IgA glomerulonephritis: beyond angiotensin-converting enzyme inhibitors

Pathological sub-analysis of a multicenter randomized controlled trial of tonsillectomy combined with steroid pulse therapy versus steroid pulse monotherapy in patients with immunoglobulin A nephropathy

Background

The IgA nephropathy (IgAN) Study Group in Japan conducted a multicenter, randomized, controlled trial of tonsillectomy with steroid pulse therapy (TSP) versus steroid pulse monotherapy in patients with IgAN (UMIN Clinical Trial Registry Number; C000000384). The effects of therapies in relation to pathological severity were analyzed in this study.

Methods

The patients with IgAN, urinary protein 1.0–3.5 g/day, serum creatinine of 1.5 mg/dl or less were randomly assigned to receiving TSP (Group A) or steroid pulses alone (Group B). The primary endpoint was the disappearance of proteinuria and/or hematuria. Twenty-six biopsies in Group A and 33 in Group B were available. The histological grades (HG) according to the percentage of glomeruli with crescent or sclerosis and the Oxford classification were analyzed.

Results

The patients in Group A had a 4.32- to 12.1-fold greater benefit of disappearance of proteinuria and 3.61- to 8.17-fold greater benefit of clinical remission (disappearance of proteinuria and hematuria) than those in Group B in patients with HG2–3, acute lesions (cellular or fibrocellular crescent) affecting more than 5 % of glomeruli, chronic lesions (fibrous crescents or sclerosis) affecting more than 20 % and S1. In contrast, odds ratios for disappearance of proteinuria or clinical remission in Group A to Group B were not significant in patients with HG 1, acute lesion in 5 % or less of glomeruli, chronic lesion in 20 % or less and S0. The disappearance of hematuria showed no relation to pathological severity.

Conclusion

TSP might be better employed according to the pathological severity.

Electronic supplementary material

The online version of this article (doi:10.1007/s10157-015-1159-2) contains supplementary material, which is available to authorized users.

A multicenter randomized controlled trial of tonsillectomy combined with steroid pulse therapy in patients with immunoglobulin A nephropathy

Background

The study aim was, for the first time, to conduct a multicenter randomized controlled trial to evaluate the effect of tonsillectomy in patients with IgA nephropathy (IgAN).

Methods

Patients with biopsy-proven IgAN, proteinuria and low serum creatinine were randomly allocated to receive tonsillectomy combined with steroid pulses (Group A; n = 33) or steroid pulses alone (Group B; n = 39). The primary end points were urinary protein excretion and the disappearance of proteinuria and/or hematuria.

Results

During 12 months from baseline, the percentage decrease in urinary protein excretion was significantly larger in Group A than that in Group B (P < 0.05). However, the frequency of the disappearance of proteinuria, hematuria, or both (clinical remission) at 12 months was not statistically different between the groups. Logistic regression analyses revealed the assigned treatment was a significant, independent factor contributing to the disappearance of proteinuria (odds ratio 2.98, 95% CI 1.01–8.83, P = 0.049), but did not identify an independent factor in achieving the disappearance of hematuria or clinical remission.

Conclusions

The results indicate tonsillectomy combined with steroid pulse therapy has no beneficial effect over steroid pulses alone to attenuate hematuria and to increase the incidence of clinical remission. Although the antiproteinuric effect was significantly greater in combined therapy, the difference was marginal, and its impact on the renal functional outcome remains to be clarified.

The role of memory B cell in tonsil and peripheral blood in the clinical progression of IgA nephropathy

BACKGROUND

B cells in tonsil, which may produce the nephritogenic IgA, have been incriminated in the pathogenesis of IgAN. The aim of the present study was to assess the role of memory B cell in clinical progression of IgAN. Methods we investigated 28 IgAN patients and 27 age-matched patients with chronic tonsillitis without IgAN, who were treated by tonsillectomy, meanwhile, the peripheral blood (PB) of 10 healthy individuals were also as control groups. In tonsil and PB, the frequency of memory B cells were tested by Flow cytometric (FCM).

RESULTS

In this study, higher percentage of memory B cells were observed in tonsil and PB of IgAN patients. After tonsillectomy, the percentage of memory B cells in IgAN patients were significantly (P<0.05) lower than before tonsillectomy. Meanwhile, in tonsil and PB, the percentage of memory B cells variated with the variation of urinary finding of IgAN patients.

