A 32-year-old man with HIV (CD4 count 70 cells/µL) presents with 2 weeks of fever, headache, and blurred vision. CSF opening pressure is 32 cmH₂O. Which finding is most specific for the diagnosis?
- A CSF lymphocytic pleocytosis
- B CSF elevated protein
- C CSF positive cryptococcal antigen ✓
- D CSF low glucose
Correct answer: C. CSF positive cryptococcal antigen
Explanation
In an HIV patient with low CD4 and subacute meningitis with raised opening pressure, cryptococcal meningitis is the diagnosis. CSF cryptococcal antigen is the most specific and sensitive test. Lymphocytic pleocytosis, elevated protein, and low glucose are nonspecific and occur in tuberculous and other chronic meningitides.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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