A new complement factor B mutation associated with crescentic C3 glomerulopathy; a case report

Background: C3 glomerulopathy is a recently described entity classified as complementassociated glomerular disease. Case Presentation: We report a case of a 48-year-old man referred to the nephrology department for nephrotic syndrome with rapidly progressive kidney failure, acquired partial lipodystrophy and drusen in Bruch’s membrane of the retina. Blood tests showed low C3 and no evidence for autoimmune diseases, monoclonal gammopathy or infection. The renal biopsy revealed a proliferative endocapillary and crescentic glomerulonephritis with glomerular deposits exclusively of C3 and significant interstitial fibrosis. The electronic microscopy was consistent with dense deposit disease. The complement analysis revealed a pathogenic mutation of the complement factor B (CFB) gene not previously described in literature. Conclusions: The authors report a new mutation of CFB, in a dense deposit disease patient; this finding brings a new insight to the pathogenic pathway of C3 glomerulopathy and possibly to other complement dysregulation associated glomerular diseases. More clinical trials are needed to clarify both the pathogenicity and the optimal treatment for these entities.

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Mycophenolate Mofetil in C3 Glomerulopathy and Pathogenic Drivers of the Disease

Clinical Journal of the American Society of Nephrology ◽

10.2215/cjn.15241219 ◽

2020 ◽

Vol 15 (9) ◽

pp. 1287-1298 ◽

Cited By ~ 2

Author(s):

Fernando Caravaca-Fontán ◽

Montserrat M. Díaz-Encarnación ◽

Laura Lucientes ◽

Teresa Cavero ◽

Virginia Cabello ◽

...

Keyword(s):

Mycophenolate Mofetil ◽

Kidney Failure ◽

Dense Deposit Disease ◽

Response To Treatment ◽

Lower Probability ◽

Genetic Profile ◽

C3 Glomerulopathy ◽

Complement Components ◽

Glomerular Diseases ◽

Dense Deposit

Background and objectivesC3 glomerulopathy is a complement-mediated disease arising from abnormalities in complement genes and/or antibodies against complement components. Previous studies showed that treatment with corticosteroids plus mycophenolate mofetil (MMF) was associated with improved outcomes, although the genetic profile of these patients was not systematically analyzed. This study aims to analyze the main determinants of disease progression and response to this therapeutic regimen.Design, setting, participants, & measurements We conducted a retrospective, multicenter, observational cohort study in 35 nephrology departments belonging to the Spanish Group for the Study of Glomerular Diseases. Patients diagnosed with C3 glomerulopathy (n=81) or dense deposit disease (n=16) between January 1995 and March 2018 were enrolled. Multivariable and propensity score matching analyses were used to evaluate the association of clinical and genetic factors with response to treatment with corticosteroids and MMF as measured by proportion of patients with disease remission and kidney survival (status free of kidney failure).ResultsThe study group comprised 97 patients (84% C3 glomerulopathy, 16% dense deposit disease). Forty-two patients were treated with corticosteroids plus MMF, and this treatment was associated with a higher rate of remission and lower probability of kidney failure (79% and 14%, respectively) compared with patients treated with other immunosuppressives (24% and 59%, respectively), or ecluzimab (33% and 67%, respectively), or conservative management (18% and 65%, respectively). The therapeutic superiority of corticosteroids plus MMF was observed both in patients with complement abnormalities and with autoantibodies. However, patients with pathogenic variants in complement genes only achieved partial remission, whereas complete remissions were common among patients with autoantibody-mediated forms. The main determinant of no remission was baseline proteinuria. Relapses occurred after treatment discontinuation in 33% of the patients who had achieved remission with corticosteroids plus MMF, and a longer treatment length of MMF was associated with a lower risk of relapse.ConclusionsThe beneficial response to corticosteroids plus MMF treatment in C3 glomerulopathy appears independent of the pathogenic drivers analyzed in this study.

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Plasma protein expression profiles, cardiovascular disease, and religious struggles among South Asians in the MASALA study

Scientific Reports ◽

10.1038/s41598-020-79429-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Long H. Ngo ◽

M. Austin Argentieri ◽

Simon T. Dillon ◽

Blake Victor Kent ◽

Alka M. Kanaya ◽

...

Keyword(s):

Cardiovascular Disease ◽

Plasma Protein ◽

Expression Profiles ◽

South Asians ◽

Predictive Biomarkers ◽

Information Criteria ◽

Blood Protein ◽

Complement Factor ◽

Factor B ◽

Complement Factor B

AbstractBlood protein concentrations are clinically useful, predictive biomarkers of cardiovascular disease (CVD). Despite a higher burden of CVD among U.S. South Asians, no CVD-related proteomics study has been conducted in this sub-population. The aim of this study is to investigate the associations between plasma protein levels and CVD incidence, and to assess the potential influence of religiosity/spirituality (R/S) on significant protein-CVD associations, in South Asians from the MASALA Study. We used a nested case–control design of 50 participants with incident CVD and 50 sex- and age-matched controls. Plasma samples were analyzed by SOMAscan for expression of 1305 proteins. Multivariable logistic regression models and model selection using Akaike Information Criteria were performed on the proteins and clinical covariates, with further effect modification analyses conducted to assess the influence of R/S measures on significant associations between proteins and incident CVD events. We identified 36 proteins that were significantly expressed differentially among CVD cases compared to matched controls. These proteins are involved in immune cell recruitment, atherosclerosis, endothelial cell differentiation, and vascularization. A final multivariable model found three proteins (Contactin-5 [CNTN5], Low affinity immunoglobulin gamma Fc region receptor II-a [FCGR2A], and Complement factor B [CFB]) associated with incident CVD after adjustment for diabetes (AUC = 0.82). Religious struggles that exacerbate the adverse impact of stressful life events, significantly modified the effect of Contactin-5 and Complement factor B on risk of CVD. Our research is this first assessment of the relationship between protein concentrations and risk of CVD in a South Asian sample. Further research is needed to understand patterns of proteomic profiles across diverse ethnic communities, and the influence of resources for resiliency on proteomic signatures and ultimately, risk of CVD.

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