Try it
Microbiology · Virology: immune reconstitution inflammatory syndrome
Sample itemA man with HIV (CD4 count 25 cells/mm3) begins antitubercular therapy for pulmonary tuberculosis and starts antiretroviral therapy 3 weeks later. Four weeks after that, he develops fever, enlarging cervical nodes and worsening pulmonary infiltrates. Adherence is good, the sputum is now smear negative and the viral load has fallen. What is the most likely explanation?
Original practice item, not a recalled exam question. Nothing here is recorded.
The answer and the reasoning
D. Paradoxical tuberculosis immune reconstitution inflammatory syndrome
After starting antiretroviral therapy, recovering immune function mounts an exaggerated inflammatory response against residual mycobacterial antigen, producing paradoxical worsening despite clinical and microbiological response. The viral load falls and CD4 count rises. Management is to continue both treatments, exclude drug resistance and other infections, and give corticosteroids for severe cases.
Option by option
A. Drug fever due to rifampicin
Drug fever does not enlarge lymph nodes or worsen infiltrates.
B. Pneumocystis jirovecii pneumonia
Pneumocystis infection would be an alternative cause, but nothing in the picture suggests a new pathogen and the timing points to immune recovery.
C. Treatment failure due to multidrug-resistant tuberculosis
Drug resistance would show persistent smear positivity and would not be explained by the timing after starting antiretroviral therapy.
D. Paradoxical tuberculosis immune reconstitution inflammatory syndrome (correct)
Worsening with a falling viral load and negative smear after starting antiretrovirals fits paradoxical immune reconstitution.
Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.
More Microbiology questions
- BacteriologyA patient has profuse painless watery 'rice-water' stools and rapid dehydration. The cau…
- Culture mediaThayer–Martin medium is used selectively to isolate which organism?
- Immunology and serologyWhich of the following is a non-treponemal test for syphilis?
- BacteriologyAlbert's stain is used to demonstrate which of the following?