Characteristics and clinical courses of patients with atypical haemolytic uraemic syndrome on dialysis withdrawal after eculizumab treatment: sub-analysis of post-marketing surveillance in Japan

Abstract Background Atypical haemolytic uraemic syndrome (aHUS) leads to acute kidney injury, necessitating dialysis in about half of patients. A certain proportion of patients treated with C5 inhibitors discontinue dialysis; however, little is known about the patient characteristics and clinical courses relating to discontinuation. Methods We compared the characteristics and clinical courses of patients with aHUS on dialysis at the initiation of eculizumab during post-marketing surveillance in Japan, stratified by those who did (Group A) and did not (Group B) discontinue dialysis within 26 weeks of eculizumab treatment. Results Of 38 included patients, 21 (55.3%) and 17 (44.7%) were placed in Groups A and B, respectively. No patient re-started dialysis. Hypertension was less frequent in Group A than in Group B (6/21 [28.6%] vs. 11/17 [64.7%], p = 0.022). Both the duration of dialysis before eculizumab initiation (6 vs. 17 days, p = 0.011) and the time from thrombotic microangiopathy onset to eculizumab initiation (9 vs. 25 days, p = 0.008) were shorter in Group A. A duration of less than 15 days from thrombotic microangiopathy onset to eculizumab initiation was associated with dialysis discontinuation. Kidney function improvement and normalisation of platelet count and lactate dehydrogenase levels were achieved earlier in Group A than in Group B ( p = 0.050, 0.014, and < 0.001, respectively). Five (29.4%) of 17 patients in Group B discontinued dialysis after 27 weeks of eculizumab treatment, including one patient who underwent kidney transplantation. Conclusions Early initiation of eculizumab was significantly correlated with dialysis discontinuation. Graphical Abstract