Real-World Patient Characteristics, Burden, and Quality of Life in C3 Glomerulopathy and Primary Immune Complex Membranoproliferative GN

Key Points. C3 glomerulopathy and primary immune complex-mediated membranoproliferative GN lead to a significant clinical, economic, and health care burden among affected patients and their families. C3 glomerulopathy and primary immune complex-mediated membranoproliferative GN drive high costs for health systems (health care professional visits, tests, dialysis) and patients (lost work capacity, caregiver needs). Patients face high daily burden, where fatigue is common and most doctors report a major effect on patient lives. Background. C3 glomerulopathy (C3G) and primary immune complex-mediated membranoproliferative GN (IC-MPGN) are rare, progressive kidney disorders affecting both children and adults. This real-world study aimed to assess the clinical, economic, and humanistic burden of these conditions in Europe and the United States, addressing key evidence gaps. Methods. A large, multinational, cross-sectional survey gathered data from treating health care professionals and patients during routine clinical care. Both groups completed surveys reflecting their experiences with C3G or primary IC-MPGN. Results. In C3G 93 physicians returned data for 289 patients, and 52 patients completed a survey themselves, and for primary IC-MPGN 61 physicians returned data for 215 patients, and 54 patients completed a survey themselves. Baseline clinical characteristics and comorbidity rates were similar across both groups. At the time of survey, 81% (C3G) and 89% (primary IC-MPGN) of patients had stable or improving disease. Average 24-hour proteinuria levels were 2.3 g/24 hours (C3G) and 1.6 g/24 hours (IC-MPGN). Proteinuria was the most commonly reported symptom by physicians (69% and 56%), while fatigue or low energy was most frequently reported by patients (50% and 53%). Overall, patient-reported Functional Assessment of Chronic Illness Therapy Fatigue score was 34.7 (C3G) and 34.9 (primary IC-MPGN), on a scale of 0–52 where a higher score indicates better quality of life. On average, patients saw a physician 12.3 (C3G) and 10.7 (IC-MPGN) times in the past year, relating to their C3G/IC-MPGN. Among adults, 42% (C3G) and 31% (IC-MPGN) were not employed full-time. Caregiver support was reported in 15% (C3G) and 25% (IC-MPGN) of cases. Conclusions. Despite slowly progressing disease in the current cohort, C3G and primary IC-MPGN create a significant clinical, economic, and health care burden among affected patients and their families.