Abstract:

Objective To discuss the clinical characteristics， intervention timing， diagnosis and treatment plan， and prognosis of one patient with immune thrombotic thrombocytopenic purpura （iTTP）， and to provide more clinical evidences for the precise diagnosis and treatment of this rare disease. Methods The clinical data of one patient with iTTP were collected， who had been previously misdiagnosed with acute infection after receiving a virus-inactivated vaccine. The data included clinical manifestations and ancillary examination informations. The relevant literatures were reviewed. Results The patient， a 60-year-old male， was admitted with “fever for 6 d.” The physical examination results showed scattered red maculopapules on the lower limbs， with only mild thrombocytopenia initially， and the admission PLASMIC score was 5 points. Initially diagnosed with acute infection， the patient was treated with anti-inflammatory， anti-infective， and corticosteroid therapies， but the response was poor. After one week， the re-evaluation results showed a significant decrease in the platelet count， progressing to severe thrombocytopenia， hematuria， dark-colored urine， and neurological and psychiatric symptoms as the disease progressed. The further examination results showed the PLASMIC score was increased to 7 points. After high suspicion of iTTP， therapeutic plasma exchange （TPE） was initiated immediately. The a disintegrin and metalloproteinase with thrombospondin type 1 motif member 13（ADATMS13） activity level was<1% during treatment， and the test for ADAMTS13 inhibitors was positive. The genetic testing results revealed a missense mutation in an iTTP-susceptible gene. After a confirmed diagnosis， the patient was treated regularly with intravenous rituximab， completing four treatment cycles， and followed up to the present； the treatment deemed effective. Conclusion iTTP is often delayed in the diagnosis due to atypical initial clinical symptoms. Once suspected， the treatment based on TPE and glucocorticoids should be initiated immediately. New drugs like rituximab provide a multidisciplinary treatment strategy option for iTTP.

Key words: Thrombotic thrombocytopenic purpura, Clinical analysis, Plasma exchange, Rituximab