Management of IgA nephropathy: evidence-based recommendations

Non-immunosuppressive treatment for IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) is the most common primary glomerular disease, with approximately 20% to 40% of patients progressing to kidney failure within 25 years. Non-immunosuppressive treatment has become a mainstay in the management of IgAN by improving blood pressure (BP) management, decreasing proteinuria, and avoiding the risks of long-term immunosuppressive management. Due to the slowly progressive nature of the disease, clinical trials are often underpowered, and conflicting information about management with non-immunosuppressive treatment is common. This is an update of a Cochrane review, first published in 2011.

OBJECTIVES

To assess the benefits and harms of non-immunosuppressive treatment for treating IgAN in adults and children. We aimed to examine all non-immunosuppressive therapies (e.g. anticoagulants, antihypertensives, dietary restriction and supplementation, tonsillectomy, and herbal medicines) in the management of IgAN.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to December 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of non-immunosuppressive agents in adults and children with biopsy-proven IgAN were included.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed search results, extracted data and assessed study quality. Results were expressed as mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CI) using random-effects meta-analysis. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

This review includes 80 studies (4856 participants), of which 24 new studies (2018 participants) were included in this review update. The risk of bias within the included studies was mostly high or unclear for many of the assessed methodological domains, with poor reporting of important key clinical trial methods in most studies. Antihypertensive therapies were the most examined non-immunosuppressive therapy (37 studies, 1799 participants). Compared to placebo or no treatment, renin-angiotensin system (RAS) inhibition probably decreases proteinuria (3 studies, 199 participants: MD - 0.71 g/24 h, 95% CI -1.04 to -0.39; moderate certainty evidence) but may result in little or no difference to kidney failure or doubling of serum creatinine (SCr), or complete remission of proteinuria (low certainty evidence). Death, remission of haematuria, relapse of proteinuria or > 50% increase in SCr were not reported. Compared to symptomatic treatment, RAS inhibition (3 studies, 168 participants) probably decreases proteinuria (MD -1.16 g/24 h, 95% CI -1.52 to -0.81) and SCr (MD -9.37 µmol/L, 95% CI -71.95 to -6.80) and probably increases creatinine clearance (2 studies, 127 participants: MD 23.26 mL/min, 95% CI 10.40 to 36.12) (all moderate certainty evidence); however, the risk of kidney failure is uncertain (1 study, 34 participants: RR 0.20, 95% CI 0.01 to 3.88; very low certainty evidence). Death, remission of proteinuria or haematuria, or relapse of proteinuria were not reported. The risk of adverse events may be no different with RAS inhibition compared to either placebo or symptomatic treatment (low certainty evidence). In low certainty evidence, tonsillectomy in people with IgAN in addition to standard care may increase remission of proteinuria compared to standard care alone (2 studies, 143 participants: RR 1.90, 95% CI 1.45 to 2.47) and remission of microscopic haematuria (2 studies, 143 participants: RR 1.93, 95% CI 1.47 to 2.53) and may decrease relapse of proteinuria (1 study, 73 participants: RR 0.70, 95% CI 0.57 to 0.85) and relapse of haematuria (1 study, 72 participants: RR 0.70, 95% CI 0.51 to 0.98). Death, kidney failure and a > 50% increase in SCr were not reported. These trials have only been conducted in Japanese people with IgAN, and the findings' generalisability is unclear. Anticoagulant therapy, fish oil, and traditional Chinese medicines exhibited small benefits to kidney function in patients with IgAN when compared to placebo or no treatment. However, compared to standard care, the kidney function benefits are no longer evident. Antimalarial therapy compared to placebo in one study reported an increase in a > 50% reduction of proteinuria (53 participants: RR 3.13 g/24 h, 95% CI 1.17 to 8.36; low certainty evidence). Although, there was uncertainty regarding adverse events from this study due to very few events.

AUTHORS' CONCLUSIONS

Available RCTs focused on a diverse range of interventions. They were few, small, and of insufficient duration to determine potential long-term benefits on important kidney and cardiovascular outcomes and harms of treatment. Antihypertensive agents appear to be the most beneficial non-immunosuppressive intervention for IgAN. The antihypertensives examined were predominantly angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. The benefits of RAS inhibition appear to outweigh the harms in patients with IgAN. The certainty of the evidence of RCTs demonstrating a benefit of tonsillectomy to patients with Japanese patients with IgAN was low. In addition, these findings are inconsistent across observational studies in people with IgAN of other ethnicities; hence, tonsillectomy is not widely recommended, given the potential harm of therapy. The RCT evidence is insufficiently robust to demonstrate efficacy for the other non-immunosuppressive treatments evaluated here.

Efficacy and safety of artesunate for patients with IgA nephropathy: a study protocol for a multicenter, double-blind, randomized, placebo-controlled trial

BACKGROUND

IgA nephropathy is the most common glomerular disease and is a common cause of progression to end-stage renal disease in patients with kidney diseases. Proteinuria levels are critical for the prognosis of patients with IgA nephropathy, but many patients are still unable to effectively control their proteinuria levels after receiving RAAS blockers. Antimalarial drugs have shown good efficacy in the treatment of kidney disease in previous studies; however, there have been no strictly designed randomized controlled trials to confirm the clinical efficacy of artesunate for treating IgA nephropathy patients. Therefore, we designed this clinical trial to compare the effect of artesunate versus placebo in patients with IgA nephropathy.

METHODS

This study is a randomized, double-blind, three-group-parallel, placebo-controlled clinical trial. One hundred and twenty eligible IgA nephropathy patients at risk of progression will be randomly divided into the artesunate 100-mg group, artesunate 50-mg group, and placebo group. Changes in proteinuria and renal function will be measured 6 months after the intervention. The levels of Gd-IgA1 and anti-Gd-IgA1 in the patient's blood will also be tested to explore the possible immune mechanisms.

DISCUSSION

Clinical evidence supporting artesunate treatment of IgA nephropathy is currently lacking, and we expect that the results of this trial will provide high-quality clinical evidence for artesunate as a treatment option for IgA nephropathy in the future.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2000038104 . Registered on 10 September 2020.

Immunosuppressive agents for treating IgA nephropathy

BACKGROUND

IgA nephropathy is the most common glomerulonephritis world-wide. IgA nephropathy causes end-stage kidney disease (ESKD) in 15% to 20% of affected patients within 10 years and in 30% to 40% of patients within 20 years from the onset of disease. This is an update of a Cochrane review first published in 2003 and updated in 2015.

OBJECTIVES

To determine the benefits and harms of immunosuppression strategies for the treatment of IgA nephropathy.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 9 September 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs of treatment for IgA nephropathy in adults and children and that compared immunosuppressive agents with placebo, no treatment, or other immunosuppressive or non-immunosuppressive agents.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study risk of bias and extracted data. Estimates of treatment effect were summarised using random effects meta-analysis. Treatment effects were expressed as relative risk (RR) and 95% confidence intervals (95% CI) for dichotomous outcomes and mean difference (MD) and 95% CI for continuous outcomes. Risks of bias were assessed using the Cochrane tool. Evidence certainty was evaluated using GRADE methodology.

