Should we perform the serum cryptococcal antigen test in people living with HIV hospitalized due to a community-acquired pneumonia episode?

ABSTRACT

Community-acquired pneumonia (CAP) is a common cause of hospitalization among people living with human immunodeficiency virus (PLWH), particularly those with severe immunosuppression. Pulmonary disease due to cryptococcosis is uncommonly reported and likely under-diagnosed. There is scarce information about cryptococcal antigen (CrAg) prevalence in PLWH with CAP. The objectives of this study were to identify among PLWH who were hospitalized with CAP (i) the prevalence of serum CrAg positivity, (ii) the proportion with asymptomatic vs. symptomatic cryptococcosis; and (iii) the prevalence of serum CrAg positivity in CD4þ T-cell count <100 cells/mm3.We performed a sub-analysis of a prospective cohort of hospitalized adults enrolled into a randomized clinical trial testing therapy for CAP. We included 202 participants who had serum CrAg testing performed. We found a 3.5% prevalence of serum CrAg-positivity overall, being higher (5.7%) in CD4þ T-cell count <100 cells/mm3. Overall, asymptomatic and symptomatic cryptococcosis were present in 2.0% and 1.5%, respectively. This study identifies a target population for CrAg testing PLWH hospitalized with diagnosis of CAP, particularly those with CD4þ T-cell count <100 cells/mm3 where the number needed to test was 18 to detect 1 CrAg-positive person. This approach may facilitate the detection of asymptomatic cryptococcal infection and allow a timely diagnosis of symptomatic cryptococcal disease