Transplant-associated thrombotic microangiopathy: opening Pandora's box

Area of Science:

• Hematology
• Immunology
• Transplantation Medicine

Background:

• Transplant-associated thrombotic microangiopathy (TA-TMA) is a critical early complication following hematopoietic cell transplantation (HCT).
• TA-TMA carries a high mortality rate, particularly in patients refractory to standard treatments like calcineurin inhibitor cessation.
• Prevalence estimates vary, with higher rates observed in allogeneic HCT compared to autologous HCT.

Purpose of the Study:

• To critically evaluate diagnostic criteria for TA-TMA.
• To review the epidemiology and prognosis of TA-TMA.
• To summarize current knowledge on complement activation, endothelial damage, and treatment strategies for TA-TMA.

Main Methods:

• Literature review and critical analysis of existing data on TA-TMA.
• Evaluation of diagnostic criteria and epidemiological studies.
• Synthesis of recent evidence linking TA-TMA to complement pathway activation and endothelial damage.

Main Results:

• TA-TMA pathophysiology is not fully understood, but links to atypical hemolytic uremic syndrome and complement activation are emerging.
• Conventional treatments for TA-TMA are often inefficient.
• Early detection of complement activation may identify patients who could benefit from complement inhibition therapies.

Conclusions:

• Understanding TA-TMA requires a critical evaluation of diagnostic criteria and epidemiology.
• Emerging evidence points to complement pathway dysregulation as a key factor in TA-TMA pathogenesis.
• Targeting complement inhibition represents a promising therapeutic avenue for TA-TMA, warranting further investigation.