CONCLUSIONS

The percentage of memory B cell in tonsil and PB could predict disease progression of IgAN to a certain extend; it's variation in pre- and post- tonsillectomy can provide theoretical basis to cure IgAN patients indirectly.

Comparison of inhibitors of renin-angiotensin-aldosterone system (RAS) and combination therapy of steroids plus RAS inhibitors for patients with advanced immunoglobulin A nephropathy and impaired renal function

BACKGROUND

The adaptation of steroid therapy and the effect of renin-angiotensin-aldosterone system inhibitors (RASIs) for advanced immunoglobulin A nephropathy (IgAN) patients with impaired renal function are still controversial.

METHODS

We divided 63 IgAN patients with an estimated glomerular filtration rate (eGFR) of <60 ml/min/1.73 m(2) and proteinuria ≥ 0.5 g/day into two groups: the RASI group (RASI, n = 33), treated with RASIs alone; and the combination group (COMBI, n = 30), treated with corticosteroids and RASIs. We analyzed the clinical and histological background, renal survival rate, and the risk factors for progression.

RESULTS

Renal function (mean eGFR: COMBI 46.4 vs. RASI 47.0 ml/min/1.73 m(2)), the amount of proteinuria (median: COMBI 1.39 vs. RASI 1.17 g/g creatinine) and histological backgrounds were not significantly different between the groups, but urinary red blood cells (U-RBCs) were significantly higher in the COMBI group than in the RASI group (median: COMBI 30.0 vs. RASI 10.0 counts/high-power field, P = 0.0171). The serial change in proteinuria did not differ until 5 years after treatment, but U-RBCs were significantly decreased in both groups (P < 0.0001), and eGFR was significantly decreased in the RASI group (P < 0.001) but not in the COMBI group. The results for each year after treatment did not differ significantly between both groups. The renal survival rate was not significantly different between the groups. There was no independent risk factor for progression by Cox regression analysis.

CONCLUSION

Combination therapy with steroids and RASIs was not superior to monotherapy with RASIs for advanced IgAN with impaired renal function.

Long-term beneficial effects of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker therapy for patients with advanced immunoglobulin A nephropathy and impaired renal function

BACKGROUND

There are few reports analyzing the effects of angiotensin-converting enzyme inhibitors (ACEIs) and/or angiotensin receptor blockers (ARBs) on the long-term renal survival of advanced immunoglobulin A nephropathy (IgAN) patients.

PATIENTS AND METHODS

In this retrospective cohort analysis, we divided 66 IgAN patients with an estimated glomerular filtration rate (eGFR) <60 ml/min into three groups: ACEI group (n = 20, treated with ACEIs), ARB group (n = 23, treated with ARBs), and control group (n = 23, treated with antiplatelet agents), and analyzed the clinical and histological background, renal survival rate until the primary endpoint of 50% decrease of eGFR from baseline, and the secondary endpoint of progression to end-stage renal disease, and the risk factors for progression.

RESULTS

The clinical and histological background without serum IgA and C3 were not significantly different among the three groups. The renal survival rate until the primary and secondary endpoints was significantly higher in the ACEI and ARB groups than in the control group. The independent risk factors for progression were higher mean blood pressure (hazard ratio [HR] 1.76, P = 0.04), higher histological grade (HR 2.54, P = 0.0184) at baseline, and without ACEIs or ARBs (HR 7.09, P = 0.001), but decreased proteinuria and blood pressure. The risk factors with resistance to ACEIs or ARBs were higher blood pressure and lower eGFR at baseline. There was no difference regarding the survival rate and the risk for progression between ACEI s and ARBs.

CONCLUSION

ACEIs or ARBs were effective for long-term renal survival of advanced IgAN, although proteinuria and blood pressure did not decrease.

Omega-3 and renal function in older adults

Chronic kidney disease (CKD) is a major public health problem and can result in end-stage renal disease with need for dialysis or transplantation. In Europe up to 12% of the adult population had some renal impairment, while in the United States the end stage of CKD has increased dramatically from 209.000 in 1991 to 472.000 in 2004. Diabetes and hypertension are major causes of kidney pathology. Infection, particularly ascending infection, is more common with increasing age, as both immune function declines and associated pathology predisposing to infection, such as obstructive uropathy, becomes more common. Most pathological changes in the kidney appear to be initiated by oxidative stress, followed by an inflammatory reaction. Oxidative stress results from an imbalance between free radicals and their detoxification by endogenous and exogenous scavengers, including polyunsaturated fatty acids (PUFA). Recent studies showed that PUFA supplementation slowed the rate of loss of renal function in patients with IgA nephropathy. Then, studies of omega-3 supplementation in dialysis patients describe salutary effects on triglyceride levels and dialysis access patency. We examined the relationship between total plasma PUFA levels and change in creatinine clearance over a three-year follow-up in the older persons enrolled in the InCHIANTI study, a population-based epidemiology study conducted in Tuscany, Italy. This study showed that older adults with low total plasma PUFA levels have a greater decline in creatinine clearance over three years of follow-up. These findings suggest that a higher dietary intake of PUFA may be protective against progression to chronic kidney disease.

