Treating TTP/HUS with plasma exchange: a single centre's 25-year experience

Area of Science:

• Hematology
• Internal Medicine
• Clinical Research

Background:

• Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS) is a serious thrombotic microangiopathy.
• Existing TTP/HUS literature indicates a significant 6-month mortality rate of 16-29%.

Purpose of the Study:

• To describe the clinical features, treatment, and outcomes of TTP/HUS patients.
• To determine the 6-month all-cause mortality rate for TTP/HUS patients at LHSC, Canada.
• To compare outcomes across different TTP/HUS classifications: idiopathic primary, relapsed, and secondary responsive/non-responsive.

Main Methods:

• Retrospective cohort study design.
• Data collected from inpatient and outpatient records at London Health Sciences Centre (LHSC), Canada.
• Inclusion criteria: patients referred for plasma exchange therapy between 1981 and 2006 (n=110).

Main Results:

• Overall 6-month all-cause mortality rate was 19%.
• Mortality rates varied by TTP/HUS type: 12% for idiopathic and 26% for secondary.
• No mortality events were observed in relapsed TTP/HUS patients (n=17), who also presented with less severe characteristics and faster treatment response.

Conclusions:

• Relapsed TTP/HUS patients demonstrate an excellent prognosis.
• Aggressive plasma exchange therapy, patient education, and surveillance are hypothesized to enhance survival.
• Further randomized controlled trials are recommended to validate these hypotheses.