Evaluating the clinical course and prognostic factors of posttransplantation immunoglobulin A nephropathy

Comparative Long-Term Renal Allograft Outcomes of Recurrent Immunoglobulin A with Severe Activity in Kidney Transplant Recipients with and without Rituximab: An Observational Cohort Study

Recurrent IgA nephropathy (IgAN) remains an important cause of allograft loss in renal transplantation. Due to the limited efficacy of corticosteroid in the treatment of recurrent glomerulonephritis, rituximab was used in kidney transplant (KT) recipients with severe recurrent IgAN. A retrospective cohort study was conducted between January 2015 and December 2020. Accordingly, there were 64 KT recipients with biopsy-proven recurrent IgAN with similar baseline characteristics that were treated with the conventional standard therapy alone (controls, n = 43) or together with rituximab (cases, n = 21). All of the recipients had glomerular endocapillary hypercellularity and proteinuria (>1 g/d) with creatinine clearance (CrCl) > 30 mL/min/1.73 m² and well-controlled blood pressure using renin–angiotensin–aldosterone blockers. The treatment outcomes were renal allograft survival rate, proteinuria, and post-treatment allograft pathology. During 3.8 years of follow-up, the rituximab-based regimen rapidly decreased proteinuria within 12 months after rituximab administration and maintained renal allograft function—the primary endpoint—for approximately 3 years. There were eight recipients in the case group (38%), and none in the control group reached a complete remission (proteinuria < 250 mg/d) at 12 months after treatment. Notably, renal allograft histopathology from patients with rituximab-based regimen showed the less severe endocapillary hypercellularity despite the remaining strong IgA deposition. In conclusion, adjunctive treatment with rituximab potentially demonstrated favorable outcomes for treatment of recurrent severe IgAN post-KT as demonstrated by proteinuria reduction and renal allograft function in our cohort. Further in-depth mechanistic studies with the longer follow-up periods are recommended.

Clinical Features, Treatment and Prognostic Factors of Post-Transplant Immunoglobulin A Nephropathy

Background

Initially described as a relatively benign condition, recent studies report graft loss in up to 50% of the patients with post-transplant IgA nephropathy. There is no evidence for the best therapeutic approach, and prognostic factors remain to be elucidated.

Material/Methods

Single center retrospective analysis of patients >12 years old, with clinically relevant post-transplant IgA nephropathy (proteinuria ≥1.0 g/g and/or graft dysfunction) and ≥6 months follow-up after diagnosis (n=47).

Results

Living donor transplants represented 85% of cases. Dysmorphic hematuria (100%), blood pressure elevation (95.7%), renal dysfunction (70.2%) and subnephrotic proteinuria (60.6%) predominated at presentation. Using the Oxford Classification, mesangial proliferation was the main histological lesion (91%). Treatment consisted mostly of blockade of the renin angiotensin system (89.4%) and modification of immunosuppression (85.1%), mainly by increasing oral steroids dose (83%), with venous pulse therapy in 63.8% of cases. Partial and complete remission occurred in 48.9% and 17% of cases, respectively. One patient died (sepsis) and 15 patients (31.9%) lost their grafts due to nephropathy. The percentage of decrease in glomerular filtration rate at diagnosis was independently associated with partial remission (HR 0.97, 95% CI 0.94–0.99, p=0.01) and graft loss (HR 1.13, 95% CI 1.06–1.20, p<0.001). Deceased donor (HR 28.04, 95% CI 4.41–178.39, p<0.001) and donor age (HR 1.1, 95% CI 1.04–1.16, p=0.001) were also risk factors for graft loss.

Conclusions

Despite treatment, most patients with post-transplant IgA nephropathy in this cohort study presented unfavorable outcomes, and graft dysfunction at diagnosis appeared to be the main prognostic marker.

Rituximab for recurrent IgA nephropathy in kidney transplantation: A report of three cases and proposed mechanisms

AIM

Recurrent IgA nephropathy (IgAN) is a common recurrent glomerular disease after kidney transplantation. Recurrent IgAN, in particular, with crescent formation or endocapillary proliferation might result in kidney allograft loss. However, the current treatment options of recurrent IgAN are conflicting.

METHODS

We have reported three kidney-transplanted recipients with biopsy-proven recurrent IgAN treated with four consecutive months of rituximab at the dose of 375 mg/1.73m² without corticosteroids.

RESULTS

At median follow-up 20 months following rituximab administration, all three recipients demonstrated decrease in proteinuria severity, slow disease progression with a well-tolerated condition. This therapeutic effect is most probably mediated by the B cell depletion.

