Immune reconstitution inflammatory syndrome in adult human immunodeficiency virus-infected patients in Thailand

Immune reconstitution inflammatory syndrome (IRIS) is an important adverse event among human immunodeficiency virus (HIV)-infected patients taking highly active antiretroviral therapy (HAART). The epidemiology of IRIS in Thailand has not been well examined, especially among adult HIV-infected patients. In the present study, we reviewed the medical records of 174 HIV-infected, antiretroviral therapy-naive patients older than 15 years (the median CD4 count at commencement of HAART was 37 cells/mm3) and compared characteristics of patients with and without IRIS. During a 12-month follow-up period after commencement of HAART, 11 cases (6.3%) of IRIS were identified (4.2/100 patient-years HAART). The cases included nine cases with mycobacterial infection, one with cytomegalovirus retinitis and one with cryptococcal meningitis. The patients with IRIS were significantly younger than those without IRIS (29 vs 36 on medians, p = 0.022). The median interval between commencement of HAART and the onset of IRIS was 22 days. Although all patients with IRIS improved with or without corticosteroids, they were more frequently hospitalized during a 12-month follow-up period while taking HAART (1 vs 0 on medians, p0.001). The incidence of IRIS in advanced adult HIV-infected patients in Thailand was lower than that reported from Europe and the United States, which may be attributable to deferment of HAART after diagnosing opportunistic infections.