Nephritic factor and recurrence in the renal transplant of membranoproliferative glomerulonephritis type II

Clinical course and outcome after kidney transplantation in patients with C3 glomerulonephritis due to CFHR5 nephropathy

BACKGROUND

Complement factor H-related protein 5 (CFHR5) nephropathy is an inherited renal disease characterized by microscopic and synpharyngitic macroscopic haematuria, C3 glomerulonephritis and renal failure. It is caused by an internal duplication of exons 2-3 within the CFHR5 gene resulting in dysregulation of the alternative complement pathway. The clinical characteristics and outcomes of transplanted patients with this rare familial nephropathy remain unknown.

METHODS

This is a retrospective case series study of 17 kidney transplant patients with the established founder mutation, followed-up over a span of 30 years.

RESULTS

The mean (±SD) age of patients at the time of the study and at transplantation was 58.6 ± 9.9 and 46.7 ± 8.8 years, respectively. The 10- and 15-year patient survival rates were 100 and 77.8%, respectively. Proteinuria was present in 33.3% and microscopic haematuria in 58.3% of patients with a functional graft. Serum complement levels were normal in all. 'Confirmed' and 'likely' recurrence of CFHR5 nephropathy were 16.6 and 52.9%, respectively; however, 76.5% of patients had a functional graft after a median of 120 months post-transplantation. Total recurrence was not associated with graft loss (P = 0.171), but was associated with the presence of microscopic haematuria (P = 0.001) and proteinuria (P = 0.018). Graft loss was associated with the presence of proteinuria (P = 0.025).

CONCLUSIONS

We describe for the first time the clinical characteristics and outcome of patients with CFHR5 nephropathy post-transplantation. Despite the recurrence of CFHR5 nephropathy, we provide evidence for a long-term favourable outcome and support the continued provision of kidney transplantation as a renal replacement option in patients with CFHR5 nephropathy.

A simple immunofixation test for induced C3 degradation in disease states (including C3 nephritic factor) and its correlation with kidney biopsy

Complement dysregulation from an uncontrolled activation of the alternate pathway can be mediated by C3 Nephritic Factor and results in C3 glomerulopathy. Identification of C3 degradation products C3c and C3d in patient serum provides evidence of uncontrolled complement activation. It is possible to detect C3c and C3d in patient serum by an immunofixation assay which induces in vitro C3 degradation. The clinical performance of the immunofixation assay has been assessed by comparing the assay results with findings from immunostaining of kidney biopsies. The immunofixation assay is a simple and reliable technique for detection of C3 degradation on a widely available platform and can be used to provide corroborative evidence of acquired complement dysregulation in patients with C3 glomerulopathy.

Recurrent glomerular disease after kidney transplantation

PURPOSE OF REVIEW

Recurrent glomerulonephritis is the third most common cause of graft failure, ranking only behind immunologic rejection and death with a functioning graft. Knowledge of the rates and timing of recurrent glomerular disease are important in counseling potential transplant recipients and preventive and therapeutic treatment strategies are necessary for those patients at risk.

RECENT FINDINGS

Large observational studies that have analyzed posttransplant biopsies have confirmed the high rates of glomerular disease recurrence in renal allografts. Newer immunosuppressive protocols over the past 10 years have not affected the rate of disease recurrence or graft loss. There is emerging evidence that rituximab may be efficacious in treating recurrent membranous nephropathy and focal segmental glomerulosclerosis; however, larger clinical trials are warranted.

SUMMARY

Recurrent glomerulonephritis is an important determinant of long-term outcomes after transplantation, requiring appropriate counseling to potential transplant recipients. Currently, there are no proven strategies to prevent recurrent glomerulonephritis in renal transplant recipients. Despite the high rates of recurrent disease, long-term graft survival is still very good and transplantation remains the best treatment option for patients with end-stage renal disease from primary glomerulonephritis.

Allograft failure in kidney transplant recipients with membranoproliferative glomerulonephritis

BACKGROUND

Membranoproliferative glomerulonephritis types I (MPGN-I) and II (MPGN-II) are rare diseases that in limited case series have been reported to recur frequently in kidney transplants and have a negative impact on allograft survival.

STUDY DESIGN

Retrospective database review.

SETTING & PARTICIPANTS

189,211 primary kidney transplants in the United Network for Organ Sharing (UNOS) database from September 1987 to May 2007.

PREDICTOR OR FACTOR

MPGN-I (811 patients; 0.4%), MPGN-II (179 patients; 0.1%), other GN (58,129 patients; 30.7%), and all other diagnoses (130,092 patients; 68.7%).

OUTCOMES

Death-censored and non-death-censored allograft survival.

RESULTS

Compared with controls, patients with MPGN-I and MPGN-II were significantly younger at the time of transplant, with a median age of 36 and 27 years compared with 44 years in the GN group and 46 years in all other disease groups, respectively (all P < 0.001). Mortality in patients with MPGN-I (8.8%) was significantly lower compared with the GN (11.3%; P = 0.02) and other disease (16.6%; P < 0.001) populations and lower in those with MPGN-II (9.5%) compared with the other disease (16.6%; P = 0.01) population. Graft failure rates were significantly higher in the MPGN-I (44.5%) cohort, but not in the MPGN-II (45.3%) cohort compared with the GN (38.0%) population (P < 0.001 and P = 0.05, respectively); neither MPGN cohort differed from the other disease (43.0%) population (P = 0.4 and P = 0.5). Overall, 10-year death-censored graft survival was similar for MPGN-I (56.2%) and MPGN-II (57.5%); both were significantly worse than for GN (65.2%; P < 0.001 and P = 0.003, respectively), and only MPGN-I was significantly worse than the other disease (60.0%) population (P = 0.004). Of allograft failures with a reported cause, disease recurrence was the primary cause in 36 (14.5%) MPGN-I and 18 (29.5%) MPGN-II transplant recipients and was significantly higher compared with 879 (6.6%) GN and 1,319 (4.4%) all-other-disease recurrence failures (P < 0.001).

LIMITATIONS

Limited pretransplant clinical and biopsy data.

CONCLUSIONS

A diagnosis of MPGN-I or MPGN-II has a significant negative impact on overall primary allograft survival compared with other forms of glomerulonephritis, whereas only MPGN-I has a significant, but modest, negative effect compared with other causes of end-stage renal disease.