MAIN RESULTS

Fifty-eight studies involving 3933 randomised participants were included. Six studies involving children were eligible. Disease characteristics (kidney function and level of proteinuria) were heterogeneous across studies. Studies evaluating steroid therapy generally included patients with protein excretion of 1 g/day or more. Risk of bias within the included studies was generally high or unclear for many of the assessed methodological domains. In patients with IgA nephropathy and proteinuria > 1 g/day, steroid therapy given for generally two to four months with a tapering course probably prevents the progression to ESKD compared to placebo or standard care (8 studies; 741 participants: RR 0.39, 95% CI 0.23 to 0.65; moderate certainty evidence). Steroid therapy may induce complete remission (4 studies, 305 participants: RR 1.76, 95% CI 1.03 to 3.01; low certainty evidence), prevent doubling of serum creatinine (SCr) (7 studies, 404 participants: RR 0.43, 95% CI 0.29 to 0.65; low certainty evidence), and may lower urinary protein excretion (10 studies, 705 participants: MD -0.58 g/24 h, 95% CI -0.84 to -0.33;low certainty evidence). Steroid therapy had uncertain effects on glomerular filtration rate (GFR), death, infection and malignancy. The risk of adverse events with steroid therapy was uncertain due to heterogeneity in the type of steroid treatment used and the rarity of events. Cytotoxic agents (azathioprine (AZA) or cyclophosphamide (CPA) alone or with concomitant steroid therapy had uncertain effects on ESKD (7 studies, 463 participants: RR 0.63, 95% CI 0.33 to 1.20; low certainty evidence), complete remission (5 studies; 381 participants: RR 1.47, 95% CI 0.94 to 2.30; very low certainty evidence), GFR (any measure), and protein excretion. Doubling of serum creatinine was not reported. Mycophenolate mofetil (MMF) had uncertain effects on the progression to ESKD, complete remission, doubling of SCr, GFR, protein excretion, infection, and malignancy. Death was not reported. Calcineurin inhibitors compared with placebo or standard care had uncertain effects on complete remission, SCr, GFR, protein excretion, infection, and malignancy. ESKD and death were not reported. Mizoribine administered with renin-angiotensin system inhibitor treatment had uncertain effects on progression to ESKD, complete remission, GFR, protein excretion, infection, and malignancy. Death and SCr were not reported. Leflunomide followed by a tapering course with oral prednisone compared to prednisone had uncertain effects on the progression to ESKD, complete remission, doubling of SCr, GFR, protein excretion, and infection. Death and malignancy were not reported. Effects of other immunosuppressive regimens (including steroid plus non-immunosuppressive agents or mTOR inhibitors) were inconclusive primarily due to insufficient data from the individual studies in low or very low certainty evidence. The effects of treatments on death, malignancy, reduction in GFR at least of 25% and adverse events were very uncertain. Subgroup analyses to determine the impact of specific patient characteristics such as ethnicity or disease severity on treatment effectiveness were not possible.

AUTHORS' CONCLUSIONS

In moderate certainty evidence, corticosteroid therapy probably prevents decline in GFR or doubling of SCr in adults and children with IgA nephropathy and proteinuria. Evidence for treatment effects of immunosuppressive agents on death, infection, and malignancy is generally sparse or low-quality. Steroid therapy has uncertain adverse effects due to a paucity of studies. Available studies are few, small, have high risk of bias and generally do not systematically identify treatment-related harms. Subgroup analyses to identify specific patient characteristics that might predict better response to therapy were not possible due to a lack of studies. There is no evidence that other immunosuppressive agents including CPA, AZA, or MMF improve clinical outcomes in IgA nephropathy.

Effects of warfarin on biological processes other than haemostasis: A review

Warfarin is the world's most widely used anticoagulant drug. Its anticoagulant activity is based on the inhibition of the vitamin K-dependent (VKD) step in the complete synthesis of a number of blood coagulation factors that are required for normal blood coagulation. Warfarin also affects synthesis of VKD proteins not related to haemostasis including those involved in bone growth and vascular calcification. Antithrombotic activity of warfarin is considered responsible for some aspects of its anti-tumour activity of warfarin. Some aspects of activities against tumours seem not to be related to haemostasis and included effects of warfarin on non-haemostatic VKD proteins as well as those not related to VKD proteins. Inflammatory/immunomodulatory effects of warfarin indicate much broader potential of action of this drug both in physiological and pathological processes. This review provides an overview of the published data dealing with the effects of warfarin on biological processes other than haemostasis.

Efficacy and safety of calcineurin inhibitor treatment for IgA nephropathy: a meta-analysis

Background

IgA nephropathy is the most common progressive glomerular disease to end stage renal failure worldwide. Calcineurin inhibitors (CNIs) is a selective immunosuppressant widely used in organ transplantation. The efficacy and safety of calcineurin inhibitors for the treatment of IgA nephropathy remain uncertain.

Methods

We performed a systematic literature search using the PubMed, Embase, Science Citation Index, Ovid evidence-based medicine, Chinese Biomedical Literature (CBM) and Chinese science and technology periodicals (CNKI, VIP, and Wan Fang) for randomized, controlled trials of CNIs therapy of IgA nephropathy. Complete remission rate (CR) was defined as proteinuria less than 0.5 or 0.3 g/d. Partial remission rate (PR) was defined as proteinuria reduced to at least half of the baseline measurement and an absolute value of >0.5 or 0.3 g/d.

Results

Seven relevant trials were conducted with 374 patients enrolled. CNIs plus medium/low-dose steroid had a higher CR (RR = 2.51 [95% CI,1.25 to 5.04], P = 0.02) compared to therapy with steroid alone or placebo, but were not significant on PR (RR = 0.87 [95% CI,0.32 to 2.38]; P = 0.78). Also, significant alterations were observed in proteinuria (weighted mean difference, −0.46 g/d,[95% CI:-0.55 to −0.24], P < 0.01) with no differences were found in serum creatinine (SCr) (weighted mean difference, 0.57,95% CI:-4.05 to 5.19; P = 0.78) and estimated glomerular filtration rate (eGFR) (weighted mean difference, 1.13,95% CI:-4.05 to 6.32; P = 0.34) level between the two groups. CNI therapy was associated with an increased risk for adverse events (RR = 2.21,95% CI:1.52 to 3.21, P < 0.01), such as gastrointestinal and neurological symptoms or hirsutism.

Conclusions

CNIs might provide renal protection in patients with IgAN, but at an increased risk of adverse events. Reliably defining the efficacy and safety of CNIs in IgAN requires a high-quality trial with a large sample size.

Indications for tonsillectomy stratified by the level of evidence

Background: One of the most significant clinical trials, demonstrating the efficacy of tonsillectomy (TE) for recurrent throat infection in severely affected children, was published in 1984. This systematic review was undertaken to compile various indications for TE as suggested in the literature after 1984 and to stratify the papers according to the current concept of evidence-based medicine. Material and methods: A systematic Medline research was performed using the key word of "tonsillectomy" in combination with different filters such as "systematic reviews", "meta-analysis", "English", "German", and "from 1984/01/01 to 2015/05/31". Further research was performed in the Cochrane Database of Systematic Reviews, National Guideline Clearinghouse, Guidelines International Network and BMJ Clinical Evidence using the same key word. Finally, data from the "Trip Database" were researched for "tonsillectomy" and "indication" and "from: 1984 to: 2015" in combination with either "systematic review" or "meta-analysis" or "metaanalysis". Results: A total of 237 papers were retrieved but only 57 matched our inclusion criteria covering the following topics: peritonsillar abscess (3), guidelines (5), otitis media with effusion (5), psoriasis (3), PFAPA syndrome (6), evidence-based indications (5), renal diseases (7), sleep-related breathing disorders (11), and tonsillitis/pharyngitis (12), respectively. Conclusions: 1) The literature suggests, that TE is not indicated to treat otitis media with effusion. 2) It has been shown, that the PFAPA syndrome is self-limiting and responds well to steroid administration, at least in a considerable amount of children. The indication for TE therefore appears to be imbalanced but further research is required to clarify the value of surgery. 3) Abscesstonsillectomy as a routine is not justified and indicated only for cases not responding to other measures of treatment, evident complications, or with a significant history of tonsillitis. In particular, interval-tonsillectomy is not justified as a routine. 4) TE, with or without adenoidectomy, is efficacious to resolve sleep-related breathing disorders resulting from (adeno)tonsillar hypertrophy in children. However, the benefit is reduced by co-morbidities, such as obesity, and further research is required to identify prognostic factors for this subgroup of patients. Further research is indicated to clarify selection criteria not only for this subpopulation that may benefit from less invasive procedures such as tonsillotomy in the long-term. 5) Further trials are also indicated to evaluate the efficacy of TE on the clinical course in children with psoriasis guttata as well as on psoriasis vulgaris in adults, not responding to first-line therapy. 6) Conflicting results were reported concerning the role of TE in the concert to treat Ig-A nephropathy, mandating further clinical research. 7) Most importantly, randomized-controlled clinical trials with an adequate long-term follow-up are desirable to clarify the benefit of TE in patients with recurrent episodes of tonsillitis, with or without pharyngitis. Factors like age, spontaneous healing rate and postoperative quality of life have to be included when comparing TE with antibiotic therapy.

