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Abstract: FR-OR086

Hypertension or Complement-Associated Thrombotic Microangiopathy Diagnostic Implications and Response to Eculizumab

Session Information

Category: Glomerular Diseases

  • 1203 Glomerular Diseases: Clinical, Outcomes, and Trials


  • Caravaca-Fontan, Fernando, Hospital Universitario Ramón y Cajal, Madrid, Spain, Madrid, Spain
  • Cavero escribano, Teresa, Hospital 12 de Octubre, Madrid, Spain
  • Rodriguez de Cordoba, Santiago, Consejo Superior de Investigaciones Cientificas, Madrid, Spain
  • Praga, Manuel, Hospital 12 de Octubre, Madrid, Spain

Group or Team Name

  • Spanish Group for the Study of Glomerular Diseases (GLOSEN)

Malignant hypertension is listed among the causes of secondary thrombotic microangiopathy (TMA), but the presence of pathogenic mutations in complement genes have been recently reported in patients with hypertension-induced. No studies have investigated the frequency and severity of hypertension (HTN) in primary, complement-mediated atypical hemolytic uremic syndrome (aHUS).


Seventy-five patients with primary aHUS were collected in 21 hospitals in Spain and Portugal. Primary outcome was hematologic and renal response. Patients were classified according to the severity of HTN in normal blood pressure (8 patients, 10%), stage 1 HTN (13, 17%) and stage 2 HTN (54, 72%). Among the latter, malignant HTN (defined by the presence of hypertensive retinopathy grades III/IV) was found in 24 (55%) out of 43 patients in whom retinal examination was performed.


Median age was 34 years and 27 patients (36%) had history of HTN. Fifty-five (75%) patients required acute hemodialysis at presentation. Plasmapheresis was performed in 64 patients and 35 received eculizumab. Abnormalities in complement genes were found in 36 /64 patients (56%) in whom genetic study was performed (68% among patients with malignant HTN). Response was significantly lower after plasmapheresis (25%) than after eculizumab (82%), as well as the rate of dialysis discontinuation (38% and 79%, respectively). Response to eculizumab was similar in normotensive (100%), stage 1 HTN (71%), stage 2 HTN (84%) and malignant HTN patients (90%) and was independent of the presence of genetic abnormalities. Renal survival was significantly higher in patients treated with eculizumab (87% at 1, 3 and 5 years) compared to patients who did not receive this treatment (55%, 46% and 38% at 1, 3 and 5 years, respectively).


Severe hypertension is very common in aHUS, frequently fulfilling the criteria of malignant HTN. The efficacy of eculizumab was observed also in patients with HTN, having or not abnormalities in complement genes.