Recurrent immunoglobulin A nephropathy after renal transplantation: a significant contributor to graft loss

Successful management of proteinuria in recurrent immunoglobulin A nephropathy after deceased donor kidney transplantation: A case report

BACKGROUND

Immunoglobulin A nephropathy (IgAN) is the most common type of primary glomerulonephritis, and recurrent IgAN is common after kidney transplantation (KT). Owing to the differences in various biopsy protocols and follow-ups in each study, the recurrence rate varies from 9.7% to 46%. Although the relapse rates are high, there is no definitive treatment for IgAN recurrence.

METHODS

We present a case of successful management of proteinuria in recurrent IgAN after deceased donor KT. A 60-year-old man diagnosed with IgAN 20 years prior, who progressed to end-stage renal disease, underwent deceased donor KT 5 years prior and was admitted to our hospital with progressively increasing proteinuria.

RESULTS

The pathological examination of the kidney biopsy specimen revealed recurrent IgAN. High-dose steroid treatment was initiated, and the patient was discharged while maintaining steroid treatment. However, outpatient follow-up showed that proteinuria did not decrease while steroids were maintained. Therefore, an angiotensin receptor blocker was administered after explaining its benefits to the patient. After the addition of angiotensin receptor blocker, proteinuria continued to decrease.

CONCLUSION

This case report highlights the importance of using renin-angiotensin system inhibitors with supportive care in cases of suspected of recurrent IgAN after KT. It also emphasizes the need to prescribe renin-angiotensin system inhibitors when steroid therapy is unsuccessful in cases of recurrent IgAN after KT.

Two Decades Outcomes of Posttransplant Immunoglobulin A Nephropathy in Live Donor Renal Transplantation

Background:

The data on long-term outcomes of posttransplant immunoglobulin A nephropathy (IgAN) are confounding and vary with geography and ethnicity worldwide. We aimed to study the long-term graft outcomes of patients with posttransplant IgAN in the northern Indian cohort.

Methods:

The long-term graft outcomes of 51 live donor renal transplant recipients with biopsy-proven posttransplant IgAN (recurrence/de novo) were analyzed. The risk factors for graft failure in the posttransplant IgA groups were analyzed using the Cox regression analysis.

Results:

Out of the total of 51 patients who had posttransplant IgAN, 40 patients had a biopsy-proven native kidney IgAN. The mean duration of the clinical presentation of posttransplant IgAN was 62.4 months (5.2 years) posttransplant. Proteinuria at the time of biopsy was 3.03 ± 2.2 g/day, and 41.2% had proteinuria of more than 3 g/day at the time of biopsy. The estimated 1, 5, 10, and 20 years patient survival was 98%, 95.4%, 75.9%, and 25.2%, respectively, and the estimated 1, 5, 10, and 20 years graft survival was 98%, 88.5%, 44.6%, and 11.9%, respectively, in patients who had posttransplant IgA. Many of the traditional risk factors associated with progression in native kidney IgAN, such as the degree of proteinuria, Oxford MEST (mesangial and endocapillary hypercellularity, segmental sclerosis, and interstitial fibrosis/tubular atrophy) scoring, recipient's age, and sex were not predictive of early graft failure among patients with posttransplant IgAN. In our cohort, the only significant graft failure predictor was serum creatinine at 5 years. Chronic antibody-mediated rejection (ABMR) was seen in 21.6% of patients with posttransplant IgAN. Whether this coexistence of chronic ABMR is an incidental finding or posttransplant IgAN predisposes to chronic ABMR requires further investigation.

Conclusion:

Posttransplant IgAN is associated with poor long-term graft outcomes in live donor renal transplants. Proteinuria and MEST scoring were not predictive of graft failure in living donor posttransplant IgAN.

Outcome of 313 Czech Patients With IgA Nephropathy After Renal Transplantation

The recurrence of IgA nephropathy (IgAN) after kidney transplantation occurs in 20–35% of patients. The main aim of this study is to evaluate risk factors affecting the course of IgAN after renal biopsy of native kidney and kidney transplant. We evaluated clinical parameters and histological findings at the time of biopsy of native kidney and after kidney transplantation in 313 patients with IgAN with a follow-up of up to 36 years. Using hierarchical clustering method, patients with graft failure (n=50) were divided into two groups based on the mean time from kidney transplant to graft failure (11.2 versus 6.1 years). The time-to-graft failure corresponded well to the time from the renal biopsy of native kidney to end-stage renal disease (5.9 versus 0.4 years). Body mass index, proteinuria, microscopic hematuria, histological evaluation of fibrosis, and crescents at the time of renal biopsy of native kidney were the main variables for the differentiation of the two groups. Higher age of kidney-transplant donor, histological recurrence of IgAN, antibody-mediated rejection, and the onset of microscopic hematuria and proteinuria within 1 year after kidney transplant were also associated with worse graft survival in multivariate Cox regression analysis.

Recurrent Glomerulonephritis in the Kidney Allograft

Renal transplantation is the preferred form of renal replacement therapy in patients who develop end-stage kidney disease (ESKD). Among the diverse etiologies of ESKD, glomerulonephritis is the third most common cause, behind hypertensive and diabetic kidney disease. Although efforts to prolong graft survival have improved over time with the advent of novel immunosuppression, recurrent glomerulonephritis remains a major threat to renal allograft survival despite concomitant immunosuppression. As a result, clinical expertise, early diagnosis and intervention will help identify recurrent disease and facilitate prompt treatment, thus minimizing graft loss, resulting in improved outcomes. In this review, we highlight the clinicopathologcal characteristics of certain glomerular diseases that recur in the renal allograft.

