Factors associated with cryptococcal capsular antigen positivity among people living with HIV: A retrospective observational cohort study

Abstract

Introduction

Cryptococcosis, caused by Cryptococcus, is an aggressive fungal disease posing a high mortality risk among people living with HIV (PLHIV). However, factors associated with the prevalence of cryptococcal capsular antigen (CrAg) among PLHIV remain unclear.

Material and Methods

We recruited PLHIV from a designated HIV/AIDS clinic in Southern China between March 2018 and December 2019. Serum CrAg was qualitatively detected using Lateral Flow Assay (LFA). Fungal culture and pathological examinations were performed using the cerebrospinal fluid (CSF). Chi-squared test and multivariable logistic regression were utilized to assess factors associated with the prevalence of CrAg.

Results

A total of 1478 PLHIV were included, among whom 297 were antiretroviral therapy-naïve (ART-naïve), 1181 (79.9%) were ART-experienced. The median baseline CD4+ T cell count was 43 cells/µl (interquartile range [IQR]: 13-117). The majority (94.7%) CrAg-positive PLHIV had a baseline CD4+ T cell count ≤ 200 cells/µl. The overall CrAg positivity rate was 5.1%. The CrAg positivity rate among ART-naïve PLHIV was 6.4%, which was similar to that among ART-experienced PLHIV. Notably, within the ART-experienced group, CrAg-positive PLHIV displayed lower baseline and latest CD4+ T cell counts than those in CrAg-negative. CrAg status was significantly associated with shorter ART duration (≤1 year vs. >2 year: adjusted odds ratio [aOR], 2.53; 95% confidence interval [CI], 1.20–5.34. 1-2 year vs. >2 year: 4.61, 2.10-10.12) and other opportunistic infections (2.56, 1.41-4.63) among ART-experienced PLHIV. Among CrAg-positive PLHIV, 44 were diagnosed with cryptococcosis, including 28 previously diagnosed and 16 newly diagnosed cases (8 ART-naïve and 8 ART-experienced).

Discussion

We found a sizable CrAg positivity rate among ART-naïve and ART-experienced PLHIV. A lower baseline CD4+ T cell count was the primary factor associated with CrAg positivity among PLHIV. Serum CrAg screening should be recommended for both ART-naïve and ART-experienced PLHIV with CD4+ T cell counts ≤200 cells/µl.