Immunosuppressive agents for treating IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) is the most common glomerulonephritis world-wide and a cause of end-stage kidney disease (ESKD) in 15% to 20% of patients within 10 years and in 30% to 40% of patients within 20 years from the onset of disease. This is an update of a review first published in 2003.

OBJECTIVES

To determine the benefits and harms of immunosuppression for the treatment of IgAN.

SEARCH METHODS

For this review update we searched the Specialised Register to 19 February 2015 through contact with the Trials Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs of treatment for IgAN in adults and children and that compared immunosuppressive agents with placebo, no treatment, or other immunosuppressive or non-immunosuppressive agents.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study risk of bias and extracted data for population characteristics, interventions and outcomes including mortality, infection, hospitalisation, ESKD requiring renal replacement therapy (dialysis or kidney transplantation), doubling of serum creatinine, remission of proteinuria, and end of treatment urinary protein excretion, serum creatinine, and glomerular filtration rate.Estimates of treatment effect and hazards were summarised using random effects meta-analysis. Treatment effects were expressed as relative risk (RR) and 95% confidence intervals (95% CI) for dichotomous outcomes and mean difference (MD) and 95% CI for continuous outcomes.

MAIN RESULTS

We included 32 studies comprising 1781 participants. Risk of bias within the included studies was generally high: 22 studies (69%) did not describe the method used to generate the randomisation sequence; 24 (75%) did not describe the methods used to conceal allocation; performance bias was not reported or high in 30 studies (94%); detection bias was unclear in 31 studies (97%); attrition bias was low in 14 studies (44%), unclear in eight (25%) and high in 12 studies (38%); reporting bias was low in 21 studies (67%) and high in 10 studies (31%); and four studies received industry funding or were terminated early (13%).Steroids lowered risks of progression to ESKD (6 studies, 341 participants: RR 0.44, 95% CI 0.25 to 0.80), and doubling of serum creatinine (6 studies, 341 participants: RR 0.45, 95% CI 0.29 to 0.69), lowered urinary protein excretion (6 studies, 263 participants: MD -0.49 g/24 h, 95% CI -0.72 to -0.25); and preserved glomerular filtration rate (4 studies, 138 participants: MD 17.87 mL/min/1.73 m(2), 95% CI 4.93 to 30.82) compared to no treatment or placebo. Combining steroids plus renin-angiotensin-system (RAS) inhibitors lowered the risk of progression to ESKD (2 studies, 160 participants: RR 0.16, 95% CI 0.04 to 0.59) and reduced urinary protein excretion (1 study, 38 participants: MD -0.20 g/24 h, 95% CI -0.26 to -0.14) compared with RAS inhibitors or steroids alone. Cytotoxic agents (azathioprine) plus steroid regimens plus dipyridamole increased remission of proteinuria (1 study, 78 participants: RR 1.24, 95% CI 1.01 to 1.52) compared to steroids alone but had uncertain effects on other outcomes.Mycophenolate mofetil plus RAS inhibitors lowered the risk of progression to ESKD (1 study, 40 participants: RR 0.22, 95% CI 0.05 to 0.90), improved remission of proteinuria (1 study, 40 participants: RR 2.67, 95% CI 1.32 to 5.39) and reduced urinary protein excretion (1 study, 40 participants: MD -1.26 g/24 h, 95% CI -1.46 to -1.06). Effects of other immunosuppressive regimens (including cyclosporin, leflunomide) were inconclusive primarily due to insufficient data from the individual studies. Subgroup analyses to determine the impact of patient characteristics on treatment effectiveness were not possible.

AUTHORS' CONCLUSIONS

The optimal management of IgAN remains uncertain although corticosteroid therapy may lower the risks of kidney disease progression and need for dialysis or transplantation. Evidence for treatment effects of immunosuppressive agents on mortality, infection, and cancer is generally sparse or low-quality and insufficient to guide clinical practice. Available RCTs are few, small, have high risk of bias - particularly selective reporting - and generally do not systematically identify treatment-related harms. Subgroup analyses to identify specific patient characteristics that might predict better response to therapy were not possible. Larger placebo-controlled studies of corticosteroid therapy or mycophenolate mofetil which are sufficiently powered to evaluate patient-relevant end points including adverse events and that examine the optimal duration of treatment are now required in populations with IgAN with a range of kidney function.

Fasting plasma glucose levels predict steroid-induced abnormal glucose metabolism in patients with non-diabetic chronic kidney disease: a prospective cohort study

BACKGROUND/AIMS

Glucocorticoids-induced abnormal glucose metabolism (AGM) is a common medical problem in patients with non-diabetic chronic kidney disease (CKD). However, little information is available regarding the prediction of steroid-induced AGM in this patient population.

METHODS

In this prospective cohort study, we consecutively enrolled 303 non-diabetic CKD patients with fasting plasma glucose (FPG) levels <5.6 mmol/l and normal oral glucose tolerance test (OGTT). OGTT was performed every 3 months during glucocorticoid treatment to identify new-onset AGM, and patients were followed for 12 months post steroid withdrawal.

RESULTS

During 593 person-years, there were 107 incident cases of steroid-induced AGM (18/100 person-year), including 55 (51.4%) diabetes and 52 (48.6%) pre-diabetes. In a multivariate model, each millimole increase per liter in FPG enhanced the risk of AGM by 4.6-fold (hazard ratio 4.58, 95% confidence interval, 2.67-7.83). After adjusting other risk factors, a progressively increased risk of AGM or DM was observed in patients with FPG levels ≥4.8 mmol/l, as compared with those whose levels were ≤4.3 mmol/l (p for trend <0.001). Furthermore, a greater increase in FPG level (≥0.3 mmol/l) during the first 3 months of glucocorticoid treatment was associated with an increased risk for future diabetes. For predicting steroid-induced diabetes, the area under the receiver-operating characteristic curve was 0.90 for the combination of FPG and changes in FPG levels at month 3.

CONCLUSION

Higher-normal FPG and a greater increase in FPG levels during glucocorticoid treatment may help to identify non-diabetic CKD patients at increased risk of steroid-induced AGM or diabetes.

Atypical triad of IgA nephropathy: reversible acute kidney injury, gross hematuria, and severe bilateral flank pain

Reversible acute kidney injury very rarely complicates the course of immunoglobulin A (IgA) nephropathy. We report an atypical case of reversible acute kidney injury, gross hematuria, and severe bilateral flank pain as the presenting triad of IgA nephropathy. Renal biopsy revealed mesangial IgA deposition without glomerular crescents. The patient's renal dysfunction, mediated by red cell tubular obstruction, interstitial nephritis, and tubular necrosis, resolved without intervention. We conclude that IgA nephropathy should be considered in the differential diagnosis for transient acute kidney injury with gross hematuria, and should be appropriately treated based on known prognostic factors.