Recurrent Glomerulonephritis after Renal Transplantation: The Clinical Problem

Glomerulonephritis (GN) continues to be one of the main causes of end-stage kidney disease (ESKD) with an incidence rating from 10.5% to 38.2%. Therefore, recurrent GN, previously considered to be a minor contributor to graft loss, is the third most common cause of graft failure 10 years after renal transplantation. However, the incidence, pathogenesis, and natural course of recurrences are still not completely understood. This review focuses on the most frequent diseases that recur after renal transplantation, analyzing rate of recurrence, epidemiology and risk factors, pathogenesis and bimolecular mechanisms, clinical presentation, diagnosis, and therapy, taking into consideration the limited data available in the literature. First of all, the risk for recurrence depends on the type of glomerulonephritis. For example, recipient patients with anti-glomerular basement membrane (GBM) disease present recurrence rarely, but often exhibit rapid graft loss. On the other hand, recipient patients with C3 glomerulonephritis present recurrence in more than 50% of cases, although the disease is generally slowly progressive. It should not be forgotten that every condition that can lead to chronic graft dysfunction should be considered in the differential diagnosis of recurrence. Therefore, a complete workup of renal biopsy, including light, immunofluorescence and electron microscopy study, is essential to provide the diagnosis, excluding alternative diagnosis that may require different treatment. We will examine in detail the biomolecular mechanisms of both native and transplanted kidney diseases, monitoring the risk of recurrence and optimizing the available treatment options.

Recurrence of immunoglobulin A nephropathy after kidney transplantation: a narrative review of the incidence, risk factors, pathophysiology and management of immunosuppressive therapy

Glomerulonephritis (GN) is the underlying cause of end-stage renal failure in 30–50% of kidney transplant recipients. It represents the primary cause of end-stage renal disease for 25% of the dialysis population and 45% of the transplant population. For patients with GN requiring renal replacement therapy, kidney transplantation is associated with superior outcomes compared with dialysis. Recurrent GN was previously considered to be a minor contributor to graft loss, but with the prolongation of graft survival, the effect of recurrent disease on graft outcome assumes increasing importance. Thus the extent of recurrence of original kidney disease after kidney transplantation has been underestimated for several reasons. This review aims to provide updated knowledge on one particular recurrent renal disease after kidney transplantation, immunoglobulin A nephropathy (IgAN). IgAN is one of the most common GNs worldwide. The pathogenesis of IgAN is complex and remains incompletely understood. Evidence to date is most supportive of a several hit hypothesis. Biopsy is mandatory not only to diagnose the disease in the native kidney, but also to identify and characterize graft recurrence of IgAN in the kidney graft. The optimal therapy for IgAN recurrence in the renal graft is unknown. Supportive therapy aiming to reduce proteinuria and control hypertension is the mainstream, with corticosteroids and immunosuppressive treatment tailored for certain subgroups of patients experiencing a rapidly progressive course of the disease with active lesions on renal biopsy and considering safety issues related to infectious complications.

Successful treatment of a patient with posttransplant IgA nephropathy with targeted release formulation of budesonide

Recurrence of glomerulonephritis is the third-leading cause of allograft loss. Graft loss due to IgA nephropathy occurs in 10% at 10-year follow-up. The NEFIGAN trial demonstrated that Target Release Formulation (TRF) of budesonide is a specific treatment for IgA nephropathy targeting intestinal mucosal immunity upstream of disease manifestation with favorable safety profile. We are reporting a case of successful treatment of a patient with posttransplant IgA nephropathy with TRF of budesonide.

Immunoglobulin A Nephropathy. Recurrence After Renal Transplantation

IgA nephropathy (IgAN) is the most common primary glomerular disease worldwide. The disease generally runs an indolent course but may lead to ESRD in 20-30% of patients in 20 years or more after diagnosis. Patients with IgA nephropathy are ideal candidates for renal transplant because they are generally relatively young and with few comorbidities. Their graft survival is better or comparable to that of controls at 10 years, though few data are available after 10 years of follow-up. Recurrence of the original disease in the graft is a well-known complication of transplant in IgAN and is a significant cause of deterioration of graft function. Recurrent IgAN rarely manifests clinically before 3 years post transplantation. Recurrence rate is estimated to be around 30% with considerable differences among different series. Despite these factors there is no certain recurrence predictor, young age at renal transplant, rapid progression of the original disease and higher levels of circulating galactose-deficient IgA1 and IgA-IgG immune complexes are all associated with a higher rate of recurrence. Which pathogenetic mechanisms are responsible for the progression of the recurrence to graft function deterioration, and what therapy can prevent or slow down the progression of the disease in the graft, are open questions. The aim of this review is to describe the clinical outcome of renal transplantation in IgA patients with attention to the rate and the predictors of recurrence and to discuss the available therapeutic options for the management of recurrence.

Recurrent glomerulonephritis following renal transplantation and impact on graft survival

Background

Recurrence of primary glomerulonephritis in the post-transplant period has been described in the literature but the risk remains poorly quantified and its impact on allograft outcomes and implications for subsequent transplants remain under-examined. Here we describe the rates and timing of post-transplant glomerulonephritis recurrence for IgA nephropathy, focal segmental glomerulosclerosis, mesangiocapillary GN and membranous GN based on 28 years of ANZDATA registry transplant data.

Methods

We investigated the rates of GN recurrence and subsequent graft outcomes in 7236 patient from 28 years of ANZDATA transplant registry data. Data were analysed in R, using Kaplan Meier Survival analysis and adjusted analyses performed using Cox Proportional Hazards methods. A competing risk model was also analysed.

Results

GN recurrence occurred in 10.5% of transplants and was most common in mesangiocapillary GN. Median time to recurrence was shorter for FSGS compared to IGAN. GN recurrence was less common in patients over 50 years of age and after unrelated kidney donation. We identified a significantly higher risk of recurrence in secondary grafts following recurrence in a primary allograft for FSGS (RR 5.70, 95 CI: 2.41–13.5, p < 0.001) but not IGAN, MCGN or MN. At 10 years, recurrence occurs in 8.7, 10.8, 13.1, and 13.4% of allografts for FSGS, IGAN, MCGN and MN respectively. In all GN, recurrence significantly reduced death censored graft survival at 5 and 10 years.

Conclusions

GN recurrence occurs in a minority of patients at a significantly different rate for each GN. After a recurrence, there is no evidence for an increased risk of further recurrence in a subsequent graft except in FSGS.

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.

