Influence of age at virologic control on peripheral blood human immunodeficiency virus reservoir size and serostatus in perinatally infected adolescents

Abstract

Importance: Combination antiretroviral therapy initiated within several weeks of human immunodeficiency virus (HIV) infection in adults limits proviral reservoirs that preclude HIV cure. Biomarkers of restricted proviral reservoirs may aid in the monitoring of HIV remission or cure.

Objectives: To quantify peripheral blood proviral reservoir size in perinatally HIV-infected (PHIV+) adolescents and to identify correlates of limited proviral reservoirs.

Design, setting, and participants: A cross-sectional study including 144 PHIV+ youths (median age, 14.3 years) enrolled in the United States-based Pediatric HIV/AIDS Cohort Study and receiving durable (median duration, 10.2 years) combination antiretroviral therapy, stratified by age at virologic control.

Main outcomes and measures: The primary end point was peripheral blood mononuclear cell (PBMC) proviral load after virologic control at different ages. Correlations between proviral load and markers of active HIV production (ie, HIV-specific antibodies, 2-long terminal repeat circles) and markers of immune activation and inflammation were also assessed.

Results: Proviral reservoir size was markedly reduced in the PHIV+ youth who achieved virologic control before 1 year of age (4.2 [interquartile range, 2.6-8.6] copies per 1 million PBMCs) compared with those who achieved virologic control at 1 to 5 years of age (19.4 [interquartile range, 5.5-99.8] copies per 1 million PBMCs) or after 5 years of age (70.7 [interquartile range, 23.2-209.4] copies per 1 million PBMCs; P < .001). A proviral burden of less than 10 copies per 1 million PBMCs in PHIV+ youth was measured in 11 (79%), 20 (40%), and 13 (18%) participants with virologic control before 1 year, at 1 to 5 years, and after 5 years of age, respectively (P < .001). Lower proviral load was associated with undetectable 2-long terminal repeat circles (P < .001) and HIV-negative or indeterminate serostatus (P < .001) but not with concentrations of soluble immune activation markers CD14 and CD163.

Conclusions and relevance: Early effective combination antiretroviral therapy with prolonged virologic suppression after perinatal HIV infection leads to negligible peripheral blood proviral reservoirs in adolescence and is associated with negative or indeterminate HIV serostatus. These findings highlight the long-term effect of early effective control of HIV replication on biomarkers of HIV persistence in perinatal infection and the utility of HIV serostatus as a biomarker for small proviral reservoir size, although not necessarily for cure.

Figure 1

Derivation of study population.

Figure 2

Distribution of proviral load at last visit by age at virologic control. The limit of detection for proviral load varies based on the number of cells available for analysis. Values of proviral load below the limit of detection were set to the limit of detection. Filled and open shapes represent samples tested above and below PBMC assay detection limit, respectively. Triangles and circles represent samples tested above and below 2-LTR circle assay detection limit, respectively.

Figure 3

Distribution of proviral load by HIV serostatus at last visit. The limit of detection for proviral load varies based on the number of cells available for analysis. Values of proviral load below the limit of detection were set to the limit of detection. Filled and open shapes represent samples tested above and below PBMC assay detection limit, respectively. Circles, squares, and triangles represent samples tested as western blot positive, negative, and indeterminate, respectively.