Gamma linolenic acid exerts anti-inflammatory and anti-fibrotic effects in diabetic nephropathy

PURPOSE

This study was undertaken to investigate the effects of gamma linolenic acid (GLA) on inflammation and extracellular matrix (ECM) synthesis in mesangial and tubular epithelial cells under diabetic conditions.

MATERIALS AND METHODS

Sprague-Dawley rats were intraperitoneally injected with either a diluent [n=16, control (C)] or streptozotocin [n=16, diabetes (DM)], and eight rats each from the control and diabetic groups were treated with evening primrose oil by gavage for three months. Rat mesangial cells and NRK-52E cells were exposed to medium containing 5.6 mM glucose and 30 mM glucose (HG), with or without GLA (10 or 100 μM). Intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1), and fibronectin (FN) mRNA and protein expression levels were evaluated.

RESULTS

Twenty-four-hour urinary albumin excretion was significantly increased in DM compared to C rats, and GLA treatment significantly reduced albuminuria in DM rats. ICAM-1, MCP-1, FN mRNA and protein expression levels were significantly higher in DM than in C kidneys, and these increases were significantly abrogated by GLA treatment. In vitro, GLA significantly inhibited increases in MCP-1 mRNA expression and protein levels under high glucose conditions in HG-stimulated mesangial and tubular epithelial cells (p<0.05, respectively). ICAM-1 and FN expression showed a similar pattern to the expression of MCP-1.

CONCLUSION

GLA attenuates not only inflammation by inhibiting enhanced MCP-1 and ICAM-1 expression, but also ECM accumulation in diabetic nephropathy.

Immunotherapy in renal diseases

Immunotherapy has been used for the treatment of renal diseases for a long time, and there has been significant progress in such treatment. This review focuses on the use of immunotherapy for the treatment of glomerular diseases. The use of immunosuppression in the treatment of minimal change disease, membranous nephropathy, primary focal segmental glomerulosclerosis, lupus nephritis, immunoglobulin-A nephropathy, antineutrophil cytoplasmic antibody-associated disease, and anti-glomerular basement membrane disease is discussed.

Treatment of IgA nephropathy: an update

OBJECTIVE

To review current literature regarding treatment options for immunoglobulin A nephropathy (IgAN).

DATA SOURCES

A MEDLINE search was performed using the terms IgA nephropathy, Berger's disease, immunoglobulin A nephropathy, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, fish oil, omega-3 fatty acids, statins, hydroxymethylglutaryl-CoA reductase inhibitors, immunosuppressive therapy, corticosteroids, mycophenolate mofetil, cyclophosphamide, cyclosporine, azathioprine, leflunomide, antiplatelets, anticoagulants, vitamin E, infliximab, calcitriol, and intravenous immunoglobulins. A date limit was not set; however, focus was on publications from 1999 to June 2011 to review recent literature and therapeutic recommendations.

STUDY SELECTION AND DATA EXTRACTION

All articles in English, including studies conducted in humans, meta-analyses, review articles, guidelines, statements, and reference citations, were identified and evaluated.

DATA SYNTHESIS

IgAN is the most common primary glomerulonephritis worldwide, leading to end-stage renal disease in 20-30% of patients. Evidence guiding management of IgAN has been sparse and clinical trials have not conclusively demonstrated effective treatments, largely due to suboptimal methodologies. Treatment strategies have included management of blood pressure and lipids, improvement or stabilization of kidney function, and reduction of proteinuria. This review of IgAN provides an update regarding standard and nonconventional treatment options based on recently published literature.

CONCLUSIONS

Supportive therapies, including angiotensin blockade, should be considered as first-line therapy for patients with urine protein >0.5 g/day and/or blood pressure >140/90 mm Hg. Corticosteroids could be considered as add-on or monotherapy for patients with urine protein >1 g/day with preserved renal function. Conclusive data are lacking for general treatment recommendations for the use of other therapies for IgAN.

Steroids in the treatment of IgA nephropathy to the improvement of renal survival: a systematic review and meta-analysis

BACKGROUND

Studies have shown that steroids can improve kidney survival and decrease the risk of proteinuria in patients with Immunoglobulin A nephropathy, but the overall benefit of steroids in the treatment of Immunoglobulin A nephropathy remains controversial. The aim of this study was to evaluate the benefits and risks of steroids for renal survival in adults with Immunoglobulin A nephropathy.

METHODOLOGY AND PRINCIPAL FINDINGS

We searched the Cochrane Renal Group Specialized Register, Cochrane Controlled Trial Registry, MEDLINE and EMBASE databases. All eligible studies were measuring at least one of the following outcomes: end-stage renal failure, doubling of serum creatinine and urinary protein excretion. Fifteen relevant trials (n = 1542) that met our inclusion criteria were identified. In a pooled analysis, steroid therapy was associated with statistically significant reduction of the risk in end-stage renal failure (RR: 0.46, 95% CI: 0.27 to 0.79), doubling of serum creatinine (RR = 0.34, 95%CI = 0.15 to 0.77) and reduced urinary protein excretion (MD = -0.47 g/day, 95%CI = -0.64 to -0.31).

CONCLUSIONS/SIGNIFICANCE

We identified that steroid therapy was associated with a decrease of proteinuria and with a statistically significant reduction of the risk in end-stage renal failure. Moreover, subgroup analysis also suggested that long-term steroid therapy had a higher efficiency than standard and short term therapy.

Non-immunosuppressive treatment for IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) is the most common primary glomerular disease with approximately 30% to 40% of patients progressing to end-stage kidney disease (ESKD) within 20 years. The most common regimens include immunosuppressive agents, however the risks of long-term treatment often outweigh the potential benefits. Non-immunosuppressive options, including fish oils, anticoagulants, antihypertensive agents and tonsillectomy have also been examined but not reviewed systematically.

OBJECTIVES

To assess the benefits and harms of non-immunosuppressive treatments for treating IgAN in adults and children.

SEARCH STRATEGY

In July 2010 we searched the Cochrane Renal Group's specialised register, CENTRAL (in The Cochrane Library), MEDLINE (from 1966) and EMBASE (from 1980). We also searched reference lists of included studies, review articles and contacted local and international experts.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of non-immunosuppressive agents in adults and children with biopsy-proven IgAN were included.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed search results, extracted data and assessed study quality. Results were expressed as mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CI) using a random-effects model.

MAIN RESULTS

We included 56 studies (2838 participants). Antihypertensive agents were the most beneficial non-immunosuppressive intervention for IgAN. The antihypertensives examined were predominantly angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB) or combinations of both, versus other antihypertensives and other agents. The benefits of antihypertensive agents, particularly inhibitors of the renin angiotensin system, appear to potentially outweigh the harms in patients with IgAN. The benefits are largely manifest as a reduction in proteinuria, a surrogate outcome. There is no evidence that treatment with any of the antihypertensive agents evaluated affect major renal and/or cardiovascular endpoints or long-term mortality risk beyond the benefit that arises from controlling hypertension in patients with IgAN. The RCT evidence is insufficiently robust to demonstrate efficacy for any of the other non-immunosuppressive therapies evaluated here.

