[Acquired idiopathic thrombotic thrombocytopenic purpura: arguments for an autoimmune disease].
Thrombotic thrombocytopenic purpura (TTP) is a severe form of thrombotic microangiopathy (TMA) characterized by systemic platelet clumping, hemolytic anemia, and multiorgan failure. TTP results from a defect in ADAMTS13, a plasma enzyme specifically involved in the cleavage of highly hemostatic unusually large (UL) von Willebrand factor (vWF) multimers into smaller and less adhesive vWF forms. Failure to degrade these UL-vWF multimers leads to excessive platelet aggregation and capillary occlusion. ADAMTS13 deficiency is related to mutations of the encoding gene in hereditary TTP, whereas in acquired forms it results from autoantibodies that may alter the protein function. This latter finding strongly suggests that acquired idiopathic TTP corresponds to an autoimmune disease. Acquired idiopathic TTP appears to be associated with clinical features suggestive of autoimmunity in one third of cases. In two thirds, autoantibodies such as antinuclear antibodies may be observed. This review, based on an analysis of the literature and on French experience with TMA, focuses on the different autoimmune manifestations that may be observed in TTP, as well as the putative pathophysiological link between autoimmune manifestations and TTP.
Coppo
Paul
P
Service d'Hématologie et de Thérapie Cellulaire, Hôpital Saint-Antoine, Paris. paulcoppo@aol.com
Veyradier
Agnès
A
Monge
Matthieu
M
D051722:ADAM Proteins / Q000235:genetics; D000071120:ADAMTS13 Protein; D000293:Adolescent; D000328:Adult; D000974:Antibodies, Antinuclear / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000627:therapeutic use; D058846:Antibodies, Monoclonal, Murine-Derived; D001323:Autoantibodies / Q000032:analysis; D001327:Autoimmune Diseases; D015551:Autoimmunity; D002648:Child; D002986:Clinical Trials as Topic; D003520:Cyclophosphamide / Q000008:administration & dosage / Q000627:therapeutic use; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000008:administration & dosage / Q000627:therapeutic use; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000627:therapeutic use; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015337:Multicenter Studies as Topic; D009154:Mutation; D010951:Plasma Exchange; D010974:Platelet Aggregation; D011247:Pregnancy; D015995:Prevalence; D011697:Purpura, Thrombotic Thrombocytopenic / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000235:genetics / Q000276:immunology / Q000503:physiopathology; D012307:Risk Factors; D000069283:Rituximab; D013997:Time Factors; D014841:von Willebrand Factor
D000974:Antibodies, Antinuclear; D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D001323:Autoantibodies; D000939:Epitopes; D007155:Immunologic Factors; D007166:Immunosuppressive Agents; D014841:von Willebrand Factor; D000069283:Rituximab; D003520:Cyclophosphamide; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human