Selection of Patients for Initial Clinical Trials of Solid Organ Xenotransplantation

Several groups have reported extended survival of genetically engineered pig organs in nonhuman primates, varying from almost 10 months for life-supporting kidney grafts and more than 2 years for non-life-supporting heart grafts to less than 1 month for life-supporting liver and lung grafts. We have attempted to define groups of patients who may not have an option to wait for an allograft. These include kidney, heart, and lung candidates who are highly-allosensitized. In addition, some kidney candidates (who have previously lost at least 2 allografts from rapid recurrence of native kidney disease) have a high risk of further recurrence and will not be offered a repeat allotransplant. Patients with complex congenital heart disease, who may have undergone previous palliative surgical procedures, may be unsuitable for ventricular assist device implantation. Patients dying of fulminant hepatic failure, for whom no alternative therapy is available, may be candidates for a pig liver, even if only as a bridge until an allograft becomes available. When the results of pig organ xenotransplantation in nonhuman primates suggest a realistic potential for success of a pilot clinical trial, highly selected patients should be offered participation.

The clinical course of IgA nephropathy after kidney transplantation and its management

Immunoglobulin (Ig) A nephropathy is one of the most common primary glomerulonephritides worldwide causing end stage renal disease in up to 20-40% of affected patients, nearly two decades post diagnosis. Kidney transplantation is the treatment of choice for patients with renal failure, secondary to glomerular diseases. However, IgA nephropathy has a strong tendency to recur in the graft, and although initially thought to be a benign condition, several reports of graft loss, due to recurrent IgA nephropathy, there have been over the last three decades. Overall graft survival has been significantly improved in kidney transplantation, as a result of reduced incidence of acute rejection, as more potent and more specific immunosuppressive agents are now available in clinical practice. Thus, the rates of IgA nephropathy and other glomerulonephritides recurrence are expected to increase, since graft survival has been improved. However, the reported incidence of IgA nephropathy recurrence in the graft varies substantially across centers, as a consequence of different levels of interest, diverse biopsy policies and differing durations of follow up, of the published studies. Notably, recurrence rates of patients receiving graft biopsies by clinical indication only, ranges from 13% to 50% with graft loss being between 1.3% and 16%. The aim of this review is to underline important pathogenetic insights of IgA nephropathy, describe the clinical course of the disease after kidney transplantation, with emphasis on the incidence of recurrence and the associated risk factors, and finally provide all available options for its management in transplant recipients.

Early recurrence of active IgA nephropathy after kidney transplantation

IgA nephropathy (IgAN) is recurrent after transplantation; however, its time of recurrence is unpredictable. To date, factors influencing IgAN recurrence have not been elucidated. We present a case of a 23-year-old man with end-stage renal disease (ESRD) who underwent living-related ABO-identical pre-emptive kidney transplantation (PEKT) using his 57-year-old mother as a donor. IgAN started when the patient was 19 years old, and renal biopsy revealed the usual pathological findings of IgAN. In spite of steroid therapy including steroid pulse and tonsillectomy, the patient developed nephrotic syndrome and progressed to ESRD in 4 years. Protocol biopsy on day 19 following PEKT revealed active recurrent IgAN. Nephrotic-range proteinuria and mild deterioration of kidney function developed regardless of strong immunosuppressive therapy such as steroid pulse, double filtration plasmapheresis and rituximab. We report a case of refractory IgAN that recurred 19 days after transplantation. This case is considered of value to elucidate factors leading to active IgAN recurrence.

Outcome of tonsillectomy for recurrent IgA nephropathy after kidney transplantation

Since 2007, we have performed tonsillectomies for patients with recurrent immunoglobulin A nephropathy (IgAN) after kidney transplantation. Seven patients with primary IgAN showed biopsy-proven recurrent IgAN after living-donor kidney transplantation. They had persistent proteinuria or hematuria for an average of 40.3 months, and tonsillectomy was performed, on average, 75.6 months after kidney transplantation. In six patients with observation periods of more than one year, good remission of urinary findings was observed after tonsillectomy. We classified the seven patients into three types of renal injury based on histological findings: severe, moderate, and mild. Two patients classified with severe renal injury at the time of tonsillectomy had other problems, such as refractory hypertension and bilateral sinusitis. They followed a rapidly progressive clinical course. One case already had moderate histological renal injury. He demonstrated prompt amelioration of urinary findings after tonsillectomy but immediate deviation from remission of proteinuria and hematuria. In the four cases presenting mild renal injury at tonsillectomy, the improved urinary findings and serum creatinine value after tonsillectomy have persisted. In conclusion, tonsillectomy may be a favorable treatment for cases of mild-grade IgAN. However, other treatments such as antihypertensive agents and diet therapy may be necessary in other grades.

The risk of recurrent IgA nephropathy in a steroid-free protocol and other modifying immunosuppression

Recurrent glomerulonephritis is an important cause of kidney allograft failure. The effect of immunosuppression on recurrent IgA nephropathy (IgAN) is unclear. We analyzed the impact of steroids and other immunosuppression on the risk of recurrent IgAN post-kidney transplantation. Between June 1989 and November 2008, 3311 kidney transplants were performed at our center. IgAN was the primary disease in 124 patients; of these, 75 (60.5%) patients received steroid-based immunosuppression (15 undergoing late steroid withdrawal), and 49 (39.5%) were maintained on steroid-free immunosuppression. Recurrent IgAN was diagnosed in 27 of 124 (22%) patients in clinically indicated kidney allograft biopsies over a median follow-up of 6.86 ± 5.4 yr. On cox proportional hazards model multivariate analysis, the hazard risk (HR) of IgAN recurrence was significantly higher in patients managed with steroid-free (HR 8.59: 3.03, 24.38, p < 0.001) and sirolimus-based (HR = 3.00:1.16, 7.75, p = 0.024) immunosuppression without antilymphocyte globulin induction (HR = 4.5: 1.77, 11.73, p = 0.002). Mycophenolate use was associated with a lower risk (HR = 0.42: 0.19, 0.95, p = 0.036), whereas cyclosporine did not have a significant impact on the risk of IgAN recurrence (p = 0.61). These results warrant future prospective studies regarding the role of steroids and other immunosuppression drugs in reducing recurrence of IgAN and other glomerulonephritis post-transplant.

