Impact of extracorporeal photopheresis on blood and coagulation parameters.

Extracorporeal photopheresis (ECP) is considered a safe treatment modality. We aimed to assess blood parameters including coagulation during ECP over time. We performed a long-term retrospective single-center chart review (laboratory parameters) of adult patients (n = 172) who had received ECP for any indication. We observed a significant decrease (p < 0.05) in erythrocytes, hemoglobin, and leukocytes compared to baseline levels after only one ECP procedure. This decrease persisted after 3-, 6-, 9-, and 12-months of ECP. A significant pathological decline of hemoglobin was observed in a higher proportion (26.4% and 25.2%, respectively) of patients after 6 (p = 0.0007) and 12 (p = 0.012) months of ECP. Mean corpuscular volume as well as hematocrit was significantly decreased at 3-, 6-, 9-, and 12-months of evaluation compared to baseline (p < 0.05). After 9 and 12 months of ECP we observed a further decline in lymphocyte counts (p < 0.05). Various coagulation parameters did not change significantly during ECP treatment. Even though not all alterations observed in peripheral blood of ECP patients in the present study were of clinical significance, risk for developing persistent anemia must be considered in patients undergoing ECP.