In patients with pregnancy-associated complement gene variant–mediated thrombotic microangiopathy (cTMA), terminal complement blockade is used for treatment of cTMA flares during pregnancy or following delivery. We report pregnancy and delivery outcomes of 2 genetically high-risk patients with cTMA, including 1 kidney transplant recipient, during ongoing eculizumab therapy. In both patients, the first manifestation of cTMA occurred independent from pregnancy. One patient has a history of 2 uneventful pregnancies with prophylactic plasma infusions, and the other has a history of early abortion during long-term eculizumab therapy following kidney transplantation. Overall, pregnancy and delivery outcomes under ongoing eculizumab therapy in our 2 patients with preserved kidney function were excellent as compared with other patients reported in the literature. Eculizumab plasma concentrations were maintained in the therapeutic range during pregnancy and were also detectable in cord blood. Results of cord blood analysis showed deficient complement activity, with low factor and regulator levels, most likely reflecting the age of the neonates and presence of eculizumab in cord blood. In conclusion, pregnancy during ongoing eculizumab treatment appeared to be safe in 2 women with a history of high-risk genetic cTMA and excellent kidney function, even following kidney transplantation.

Background Practice patterns of eculizumab use are not well described. We examined indications for, and outcomes of, eculizumab therapy in a tertiary care nephrology center. Methods We used the “Vienna TMA cohort” and the hospital pharmacy database at the Medical University of Vienna to identify patients that received eculizumab treatment between 2012 and 2019. We describe clinical characteristics, details of eculizumab use, and outcomes of patients with complement gene-variant mediated TMA (cTMA), secondary TMA (sTMA) and C3 glomerulopathy (C3G). Results As of December 2019, 23 patients received complement blockade at the Division of Nephrology and Dialysis: 15 patients were diagnosed with cTMA, 6 patients with sTMA and 2 patients with C3G. Causes of sTMA were bone marrow transplantation (n = 2), malignant hypertension, malignant tumor, systemic lupus erythematosus, antiphospholipid syndrome and lung transplantation (each n = 1). Across all indications, patients had a median age of 31 and were predominantly female (78%) and the median duration of treatment was 227 days. Hematological recovery was seen in most patients, while renal response was best in patients with cTMA. Adverse events were recorded in 26%. Conclusions In summary, eculizumab is the treatment of choice for cTMA patients that do not respond to plasma therapy. In patients with sTMA and C3G, the response rates to therapy are much lower and therefore, the decision to start therapy needs to be considered carefully. Graphic abstract

Background Pregnancies in patients with complement gene variant-mediated thrombotic microangiopathy (cTMA) are challenging, and pregnancies in such patients after kidney transplantation (KTX) are even more so. Methods We identified nine pregnancies following KTX of three genetically high-risk cTMA patients enrolled in the Vienna thrombotic microangiopathy cohort. Preventive plasma therapy was used in three pregnancies, and one patient had ongoing eculizumab (ECU) therapy during two pregnancies. Results Seven out of nine pregnancies (78%) resulted in the delivery of healthy children. The other two included one early abortion at gestational Week 12 during ongoing ECU therapy and one late foetal death at gestational Week 33 + 3, most likely not related to complement dysregulation. Kidney transplant function after delivery remained stable in all but one pregnancy. In the aforementioned case, a severe cTMA flare occurred after delivery despite use of preventive plasma infusions. Kidney graft function could be rescued in this patient by ECU. As such, successful pregnancies can be accomplished in kidney transplant recipients (KTRs) with a history of cTMA. We used preemptive plasma therapy or ongoing ECU treatment in selected cases. Conclusions Thus, becoming pregnant can be encouraged in KTRs with native kidney cTMA. Extensive preconception counselling, however, is mandatory in such cases.

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.

Background: A positive pregnancy test in acute or chronically ill patients has implications for the use of potentially mutagenic or teratogenic products in urgent medical therapies such as the use of chemotherapies or therapies with immunosuppressants, for anesthesia, and for time-sensitive indications like urgent surgery or organ Transplantation. Despite a lack of evidence, it is currently believed that human chorionic gonadotropin serum concentrations are always elevated in female dialysis patients even without pregnancy. It is also believed that human chorionic gonadotropin cannot be used to confirm or exclude pregnancy. Methods: Human chorionic gonadotropin was examined in female dialysis patients (18-50 years of age), and was classified as positive above 5 mlU/ml. In addition, fertility status was determined. For an enhanced index test, the cutoff of 5 mIU/ml was used for potentially fertile patients and 14 mIU/ml for infertile patients to calculate diagnostic test accuracy. The ideal cutoff for human chorionic gonadotropin was estimated using Liu's method with bootstrapped 95% confidence intervals. Predictors of human chorionic gonadotropin increase were analyzed using multivariable linear regression. Results: Among 71 women, two (2.8%) were pregnant, 46 (64.8%) potentially fertile, and 23 (32.4%) infertile. We observed human chorionic gonadotropin concentrations > 5 mIU/ml in 10 patients, which had a sensitivity of 100% (95% confidence interval: 100 to 100), a specificity of 86% (95% confidence interval: 77 to 94), a positive predictive value of 17% (95% confidence interval: 8 to 25) and a negative predictive value of 100% (95% confidence interval: 100 to 100) for the diagnosis of pregnancy. Using a cutoff > 14 mIU/ml for infertile patients or the exclusion of infertile patients increased specificity to 93% or 98%, respectively. The ideal cutoff was 25 mIU/ml (95% confidence interval: 17 to 33). Pregnancy and potential fertility, but not age, were independent predictors of human chorionic gonadotropin. Conclusion: Human chorionic gonadotropin is elevated > 5mIU/ml in 14.5% of non-pregnant dialysis patients of childbearing age. In potentially fertile women, this cutoff can be used to exclude pregnancy. In case of an unknown fertility status, the ideal human chorionic gonadotropin cutoff was 25 mIU/ml.