Thrombotic Microangiopathies (TMA): First Report of 250 Cases from a Single Institution Experience in Latin America

DOS SANTOS C; BARRENECHEA M; PAIVA J; KEMPFER AC; ROMERO ML; SÁNCHEZ LUCEROS A; AGAZZONI M; CASINELLI MM; LAZZARI MA

Berlin

Congreso; 26th Congress of ISTH & 63rd Annual Scientific and Standardization Committee (SSC) Meeting; 2017

International Society on Thrombosis and Haemostasis

Background: TMA are characterized by microangiopathic hemolytic anemia (MAHA), thrombocytopenia and organ failure. Worldwide, patients?cohort studies have been of great interest to understand pathological mechanisms and develop methods to differentiate entities, specifically between atypical Hemolytic Uremic Syndrome (aHUS) and adquired or congenital Thrombotic Thrombocytopenic Purpura (aTTP/cTTP).Aims: For the first time, we described laboratory and clinical features of consecutive TMA patients studied in our department. Methods: A prospective study (n=250) from January 2013 until June 2016, requiring patients? informed consent, was approved by the institutional Ethical Committee. Laboratory (Technozyme® ADAMTS13 activity and IgG anti-ADAMTS13, platelets, creatinine, LDH) and clinical parameters were recorded. Mann-Whitney U-test was used to compare parameters across groups (p< 0.05).Results: The two major TMA groups were aHUS (n=94) and TTP (n=57). In both groups, women were more frequently affected than men (% aHUS: 38♂ vs 62♀ ; % TTP: 25♂ vs 75♀ ), particularly in the non-pediatric population (% aHUS: 17♂ vs 40♀ ; % TTP: 15♂ vs 65♀ ). Cases of aHUS (n=26) and aTTP (n=17) studied during remission or treatment were excluded from the analysis. Mean of ADAMTS13 activity was significantly lower in TTP than in aHUS patients. The presenceof IgG anti-ADAMTS13 confirmed aTTP diagnostic. Patients with deficientADAMTS13 activity presented a more severe thrombocytopenia than patients with normal activity. While LDH level was slightly higher in aHUS than in TTP groups, creatinine was significantly increased in aHUS compared to aTTP subjects. Rates of MAHA observed in all 3 entities were superior to 70%. In aHUS, 29% (n=27) of cases were associated with chronic kidney disease compared to only 12% (n=7) in TTP, a disorder more frequently related to neurological alterations (51% vs 28%).Conclusions: The first description of a TMA cohort in Argentina confirmed the importance of ADAMTS13 analysis to differentiate TTP from aHUS. Reach the World Travel Grant