Benefits of enhanced infection prophylaxis at antiretroviral therapy initiation by cryptococcal antigen status

Journal article

Objectives: To assess baseline prevalence of cryptococcal antigen (CrAg) positivity; and its contribution to reductions in all-cause mortality, deaths from cryptococcus and unknown causes, and new cryptococcal disease in the REALITY trial.

Design: Retrospective CrAg testing of baseline and week-4 plasma samples in all 1805 African adults/children with CD4+ cell count less than 100 cells/μl starting antiretroviral therapy who were randomized to receive 12-week enhanced-prophylaxis (fluconazole 100 mg/day, azithromycin, isoniazid, cotrimoxazole) vs. standard-prophylaxis (cotrimoxazole).

Methods: Proportional hazards models were used to estimate the relative impact of enhanced-prophylaxis vs. standard-cotrimoxazole on all, cryptococcal and unknown deaths, and new cryptococcal disease, through 24 weeks, by baseline CrAg positivity.

Results: Excluding 24 (1.4%) participants with active/prior cryptococcal disease at enrolment (all treated for cryptococcal disease), 133/1781 (7.5%) participants were CrAg-positive. By 24 weeks, 105 standard-cotrimoxazole vs. 78 enhanced-prophylaxis participants died. Of nine standard-cotrimoxazole and three enhanced-prophylaxis cryptococcal deaths, seven and two, respectively, were CrAg-positive at baseline. Among deaths of unknown cause, only 1/46 standard-cotrimoxazole and 1/28 enhanced-prophylaxis were CrAg-positive at baseline. There was no evidence that relative reductions in new cryptococcal disease associated with enhanced-prophylaxis varied between baseline CrAg-positives [hazard-ratio = 0.36 (95% confidence interval 0.13–0.98), incidence 19.5 vs. 56.5/100 person-years] and CrAg-negatives [hazard-ratio = 0.33 (0.03–3.14), incidence 0.3 vs. 0.9/100 person-years; Pheterogeneity = 0.95]; nor for all deaths, cryptococcal deaths or unknown deaths (Pheterogeneity > 0.3).

Conclusions: Relative reductions in cryptococcal disease/death did not depend on CrAg status. Deaths of unknown cause were unlikely to be cryptococcus-related; plausibly azithromycin contributed to their reduction. Findings support including 100 mg fluconazole in an enhanced-prophylaxis package at antiretroviral therapy initiation where CrAg screening is unavailable/impractical.

Authors: Pett, SL; Spyer, M; Haddow, L; Nhema, R; Benjamin, L

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wolters Kluwer Health
• Journal: AIDS
• Volume: 35
• Issue: 4
• Pages: 585-594
• Publication date: 2020-12-09
• Acceptance date: 2020-04-28
• DOI: 10.1097/QAD.0000000000002781
• EISSN: 1473-5571
• ISSN: 0269-9370
• Language: English
• Keywords: cryptococcus; FFR; prophylaxis; late presentation; HIV; Africa