CONCLUSION

Our three case reports suggest that the disease severity of recurrent IgAN with endocapillary proliferation regardless of crescent formation can be minimized by the four doses of monthly rituximab regimen.

IgA NEPHROPATHY IN PATIENTS RECEIVING A RENAL TRANSPLANT

BACKGROUND

IgA nephropathy (IgAN) is the third most frequent cause of renal graft loss among patients with primary glomerulonephritis.

OBJECTIVES

To assess clinical and laboratorial profile of patients with pre and/or post transplant IgAN, in addition to patient and graft survival in both groups.

DESIGN

Data from 146 patients who had received a renal transplant were retrospectively collected and were divided in two groups: group 1-patients with biopsy-documented IgAN as the underlying native kidney disease (n = 128); group 2-patients who developed post-transplant IgAN independent of the underlying disease (n = 18).

PARTICIPANTS

Patients submitted to renal transplantation (1998-2010) with pre and/or post transplant IgAN.

MEASUREMENTS

Clinical and laboratorial evaluation of renal function of 146 post transplant IgAN patients.

RESULTS

Recipients and deceased donors exhibited a higher degree of HLA compatibility (1.0 vs. 2.5 mismatches for groups 1 and 2, respectively). The main post-transplant IgAN presentation was haematuria associated with non-nephrotic proteinuria (44.4%). A histological pattern of focal segmental glomerulosclerosis was observed in 59.2% of biopsy samples. The 10-year patient survival was 93.5% in group 1 and 100% in group 2, and the graft survival rates were 58.5 and 87.2%, respectively.

CONCLUSION

The rate of post-transplant IgA diagnosis in our case series was 11%, and IgAN was diagnosed late in the course of transplantation. In most cases, IgAN manifested as haematuria and non-nephrotic proteinuria, without renal graft dysfunction, and this picture might explain late indication of graft biopsies. The 10-year patient survival rates were excellent.

Prognostic factors for renal allograft survival in patients with immunoglobulin A nephropathy: a case control study

The renal allograft survival rates of patients with immunoglobulin A nephropathy (IgAN), and patients with or without other glomerular diseases, have yet to be fully elucidated. In this study, the clinicopathological factors associated with long-term allograft survival for the prognosis of renal allograft recipients with IgAN were examined. All patients enrolled in this study were diagnosed with IgAN following clinical and pathological examinations. Patients underwent renal graft biopsy and were hospitalized at the Fuzhou General Hospital between June, 2004 and December, 2010. Common demographic and clinical indicators were recorded in patients who had graft loss and in those who had functional renal grafts. Forty-two of the 202 biopsy specimens (20.8%) met the diagnostic criteria for IgAN and were divided into two groups, the graft loss group (n=17) and the functional graft group (n=25). Patients were followed up for 1-257 months after kidney transplantation. The mean patient age was 40.6 ± 9.3 years at the time of renal graft biopsy. Examination results indicated concomitant proteinuria and hematuria in 25 patients (59.5%) and proteinuria alone in six patients (14.3%). Graft loss occurred in 17 patients during the follow-up period. Comparison of the graft loss and the functional graft groups indicated that patients in the graft loss group were more likely to have proteinuria (P=0.047), high creatinine levels at the time of biopsy (P=0.009), low glomerular filtration rates (P=0.013), low serum total protein (P=0.01), a high Banff score (P=0.001), extensive glomerulosclerosis (P=0.002), a greater likelihood of crescent formation (P=0.01), severe tubular atrophy (P=0.013) and more extensive interstitial fibrosis (P=0.033). However, the two groups showed no significant differences in blood pressure, hematuria, BUN, UA, Hb, TG and CHO levels. The allograft survival rate of patients with IgAN was identified to be similar to that of patients with and without other glomerular diseases.

Nephrotic-range proteinuria in a patient with a renal allograft treated with sorafenib for metastatic renal-cell carcinoma

A 51-year-old man with immunoglobulin A (IgA) nephropathy developed metastatic renal-cell carcinoma of his native right kidney, 3.5 years post kidney transplant. At that time renal function was stable with the presence of only mild proteinuria. Shortly after chemotherapy with sorafenib [anti-vascular endothelial growth factor (VEGF)] was initiated, progressive renal impairment, hypertension, and nephrotic-range proteinuria developed. Allograft biopsy showed extensive IgA nephropathy. After withdrawal of the anti-VEGF therapy, however, renal function and blood pressure improved, and proteinuria diminished. Based on the clinical course and histopathological findings we hypothesize that sorafenib may induce nephrotic-range proteinuria and renal impairment, possibly through anti-VEGF-mediated effects on the progression of IgA nephropathy.