Are apoptosis‐determining‐techniques useful to establish an early diagnosis of acute graft vs host disease in pediatric patients under treatment with multiple drugs?

BACKGROUND: There are no pathognomonic histopathological features to distinguish acute graft-vs-host disease (aGVHD) from skin drug reactions (SDRs) in pediatric patients with multiple drug regimens that have received blood transfusions and/or transplants. We aimed to determine if the addition of apoptosis markers is helpful to distinguish aGVHD from SDRs in these patients. METHODS: Skin biopsy specimens from patients with a clinical diagnosis of aGVHD or SDRs were evaluated for the presence of apoptotic bodies, satellitosis, interface damage, vasculitis, and inflammatory infiltrate on HE the presence of >/=4 apoptotic keratinocytes per 10 hpf was identified as the optimal cut-off point to discriminate aGVHD from SDRs. No SDRs cases had follicular apoptotic cells. TUNEL, bcl-2, and caspase-3 determination showed no difference between both groups. CONCLUSIONS: The presence of >/=4 apoptotic keratinocytes per 10 hpf (in aGVHD) and the absence of follicular apoptotic cells (in SDRs) might be a useful marker to distinguish between them.