Pathology of IgA nephropathy

IgA nephropathy is defined by the presence of IgA-dominant or co-dominant immune deposits within glomeruli. Biopsy specimens meeting these diagnostic criteria have a range of histological changes that are reflected in the variable clinical course of IgA nephropathy. The impact of histology on outcomes in IgA nephropathy has been clarified in a number of large retrospective clinicopathological studies. These studies have consistently demonstrated that the stage of disease at presentation, as indicated by the extent of interstitial fibrosis and tubular atrophy in the biopsy, is the strongest histological predictor of renal survival. The effect of active proliferative lesions on the disease course is less clear cut, owing in part to considerable treatment bias in most published retrospective studies. There is evidence that endocapillary hypercellularity and cellular crescents are responsive to immunosuppressive therapy, but this observation requires confirmation in prospective randomized controlled trials. Future challenges include improving the reproducibility of histological scoring, particularly for the presence and extent of endocapillary lesions, and to improve prognostic modelling by combining histological data with clinical variables and biomarker data.

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.

Usefulness of Oxford classification in assessing immunoglobulin A nephropathy after transplantation

BACKGROUND

We explored the efficacy of the Oxford classification for assessing native immunoglobulin A nephropathy (IgAN) in posttransplantation patients compared with the glomerular injury score and Haas classification.

METHODS

A total of 125 renal allograft biopsies obtained from 114 patients diagnosed with IgAN regardless of original disease were assessed.

RESULTS

The average time to biopsy was 70.5±45.3 months after transplantation. Glomeruli showed normal histology in 18.4%. Mesangial hypercellularity (M1), endocapillary hypercellularity (E1), segmental glomerulosclerosis (S1), and tubulointerstitial fibrosis (T1-2) were present in 12.8%, 6.4%, 45.6%, and 20.8% of the samples, respectively. There was a significant correlation between Oxford-MEST scores and glomerular injury score or Haas subclass. S1 and T1-2 were correlated with elevated serum creatinine level, proteinuria, and decreased estimated glomerular filtration rate, and E1 was correlated with decreased estimated glomerular filtration rate at the time of biopsy. The 10- and 15-year graft survival rates were 62.9% and 34.3%, respectively. The graft survival rate was significantly lower in the presence of S1 and T1-2. Endocapillary hypercellularity, segmental sclerosis, and tubulointerstitial fibrosis predicted graft survival and endocapillary hypercellularity and tubulointerstitial fibrosis also predicted serum creatinine doubling.

CONCLUSIONS

The Oxford classification scheme is useful for evaluating chronic graft dysfunction in patients with posttransplantation IgAN. In addition to tubulointerstitial fibrosis, the presence of endocapillary hypercellularity and segmental sclerosis should be included in the pathology report.

The long-term outcome of renal transplantation of IgA nephropathy and the impact of recurrence on graft survival

BACKGROUND

Few data are available on allograft survival at 15 years, the impact and the predictors of recurrence of the original disease in renal transplanted patients with IgA nephropathy (IgAN).

METHODS

In this retrospective study, we compared the long-term outcome of renal transplant in 190 patients with IgAN with that of 380 non-diabetic controls and evaluated the impact of recurrence of IgAN on the graft outcome.

RESULTS

At 15 years, the patient survival was 88.3% in IgAN patients and 82.6% in controls (P = 0.12), while the death-censored graft survival was 62.6 and 72.4%, respectively (P = 0.038). IgAN had a higher cumulative incidence of graft failures in comparison with controls even considering death as a competing risk (P = 0.025). At multivariate analysis, IgAN [relative risk (RR) = 1.468, P = 0.026], delayed graft function recovery (RR = 2.394, P = 0.000) and acute rejection (RR = 2.51, P = 0.000) were predictive of graft loss. IgAN recurred in 42 grafts (22.1%), of them, 12 were lost for recurrence and in another 6 recurrence was considered a concomitant cause of graft loss. The 15-year death censored graft survival was 68.3% in non-recurrent and 51.2% in recurrent patients (P = 0.069). Pure graft survival of non-recurrent IgAN patients was similar to that of controls (P = 0.406). At Cox analysis, the recurrence of IgAN significantly reduced from 1981 to 2010 (P = 0.0065, RR = 0.936).

CONCLUSIONS

IgAN emerged as an independent predictor of worse graft outcome in the long-term. Recurrence of IgAN seems to progressively reduce in transplants performed from 1981 to 2010.

Steroids and recurrent IgA nephropathy after kidney transplantation

We studied the impact of steroid use on kidney graft loss due to recurrent IgA nephropathy (IgAN). We used data from the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) to conduct a survival analysis of adult recipients of a first kidney transplant for IgAN who received a graft between 1988 and 2007. Predictors of graft loss due to recurrent IgAN were analyzed in a competing risk survival analysis with steroid use modeled as a time-varying covariate. Fifteen hundred twenty-one recipients with kidney failure due to biopsy-proven IgAN received a first kidney transplant during the study period. Four hundred and twenty-eight recipients experienced graft loss, of which 54 losses (12.6%) were attributed to recurrent IgAN. The overall 10-year cumulative incidence of graft loss from recurrent IgAN was 4.3% (95% CI 3.1-5.8). Prevalence of steroid use was 92% at baseline, 84% at 1 year and 64% at 5 years. After adjusting for age, sex, HLA mismatch, dialysis duration and transplant era, steroid use was strongly associated with a reduced risk of recurrence (subhazard ratio 0.50, 95% CI 0.30-0.84). These results suggest that the risk of graft loss from recurrent disease should be considered when tailoring immunosuppression for patients with IgAN.

Outcome of renal allograft in patients with Henoch-Schönlein nephritis: single-center experience and systematic review

BACKGROUND

Henoch-Schönlein nephritis (HSN) is a rare condition resulting in end-stage renal disease. Therefore, graft outcomes and recurrence rates after transplantation are not well studied. Also, the effect of donor type on graft outcome has not been evaluated thoroughly.

METHODS

The graft outcome and recurrence rate in 20 kidney recipients with HSN were compared with age-, sex-, and donor source-matched controls (control A, primary immunoglobulin A nephropathy; control B, other causes; 40 recipients per group). To assess the effect of donor type, we pooled our data with two previous cohort studies where donor type had been described in detail.

