Analysis of extracorporeal photopheresis within the frame of the WAA register

The world apheresis association registry, 2023 update

The WAA apheresis registry contains data on more than 140,000 apheresis procedures conducted in 12 different countries. The aim is to give an update of indications, type and number of procedures and adverse events (AEs). MATERIAL AND METHODS: The WAA-registry is used for registration of apheresis procedures and is free of charge. The responsible person for a center can apply at the site www.waa-registry.org RESULTS: Data includes reported AEs from 2012 and various procedures and diagnoses during the years 2018-2022; the latter in total from 27 centers registered a total of 9500 patients (41% women) that began therapeutic apheresis (TA) during the period. A total of 58,355 apheresis procedures were performed. The mean age was 50 years (range 0-94). The most common apheresis procedure was stem cell collection for which multiple myeloma was the most frequent diagnosis (51%). Donor cell collection was done in 14% and plasma exchange (PEX) in 28% of patients; In relation to all performed procedures PEX, using a centrifuge (35%) and LDL-apheresis (20%) were the most common. The main indication for PEX was TTP (17%). Peripheral veins were used in 56% as the vascular access. The preferred anticoagulant was ACD. AEs occurred in 2.7% of all procedures and were mostly mild (1%) and moderate 1.5% (needed supportive medication) and, only rarely, severe (0.15%). CONCLUSION: The data showed a wide range of indications and variability in apheresis procedures with low AE frequency.

Extracorporeal photopheresis as an immunomodulatory treatment modality for chronic GvHD and the importance of emerging biomarkers

Haematopoietic stem cell transplantation (HSCT) is the treatment of choice for malignant haematological diseases. Despite continuous improvements in pre- and post-transplantation procedures, the applicability of allo-HSCT is limited by life-threatening complications such as graft-versus-host disease (GvHD), engraftment failure, and opportunistic infections. Extracorporeal photopheresis (ECP) is used to treat steroid resistant GvHD with significant success. However, the molecular mechanisms driving its immunomodulatory action, whilst preserving immune function, require further understanding. As ECP is safe to administer with few significant adverse effects, it has the potential for earlier use in the post-HSCT treatment of GvHD. Thus, further understanding the immunomodulatory mechanisms of ECP action may justify more timely use in clinical practice, as well as identify biomarkers for using ECP as first line or pre-emptive GvHD therapy. This review aims to discuss technical aspects and response to ECP, review ECP as an immunomodulatory treatment modality for chronic GvHD including the effect on regulatory T cells and circulating vs. tissue-resident immune cells and consider the importance of emerging biomarkers for ECP response.

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. This article is protected by copyright. All rights reserved.