AUTHORS' CONCLUSIONS

IgAN remains a disease in search of adequately powered RCTs to reliably inform clinical practice. More and better evidence is needed to understand the magnitude of benefit and the possible risks of anti-hypertensive or more specifically of ACEi/ARB therapy alone or in combination and which specific types of patients with the IgAN might have the greatest potential for benefit. For other non-immunosuppressive therapies, where neither benefit nor significant harm has yet to be demonstrated, there remains some justification for further exploration of the potential benefits.

Antithrombotic drug therapy for IgA nephropathy: a meta analysis of randomized controlled trials

BACKGROUND

Antithrombotic agents, including antiplatelet agents, anticoagulants and thrombolysis agents, have been widely used in the management of immunoglobulin A (IgA) nephropathy in Chinese and Japanese populations. To systematically evaluate the effects of antithrombotic agents for IgA nephropathy.

METHODS

Data sources consisted of MEDLINE, EMBASE, the Cochrane Library, Chinese Biomedical Literature Database (CBM), Chinese Science and Technology Periodicals Databases (CNKI) and Japana Centra Revuo Medicina (http://www.jamas.gr.jp) up to April 5, 2011. The quality of the studies was evaluated from the intention to treat analysis and allocation concealment, as well as by the Jadad method. Meta-analyses were performed on the outcomes of proteinuria and renal function.

RESULTS

Six articles met the predetermined inclusion criteria. Antithrombotic agents showed statistically significant effects on proteinuria (p<0.0001) but not on the protection of renal function (p=0.07). The pooled risk ratio for proteinuria was 0.53, [95% confidence intervals (CI): 0.41-0.68; I(2)=0%] and for renal function it was 0.42 (95% CI 0.17-1.06; I(2)=72%). Subgroup analysis showed that dipyridamole was beneficial for proteinuria (p=0.0003) but had no significant effects on protecting renal function. Urokinase had statistically significant effects both on the reduction of proteinuria (p=0.0005) and protecting renal function (p<0.00001) when compared with the control group.

CONCLUSION

Antithrombotic agents had statistically significant effects on the reduction of proteinuria but not on the protection of renal function in patients with IgAN. Urokinase had statistically significant effects both on the reduction of proteinuria and on protecting renal function. Urokinase was shown to be a promising medication and should be investigated further.

Effects of eicosapentaenoic acid supplementation on immunoglobulin A nephropathy

Eicosapentaenoic acid (EPA), which is purified from fish oil, attenuates inflammatory responses by decreasing eicosanoid and cytokine production. EPA reportedly improves renal survival in patients with immunoglobulin (Ig)A nephropathy; however, this is unconfirmed. We studied the effects of EPA on IgA nephropathy patients. Eighteen biopsy-confirmed IgA nephropathy patients (aged 31 +/- 3 years) were enrolled. The prognoses based on glomerular findings were good (N = 5), relatively poor (N = 12), and poor (N = 1). EPA was administered at 1.8 g/day for 12 months. Five biopsy-confirmed IgA nephropathy patients were enrolled as control subjects. Administration of other drugs used to treat IgA nephropathy was not changed. The estimated creatinine clearance (eCCr), serum creatinine (Cr) concentration, urinary protein creatinine ratio (U/P), and other clinical parameters were checked. In the EPA group, the Cr went from 0.8 +/- 0.2 mg/dL to 0.7 +/- 0.2 mg/dL after 12 months of EPA treatment, and the U/P went from 550 +/- 580 mg/g Cr to 330 +/- 920 mg/g Cr. The values did not differ significantly; however, Cr and U/P tended to improve, with no adverse effects from the EPA. The eCCr improved significantly (99 +/- 7-110 +/- 8 mL/min, P = 0.001) in the EPA group, but not in the control group (126 +/- 12-120 +/- 13, P > 0.05). The effect of EPA in patients with IgA nephropathy is not pronounced, but these results suggest that EPA is a safe and worthwhile supplement to the drugs used to treat this disease.

The suffocating kidney: tubulointerstitial hypoxia in end-stage renal disease

Chronic kidney disease (CKD) is characterized by irreversible pathological processes that result in the development of end-stage renal disease (ESRD). Accumulating evidence has emphasized the important role of chronic hypoxia in the tubulointerstitium in the final common pathway that leads to development of ESRD. The causes of chronic hypoxia in the tubulointerstitium are multifactorial and include mechanisms such as hemodynamic changes and disturbed oxygen metabolism of resident kidney cells. Epidemiological studies have revealed an association between CKD and systemically hypoxic conditions, such as chronic obstructive pulmonary disease and sleep apnea syndrome. In addition to tubulointerstitial hypoxia, glomerular hypoxia can occur and is a crucial factor in the development of glomerular disorders. Chemical compounds, polarographic sensors, and radiographical methods can be used to detect hypoxia. Therapeutic approaches that target chronic hypoxia in the kidney should be effective against a broad range of kidney diseases. Amelioration of hypoxia is one mechanism of inhibiting the renin-angiotensin system, the current gold standard of CKD therapy. Future therapeutic approaches include protection of the vascular endothelium and appropriate activation of hypoxia-inducible factor, a key transcription factor involved in adaptive responses against hypoxia.

Omega-3 polyunsaturated fatty acids in the treatment of kidney disease

After more than 25 years of published investigation, including randomized controlled trials, the role of omega-3 polyunsaturated fatty acids in the treatment of kidney disease remains unclear. In vitro and in vivo experimental studies support the efficacy of omega-3 polyunsaturated fatty acids on inflammatory pathways involved with the progression of kidney disease. Clinical investigations have focused predominantly on immunoglobulin A (IgA) nephropathy. More recently, lupus nephritis, polycystic kidney disease, and other glomerular diseases have been investigated. Clinical trials have shown conflicting results for the efficacy of omega-3 polyunsaturated fatty acids in IgA nephropathy, which may relate to varying doses, proportions of eicosapentaenoic acid and docosahexaenoic acid, duration of therapy, and sample size of the study populations. Meta-analyses of clinical trials using omega-3 polyunsaturated fatty acids in IgA nephropathy have been limited by the quality of available studies. However, guidelines suggest that omega-3 polyunsaturated fatty acids should be considered in progressive IgA nephropathy. Omega-3 polyunsaturated fatty acids decrease blood pressure, a known accelerant of kidney disease progression. Well-designed, adequately powered, randomized, controlled clinical trials are required to further investigate the potential benefits of omega-3 polyunsaturated fatty acids on the progression of kidney disease and patient survival.

[Glomerulonephritis with IgA mesangial deposits]

IgA nephropathy is the primitive glomerulonephritis the most frequently encountered worldwide. In about one case out of three, it is responsible for the progression from progressive renal failure to end-stage renal failure. The pathophysiological mechanisms of this disease which is mediated by immune complexes remain unclear. The presentation, clinical progression and optical microscope aspect of the renal biopsy may widely vary, making any histological classification very difficult. Most therapeutic studies include the patients only on clinical criteria of severity. The only consensual management is that of patients with a nephropathy and mild glomerular lesions and a nephritic syndrome, or with an extracapillar glomerulonephritis and a rapidly progressive renal failure; corticoids are indicated in former cases while corticoids must be combined with immunosuppressive agents in the latter ones. Corticotherapy may be considered in patients with a proteinuria higher than 1g/day without renal failure. In any patient with primitive IgA nephropathy, the overall management used for chronic glomerulopathy must be initiated, including, in case of arterial hypertension or proteinuria, the renin-angiotensin system blockade.

Meta-analysis of Tripterygium wilfordii Hook F in the immunosuppressive treatment of IgA nephropathy

OBJECTIVE

Numerous Chinese patients with IgA nephropathy (IgAN) have benefited from Tripterygium wilfordii Hook F (TwHF) from two decades ago. However, to date there is no systematic evaluation of this remedy for IgAN.

