[Thrombotic thrombocytopenic purpura in 13 Dutch centres: treatment and longterm follow-up]

Analysis of the incidence, treatment modalities and disease course of thrombotic thrombocytopenic purpura (TTP) in the Netherlands.

Retrospective follow-up study.

13 centres in the Netherlands.

Regarding all patients admitted between 1-1-1979 and 1-1-1992 to one of 13 Dutch haematological centres, in whom the diagnosis of TTP was made for the first time, information was gathered from the medical records and from the patients own physicians on patient characteristics at presentation and the occurrence of relapse or death. The follow-up period tended on 1-4-1995.

A total of 65 patients with newly diagnosed TTP were identified: 0.34 per 1,000,000 persons a year (95% confidence interval (95%-CI): 0.26-0.45), increasing to 0.83 in the last year of the study. Forty-six (95%) patients were treated with fresh frozen plasma: 18 (28%) by plasma infusion and 44 (68%) by plasma exchange; 48 (74%) (additionally) received corticosteroids. All 52 patients (80%) who survived the first four weeks after admission reached complete remission. Twelve patients with relapsing TTP underwent splenectomy in remission. The 5-year survival rate was 77% (95% CI: 66-87) and the 5-year relapse-free survival rate 38% (95% CI: 25-52). Cardiac symptoms, severe thrombocytopenia and a high serum LDH were risk factors for acute mortality, but no risk factors for relapse or late-occurring death could be identified.

TTP is a rare disease which is increasingly being recognized. Plasma exchange and corticosteroids are the most frequently used therapies. The disease has a high mortality rate in the acute phase of the disease.