Primary Thrombotic Microangiopathy in Pediatric Patients

Area of Science:

• Pediatric Nephrology
• Hematology
• Infectious Diseases

Background:

• Primary thrombotic microangiopathy (TMA) encompasses Shiga toxin-producing *Escherichia coli*-hemolytic uremic syndrome (STEC-HUS), atypical HUS (aHUS), and thrombotic thrombocytopenic purpura (TTP).
• These conditions represent critical hematologic and renal emergencies in children.

Purpose of the Study:

• To describe the etiology and clinical characteristics of primary TMA in pediatric patients in Latin America.
• To provide the largest series to date on pediatric TMA in this region.

Main Methods:

• Retrospective study of patients under 18 years diagnosed with primary TMA between 2011 and 2021.
• Analysis of etiological subtypes, clinical presentation, treatment, and outcomes.

Main Results:

• Thirty pediatric patients were included; STEC-HUS (63%) and aHUS (30%) were the predominant forms.
• Median age was 2.8 years, with a female predominance (57%). Common symptoms included fever, fatigue, oliguria, and anuria.
• Hemodialysis was required in 48% of patients, and the overall mortality rate was 13%.

Conclusions:

• This study represents the largest cohort of pediatric primary TMA in Latin America.
• Findings elucidate the specific etiological landscape and clinical behavior of TMA in this population.
• Results underscore the significant morbidity and mortality associated with pediatric TMA in the region.