Sex differences among patients with complement-gene-variant-mediated thrombotic microangiopathy
(cTMA) are not well established. We examined demographic and clinical data from female
and male patients with a history of cTMA enrolled in the Vienna thrombotic microangiopathy
(TMA) cohort. Follow-up was three years after first presentation with cTMA. In this
single-center study, we identified 51 patients with a first manifestation of cTMA
between 1981 and 2019; 63% were female (p = 0.09). The median age at diagnosis did
not differ between females and males. There was also no disparity between the sexes
with regard to renal function or the need for renal replacement therapy at presentation.
Furthermore, we observed similar use of plasma or eculizumab therapy and a comparable
evolution of renal function of female and male patients. More females showed risk
haplotypes of complement factor H (CFH) and CD46 (97% vs. 68%, p = 0.01), but there
was no difference in the prevalence of rare pathogenic variants in complement-associated
genes with regard to sex. In conclusion, the majority of cTMA patients enrolled in
the Vienna TMA cohort were female. Clinical presentation and renal function did not
differ between the sexes, but females more frequently presented with cTMA risk haplotypes.