Genetic variation in the transforming growth factor-beta1 gene is associated with susceptibility to IgA nephropathy

Background. There is growing evidence of genetic risk for susceptibility to IgA nephropathy. Among several candidate genes related to immunological regulation in renal tissue, TGFB1 is known to be a contributor to proliferation and the development of fibrosis.

Methods. We analysed several SNPs in a region of this gene using 212 DNA samples from biopsy-proven IgA nephropathy patients, 146 men and 66 women and 477 healthy age-matched controls (321 men and 156 women) from the same population in Sweden.

Results. Frequencies of four out of five selected SNPs (rs6957, rs2241715, rs1800471, rs1982073 and rs1800469) were found to significantly differ between male patients and male controls in a co-dominant model (corrected P ≤ 0.05) and of two SNPs (rs1982073 and rs1800469) in the allelic model (P ≤ 0.05 in 100 000 permutation test). Haplotype analysis for five selected SNPs revealed a significant association of TGGCG with protective effect (P = 0.0012, empirical P = 0.006, 100 000 permutations) and of CTGTA with susceptibility effect (P = 0.0018, empirical P = 0.008, 100 000 permutations). In our study, no association with TGFB1 variations was found when comparing female patients and female controls. No association was found for TGFB1 markers with disease progression for selected individuals from the patient's group. In addition, meta-analysis performed for SNP rs1982073 for combined patients and controls from our study together with published data from two independent studies showed a significant association.

Conclusions. Our experimental data together with the meta-analysis suggest TGFB1 as an important candidate gene for further biological studies of IgA nephropathy and as a possible target for therapy. Our data also indicate a possibility of a gender effect in the genetic background of IgA nephropathy.

Combination therapy of prednisone and ACE inhibitor versus ACE-inhibitor therapy alone in patients with IgA nephropathy: a randomized controlled trial

BACKGROUND

Recent studies have shown that both steroids and angiotensin-converting enzyme (ACE) inhibitors improve kidney survival and decrease proteinuria in patients with immunoglobulin A nephropathy. In this study, we aim to investigate whether the addition of steroids to ACE-inhibitor therapy produces a more potent antiproteinuric effect and better protection of kidney function than an ACE inhibitor alone.

STUDY DESIGN

Randomized controlled trial.

SETTING & PARTICIPANTS

Patients with biopsy-proven immunoglobulin A nephropathy with proteinuria of 1 to 5 g/d of protein.

INTERVENTION

63 patients were randomly assigned to either cilazapril alone (ACE-inhibitor group; n = 30) or steroid plus cilazapril (combination group; n = 33).

OUTCOMES & MEASUREMENTS

The primary end point was kidney survival, defined as a 50% increase in baseline serum creatinine level.

RESULTS

After follow-up for up to 48 months, 7 patients in the ACE-inhibitor group (24.1%) reached the primary end point compared with 1 patient (3%) in the combination group. Kaplan-Meier kidney survival was significantly better in the combination group than the ACE-inhibitor group after 24 and 36 months (96.6% versus 75.7%, 96.6% versus 66.2%; P = 0.001). Urine protein excretion significantly decreased in patients in the combination group compared with the ACE-inhibitor group (time-average proteinuria, 1.04 +/- 0.54 versus 1.57 +/- 0.86 g/d of protein; P = 0.01). Multivariate analysis showed that combination treatment (hazard ratio, 0.1; 95% confidence interval, 0.014 to 0.946) and time-average proteinuria (hazard ratio, 14.3; 95% confidence interval, 2.86 to 71.92) were independent predictors of kidney survival.

LIMITATIONS

Small sample size, a single center, and slight imbalances at baseline.

CONCLUSIONS

Our results suggest that the addition of steroid to ACE-inhibitor therapy provided additional benefit compared with an ACE inhibitor alone. However, this was a pilot study with a small number of participants achieving the end points, and thus further validation is necessary.