RESULTS

Overall graft survival rates were 87.7% at 10 years. The overall recurrence rate of HSN was 15.4% over 10 years. Graft survival and recurrence rates in the HSN group were similar to those of control A and control B. The pooled data showed a 29.4% incidence rate for recurrent HSN. Living related donor transplantation showed a trend of higher recurrence compared with recipients with nonrelated grafts, although it was marginally significant (P=0.059). However, the graft survival rate in related-donor recipients was not inferior to that in the unrelated-donor recipients.

CONCLUSIONS

Long-term graft survival and recurrence rates in kidney recipients with HSN were comparable to those of recipients with primary immunoglobulin A nephropathy. The type of donor did not significantly affect long-term graft survival.

KDIGO clinical practice guideline for the care of kidney transplant recipients

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression, graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially on the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.

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

INTRODUCTION

Previous reports have suggested that posttransplantation immunoglobulin (Ig) A nephropathy displays a relatively benign course, hardly ever affecting graft function. However, more recent studies with longer follow-up have shown that posttransplantation IgA nephropathy may be a significant contributor to graft loss. Additionally, there may be other clinical or pathological factors that affect long-term graft outcome. We retrospectively analyzed 30 kidney transplant recipients with biopsy-proven IgA nephropathy in their allografts to determine the clinical course and prognostic factors in posttransplantation IgA nephropathy. The median duration of follow-up was 36 months (range, 1 month-17 years). The median onset of IgA nephropathy was 33.6 months posttransplantation (range, 5 days-103 months). The most common presentation was an abnormal urine examination (96.6%). Fifteen (50%) displayed microscopic hematuria with proteinuria more than 1 g/d. Fifteen patients (50%) lost their grafts at a median time of 24 months after the onset of disease (range, 1-93 months). Allograft loss was associated with a high serum creatinine level at the time of diagnosis (3.68 +/- 2.23 vs 1.79 +/- 0.34 mg/dL; P = .006), a greater level of proteinuria at the time of diagnosis (2.43 +/- 0.76 vs 1.29 +/- 1.07 g/d; P = .003), and more than 50% extracapillary proliferation (P = .05). Fibrinoid necrosis on allograft pathology impacted 1-year allograft survival (P = .025).

CONCLUSION

Posttransplantation IgA nephropathy worsens allograft outcomes among patients with increased serum creatinine level or significant proteinuria at presentation or significant glomerular inflammation and/or tubulointerstitial damage.

Peritubular capillary C4d deposition and renal outcome in post-transplant IgA nephropathy

BACKGROUND

Immunological staining of the transplanted kidney for C4d in peritubular capillaries (C4d(PTC)) has emerged as a useful method to detect antibody-mediated rejection in situ. In this retrospective study, we evaluated the prevalence of C4d(PTC) deposition in allograft renal biopsies diagnosed of IgA nephropathy (IgAN) and analysed its clinical significance.

METHOD

Sixty-six biopsy specimens of post-transplant IgAN, which were obtained to evaluate azotemia and/or heavy proteinuria, were examined by immunohistochemical staining of the paraffin sections with polyclonal antibody for C4d.

RESULTS

C4d was stained positively in peritubular capillaries in 16 (24%) of the 66 cases. The C4d(PTC)-negative (n=50) and C4d(PTC)-positive groups (n=16) were not different in recipient gender, age, donor age, type of donor (living vs. cadaveric), interval from transplantation to graft biopsy (41.6+/- 21.8 vs. 48.3+/-26.1 months) and post-biopsy follow-up period (60.3+/-23.3 vs. 56.9+/-25.4 months). During the follow-up period, 12 of 50 (24%) although the incidence of graft failure was not different by the C4d deposition in peritubular capillaries, intervals from renal biopsy to graft failure tended to be shorter in C4d(PTC)-positive cases than C4d(PTC)-negative cases. In Kaplan-Meier analysis, the renal allograft function of the C4d(PTC)-positive group deteriorated more rapidly than that of the C4d(PTC)-negative group (p<0.05). Histologically, the C4d(PTC)-positive group had findings suggestive of acute cellular rejection more commonly than the C4d(PTC)-negative group (p<0.01).

CONCLUSIONS

Evidence of humoral rejection, as demonstrated by C4d(PTC) deposition, was concurrently present in significant portions of post-transplant IgAN biopsy specimens and was associated with more rapid deterioration of renal function. These results suggest that C4d(PTC) positivity needs to be determined at the time of biopsy even in cases of post-transplant glomerulonephritis and immunosuppression may need to be modified accordingly.

Recurrence of IgA nephropathy among renal allograft recipients from living donors is greater among those with zero HLA mismatches

BACKGROUND

Risk factors contributing to recurrence of IgA nephropathy (IgAN) after transplantation are unclear. Some (but not all) series have suggested greater degrees of human leukocyte antigen (HLA) matching play a role.

METHODS

Using registry data including all kidney transplants performed in Australia and New Zealand between 1987 and 2004 we examined IgAN recurrence among living donors with zero HLA-mismatches.

RESULTS

Of 1354 grafts performed in recipients with IgAN, live donors (LDs) accounted for 488 including 108 with zero HLA-mismatches. Biopsy-proven IgAN recurrence was reported for 110 (7%) of grafts overall, but 17% of those who received zero HLA-mismatched LD grafts (HR for recurrence free graft survival 2.7 [95% CI 1.5-5.1], P=0.001). There was no significant difference in recurrence rates between zero and >or=1 HLA-mismatched grafts from cadaveric donors (CDs). Recurrence of IgAN was associated with worse graft survival, more so among LD recipients (HR 8.5 [4.8-15.2], P<0.001) than CD recipients (HR 4.5 [2.6-7.5], P<0.001). However, there was no difference in graft survival between zero and >or=1 HLA mismatched LD recipients whose native disease was IgAN. In contrast, zero HLA mismatched recipients of kidneys with other primary renal disease enjoyed a graft survival advantage. No difference in recurrence rates was seen among those with HLA B12, B35 or DR4.

CONCLUSIONS

The increased rates of IgAN-related graft loss among zero HLA-mismatched LD recipients counterbalance the advantage normally seen among zero HLA-mismatched recipients. However, since graft survivals are similar, there is no reason to avoid donor-recipient pairs with zero HLA-mismatches in this setting.

