the urine. 24-hour urinary protein measures the level of proteins being excreted into the urine by the body, in the case of kidney damage.

Specialists

Clinical lab technicians typically handle the entire clinical lab. They analyse body fluids like blood, urine, and tissue samples and record the normal and abnormal findings. They also study the blood samples to be used in transfusions by identifying the cell morphology, the number of cells or the blood group, blood type and compatibility with other blood types.

A clinical lab technician operates sophisticated laboratory equipment and uses automated and computerised instruments to perform multiple tests at the same time. The technician then logs data from medical tests and enters the results into patients’ medical record. Aside from discussing laboratory results with the physicians, a clinical lab technician also supervises medical laboratory training.

Related Conditions

A clinical lab helps diagnose and treat a variety of diseases based on the most relevant tests. Conditions that are covered include^1,2,3:

Low haemoglobin levels are a diagnostic feature of anaemia. A complete blood count helps determine patient haemoglobin levels, white and red blood cells count and the platelet count. The possible causes of anaemia can be determined using the Mentzer index which is the ratio of the Mean Corpuscular Volume (MCV) to the red blood cell count (RBC). If this ratio is less 13, thalassemia is more likely to be the cause of anaemia than iron deficiency.

For diabetes, fasting blood sugar levels and post-lunch blood sugar levels help determine the presence of diabetes in a patient. High blood glucose level indicates diabetes and constant monthly blood tests can reveal the prognosis of the disease. Glycosylated haemoglobin (HbA1c) is a three months average blood glucose indicator which helps evaluate the average blood sugar levels over three months and thereby determine the prognosis of diabetes.

Dyslipidaemia can be diagnosed with the help of lipid profile test which is a series of tests that measure the total blood cholesterol, HDL and LDL levels.

The liver profile helps evaluate the health status of the liver. Hepatitis leads to a rise in the levels of liver enzymes, namely Serum Glutamic Oxaloacetic Transaminase (SGOT) and Serum Glutamic Pyruvic Transaminase (SGPT).

Chronic Kidney Disease (CKD) can be determined with the help of Renal profile which measures the serum electrolyte levels and the serum creatinine levels.

Clinical labs are efficient in helping physicians diagnose and confirm most diseases. With the help of a clinical lab and clinical technicians, diagnostic procedures have proven to be an essential tool for every physician.

References

1. Staff. What Happens at a Clinical Lab? https://blog.orchardhospital.com/what-happens-at-a-clinical-lab(accessed Nov 15, 2019).
2. Medical Procedures and Medical Tests from MedicineNet - Index of information produced by doctors https://www.medicinenet.com/procedures_and_tests/article.htm (accessed Nov 15, 2019).
3. Understanding Common Blood Tests and What They Mean https://www.verywellhealth.com/understanding-common-blood-tests-and-what-they-mean-3156935 (accessed Nov 15, 2019).
4. Liver Function Test - About, Normal Range, Preparation, Test Results & More https://www.portea.com/labs/diagnostic-tests/liver-function-144/ (accessed Nov 15, 2019).