Immune thrombocytopenic purpura and thrombotic thrombocytopenic purpura — diagnostic difficulties and errors

Abstract

   Introduction. When establishing a diagnosis of thrombotic thrombocytopenic purpura (TTP) for the first time, other diseases occurring with thrombocytopenia may be misdiagnosed.   Aim: to analyze diagnostic difficulties and errors of TTP.   Materials and methods. In total, 54 patients (44 women and 10 men) aged 18 to 83 years (median 33 years), who were diagnosed TTP from 2019 to 2023, were included in the study. Anamnesis, baseline hemoglobin, platelets, erythrocytes, lactate dehydrogenase and bilirubin serum concentrations, pre-established diagnoses, treatment, and outcomes were analyzed.   Results. Initially TTP was suspected only in 19 (35 %) patients. In 12 out of 54 patients immune thrombocytopenia (ITP) was initially misdiagnosed. Fisher-Evans syndrome was initially suspected in 3 patients. In sporadic cases, myelodysplastic syndrome, systemic lupus erythematosus / antiphospholipid syndrome, autoimmune hemolytic anemia were initially suspected. Among 15 women with associated with pregnancy TTP in 8 (53.3 %), HELLP syndrome was initially misdiagnosed. In total, 12 (22.2 %) of 54 TTP patients died. In 11/12 non-survival patients, TTP treatment was never started, because the doctors were waiting for the ADAMTS13 test results. A case report of Sequential Immune Thrombocytopenia (ITP) and TTP in the same Patient is described.   Conclusion. When thrombocytopenia is combined with hemolysis and in the absence of multiple organ pathology, it is difficult to differentiate ITP and TTP without examining the plasma activity of ADAMTS113. With a combination of ITP and TTP in the same patient, the study of ADAMTS13 plasma activity makes it possible to identify the leading mechanism of thrombocytopenia and choose treatment tactics.