Thrombotic microangiopathy: current knowledge and outcomes with plasma exchange

Area of Science:

• Hematology
• Internal Medicine
• Pathophysiology

Background:

• Thrombotic microangiopathy classification has evolved with new treatments and mechanistic insights.
• Thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are distinct clinical forms, excluding disseminated intravascular coagulation (DIC).
• Plasma therapy and ADAMTS13 inhibitor identification have significantly impacted classification.

Purpose of the Study:

• To review the evolving classification of thrombotic microangiopathy.
• To highlight diagnostic challenges and therapeutic implications for TTP and HUS.
• To discuss primary and secondary forms of TTP/HUS and atypical HUS.

Main Methods:

• Literature review of thrombotic microangiopathy classification.
• Analysis of diagnostic criteria for TTP and HUS.
• Discussion of therapeutic interventions, including plasma therapy and eculizumab.

Main Results:

• The term TTP/HUS is used in adults with unexplained thrombocytopenia and microangiopathic hemolytic anemia without DIC.
• Eight secondary categories of TTP/HUS are identified in adults, alongside primary idiopathic and hereditary forms.
• HUS includes primary (atypical HUS) and secondary forms (e.g., diarrheal HUS).
• Children with HUS may have complement activation abnormalities requiring eculizumab therapy.

Conclusions:

• Plasma therapy has improved understanding of ADAMTS13's role and patient outcomes.
• Accurate and timely diagnosis of TTP/HUS is crucial for effective, life-saving treatment.
• Future surveillance and intervention strategies are needed for thrombotic microangiopathy management.