ADAMTS13 recovery in acute thrombotic thrombocytopenic purpura after caplacizumab therapy.

ABSTRACT: Caplacizumab prevents the interaction between von Willebrand factor and platelets and is used to treat immune thrombotic thrombocytopenic purpura (iTTP). Its administration has been associated with a delay in ADAMTS13 activity restoration after plasma exchange (PEX) suspension. We analyzed the outcomes of 113 iTTP episodes, 75 of which were treated with caplacizumab, in 108 patients from the Spanish Registry of Thrombotic Thrombocytopenic Purpura. Caplacizumab shortened the time to platelet count normalization and reduced PEX requirement, exacerbations, and relapses. There was no difference in the time to achieve ADAMTS13 activity ≥20% after PEX end between caplacizumab-treated and nontreated episodes (median [interquartile range], 14.5 [7.7-27.2] vs 13.0 [8.0-29.0] days, P = .653). However, considering the 36 episodes in which caplacizumab was started ≤3 days after iTTP diagnosis, the time for ADAMTS13 restoration from PEX end was higher than in those episodes in which caplacizumab was started >3 days after iTTP diagnosis (20.0 [12.0-43.0] vs 11.0 [3.5-20.0] days, P = .003) or than in non-caplacizumab-treated episodes (P = .033). This finding could be related to a significantly shorter duration of PEX in early caplacizumab-treated episodes than in late caplacizumab-treated episodes (5.5 [4.0-9.0] vs 15.0 [11.0-21.5] days, P < .001) or non-caplacizumab-treated episodes (11.0 [6.0-26.0] days, P < .001). There were no differences in time to ADAMTS-13 restoration from PEX start (28.0 [17.2-47.5], 27.0 [19.0-37.5] and 29.5 [15.2-45.0] days in early caplacizumab-treated, late caplacizumab-treated and non-caplacizumab-treated episodes). Early administered caplacizumab does not prevent the requirement for immunosuppression but has beneficial effects by shortening PEX requirement without major safety concerns.

Using the World Apheresis Association Registry Helps to Improve the Treatment Quality of Therapeutic Apheresis.

Therapeutic apheresis (TA) is prescribed to patients that suffer from a severe progressive disease that is not sufficiently treated by conventional medications. A way to gain more knowledge about this treatment is usually by the local analysis of data. However, the use of large quality assessment registries enables analyses of even rare findings. Here, we report some of the recent data from the World Apheresis Association (WAA) registry. Data from >104,000 procedures were documented, and TA was performed on >15,000 patients. The main indication for TA was the collection of autologous stem cells (45% of patients) as part of therapy for therapy. Collection of stem cells from donors for allogeneic transplantation was performed in 11% of patients. Patients with indications such as neurological diseases underwent plasma exchange (28%). Extracorporeal photochemotherapy, lipid apheresis, and antibody removal were other indications. Side effects recorded in the registry have decreased significantly over the years, with approximately only 10/10,000 procedures being interrupted for medical reasons. CONCLUSION: Collection of data from TA procedures within a multinational and multicenter concept facilitates the improvement of treatment by enabling the analysis of and feedback on indications, procedures, effects, and side effects.