Recurrent glomerulonephritis after kidney transplantation

Thirty to fifty percent of kidney transplant recipients have glomerular diseases as the underlying causes of end-stage renal failure. While recurrence of glomerulonephritis is an important cause of late renal allograft failure, the risk factors for recurrence are largely unknown or imprecise and prediction remains difficult. Recurrent disease usually presents with similar manifestations as the native disease. With regard to treatment of recurrent glomerular disease in the renal allograft, plasma exchange may be effective in reducing proteinuria in patients with early recurrence of focal and segmental glomerulosclerosis, but immunosuppressive therapy is generally ineffective in the prevention or treatment of recurrent disease. General supportive measures including strict blood pressure control and inhibition or blockade of the rennin-angiotensin pathway are helpful in retarding the rate of deterioration in renal allograft function. Despite the risk of recurrence, kidney transplantation following primary glomerulonephritides enjoys graft and patient survival rates comparable to other causes of end-stage renal failure. With a few exceptions, living related renal transplantation is not contraindicated in view of the favorable outcome and the donor shortage. This review discusses commonly encountered recurrent glomerulonephritides, with special emphasis on the influence of post-transplant prophylactic immunosuppression and emerging treatments.

Considerations in retransplantation of the failed renal allograft recipient

Routine success in kidney transplantation has significantly improved the quality and length of life for the majority of recipients and made this option the treatment of choice for suitable candidates. Improved patient survival combined with a relative static improvement in long-term graft outcomes has led to an increasing number of transplant recipients with failed allografts who face the eventual option of either returning to dialysis or seeking retransplantation. Although retransplantation is presumed to be a favorable option for many, data to support this belief is limited. Given the wide variance in predicted outcomes for retransplantation, on the basis of the underlying kidney disease and other individual patient comorbidities as well as the expected wait time for a second transplant, each case should be evaluated independently. This review discusses available data and individual considerations that should be taken into account when retransplantation is proposed after failure of a primary allograft.

Latent IgA deposition from donor kidney is the major risk factor for recurrent IgA nephropathy in renal transplantation

BACKGROUND

Previous studies have recognized risk factors for recurrent IgA nephropathy (r-IgAN) in renal transplantation. However the clinical significance of latent IgA deposition from the donor kidney remains to be determined.

PATIENTS AND METHODS

Between 1992 and 1999, 0-hour allograft biopsies were performed in 510 renal transplantation recipients at the Kidney Center of Tokyo Women's Medical University. Among these 510 patients, there were 49 whose primary disease was identified as IgAN. Among these 49 patients, 13 patients (26.5%) were diagnosed as having r-IgAN based on renal biopsy. We compared risk factors of r-IgAN, including IgA deposition, between the r-IgAN and non-r-IgAN groups.

RESULTS

We assessed factors previously reported to be risk factors for r-IgAN, such as follow-up period after transplantation, sex, ages of donors and recipients, donor type, ABO compatible or incompatible transplantation, number of HLA-A, B, and DR mismatches, number of donors with HLA-A2, B35, B46, and/or DR4, duration to end stage renal disease, duration of dialysis, and latent IgA deposition from donor kidneys. Latent IgA deposition was the only risk factor that differed significantly in frequency between patients with and without recurrence (38.5% in r-IgAN group vs. 9.1% in non-r-IgAN group, p = 0.037). Other factors did not differ significantly between the two groups. Clinical factors, such as urinary protein excretion, urinary red blood cell sediment and serum creatinine, were significantly worse and the number of patients who required hemodialysis 5 yr after transplantation was significantly higher in the r-IgAN group than in the non-r-IgAN group (38.5 vs. 5.6%, p = 0.001). Four of the five patients who required hemodialysis in the r-IgAN group had latent IgA deposition from the donor kidney.

CONCLUSION

Our data suggest that 26.5% out of patients with primary IgAN will develop recurrence within 5 yr after transplantation. Latent IgA deposition from the donor kidney was one of the risk factors of r-IgAN and it would lead to the development of r-IgAN. Moreover, r-IgAN will compromise graft survival, especially in cases with latent IgA deposition from the donor kidney.

Recurrence of IgA Nephropathy and Henoch-Schönlein Purpura After Kidney Transplantation: Risk Factors and Graft Survival

BACKGROUND

IgA nephropathy (IgA) is one of the most common glomerulonephritis. Renal transplantation is the treatment of choice for patients with ESRD due to any kind of glomerulopathy, including IgA and Henoch-Schönlein purpura nephritis (H-SP), but original disease recurrence is now the third most frequent cause of allograft loss.

METHODS

Eighty-seven cases of glomerulonephritis as the original disease were divided in two groups: group A--37 affected with 31 IgA and 6 H-SP; and group B--50 with other glomerulopathies. We compared patient and graft survivals at 5 years. To assess the presence of IgA or H-SP recurrence in group A patients, we performed an allograft biopsy in the presence of microhematuria, proteinuria, or an increased plasma creatinine. Known risk factors influencing recurrence rate were also analyzed.

RESULTS

Five-year patient (97% vs 95%) and graft survivals (81% vs 78%) were not significantly different between groups A and B. Patients with crescentic glomerulonephritis (CGN) at the moment of diagnosis of IgA or H-SP showed a 5-year graft survival of 71% in contrast with 100% graft survival among those with mesangial or focal and segmental glomerulosclerosis pattern (P = .03). Histological recurrence was diagnosed in eight patients: six IgA and two H-SP. Women (P = .013) and a good HLA match (P = .029) were significantly associated with the risk of recurrence.

CONCLUSIONS

When compared with other glomerulonephritis patients, with IgA or S-HP showed similar 5-year graft and patient survivals. Nevertheless, graft survival was shorter among patients with crescentic glomerulonephritis at the moment of diagnosis. Thus, the disease prognosis after grafting may be linked to the initial histological aggressiveness. Women and those patients transplanted with a good HLA match were prone to develop disease recurrence with a tendency toward a lower 5-year graft survival.

IgA nephropathy with crescents in kidney transplant recipients

BACKGROUND

Crescentic glomerulonephritis is an uncommon finding in renal allografts. Recurrence or de novo mesangial deposition of immunoglobulin A (IgA) in renal allografts most often is clinically benign, but some case reports have shown that IgA nephropathy in renal allografts can present as crescentic glomerulonephritis and may lead to rapid deterioration of graft function and/or graft loss.

