Therapeutic plasmapheresis for the treatment of the thrombotic thrombocytopenic purpura-haemolytic uraemic syndromes

WYK Hwang, LYA Chai, HJ Ng, YT Goh, PHC Tan
Correspondence: Dr William Hwang Ying Khee, ghehyk@sgh.com.sg

ABSTRACT
Introduction The thrombotic thrombocytopenic purpura-haemolytic uraemic syndromes (TTP-HUS) are uncommon disorders that are fatal if untreated. Therapeutic plasma exchange has resulted in excellent remission and survival rates in this patient population.
Methods We reviewed our experience of therapeutic plasmapheresis for TTP-HUS syndromes for 11 patients who presented in the last five years. Parameters captured included haemoglobin and platelet counts at presentation as well as the number of plasmapheresis sessions and adjunctive treatment given.
Results We found a response rate of 82 percent to plasma exchange, of whom 55 percent attained complete remission. Responses were excellent in the five patients who presented with primary or idiopathic TTP (100 percent response) among whom 80 percent had sustained long term responses. Responses were poor and often unsustained (only one out of six survived) in patients who presented with thrombotic microangiopathies secondary to underlying disorders such as bone marrow transplantation and metastatic carcinoma.
Conclusion Plasmapheresis is mandatory and extremely effective for primary TTP. However, it is at most an adjunct for patients who developed it secondary to an underlying disorder until and if the primary disorder can be successfully treated.

Keywords: therapeutic plasmapheresis, thrombotic thrombocytopenic purpura
Singapore Med J 2004; 45(5): 219-223