Treatment of acquired thrombotic thrombocytopenic purpura without plasma exchange in selected patients under caplacizumab.
BACKGROUND
Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare, life-threatening autoimmune thrombotic microangiopathy. Current standard of care is therapeutic plasma exchange, immunosuppression, and caplacizumab, an anti-von Willebrand factor nanobody, which is effective in treating aTTP episodes.


PATIENTS/METHODS
Here we report on seven episodes of aTTP treated without plasma exchange in six female patients in Germany and Austria. Two episodes were initial presentations of aTTP; in five instances, patients experienced a relapse. In four episodes, moderate to severe organ dysfunction was observed; three cases presented with a mild course. All patients received caplacizumab immediately once aTTP was suspected or diagnosed, and plasma exchange was omitted based on shared decision making between patient and the treating physicians.


RESULTS
We observed a rapid and robust increase of platelet counts already after the first dose of caplacizumab, leading to a doubling of platelet counts within 17 hours (median), platelet counts normalized (>150 G/L) after median 84 hours. Lactate dehydrogenase, as a surrogate parameter of organ damage, improved in parallel to the platelet counts, indicating resolving microangiopathy.


CONCLUSIONS
In conclusion, in selected cases of acute bouts of aTTP, it seems feasible to delay or omit plasma exchange if platelet counts increase and organ function is stable after start of caplacizumab therapy.
['Völker|Linus A|LA|0000-0002-4461-6128', 'Brinkkoetter|Paul T|PT|0000-0002-4287-2080', 'Knöbl|Paul N|PN|0000-0002-7909-7225', 'Krstic|Miroslav|M|', 'Kaufeld|Jessica|J|', 'Menne|Jan|J|0000-0003-0255-6590', 'Buxhofer-Ausch|Veronika|V|0000-0002-7369-9700', 'Miesbach|Wolfgang|W|']
D000071120:ADAMTS13 Protein D001317:Austria D005260:Female D005343:Fibrinolytic Agents D005858:Germany D006801:Humans D010951:Plasma Exchange D011697:Purpura, Thrombotic Thrombocytopenic D061905:Single-Domain Antibodies
thrombotic thrombocytopenic purpura plasma exchange caplacizumab platelet count ADAMTS13 protein