BACKGROUND: Extracorporeal photochemotherapy (ECP) is a valid therapeutic option in the treatment of acute and chronic graft-versus-host disease (aGVHD and cGVHD, respectively). No standard clinical and laboratory criteria of response to ECP treatment are available at the moment.

STUDY DESIGN AND METHODS: Clinical and laboratory variables on 73 pediatric patients with aGVHD (n = 50) and cGVHD (n = 23) were correlated with response to ECP and survival.

RESULTS: An overall response (OR) was obtained in 34 of 50 (68%) aGVHD and in 16 of 23 (69.5%) cGVHD patients. Steroid tapering within 30 days of 1.3 mg/kg in OR (p = 0.004) was the sole highly significant correlation with response found in aGVHD while no correlation emerged for cGVHD (p = 0.28). Among aGVHD patients, response to ECP was inversely associated with death: among OR, deaths were 13 of 34 (38.2%), while among nonresponders, deaths were 15 of 16 (93.8%; p < 0.001). On the other hand, decrease of steroid dose at 30 days was associated with survival: for each 1 mg/kg reduction, the hazard ratio was 2.2, and the 95% confidence interval was 1.5 to 3.2 (p < 0.001). No other clinical or laboratory variables statistically associated with survival were found.

CONCLUSIONS: Our results demonstrate that steroid tapering within the first 30 days of ECP treatment in aGVHD and response to ECP in acute and chronic GVHD are the only variables influencing response and survival, respectively.