Association of Mortality and Immunological Response after Initiating Antiretroviral Therapy among HIV-infected Patients in Khon Kaen: A Cohort Study

Objective: To estimate the probability of survival and predictive risk for death according to patterns of CD4 response among HIV patients initiating antiretroviral therapy (ART). Methods: A retrospective cohort study was conducted. HIV patients initiating ART, age of 18 or more were recruited at Khon Kaen Hospital, Thailand. Sociodemographic, clinical presentations, opportunistic infections and ART regimen were recorded. The CD4 cell count was performed at least every 6 months and patterns of CD4 response were analyzed. Kaplan-Meier methods were used to estimate probability of survival and cox-regression analysis was computed to find predictive risk for death by CD4 change. Results: A total of 986 patients were recruited. Mean ± SD age was 38.5 ± 7.8 years with 55.6% male. Median (interquartile range, IQR) follow-up period was 23 (12-45) months. Median (IQR) of baseline CD4 was 54 (16-130) cells/mm 3 . Of 986 patients, 2,033 patient-years were observed. One hundred and twenty-five patients (12.7%) died. Overall mortality was 4.8 per 100 patient-years, 95% confidence interval (CI); 3.6-6.1. For 841 participants who followed-up at 6 months, patterns of CD4 change including (i) persistence of less than 100 cells/mm 3 [relative risk (RR), 4.3; 95% CI, 2.2-8.4 ; p < 0.001]; (ii) Fall to baseline or below (RR, 7.2; 95% CI, 2.9-18.3; p < 0.001) while those with 50% fall to below peak level trend to have a higher risk of mortality (RR, 5.8; 95% CI, 1.3-24.9; p = 0.06) were found significantly associated with higher mortality when compared to those rising. Conclusions: The changes of CD4 at 6 months that fall below baseline or persist of less than 100 cells/ mm 3 are significantly associated with higher mortality when compared to those that rise. (J Infect Dis Antimicrob Agents 2011;28:87-97.)