Tonsillar crypt epithelium of palmoplantar pustulosis secretes interleukin-6 to support B-cell development via p63/p73 transcription factors

Palmoplantar pustulosis (PPP) is an autoimmune disease characterized by psoriasis-like erythematous lesions on palms and/or soles due to an abnormal humoral immune response. Tonsillectomy is effectively employed for the treatment of PPP; however, how tonsils are involved in the aetiology of PPP remains unclear. Here we analysed surgically resected palatine tonsils from 36 cases of PPP as well as usual recurrent tonsillitis (RT) as a control. Histological examination revealed that a unique lesion, with lymphoid follicles surrounded by reticular crypt epithelial cells, was more frequently observed in tonsils of patients with PPP than in those with RT (p < 0.0001; PPP vs RT). Interestingly, crypt epithelial cells in primary cultures derived from PPP tonsils showed marked production of interleukin-6 (IL-6). Moreover, these epithelial cells from PPP tonsils expressed p53-related transcription factors in their nuclei that were found to contribute to the up-regulation of IL-6 gene expression. These findings suggest that, at least in part, the specialized lymphoepithelial symbiosis of PPP tonsils, under the control of p53-related factors, may be relevant to the generation of the impaired micro-environment underlying the aberrant production of autoantibodies.

Histologically advanced IgA nephropathy treated successfully with prednisolone and cyclophosphamide

BACKGROUND

No definitive therapeutic consensus has been established for progressive immunoglobulin A nephropathy (IgAN).

METHODS

We retrospectively investigated 35 patients with histologically advanced IgAN. The patients were divided into two groups: 27 received prednisolone and cyclophosphamide (PSL+CPA group) and 8 received supportive treatment (control group). The initial doses of PSL and CPA were 30 mg/day and 50 mg/day, respectively. PSL was tapered to 2.5 mg/day over 2 years and CPA was discontinued at 6 months.

RESULTS

In the control group, mean follow-up duration was 22.9 months, renal progression rate was -20.9 x 10(-3) dl/mg per month, and all patients developed endstage renal disease within 5 years. In the PSL+CPA group, mean follow-up duration was 64.3 months, renal progression rate was -1.5 x 10(-3) dl/mg per month, and renal survival at 5 years was 89.8%. Renal prognosis was markedly improved in the PSL+CPA group compared with the control group. The patients in the PSL+CPA group were divided into two subgroups according to baseline serum creatinine (<2 mg/dl or > or =2 mg/dl); renal survival in the two subgroups was similar (84.4% versus 100% at 5 years). Adverse effects of PSL+CPA were minimal and mild.

CONCLUSIONS

It is possible that PSL+CPA therapy safely improved the renal prognosis of patients with severe IgAN who would otherwise have required dialysis therapy within 5 years. However, a prospective, multicenter clinical trial is required to prove the effects and safety of this treatment.

Histologically advanced IgA nephropathy treated successfully with prednisolone and cyclophosphamide

BACKGROUND

No definitive therapeutic consensus has been established for progressive immunoglobulin A nephropathy (IgAN).

METHODS

We retrospectively investigated 35 patients with histologically advanced IgAN. The patients were divided into two groups: 27 received prednisolone and cyclophosphamide (PSL+CPA group) and 8 received supportive treatment (control group). The initial doses of PSL and CPA were 30 mg/day and 50 mg/day, respectively. PSL was tapered to 2.5 mg/day over 2 years and CPA was discontinued at 6 months.

RESULTS

In the control group, mean follow-up duration was 22.9 months, renal progression rate was -20.9 x 10(-3) dl/mg per month, and all patients developed endstage renal disease within 5 years. In the PSL+CPA group, mean follow-up duration was 64.3 months, renal progression rate was -1.5 x 10(-3) dl/mg per month, and renal survival at 5 years was 89.8%. Renal prognosis was markedly improved in the PSL+CPA group compared with the control group. The patients in the PSL+CPA group were divided into two subgroups according to baseline serum creatinine (<2 mg/dl or > or =2 mg/dl); renal survival in the two subgroups was similar (84.4% versus 100% at 5 years). Adverse effects of PSL+CPA were minimal and mild.

CONCLUSIONS

It is possible that PSL+CPA therapy safely improved the renal prognosis of patients with severe IgAN who would otherwise have required dialysis therapy within 5 years. However, a prospective, multicenter clinical trial is required to prove the effects and safety of this treatment.