Eradicating latent tuberculosis: use of interferon gamma release assay and isoniazid/rifapentine in people living with HIV/AIDS

Abstract

Tuberculosis (TB) is the most common comorbidity in people living with HIV/AIDS (PLWH), including those under antiretroviral treatment. PLWH are 28 times more likely to develop TB in Brazil, the leading cause of HIV-related deaths globally, with approximately 161,000 reported deaths worldwide in 2023. Early diagnosis of latent tuberculosis infection (LTBI) and prophylactic therapy can reduce TB cases, prevent disease progression, and decrease transmission in high-risk populations. This study assessed the prevalence of LTBI in PLWH using the interferon-gamma release assay (IGRA) and the impact of the 3HP regimen (isoniazid [INH]/rifapentine [RPT]) as prophylactic treatment. Blood samples from 335 PLWH (78% of the 427 in the cohort) were tested for IGRA; 50 PLWH (15%) tested positive and were treated with 3HP. Treatment included 900 mg of INH and 900 mg of RPT in 12 weekly doses according to the Brazilian health guidelines. No specific risk factors, including nadir CD4+T count, age, gender, or antiretroviral therapy (ART), were more frequently observed in the PLWH with LTBI compared to the PLWH without LTBI. All PLWH with LTBI received treatment and no cases of active TB were observed. Our findings highlight the need for wider LTBI screening and treatment among PLWH in the latent phase, emphasizing more stringent approaches for implementing 3HP prophylaxis.