title: Thrombotic thrombocytopenic purpura in pediatric patients.
abstract: Although thrombotic thrombocytopenic purpura (TTP) is rarely seen in pediatric patients, failure to recognize this condition often leads to severe consequences and poor outcomes. Classic features of TTP include thrombocytopenia, microangiopathic hemolytic anemia, acute kidney injury, fever, and central nervous system involvement. However, patients suffering from this condition may not present with all of the symptoms simultaneously. Therefore, it is of utmost importance for healthcare providers to have a high index of suspicion. Laboratory investigations may reveal the presence of schistocytes on peripheral blood smear, negative Coombs test, high lactate dehydrogenase levels and severely low platelet counts. The etiology of TTP is mainly due to insufficient cleavage of the large multimers of von Willebrand factor (vWF) secondary to decreased activity of ADAMTS13 (a disintegrin and metalloprotease with Thrombospondin type 1 repeats, member 13). TTP can be broadly classified into familial TTP (Upshaw Schulman syndrome) and non-familial TTP. Familial TTP is due to a congenital deficiency of ADAMTS13. Its mainstay of therapy is initiation of plasmapheresis during the acute phase, followed by regular fresh frozen plasma (FFP) infusions. Alternatively, non-familial TTP is due to a decrease in ADAMTS13 activity secondary to the presence of anti-ADAMTS13 antibodies. Once again, the primary treatment is plasmapheresis; however, recent anecdotal data also supports the use of rituximab in select cases.
authors.affiliation: Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Melanie
authors.initials: M
authors.lastname: Steele
authors.forename: Howard H W
authors.initials: HH
authors.lastname: Chen
authors.forename: Jeremy
authors.initials: J
authors.lastname: Steele
authors.forename: Anthony K C
authors.initials: AK
authors.lastname: Chan
authors.forename: Keith K
authors.initials: KK
authors.lastname: Lau
mesh_terms: D051722:ADAM Proteins / Q000235:genetics; D000071120:ADAMTS13 Protein; D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use; D002648:Child; D006801:Humans; D010956:Plasmapheresis; D011697:Purpura, Thrombotic Thrombocytopenic / Q000209:etiology / Q000628:therapy*; D000069283:Rituximab
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D000069283:Rituximab; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human