1. C3 glomerulopathy associated with monoclonal gammopathy: impact of chronic histologic lesions and beneficial effects of clone-targeted therapies
- Author
-
Amir Shabaka, Virginia Cabello, Elena Goicoechea de Jorge, Natalia Ramos, N. Serra, Juliana Draibe, Fernando Caravaca-Fontán, Raquel Rodado, Manuel Praga, Saúl Pampa-Saico, Gema Fernández-Juárez, Maria Esperanza López-Rubio, Laura Lucientes, Eduardo Gutiérrez, Juana Alonso Titos, Ana Huerta, Teresa Cavero, F. González, and Luis F. Quintana
- Subjects
Male ,medicine.medical_specialty ,Glomerulonephritis, Membranoproliferative ,Paraproteinemias ,Renal function ,clone-targeted therapy ,Monoclonal Gammopathy of Undetermined Significance ,Gastroenterology ,Glomerulopathy ,Internal medicine ,Biopsy ,medicine ,histologic index ,Humans ,C3 glomerulopathy ,Retrospective Studies ,Complement C3 Nephritic Factor ,Transplantation ,Kidney ,Proteinuria ,medicine.diagnostic_test ,biology ,business.industry ,monoclonal gammopathy ,Complement C3 ,Middle Aged ,medicine.disease ,kidney failure ,Clone Cells ,medicine.anatomical_structure ,Nephrology ,Immunoglobulin G ,Cohort ,biology.protein ,Female ,Kidney Diseases ,Observational study ,medicine.symptom ,Antibody ,business - Abstract
BackgroundC3 glomerulopathy associated with monoclonal gammopathy (C3G-MIg) is a rare entity. Herein we analysed the clinical and histologic features of a cohort of C3G-MIg patients.MethodsWe conducted a retrospective, multicentre, observational study. Patients diagnosed with C3G-MIg between 1995 and 2021 were enrolled. All had genetic studies of the alternative complement pathway. The degree of disease activity and chronicity were analysed using the C3G histologic index. Descriptive statistics and propensity score matching (PSM) analysis were used to evaluate the main outcome of the study [kidney failure (KF)].ResultsThe study group included 23 patients with a median age 63 of years [interquartile range (IQR) 48–70], and 57% were males. Immunoglobulin G kappa was the most frequent MIg (65%). The diagnosis of C3G-MIg was made in transplanted kidneys in seven patients (30%). Five (22%) patients had C3 nephritic factor and five (22%) had anti-factor H antibodies. One patient carried a pathogenic variant in the CFH gene. During a follow-up of 40 months (IQR 14–69), nine patients (39%) reached KF and these patients had a significantly higher total chronicity score on kidney biopsy. Patients who received clone-targeted therapy had a significantly higher survival compared with other management. Those who achieved haematological response had a significantly higher kidney survival. Outcome was remarkably poor in kidney transplant recipients, with five of them (71%) reaching KF. By PSM (adjusting for age, kidney function, proteinuria and chronicity score), no significant differences were observed in kidney survival between C3G patients with/without MIg.ConclusionsThe C3G histologic index can be used in patients with C3G-MIg to predict kidney prognosis, with higher chronicity scores being associated with worse outcomes. Clone-targeted therapies and the development of a haematological response are associated with better kidney prognosis.
- Published
- 2021