Drug-induced severe adverse reaction enhanced by human herpes virus-6 reactivation.

Reactivation of certain latent viruses has been linked with a more severe course of drug-induced hypersensitivity reaction (HSR). For example, reactivation of human herpes virus (HHV)-6 is associated with severe organ involvement and a prolonged course of disease. The present study discusses an HSR developed in a previously healthy male exposed to ceftriaxone, doxycycline, vancomycin, and trimethoprim/sulfamethoxazole (co-trimoxazole; TMP/SMX). Initially, the patient presented clinical manifestations of HSR, as well as clinical and laboratory measurements compatible with liver and renal failure. Moreover, the patient presented skin desquamation compatible with Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis. During the reaction, it was observed HHV-6 reactivation. The severity of clinical symptoms is correlated with HHV-6 titer, as well as with results of the in vitro lymphocyte toxicity assay (LTA). Serum levels of a large panel of cytokines are compared between the patient, a large population of SJS patients, and a cohort of healthy controls, using data collected by our laboratory over the years. HHV-6 was measured in the cell culture media from lymphocytes incubated with each of the 4 drugs. Moreover, we describe a new assay using cytokines released by patient lymphocytes following in vitro exposure to the incriminated drugs as biomarkers of HSR. Based on LTA results, HHV-6 reactivation and cytokine measurements, we establish that only doxycycline and TMP/SMX were involved in the HSR. As result of this analysis, the patient could continue to use the other 2 antibiotics safely.