Outcomes in 1096 patients with severe thrombotic thrombocytopenic purpura before the Caplacizumab era

Introduction Thrombotic thrombocytopenic purpura (TTP) is a diagnostic and therapeutic emergency. Therapeutic plasma exchange (TPE) combined with immunosuppression has been the cornerstone of the initial management. To produce optimal benefits, emerging treatments must be used against a background of best standard of care. Clarifying current uncertainties is therefore crucial. Methods The objective of this study was to analyze a large high-quality database (Marketscan) of TTP patients managed between 2005 and 2014, in the pre-caplacizumab era, in order to assess the impact of time to first TPE and use of first-line rituximab on mortality, and whether mortality declines over time. Results Among the 1096 included patients (median age 46 [IQR 35-55], 70% female), 28.8% received TPE before day 2 in the ICU. Hospital mortality was 7.6% (83 deaths). Mortality was independently associated with older age (hazard ratio [HR], 1.024/year; 95% confidence interval [95%CI], [1.009-1.040]), diagnosis of sepsis (HR, 2.360; 95%CI [1.552-3.588]), and the need for mechanical ventilation (HR, 4.103; 95%CI, [2.749-6.126]). Factors independently associated with lower mortality were TPE at ICU admission (HR, 0.284; 95%CI, [0.112-0.717]), TPE within one day after ICU admission (HR, 0.449; 95%CI, [0.275-0.907]), and early rituximab therapy (HR, 0.229; 95% CI, [0.111-0.471]). Delayed TPE was associated with significantly higher costs. Conclusions Immediate TPE and early rituximab are associated with improved survival in TTP patients. Improved treatments have led to a decline in mortality over time, and alternate outcome variables such as the use of hospital resources or longer term outcomes therefore need to be considered.

Automated summary

Immediate TPE and early rituximab therapy are associated with improved survival in TTP patients. The use of improved treatments has led to a decrease in mortality over time, and other outcome variables such as hospital resource utilization or long-term outcomes should be considered.