Outcomes of second-line antiretroviral therapy among children living with HIV : a global cohort analysis

Introduction : Limited data describe outcomes on second-line antiretroviral therapy (ART) among children globally. Our objective was to contribute data on outcomes among children living with HIV after initiation of second-line ART in the context of routine care within a large global cohort collaboration. Methods : Patient-level data from 1993 through 2015 from 11 paediatric HIV cohorts were pooled. Characteristics at switch and through two years of follow-up were summarized for children who switched to second-line ART after starting a standard first-line regimen in North America, Latin America, Europe, Asia, Southern Africa (South Africa & Botswana) and the rest of sub-Saharan Africa (SSA). Cumulative incidences of mortality and loss to follow-up (LTFU) were estimated using a competing risks framework. Results : Of the 85,389 children on first-line ART, 3,555 (4%) switched to second-line after a median of 2.8 years on ART (IQR: 1.6, 4.7); 69% were from Southern Africa or SSA and 86% of second-line regimens were protease inhibitor-based. At switch, median age was 8.4 years and 50% had a prior AIDS diagnosis. Median follow-up after switch to second-line ranged from 1.8 years in SSA to 5.3 years in North America. Median CD4 counts at switch to second-line ranged from 235 cells/mm(3) in SSA to 828 cells/mm(3) in North America. Improvements in CD4 counts were observed over two years of follow-up, particularly in regions with lower CD4 counts at second-line switch. Improvements in weight-for-age z-scores were not observed during follow-up. Cumulative incidence of LTFU at two years was