Immune thrombotic thrombocytopenic purpura in older patients: prognosis and long-term survival

Older age is associated with increased mortality in immune thrombotic thrombocytopenic purpura (iTTP). Yet, data are scarce regarding iTTP occurring among older patients. To assess clinical features and long-term impact of iTTP on mortality in older patients (>60 years old), characteristics and prognoses of adult iTTP patients enrolled in the French Reference Center for Thrombotic Microangiopathies registry between 2000 and 2016 were described according to age (<60 years old or ≥60 years old). Long-term mortality of iTTP older survivors was compared with that of non-iTTP geriatric subjects. Comparing, respectively, older iTTP patients (N = 71) with younger patients (N = 340), time from hospital admission to diagnosis was longer (P < .0001); at diagnosis, delirium (P = .034), behavior impairment (P = .045), renal involvement (P < .0001), and elevated troponin level (P = .025) were more important whereas cytopenias were less profound (platelet count, 22 × 103/mm3 [9-57] vs 13 × 103/mm3 [9-21], respectively [P = .002]; hemoglobin level, 9 g/dL [8-11] vs 8 g/dL [7-10], respectively [P = .0007]). Short- and mid-term mortalities were higher (P < .0001) and increased for every 10 years of age range. Age ≥60 years, cardiac involvement, increased plasma creatinine level, and total plasma exchange volume were independently associated with 1-month mortality. Compared with a non-iTTP geriatric population, older survivors showed an increased long-term mortality (hazard ratio = 3.44; P < .001). In conclusion, older iTTP patients have atypical neurological presentation delaying the diagnosis. Age negatively impacts short-term but also long-term mortality.