A 35-year-old HIV-positive man on ART with CD4 count of 85 cells/µL develops fever, cough, and bilateral interstitial infiltrates. LDH is 620 IU/L. Bronchoalveolar lavage with silver staining shows cysts. He is started on cotrimoxazole. At which CD4 threshold should cotrimoxazole primary prophylaxis for PCP have been initiated?

• A CD4 < 500 cells/µL
• B CD4 < 200 cells/µL ✓
• C CD4 < 350 cells/µL
• D CD4 < 100 cells/µL

Explanation

Pneumocystis jirovecii pneumonia (PCP) prophylaxis with cotrimoxazole (TMP-SMX) is indicated when CD4 count falls below 200 cells/µL. PCP is the most common AIDS-defining opportunistic infection in countries with good access to care and can be rapidly fatal. Primary prophylaxis can be discontinued when CD4 increases to >200 cells/µL for ≥3 months on ART. MAC prophylaxis is initiated at CD4 <50 cells/µL; toxoplasma prophylaxis at CD4 <100 cells/µL.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.