TY - JOUR
T1 - Incidence and factors associated with active tuberculosis among people living with HIV after long-term antiretroviral therapy in Thailand
T2 - a competing risk model
AU - Gatechompol, Sivaporn
AU - Sophonphan, Jiratchaya
AU - Ubolyam, Sasiwimol
AU - Avihingsanon, Anchalee
AU - van Leth, Frank
AU - Cobelens, Frank
AU - Kerr, Stephen J.
N1 - Funding Information: This work was supported by HIV-NAT, Thai Red Cross AIDS Research Centre, Bangkok, Thailand and Center of Excellence in Tuberculosis, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. Publisher Copyright: © 2022, The Author(s).
PY - 2022/12/1
Y1 - 2022/12/1
N2 - Background: Antiretroviral therapy (ART) is known to reduce tuberculosis (TB) incidence among people living with HIV (PLWH). However, studies describing the impact of long-term ART and CD4 count recovery on TB incidence remain scarce due to limited follow up in previous studies. We evaluated TB incidence in a long-term cohort of PLWH on ART in Thailand. Methods: We conducted an analysis of PLWH aged ≥ 18 years who started ART between 1996 and December 2020. Participants were followed up every 6 months for routine HIV care. TB risk factors, body mass index (BMI), physical examination and full differential blood counts were evaluated at each clinic visit, and CD4 cell counts and HIV RNA every 12 months. Participants diagnosed with TB > 3 months after starting ART were classified as incident cases. Time to event models with death as a competing risk, were used to derive the TB cumulative incidence function (CIF) after ART initiation, and assess time-updated factors associated with incident TB using a six month lag. Results: A total of 2,636 PLWH contributing 24,229 person years (PY) of follow-up on ART were analysed. Median age was 32.0 (IQR 27.4–37.6) years; 67.5% were male. Median CD4 cell count at ART initiation was 264 (IQR 167–379) cells/mm3 and median follow-up duration was 7.6 (IQR 1.9–15.7) years. During follow-up, 113 PLWH developed TB. The probability of incident TB was 0.7%, 1.7%, 3.3% and 4.3%, at 1, 2, 5 and 7 years after ART initiation, respectively. TB CIF was highest among participants with CD4 < 50 cells/mm3. The overall crude incidence of TB was 4.66 (95% CI 3.87–5.60) per 1000 PY. Low CD4 count, BMI < 18 kg/m2, and substance use in the previous six months were significantly associated with incident TB. Incidence declined with time on suppressive ART, but remained higher than the Thai general population 7 years after ART initiation (2.2 vs 1.5/1000 PY, respectively). Conclusion: Despite a marked reduction in TB incidence following ART, ongoing TB risk remains high among PLWH, despite long-term suppressive ART. Those with low CD4 cell counts, who are underweight, or currently having substance abuse should be carefully monitored.
AB - Background: Antiretroviral therapy (ART) is known to reduce tuberculosis (TB) incidence among people living with HIV (PLWH). However, studies describing the impact of long-term ART and CD4 count recovery on TB incidence remain scarce due to limited follow up in previous studies. We evaluated TB incidence in a long-term cohort of PLWH on ART in Thailand. Methods: We conducted an analysis of PLWH aged ≥ 18 years who started ART between 1996 and December 2020. Participants were followed up every 6 months for routine HIV care. TB risk factors, body mass index (BMI), physical examination and full differential blood counts were evaluated at each clinic visit, and CD4 cell counts and HIV RNA every 12 months. Participants diagnosed with TB > 3 months after starting ART were classified as incident cases. Time to event models with death as a competing risk, were used to derive the TB cumulative incidence function (CIF) after ART initiation, and assess time-updated factors associated with incident TB using a six month lag. Results: A total of 2,636 PLWH contributing 24,229 person years (PY) of follow-up on ART were analysed. Median age was 32.0 (IQR 27.4–37.6) years; 67.5% were male. Median CD4 cell count at ART initiation was 264 (IQR 167–379) cells/mm3 and median follow-up duration was 7.6 (IQR 1.9–15.7) years. During follow-up, 113 PLWH developed TB. The probability of incident TB was 0.7%, 1.7%, 3.3% and 4.3%, at 1, 2, 5 and 7 years after ART initiation, respectively. TB CIF was highest among participants with CD4 < 50 cells/mm3. The overall crude incidence of TB was 4.66 (95% CI 3.87–5.60) per 1000 PY. Low CD4 count, BMI < 18 kg/m2, and substance use in the previous six months were significantly associated with incident TB. Incidence declined with time on suppressive ART, but remained higher than the Thai general population 7 years after ART initiation (2.2 vs 1.5/1000 PY, respectively). Conclusion: Despite a marked reduction in TB incidence following ART, ongoing TB risk remains high among PLWH, despite long-term suppressive ART. Those with low CD4 cell counts, who are underweight, or currently having substance abuse should be carefully monitored.
KW - Adolescent
KW - Adult
KW - Antiretroviral Therapy, Highly Active
KW - CD4 Lymphocyte Count
KW - Competing risk model
KW - HIV Infections/complications
KW - Humans
KW - Incidence
KW - Long term ART
KW - Male
KW - PWPH
KW - Risk Factors
KW - TB incidence
KW - Thailand/epidemiology
KW - Tuberculosis/complications
UR - http://www.scopus.com/inward/record.url?scp=85127687917&partnerID=8YFLogxK
U2 - https://doi.org/10.1186/s12879-022-07332-3
DO - https://doi.org/10.1186/s12879-022-07332-3
M3 - Article
C2 - 35387594
SN - 1471-2334
VL - 22
SP - 1
EP - 8
JO - BMC Infectious Diseases
JF - BMC Infectious Diseases
IS - 1
M1 - 346
ER -
