Severe and Malignant Hypertension Are Common in Primary Atypical Hemolytic Uremic Syndrome

Malignant hypertension is listed among the causes of secondary thrombotic microangiopathy, but pathogenic mutations in complement genes have been reported in patients with hypertension-induced thrombotic microangiopathy. Here we investigated the frequency and severity of hypertension in 55 patients with primary atypical hemolytic uremic syndrome (aHUS). A genetic analysis was performed in all patients, and funduscopic examination was performed in all the patients with Grades 2 and 3 hypertension. A cohort of 110 patients with malignant hypertension caused by diseases other than aHUS served as control. Thirty-six patients with aHUS presented Grade 2 or Grade 3 hypertension and funduscopic examination showed malignant hypertension in 19. Genetic abnormalities in complement were found in 19 patients (37% among patients with malignant hypertension). Plasmapheresis was performed in 46 patients and 26 received eculizumab. Renal and hematological responses were significantly lower after plasmapheresis (24%) than after eculizumab (81%). Renal survival was significantly higher in patients treated with eculizumab (85% at one, three and five years) compared to patients who did not receive this treatment (54%, 46% and 41%), respectively. Response to eculizumab was independent of hypertension severity and the presence of complement genetic abnormalities. Among patients with malignant hypertension caused by other diseases the prevalence of thrombotic microangiopathy was very low (5%). Thus, severe and malignant hypertension are common among patients with aHUS and eculizumab treatment leads to a higher renal survival when compared to plasmapheresis. However, thrombotic microangiopathy is uncommon among patients presenting with malignant hypertension caused by diseases other than aHUS.info:eu-repo/semantics/publishedVersio

Severe and malignant hypertension are common in primary atypical hemolytic uremic syndrome

Malignant hypertension is listed among the causes of secondary thrombotic microangiopathy (TMA), but pathogenic mutations in complement genes have been reported in patients with hypertension-induced TMA. Here we investigated the frequency and severity of hypertension in 55 patients with primary atypical hemolytic uremic syndrome (aHUS). A genetic analysis was performed in all patients, and funduscopic examination was performed in all the patients with Grades 2 and 3 hypertension. A cohort of 110 patients with malignant hypertension caused by diseases other than aHUS served as control. Thirty-six patients with aHUS presented Grade 2 or Grade 3 hypertension and funduscopic examination showed malignant hypertension in 19. Genetic abnormalities in complement were found in 19 patients (37% among patients with malignant hypertension). Plasmapheresis was performed in 46 patients and 26 received eculizumab. Renal and hematological responses were significantly lower after plasmapheresis (24%) than after eculizumab (81%). Renal survival was significantly higher in patients treated with eculizumab (85% at one, three and five years) compared to patients who did not receive this treatment (54%, 46% and 41%), respectively. Response to eculizumab was independent of hypertension severity and the presence of complement genetic abnormalities. Among patients with malignant hypertension caused by other diseases the prevalence of TMA was very low (5%). Thus, severe and malignant hypertension are common among patients with aHUS and eculizumab treatment leads to a higher renal survival when compared to plasmapheresis. However, TMA is uncommon among patients presenting with malignant hypertension caused by diseases other than aHUS.Work in this study was supported by the Instituto de Salud Carlos III /Fondo Europeo de Desarrollo Regional (ISCIII/FEDER) grants PI13/02502, PICI14/00350, and PI16/01685 (to MP), and grants PI13/00802, PI14/00883 and PI17/00130 (to JAM.); the ISCIII/FEDER Programa Miguel Servet, grants CP10/00479 and CPII16/00017 (to JAM); the Spanish “Ministerio de Economía y Competitividad/FEDER” [SAF2015-66287-R] (to SRdeC); the Autonomous Region of Madrid (S2017/BMD-3673) (to SRdeC, EA and MP); Red de Investigación Renal (RedInRen) (RD12/0021/0029) (to MP), the “Fundación Inocente” (Madrid, Spain).] (to SRdC), and the Spanish Society of Nephrology and Fundación Renal Ínigo Álvarez de Toledo (FRIAT) (to JAM).Peer reviewe