METHODS

We reviewed diagnoses of all allograft biopsies at University of Washington Medical Center (Seattle, WA) from 1989 to 2003 and found 33 cases of glomerulonephritis with crescents. Eight of these cases were the result of recurrent or de novo IgA nephropathy. Clinical and pathological features of these patients were reviewed.

RESULTS

Six of 8 cases with crescents were the result of recurrent IgA nephropathy, and 2 cases were presumptive de novo IgA nephropathy. Of the 8 patients with IgA nephropathy with crescents, 6 patients presented clinically with increasing serum creatinine levels; 4 patients, with proteinuria; and 4 patients, with hematuria. In 6 patients, there was 10% to 30% involvement of glomeruli, with crescents partially or completely filling urinary spaces. The other patients showed lesser (approximately 7% of sampled glomeruli) involvement. Four patients with IgA nephropathy with crescents developed renal failure and returned to hemodialysis therapy. Three patients had a benign clinical course, with stabilization of renal function. One patient was lost to follow-up.

CONCLUSION

We identified a cohort of patients with glomerulonephritis with crescents in renal allografts with IgA nephropathy as the cause. In half the affected patients, this led to early progressive renal insufficiency and return to hemodialysis therapy.

Glomerular crescents are responsible for chronic graft dysfunction in post-transplant IgA nephropathy

Information is limited regarding the histological features related to chronic graft dysfunction and failure in patients with IgA nephropathy developing after renal transplantation. The prevalence and significance of glomerular crescents in post-transplant IgAN including recurrent, de novo and transmitted forms (TxIgAN), were studied. Renal morphology was evaluated in 71 patients of TxIgAN, obtained at more than 6 months post-transplant, and compared with regard to the presence (C-TxIgAN) or absence (N-TxIgAN) of glomerular crescents. Crescents were demonstrated in 12 samples of 10 patients (14.1%). The percentages of crescents were from 4.8% to 83.3% (median, 28.6%) in each sample. Ten samples of C-TxIgAN had cellular to fibrocellular crescents, and four of these were associated with diffuse mesangial proliferation. Serum creatinine levels and the frequency of nephrotic range proteinuria at the time of biopsy and the degree of interstitial inflammation were significantly different in the two groups. Graft survival after allograft biopsies was significantly lower in C-TxIgAN (P = 0.0017). Chronic rejection was a major cause of graft loss in N-TxIgAN (31.8%), whereas TxIgAN was the major cause in C-TxIgAN (66.7%). In conclusion, the current study suggests that glomerular crescents are not rare and that they are responsible for chronic graft dysfunction in TxIgAN patients.

Two cases of recurrent IgA nephropathy following kidney transplantation

Recurrence of immunoglobulin (Ig) A nephropathy following kidney transplantation has been described as occurring in 40% to 60% of cases. Although this type of recurrence was considered a benign condition for a long time, more recent data showed that recurrent transplant IgA nephropathy may be a significant contributor to graft loss. We present 2 cases of recurrent IgA nephropathy following kidney transplantation. In case 1, renal function remained stable with a creatinine level of 1.2 mg/dL at 5 months after diagnosis and 61 months after transplantation. In case 2, the patient lost his graft and returned to regular hemodialysis at 36 months after diagnosis and 125 months after kidney transplantation.

Recurrent IgA nephropathy after renal transplantation

Recurrence of the original disease is now the third most frequent cause of allograft loss at 10 years after transplantation in patients with underlying glomerulonephritis. IgA nephropathy (IgAN), the most common type of glomerulonephritis, histologically recurs in up to 60% of the patients. Initially considered to be a relatively benign phenomenon, several studies, which included a total of almost 1200 patients with underlying IgAN, have now established that after a mean follow up of 5 years, approximately 13% of the patients will exhibit some recurrence-related renal graft dysfunction and approximately 5% will have lost their graft as a result of recurrent IgAN. The only established predictor of graft loss is the time elapsed since renal transplantation. The risk of recurrence-associated graft loss increases to approximately 25% if a prior graft has already been lost as a result of recurrent IgAN. Whether living, related donor kidneys are at higher risk for recurrence is controversial. Despite all these issues, graft survival in patients with underlying IgAN compared with patients with other renal diseases is excellent. In patients with recurrent IgAN, no specific therapy other than optimal supportive care has been established.

Renal transplantation in patients with IgA mesangial glomerulonephritis

Most patients with IgA nephritis are suitable candidates for renal transplantation. In about 33% of patients the disease may recur after transplantation, although there are differences in the various series because of the different criteria for biopsy, the different length of follow-up and the different ethnicities. Living donation, genetic factors and time of progression of original disease have been found to be related with the risk of recurrence by some investigators, but these associations were not confirmed by other studies. The graft survival in patients with IgA nephritis is similar or even better than that observed with other renal diseases. The available data indicate that recurrence has a little impact on the 10-yr graft survival. However, a minority of patients may show a rapid progressive course after recurrence. Little information is available on the impact of recurrence in the very long term. There is no established treatment for preventing or treating the recurrence of IgA nephritis.

Persistent dipstick haematuria following renal transplantation

Despite widespread testing for dipstick haematuria following renal transplantation, there are no published series describing the prevalence and possible causes of this complication in an adult population. A cross-sectional study of 640 renal transplant recipients under review at our follow-up clinic was performed. Persistent haematuria was defined as a minimum of 1+ of blood on urinalysis stick testing detected at not fewer than 75% of clinic visits since its onset, or since the start of routine testing, present over a period of at least 4 weeks. The prevalence of persistent dipstick haematuria was 13.3%. Median serum creatinine was higher in patients with persistent haematuria but age, gender and length of time since transplantation were not significantly different. Potential explanations for persistent haematuria in 21 of 85 affected patients were chronic infection, ureteric stent without chronic infection, regular or intermittent self-catheterization, persistent menstrual bleeding, anticoagulant therapy, graft calculus, and allograft renal cell carcinoma. Recurrent or de novo glomerular disease was confirmed by graft biopsy in 10 of 85 patients. Among the 41 recipients whose original cause of renal failure was IgA nephropathy (IgAN), the prevalence of persistent haematuria was 31.7% compared with 12% in the remaining patients (relative risk 2.6, 95% CI: 1.6-4.3). Persistent haematuria in IgAN patients was not associated with gender, age or time since transplantation. After 29 months of follow-up, 20% of patients with haematuria had progressed to graft failure or death compared with 11.6% of the unaffected group (p = 0.029). However, despite the association with earlier graft failure, haematuria did not predict this endpoint independently of renal function.

