Relapse of congenital thrombotic thrombocytopenic purpura, after spontaneous remission, in a second-trimester primigravida: case report and review of the literature.

CONTEXT: Thrombotic microangiopathy syndrome or thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) describes distinct diseases sharing common pathological features: microangiopathic hemolytic anemia and thrombocytopenia, without any other apparent cause.

CASE REPORT: An 18-year-old second-trimester primigravida presented with a history of fifteen days of intense weakness, followed by diarrhea over the past six days. She reported having had low platelets since childhood, but said that she had never had bleeding or menstrual abnormalities. Laboratory investigation showed anemia with schistocytes, thrombocytopenia and hypohaptoglobulinemia. Red blood cell concentrate and platelet transfusions were performed. The hypothesis of TTP or HUS was put forward and ADAMTS13 enzyme activity was investigated. The patient evolved with increasing platelet counts, even without specific treatment, and she was discharged. One month afterwards, she returned presenting weakness and swollen face and legs, which had developed one day earlier. The ADAMTS13 activity was less than 5%, without presence of autoantibodies. Regarding the two previous admissions (at 9 and 16 years of age), with similar clinical features, there was spontaneous remission on the first occasion and, on the second, the diagnosis of TTP was suspected and plasmapheresis was performed, but ADAMTS13 activity was not investigated.

CONCLUSION: To date, this is the only report of congenital TTP with two spontaneous remissions in the literature This report reveals the importance of suspicion of this condition in the presence of microangiopathic hemolytic anemia and thrombocytopenia without any other apparent cause.