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.

Introduction The association between a change in proteinuria over time and its impact in kidney prognosis has not been analyzed in C3 glomerulopathy. This study aims to investigate the association between the longitudinal change in proteinuria and the risk of kidney failure. Methods Retrospective, multicenter observational cohort study in 35 nephrology departments belonging to the Spanish Group for the Study of Glomerular Diseases (GLOSEN). Patients diagnosed with C3 glomerulopathy between 1995 and 2020 were enrolled. A joint modeling of linear mixed-effects models was applied to assess the underlying trajectory of a repeatedly measured proteinuria, and a Cox model to evaluate the association of this trajectory with the risk of kidney failure. Results The study group consisted of 85 patients, 70 C3 glomerulonephritis and 15 dense deposit disease, with a median age of 26 years (range 13–41). During a median follow-up of 42 months, 25 patients reached kidney failure. The longitudinal change in proteinuria showed a strong association with the risk of this outcome, with a doubling of proteinuria levels resulting in a 2.5-fold increase of the risk. A second model showed that a ≥ 50% proteinuria reduction over time was significantly associated with a lower risk of kidney failure (HR: 0.79; 95% CI : 0.56–0.97; p < 0.001). This association was also found when the ≥50% proteinuria reduction was observed within the first 6 and 12 months of follow-up. Conclusion The longitudinal change in proteinuria is strongly associated with the risk of kidney failure. The change in proteinuria over time can provide clinicians a dynamic prediction of kidney outcomes.

Objective We analyzed malfunction rates (obstruction, omental wrapping, displacement) and catheter survival for self-locating catheters as compared with other Tenckhoff catheter designs. Patients and Methods We conducted our survey at two centers, prospectively studying all self-locating catheters implanted from May 1997 to October 2000 and used for peritoneal dialysis (PD). Tenckhoff catheters of other designs used previously in our units were used as the control group. We analyzed removal causes and catheter survival. Results We studied 173 catheters (105 self-locating catheters, 53 straight catheters, and 15 coiled catheters) implanted in 139 patients (43% of them women) with a mean age of 53 ± 14 years. The analysis of catheter removal showed that 3 of 105 self-locating catheters, 3 of 15 coiled catheters, and 17 of 53 straight catheters were removed owing to malfunction (c 2: p = 0.0000). Kaplan–Meier curves showed that the bulk of removals for malfunction occurred within the first 3 months after PD start. The group of self-locating catheters showed better survival (log-rank: p = 0.0009). Other causes for catheter removal included peritonitis ( n = 22), exit-site infection alone ( n = 4), and end of PD treatment ( n = 66). No significant differences were seen in the annual peritonitis rate (straight-tip: 0.955 ± 2.315 episodes annually; coiled-tip: 0.651 ± 0.864 episodes annually; self-locating: 0.720 ± 1.417 episodes annually; t-test: p > 0.400). No gut or bladder perforations were observed. Conclusion In our survey, self-locating catheters were associated with better survival and fewer removals for malfunction than were Tenckhoff catheters of other designs.

Objective To evaluate catheter-related complications among self-locating and other variants of Tenckhoff catheters. Patients and Methods We studied all self-locating catheters implanted in our hospitals from May/97 to Dec/05. We extended the follow-up to Jun/05. We collected demographic data, causes of catheter withdrawal and dropping of PD. We studied data about technique and catheter related complications. Results We included 328 catheters in 285 patients. There were 258 self-locating, 55 straight and 15 curled. There was a higher rate of catheter withdrawal due to malfunction in patients with straight or pig-tail catheters than in self-locating ones (log-rank, p<0.001). Conclusion In our patients, self-locating catheters have a lower malfunction rate than other variants of Tenckhoff catheters.

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