METHODS

We conducted a meta-analysis of all eligible randomized clinical trials (RCTs) to assess the effect of TwHF on IgAN for the first time. In August 2009 a systematic search was performed among eight electronic databases. Review Manager (RevMan) version 5.0 was used.

RESULTS

(i) Four eligible RCTs with 188 participants were included; (ii) The validities of included RCTs were generally acceptable; (iii) TwHF brought about a favorable increase in complete remission (CR) (RR 1.53, 95%CI 1.09 to 2.16, I(2)=12%) and total remission (TR) (RR 1.27, 95%CI 1.08 to 1.48, I(2)=0%) compared with non-TwHF treatment; and this result was further confirmed by intention-to-treat analysis; (iv) Exploiting subgroup meta-analysis, TwHF led to significantly greater improvements of IgAN with non-nephrotic proteinuria with regard to the increase of CR (RR 1.80, 95%CI 1.21 to 2.68, I(2)=0%) and TR (RR 1.32, 95%CI 1.11 to 1.57, I(2)=0%), and decrease of urinary proteinuria excretion (UPE) (MD -467.41 mg/24h, 95%CI -633.99 to -300.82, I(2)=0%). Meanwhile, the renal function was well preserved (MD -2.66 µmol/L, 95%CI -9.26 to 3.94, I(2)=0%). Conclusion Although the results of this meta-analysis should be interpreted with caution and warrant further investigation, TwHF was certainly a valuable and promising immunosuppressive remedy for IgAN, which was in accordance with the accruing evidence from numerous large clinical and experimental studies.

Predictors of poor outcomes in steroid therapy for immunoglobulin A nephropathy

BACKGROUND

Steroid therapy appears to be beneficial in patients of immunoglobulin A nephropathy (IgAN), as it causes a reduction in the proteinuria and improves the renal survival.

METHODS

A retrospective review of the 5 year follow-up data of 60 patients with IgAN who were treated with steroids was conducted. Steroid non-responders were defined as patients in whom the primary end-point of a 30% decrease of the estimated glomerular filtration rate from baseline was reached. The patients were divided into two groups, namely, the steroid responder group (n = 47) and the steroid non-responder group (n = 13), and the clinicopathophysiological characteristics were compared between the two groups.

RESULTS

Significant decrease of the proteinuria was observed in the responder group over the 5 year follow-up period, whereas no significant change of the urinary protein excretion was observed in the non-responder group during the same period. In regard to the pathological findings, significantly higher ratios of glomerular obsolescence and glomerular tuft adhesion to the Bowman's capsule, and significantly higher severity of interstitial fibrosis at the time of diagnosis in the non-responder group than in the responder group were found. The rates of glomerular obsolescence and glomerular tuft adhesion to the Bowman's capsule, the severity of interstitial fibrosis, serum albumin and urinary protein excretion were identified as independent risk factors influencing the rate of renal function deterioration.

CONCLUSION

To develop effective therapeutic modalities, it is important to have a thorough understanding of the clinicopathophysiological characteristics of IgAN patients showing poor treatment response to steroids (non-responder group in this study).

Management of leukocytoclastic vasculitis

Leukocytoclastic vasculitis (LcV) is the most common form of vasculitis of the skin and usually results from deposition of immune complexes at the vessel wall. It presents in different forms and in association with different diseases. When IgA is the dominant immunoglobulin in immune complexes, systemic involvement is likely in both children and adults (Henoch-Schönlein purpura--HSP). LcV due to IgG- or IgM-containing immune complexes has less systemic involvement and a better prognosis than HSP. Other forms of LcV include cryoglobulinaemic, urticarial and ANCA-associated LcV as well as LcV associated with vasculopathy and coagulopathy in SCLE/SLE or in bacteraemia/sepsis. The aim of diagnostic guidelines is to determine the specific type and systemic involvement of LcV and to identify an underlying cause. Basic work-up should encompass history of drug intake and of preceding infections, biopsy with immunofluorescence, differential blood count, urine analysis and throat swabs. Therapy of immune complex LcV often does not require aggressive therapy due to a usually favourable course. It includes avoidance or treatment of eliciting agents and use of compression stockings to reduce purpura. There are no large prospective randomized controlled studies. Corticosteroids are indicated when there are signs of incipient skin necrosis. In chronic or relapsing LcV we suggest colchicine as a first-line and dapsone as a second-line therapy. Corticosteroids may reduce the incidence of severe renal insufficiency in children according to some studies, but there is no study showing such an effect in adults. Severe systemic vasculitis requires immunosuppressive strategies.

Therapeutic Approach of Patients with IgA Nephropathy

Immunoglobulin A nephropathy (IgAN) is the most commonly encountered primary glomerulonephritis and it usually follows an indolent clinical course. However, hypertensive patients with proteinuria and renal insufficiency at presentation and patients with severe histological involvement are at high risk to develop end stage renal failure. There is no consensus for the treatment of patients with IgA nephropathy. In general, patients with normal renal function, mild proteinuria (<I g/24 h) and mild histopathological involvement need only observation, whereas patients with heavy proteinuria, impaired renal function and moderate to severe histopathological involvement are candidates for specific treatment. Angiotensin converting enzyme (ACE) inhibitors are used in patients with arterial hypertension and/or proteinuria 1-2 g/24 h. Corticosteroids are indicated in patients with heavy proteinuria (>3 g/24 h) and in progressive disease despite treatment with ACE inhibitors. Fish oil might be an alternative to corticosteroids in cases with renal insufficiency and chronic histological lesions. Combinations of corticosteroids and cytotoxic drugs are saved for patients with IgA nephropathy and a rapidly progressive course.

ACEI/ARB therapy for IgA nephropathy: a meta analysis of randomised controlled trials

BACKGROUND

Published reports examining the efficacy of RAS blockers: angiotensin converting-enzyme inhibitor (ACEI) and angiotensin II receptor blocker (ARB) agents for preserving renal function in IgA nephropathy (IgAN) have yielded conflicting results. To evaluate systematically the effects of ACEI/ARB agents on IgAN, we conducted a meta analysis of published randomised controlled trials (RCTs).

METHODS

MEDLINE, EMBASE, the Cochrane Library and article reference lists were searched for RCTs that compared ACEI/ARB with placebo and any other antihypertensive agents or non-immunosuppressive agents for treating IgAN. The quality of the studies was evaluated with the method of intention to treat analysis and allocation concealment, as well as with the Jadad method. Meta analyses were performed on the outcomes of proteinuria and renal function in patients with IgAN.

RESULTS

Eleven RCTs involving 585 patients were included in the review. Seven trials used placebo/no treatment as controls. Four trials used other antihypertensive agents as controls. Overall, ACEI/ARB agents had statistically significant effects on protecting renal function(p < 0.00001) and reduction of proteinuria (p < 0.00001) when compared with control group. Tests for heterogeneity showed no difference in effect among the studies. Systolic and diastolic blood pressure, glomerular filtration rate (GFR), age, did not influence treatment response. ACEI/ARB agents were well tolerated.

CONCLUSIONS

The current cumulative evidence suggests that ACEI/ARB agents had statistically significant effects on protecting renal function and reduction of proteinuria in patients with IgAN when compared with control groups. ACEI/ ARB agents are a promising medication and should be investigated further.