Risk factors for graft loss in patients with recurrent IGA nephropathy after renal transplantation

BACKGROUND

The recurrence rate of IgA nephropathy (IgAN) in transplanted kidneys has been reported to be >50%. Although recurrent IgAN has a benign clinical course, recent data suggest that it leads to graft loss in a substantial number of patients.

METHODS

We performed a retrospective single-center analysis of 34 renal transplant recipients, with biopsy-proven IgAN as the cause of end-stage renal failure.

RESULTS

Renal allograft biopsies were performed in 30 patients, of whom 24 did and 6 did not have biopsy-confirmed recurrent transplant IgAN. Recurrent transplant IgAN was more often detected in men and at later timepoints after post-transplantation. Four patients with recurrent transplant IgAN progressed to graft failure. Progression to graft failure was associated with worsened renal function, higher systolic blood pressure, and the lack of presenation of angiotensin-converting enzyme inhibitors (ACEs) at the time of allograft biopsy. Immunologic factors such as frequency of acute rejection, HLA typing, and immunosuppression did not show a relation to recurrence or graft loss.

CONCLUSIONS

Recurrent transplant IgAN increased with long-term graft survival and risk factors for graft loss due to recurrent IgAN were similar to those among IgAN in native kidneys.

Dysregulated LIGHT expression on T cells mediates intestinal inflammation and contributes to IgA nephropathy

Whether and how T cells contribute to the pathogenesis of immunoglobulin A nephropathy (IgAN) has not been well defined. Here, we explore a murine model that spontaneously develops T cell-mediated intestinal inflammation accompanied by pathological features similar to those of human IgAN. Intestinal inflammation mediated by LIGHT, a ligand for lymphotoxin beta receptor (LTbetaR), not only stimulates IgA overproduction in the gut but also results in defective IgA transportation into the gut lumen, causing a dramatic increase in serum polymeric IgA. Engagement of LTbetaR by LIGHT is essential for both intestinal inflammation and hyperserum IgA syndrome in our LIGHT transgenic model. Impressively, the majority of patients with inflammatory bowel disease showed increased IgA-producing cells in the gut, elevated serum IgA levels, and severe hematuria, a hallmark of IgAN. These observations indicate the critical contributions of dysregulated LIGHT expression and intestinal inflammation to the pathogenesis of IgAN.

The role of fish oil/omega-3 fatty acids in the treatment of IgA nephropathy

Beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFA) have been reported in recent epidemiologic studies and randomized clinical trials in a variety of cardiovascular and autoimmune diseases. Fish and marine oils are the most abundant and convenient sources of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the two major n-3 fatty acids that serve as substrates for cyclooxygenase and lipoxygenase pathways leading to less potent inflammatory mediators than those produced through the n-6 PUFA substrate, arachidonic acid. N-3 PUFA can also suppress inflammatory and/or immunologic responses through eicosanoid-independent mechanisms. Although the pathophysiology of IgA nephropathy is incompletely understood, it is likely that n-3 PUFA prevents renal disease progression by interfering with a number of effector pathways triggered by mesangial immune-complex deposition. In addition, potential targets of n-3 PUFA relevant to renal disease progression could be similar to those involved in preventing the development and progression of cardiovascular disease by lowering blood pressure, reducing serum lipid levels, decreasing vascular resistance, or preventing thrombosis. In IgA nephropathy, efficacy of n-3 PUFA contained in fish oil supplements has been tested with varying results. The largest randomized clinical trial performed by our collaborative group provided strong evidence that treatment for 2 years with a daily dose of 1.8 g of EPA and 1.2 g of DHA slowed the progression of renal disease in high-risk patients. These benefits persisted after 6.4 years of follow up. With safety, composition, and dosing convenience in mind, we can recommend two products that are available as pharmaceutical-grade fish-oil concentrates, Omacor (Pronova Biocare, Oslo, Norway) and Coromega (European Reference Botanical Laboratories, Carlsbad, CA).

Segmental glomerulosclerosis in IgA nephropathy after renal transplantation: relationship with proteinuria and therapeutic response to enalapril

INTRODUCTION

Although graft dysfunction has been increasingly reported in post-transplant IgA nephropathy (Tx-IgAN), intragraft morphological changes have been largely overlooked. We evaluated glomerular changes in Tx-IgAN to identify the histological features pertaining to significant proteinuria and therapeutic response to enalapril.

MATERIALS AND METHODS

Fifty-four renal allograft biopsies, diagnosed as Tx-IgAN at a median of 46 months after transplantation, were the subject of the study. In 10 patients, glomerular morphometry was performed. In 14 patients who have been treated with enalapril for more than 12 months, we correlated the therapeutic response to enalapril with allograft histology.

RESULTS

No uniform pattern was found in the glomeruli of Tx-IgAN. The glomerular mesangium was mostly indistinct. Interstitial fibrosis was negative or mild in 88.9%. By morphometry, the glomerular tuft areas and mesangial areas were significantly larger in Tx-IgAN than those of the normal native kidney (p < 0.05), but were not different from transplant cases without glomerulonephritis. Proteinuria of >/=1 g/24 h was correlated with glomerulosclerosis, interstitial fibrosis and interstitial inflammation at time of biopsy (p < 0.005). The presence of segmental sclerosis (SS) correlated well with the amount of 24-h proteinuria (p < 0.001). After treatment with enalapril, the amount of proteinuria reduced in 64.3%. Therapeutic response to enalapril tended to be less effective in patients having SS (28.6 versus 71.4%), but this finding did not reach a statistical significance.

CONCLUSIONS

Significant proteinuria was associated with advanced chronic injury, especially with the presence of SS in Tx-IgAN, but anti-proteinuric effect of enalapril was not affected by graft histology. It remains to be clarified whether glomerular mesangial expansion plays a role in graft dysfunction in a subset of Tx-IgAN showing prominent mesangial changes.