Serum Cryptococcal Antigen Testing in Immunosuppressed HIV-positive Children and Adolescents

Describe the epidemiology of immunocompromised HIV-infected pediatric (children and adolescents ≤ 19 years) and adults (> 19 years) with positive serum cryptococcal antigen lateral flow assay (CrAg-LFA) in KwaZulu-Natal.

Retrospective review of laboratory-based database and clinical charts.

A review of the National Health Laboratory Services database of all serum CrAg-LFA performed in KwaZulu-Natal between June 2015 and December 2016 and comparison of the epidemiology of pediatric and adult patients was conducted. A reflex serum CrAg-LFA (IMMY CrAg-LFA) was performed on samples with CD4 counts < 100 cells/μL. Charts of all pediatric patients with a positive CrAg-LFA at Prince Mshiyeni Memorial Hospital were reviewed and 1-year outcome assessed.

A total of 22,741 laboratory records were retrieved, and 1140 records were removed because of duplicate entries (1074) and insufficient data (64). There was a statistically significant difference in the incidence of positive CrAg-LFA in pediatrics and adults, respectively [40 (3.5%) versus 1194 (5.8%), P = 0.001]. The incidence of positive CrAg-LFA in Ethekwini district was 59 and 56 cases per 100,000 persons in adolescents 10-14 years and 15-19 years, respectively. Six of the 8 patients with available treatment history were on antiretroviral treatment (ART) with immune failure at the time of CrAg-LFA testing.

Severe immune suppression in adolescents on ART is a risk factor for cryptococcal antigenemia. A concerted effort to timeously manage ART failure in adolescents with appropriate changing of ART regimens is urgently warranted.