*Best initial test= ELISA test.
*Confirmatory test= western blot (considered +ve if patient demonstrated the presence of antibodies to at least 2 of 3 important HIV antigens which are gp120, gp41, and gp24).
*Early marker of infection is p24 Antigen.
* ELISA/Western blot are often falsely –ve in first 1-2 mths of HIV infection.
*Viral load testing (detected by RT PCR) useful to:
1- Measure response to therapy
2- Detect treatment failure
3- Diagnose HIV in babies
*Diagnosis in babies of HIV +ve mother:
• Test of choice is detect HIV-DNA by PCR
• Can culture HIV with antigens detection
• ELISA/Western blot are often falsely +ve in infant(anti-gp 120 cross the placenta)
• In children> 18 mths can use ELISA(IgG Ab) and Westren blot
*Best single prognostic indicator is plasma viral load
*Evaluate progression of disease: CD4:CD8 ratio by flow cytometery.
HIV- associated infections and CD4 count:
Normal CD4 count 600—1000
*CD4 >200: Increase risk of
VZ,TB, HSV, Oral and Vaginal Candidiasis, Bacterial pneumonia.
*CD4 < 200: Increase risk of
1- PCP: *Prophylaxis= TMP/SMX, and if patient allergy give Dapsone or Atorvoqine *treatment =TMP/SMX is best initial therapy, add steroids if PCP is sever.
2- Cryptosporidiosis: *treatment= by increase CD4 count
3- Disseminated Coccidioidomycosis: *treatment= Amphotericin B
*CD4 < 100: Increase risk of
1- Toxoplasmosis:* prophylaxis= TMP/SMX , Dapsone *treatmen=Primethamine/sulfadiazine
2- Candida esophagitis: *treatment= fluconazole
*CD4 < 50: Increase risk of
1- Mycobacterium avium*Prophylaxis = Azithromycin *treatment = clarithromycin + ethambutol+/-rifambutin
2- CMV:Prophylaxis and treatment by Valgancyclovir
3- Cryptococcal meningoencephalitis: treatment I.V amphotricin for 10-14 days followed by fluconazole as mentinance
4- PML= caused by JC virus= No effective treatment
5- NHL= associated with EBV
*HIV with any cell count:
1- If patient PPD >5mm= INH for 9 mths
2- Pneumococal vaccine, influenza vaccine, and Hep B vaccine, Hep A vaccine