Expression of fibrosis-associated molecules in IgA nephropathy treated with cyclosporine

Cyclosporine (CsA) treatment in immunoglobulin A nephropathy (IgAN) is controversial and has not been widely studied. The aim of this study was to investigate the effects of CsA on renal histology and the expression of interstitial fibrosis-associated molecules in childhood IgAN. The subjects were 18 children (age 4.2-13.9 years; male:female 13:5) who had been treated with CsA for 8 or 12 months and who had renal biopsies before and after treatment. Renal biopsies were assessed by routine histology and immunohistochemistry against osteopontin (OPN), transforming growth factor-beta (TGF-beta), CD68, and CD34. The degree of proteinuria and mesangial IgA deposits decreased or disappeared after treatment in all cases, and the percentage of patients with diffuse mesangial proliferation decreased from 44.4 to 22.2%. However, interstitial fibrosis developed or was aggravated in nine patients (50%) after treatment and was associated with an increased degree of interstitial inflammation in five patients. Tubular OPN expression (45.3 +/- 23.4 vs. 37.6 +/- 19.3%) and the degree of CD68-positive macrophage infiltration (136.1 +/- 88.2 vs. 132 +/- 86.0/mm(2)) were not increased after CsA treatment, but TGF-beta expression was significantly increased (6.4 +/- 4.2 vs. 13.3 +/- 9.9%; p = 0.025). Microvascular density was increased and peritubular capillaries were of small caliber in inflamed areas. We conclude that increased levels of TGF-beta and the development of interstitial fibrosis limit the long-term use of CsA in IgAN patients. Osteopontin and macrophages may be indirectly involved in renal fibrosis by prolonging interstitial inflammation rather than by directly increasing TGF-beta expression.

Long-term renal prognosis of IgA nephropathy with therapeutic trend shifts

OBJECTIVE

We compared the effect of treatments in the long-term renal survival of IgA nephropathy.

METHODS

One hundred and fourteen patients with biopsy-proven IgA nephropathy were retrospectively divided into 4 groups, reflecting shifts in treatment trends from 1985 to 2005: patients without treatment (no treatment group; n=36), patients treated only with anti-platelet drugs (anti-platelet group; n=12), those treated mainly with angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) (ACEI/ARB group; n =29), and prednisolone-treated patients (PSL group; n =37).

RESULTS

Baseline blood pressure, serum creatinine and renal histological findings were similar among the 4 groups; however, the urinary protein level was significantly severer in the PSL group. After a mean follow-up of 7.0+/-0.5 years, end-stage renal disease occurred in 11 patients (31%) in the no treatment group, 5 patients (42%) in the anti-platelet group and 3 patients (8%) in the PSL group, but in only 1 patient (3%) in the ACEI/ARB group. Kaplan-Meier renal survival after 20 years was significantly better in the ACEI/ARB group than in the anti-platelet group or in the no treatment group (p<0.05). The patients that reached complete remission (CR) by steroid therapy showed less baseline urinary protein and milder histological lesions than those who did not reach CR. The non-CR group showed increases in serum creatinine and eGFR reduction rate.

CONCLUSION

Treatment with renin-angiotensin system inhibitors showed the greatest improvement of 20-year renal survival in IgA nephropathy patients. Steroid therapy achieved complete remission in some early-stage cases.

Treatment of IgA nephropathy of adults presented by nephrotic syndrome

The aim of this retrospective study was to evaluate the results of the immunosuppressive regiment in managing of IgA nephropathy associated with primary nephrotic syndrome at the Nephrology Clinic, University of Sarajevo Clinics Centre in period of 1997-2007. We studied 19 patients (4 women and 15 men) with idiopathic nephrotic syndrome, where pathomorphologic changes of IgA nephropathy were proved by kidney biopsy. The levels of diuresis, proteinuria, albuminemia, lipidemia and kidney function, as measure of efficiency of used therapy, were monitored. The IgA nephropathy present with the nephrotic syndrome was shown in 15.8% (19) patients underwent renal biopsy due to primary nephrotic syndrome in the period of observation. The average age of patients with IgA nephropathy was 34.9+/-14.1 years. Eight patients from this group were treated with corticosteroid therapy (1-1.5 mg/kg of body weight for 4 weeks, followed by 0.5 mg/ kg of body weight until therapeutic response was achieved, and finally gradual exclusion of therapy after eight weeks in responsive patients), 6 patients with corticosteroids and bolus cyclophosphamide (10-15 mg/kg BW), and in 5/19 patients cyclosporine therapy was used (3 mg/kg BW). Complete remission of nephrotic syndrome was achieved in 42.1% of the patients. In conclusion, in adults patients with primary nephrotic syndrome associated with IgA nephropathy, used immunosuppressive therapy resulted in a high percentage of achieved remissions.

Immune modulating therapy for IgA nephropathy: rationale and evidence

Our current understanding of the initial pathogenetic steps in IgA nephropathy (IgAN) provides relatively limited rationale for immunosuppressive therapy. However, it is conceivable that immunosuppressive drugs might affect secondary inflammatory events triggered by glomerular immune deposits or even proteinuria per se. Some, but not all, randomized clinical trials on either corticosteroid monotherapy, mycophenolate mofetil monotherapy, or immunosuppressive combination therapy have provided evidence for a benefit on either surrogate parameters such as proteinuria or hard end points such as renal failure. The central problem of these studies is that most were designed in the 1980s or 1990s, when recommendations for supportive therapy were strikingly different from those of today. In the meantime an equal number of randomized clinical studies reporting a benefit of supportive therapy has been published only regarding patients with IgAN and, unfortunately, no head-to-head comparisons of these 2 approaches currently are available. Several ongoing clinical trials may help to resolve this dilemma. Until the data of such studies become available, a pragmatic approach is to first optimize supportive therapy and reserve immunosuppressive medication for those patients failing a supportive approach and remaining at risk for progressive loss of renal function.

Clinical assessment of low-dose steroid therapy for patients with IgA nephropathy: a prospective study in a single center

BACKGROUND/AIM

No accepted therapy has been established for progressive IgA nephropathy (IgAN). The purpose of the present study was to assess low-dose steroid therapy in the treatment of patients with IgAN.

METHODS

A prospective trial of low-dose steroid therapy was performed in patients with IgAN with mild histological activities. Twenty-four patients in the steroid group and 24 patients in the control group were included in this study. The initial dose of prednisolone was 0.4 mg/kgBW/day (20-30 mg/day), gradually tapered to 5-10 mg/day over 24 months. The patients with mild active inflammatory lesions were treated with prednisolone. The patients assigned to the control group were treated with dipyridamole or zilazep hydrochloride in a dose of 150 or 300 mg/day.

RESULTS

In all of the patients studied, serum creatinine levels did not significantly change over 24 months. However, daily proteinuria significantly reduced after 24 months of steroid therapy (0.97 +/- 0.75 vs. 0.31 +/- 0.51 g/day, P = 0.0012), even if did not change after 24 months of anti-platelet drugs (0.89 +/- 0.49 vs. 0.68 +/- 0.69 g/day, P = 0.2289), respectively. In addition, the grade of hematuria significantly reduced after 24 months of steroid therapy (35.6 +/- 36.3 RBC/HPF vs. 13.7 +/- 28.4 RBC/HPF, P = 0.0249) and 24 months of anti-platelet drugs (30.1 +/- 37.1 RBC/HPF vs. 12.4 +/- 20.3 RBC/HPF, P = 0.0465), respectively. Systolic and diastolic blood pressures did not significantly change during treatment with steroid or anti-platelet drugs. Vascular changes (0.63 +/- 0.73) in the steroid group were lower than those (1.08 +/- 0.88) in the control group (P = 0.008).

CONCLUSION

Our data suggested that low-dose steroid therapy for IgAN patients with mild inflammatory lesions could reduce the amount of urinary protein excretion and prevent deterioration of renal function, provided the histological findings in the renal biopsies showed mild vascular lesions.

