Comparative characteristics of obstetric and "population-wide" atypical hemolytic-uremic syndrome in adults; [Сравнительная характеристика акушерского и «общепопуляционного» атипичного гемолитико-уремического синдрома у взрослых]

Atypical hemolytic uremic syndrome (aHUS) is an ultra-rare disease. The development of the disease is preceded by various triggers: infection, diarrhea, systemic pathology, and pregnancy. Pregnancy-associated aHUS accounts for 1/3 of all cases in adults. Obstetric aHUS (O-aHUS) have special features, severe course, and a high risk of an unfavorable outcome compared to "population-wide" aHUS. Aim: to compare the characteristics of the development, course, and outcomes of obstetric and non-obstetric aHUS in adults. Patients and methods: the study included 161 patients(pts) with an established diagnosis of aHUS who were observed in various medical institutions of the Russian Federation from 2012 to 2021: 76 pts with O-aHUS and 85 adult pts with non-obstetric aHUS. Results: in the O-aHUS group there were more pronounced signs of microangiopathic hemolysis (LDH 2487.0 vs 815.0, p<0.001]), a lower number of platelets (48.0 vs 84.5 <0.001), and more severe multiple organ failure (mean number of affected organs 3.64 vs 2.57, p<0.001). Kidney damage in all pts was presented by AKI requiring dialysis treatment in 136 cases (84.5%). The SСr values were higher in non-obstetric aHUS (758.0 vs 441.0 μmol/L, p<0.001). In the O-aHUS group all pts received fresh frozen plasma and 46 pts (60.5%) – complement-blocking drug Eculizumab (Ecu+). In the non-obstetric aHUS group only 53% of pts received plasma therapy, and 20% – Ecu+. Among pts with O-aHUS an improvement in renal function was noted in 78.3% of women Ecu+ and in 56.6% of pts receiving plasma therapy alone. In this group 12 pts died: 9 did not receive Eculizumab (30%), and 3 – Ecu+ (6.5%). In the non-obstetric aHUS group improvement in renal function was observed in 52.9% of pts Ecu+ and in 33.8% who did not receive pathogenetic therapy. Remained dialysis-dependent or died, respectively, 7 (41.2%), and 1 (5.9%) of 17 Ecu+, and 36 (52.9%) and 10 (13.2%) among 68 pts who did not receive Eculizumab. Conclusion: this study confirmed the existence of differences during obstetric and "general population" aHUS. Early initiation of Eculizumab allows patients to survive and achieve remission in both obstetric and non-obstetric aHUS. © 2022 JSC Vidal Rus. All rights reserved.