LAB DIAGNOSIS OF COVID-19 & HIV

 Covid-19 – laboratory analysis

1.RT PCR

• Detects the number of copies of viral gene
• Confirmatory test for COVID-19

2.TrueNat –

• Chip based real time PCR
• Used in remote areas with poor infrastructure
• Single step test for both screening & confirmation

3.LAMP test

•  the amplification is carried out at constant temperature
• In PCR  - amplification occurs with a series of alternating temperature steps or cycles .

4.Rapid Antigen Test

• Card based test which detects the presence of viral protein in swabs
• Good sensitivity but poor specificity

5.Serological Tests – lateral flow assays and ELISA

• For the detection of bodies
•  Particularly in patients who were infected & recovered 

6.Biochemical Tests for Monitoring

• Cardiac biomarkers –  Troponin, NT-ProBNP, CK-MB,PT, myoglobin
• Hepatic biomarkers-  AST, ALT, GGT, LDH, Bilirubin
• Renal markers –  Blood Urea, Se.Creatinine
• Critical care markers –  Blood gases, electrolytes
• Routine urine biochemical markers-  for occult blood, specific gravity, pH, Proteins, ketones, RBC, WBC count

7.Inflammatory markers

• Pro-inflammatory cytokines - IL-6,IL-10 & TNF-α
• Inflammatory markers – ferritin, procalcitonin, CRP, ESR
• Biomarker for blood clotting – D-Dimer

HIV – laboratory analysis

1.ELISA –

• for detection of antibodies
• ELISA positive blood confirmed with western blot analysis

2.Western blot detects

• antibodies against 6 different components      

3.T-helper count –

• lowered to less than 300 in AIDS patient.
• (Normal > 400cumm)

4.RT PCR – to detect the number of HIV particles in blood

• <5000 copies/ml of blood – good prognosis
• >1 lakh copies/ml of blood – bad prognosis