Mini buffy coat photopheresis for children and critically ill patients with extracorporeal photopheresis contraindications

BACKGROUND: Conventional extracorporeal photopheresis (ECP) has proven efficacy for the treatment of several diseases but is limited to patients with sufficient body weight. A novel simplified mini buffy coat ECP technique that allows treatment of small children and patients with apheresis contraindications has been developed. STUDY DESIGN AND METHODS: White blood cell (WBC)-rich buffy coat fractions were prepared from 5 to 8 mL/kg whole blood in a closed system, diluted, and ultraviolet A (UVA)-irradiated after addition of 8-methoxypsoralen (8-MOP). Apoptosis and cell death were analyzed by annexin V and 7-aminoactinomycin staining. Lymphocyte proliferation was measured after CD3/CD28 and phytohemagglutinin (PHA) stimulation. Autologous residual blood and UVA-irradiated buffy coat were returned to the patients. Fifty-six mini buffy coat ECP procedures were applied to three children with acute steroid-refractory skin graft-versus-host disease and apheresis contraindications. RESULTS: Mean whole blood and buffy coat volumes were 166 (+/- 61.8) and 8 (+/- 1.6) mL, respectively, and resulted in a hematocrit of 2.2% (+/- 0.4) after saline dilution (median +/- SD). UVA irradiation of 8-MOP buffy coat preparations resulted in significant induction of WBC apoptosis at 48-72 hours (p < 0.006). WBC proliferation was significantly inhibited both after CD3/CD28 stimulation and after PHA stimulation when compared to controls (p < 0.001). No clinical or laboratory side effects were observed during mini ECP procedures and the three patients responded to the therapy. CONCLUSION: Mini buffy coat ECP induces apoptosis and lymphocyte proliferation inhibition, both of which occur after standard ECP. This study proposes that mini buffy coat ECP be used as a simple and inexpensive alternative to classical ECP in children and adult patients with apheresis contraindications.