Later onset of herpes zoster-associated immune reconstitution inflammatory syndrome

Objectives The aim of the study was to determine whether immune reconstitution inflammatory syndrome (IRIS) associated with herpes zoster occurs on a different time frame from other instances of IRIS. Methods Statistical analysis of onset times of herpes zoster-associated IRIS and other cases of IRIS was carried out in a retrospective cohort starting antiretroviral therapy at advanced stages of HIV infection. Results Herpes zoster-associated IRIS was significantly more frequent after the first 3 months of successful highly active antiretroviral therapy (HAART), than other instances of IRIS (IRIS associated with tuberculosis, Mycobacterium avium complex, Kaposi's sarcoma, etc.) which mainly occurred during the first 3 months of treatment. Conclusions The characteristic onset time pattern of herpes zoster-associated IRIS, coincident with the second phase of immune recovery under HAART, suggests that the immune recovery events underlying herpes zoster-associated IRIS are different from those underlying other types of IRIS. Our findings may be useful in improving the follow-up of individuals who start HAART at an advanced stage of HIV infection.