Meta-analysis of antiplatelet therapy for IgA nephropathy

BACKGROUND

Antiplatelet agents have been widely used in the management of immunoglobulin A (IgA) nephropathy in the Japanese population. To systematically evaluate the effects of antiplatelet agents for IgA nephropathy, we conducted a meta-analysis of the published studies.

METHODS

Data sources consisted of MEDLINE, EMBASE, the Cochrane Library, Ityu-shi (Japanese medical database), and bibliographies from the studies. The quality of the studies was evaluated from the intention to treat analysis and allocation concealment, as well as by the Jadad method. Meta-analyses were performed on the outcomes of proteinuria and renal function.

RESULTS

Seven articles met the predetermined inclusion criteria. The use of antiplatelet agents showed statistically significant effects on proteinuria and renal function. The pooled risk ratio for proteinuria was 0.61 (95% confidence intervals (CI) 0.39-0.94) and for renal function it was 0.74 (95% CI 0.63-0.87).

CONCLUSIONS

Antiplatelet agents resulted in reduced proteinuria and protected renal function in patients with IgA nephropathy. However, studies of high-quality design were rare, and most studies assessed surrogate outcomes. More properly designed studies are needed to reach a definitive assessment of this matter.

A scoring system to predict renal outcome in IgA nephropathy: from a nationwide prospective study

BACKGROUND

Immunoglobulin A (IgA) nephropathy is the most common form of glomerulonephritis in the world, and a substantial number of patients develop end-stage renal disease (ESRD). Although there are several prognostic indicators, it remains difficult to predict the renal outcome in individual patients.

METHODS

A prospective cohort study was conducted in 97 clinical units in Japan from 1995 to 2002. We analysed the data from 2269 patients using proportional hazards models in order to determine the predictors of ESRD in IgA nephropathy and to develop a scoring system to estimate ESRD risk.

RESULTS

During the follow-up (median, 77 months), 207 patients developed ESRD. Systolic hypertension, proteinuria, hypoproteinaemia, azotaemia and a high histological grade at initial renal biopsy were independently associated with the risk of ESRD. Mild haematuria predisposed patients to ESRD more than severe haematuria. A scoring system was developed to estimate the 7-year ESRD risk from eight clinical and pathological variables. Actually, this prognostic score accurately classified patients by risk: patients with estimates of 0.0-0.9, 1.0-4.9, 5.0-19.9, 20.0-49.9, and 50.0-100.0% had a 0.2, 2.4, 12.2, 40.2 and 80.8% of ESRD incidence over 7 years, respectively. The corresponding area under the receiver operating characteristic curve was 0.939 [95% confidence interval (CI), 0.921-0.958]. This score was verified in repetitions of the derivation-validation technique.

CONCLUSIONS

Although the quality of some data collected by the mail survey is limited and the influence of therapy could not be considered, this scoring system will serve as a useful prognostic tool for IgA nephropathy in clinical practice.

Randomised controlled trial of leflunomide in the treatment of immunoglobulin A nephropathy

AIM

To investigate the effect of leflunomide for treatment of immunoglobulin A (IgA) nephropathy.

METHODS

Sixty IgA nephropathy patients were divided into two groups at random. Patients in the test group received leflunomide and patients in the control group received fosinopril. Clinical data were obtained at weeks 2, 4, 6, 8, 12, 16, 20, 24 and 28.

RESULTS

The complete remission rate was 62.1% and the total effectiveness rate was 72.4%. In the leflunomide group, proteinuria significantly decreased from 1.66 +/- 0.42 g to 0.60 +/- 0.68 g (P < 0.05). The efficacy rate of leflunomide compared with fosinopril in treating IgA nephropathy was not statistically different (P > 0.05). Side-effects were mild in both treatment groups.

CONCLUSION

These preliminary results are encouraging, but further randomised studies are required before leflunomide can be recommended for the treatment of IgA nephropathy.

Value of urinary excretion of microalbumin in predicting glomerular lesions in children with isolated microscopic hematuria

Urinary microalbumin excretion was assessed in 76 children with asymptomatic microscopic hematuria in whom the presence of proteinuria, hypertension, reduced renal function, hypercalciuria, urinary tract infection or structural abnormality of the urinary tract had been excluded. All children underwent a percutaneous kidney biopsy to determine whether microalbumin excretion can be used as a marker to predict the source of hematuria. Microalbumin excretion was considered normal if the urinary ratio of microalbumin to creatinine (MA/Cr ug/mg) was < or =30. Twenty-two (29%) had microalbuminuria (MA/Cr 96+/-30 microg/mg) and 54 (71%) had normal albumin excretion (MA/Cr 13+/-2 microg/mg). Of those with normoalbuminuria, 38 (70%) had normal renal tissue, 15 (28%) thin glomerular basement membrane (TGBM) disease and 1 (2%) IgA nephropathy. In contrast, 20 (91%) of those with microalbuminuria had IgA nephropathy and 2 (9%) had TGBM disease. The mean urinary MA/Cr ratio for all IgA children was 89+/-32 microg/mg higher compared with a value for the children with TGBM disease (14 +/-3 microg/mg, P <0.001) or children whose renal biopsy appeared normal (11+/-2 microg/mg, P <0.001). Statistical analysis revealed no significant differences between the mean MA/Cr ug/mg ratio for children with TGBM disease and those with normal glomerular findings. Fourteen of the 20 children with IgA nephropathy who also had microalbuminuria were treated with an angiotensin-converting enzyme (ACE) inhibitor. Over a mean follow-up of 51 months, none developed overt proteinuia; hematuria resolved and microalbuminuria returned to normal in eight (57%) during therapy with the ACE-inhibitor. In contrast, hematuria persisted and prtoteinuria developed in the other untreated children. None of the children with TGBM disease developed overt proteinuria after a mean of 51 months. Hematuria was persistent in children with TGBM disease, but often resolved in those whose biopsies were completely normal. These data suggest that determination of urinary microalbumin excretion is warranted in the routine examination of children with isolated microscopic hematuria. Routine screening for microalbuminuria may help to identify a subgroup of patients with IgA nephropathy who are at high risk for progressive kidney disease and need more intensive therapy and closer follow-up.

Pediatric IgA nephropathies: clinical aspects and therapeutic approaches

The pediatric IgA nephropathies are IgA nephrothapy (Berger's Disease) and Henoch-Schönlein purpura nephritis. Both conditions are reviewed in detail with respect to epidemiology, clinical features, outcome, prognostic markers, and therapeutic approaches. For both conditions variable disease severity and outcome along with the lack of conclusive evidence for efficacy of treatment based on randomized clinical trials makes it difficult to make strong recommendations regarding therapy.

Effect of 12-month therapy with omega-3 polyunsaturated acids on glomerular filtration response to dopamine in IgA nephropathy

BACKGROUND

Omega-3 polyunsaturated acids therapy is efficient in primary IgA nephropathy. It is unknown whether doses of omega-3 smaller than those given previously are still effective. The aim of the study was to examine the effect of omega-3 therapy on renal vascular function in relation to proteinuria and urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG).

METHODS

20 IgA patients aged 36.5 +/- 10.77 with creatinine clearance (Cr(cl)) 105.71 +/- 27.3 ml/min and proteinuria 3.31 +/- 2.01 g/24 h were given orally 810 mg EPA and 540 mg DHA daily for 12 months. Before and at the end of the study, 24-hour proteinuria, serum homocysteine, and Cr(cl) were measured. At the same time, renal vascular function was estimated as dopamine-induced glomerular filtration response (DIR). DIR was measured as: two 120-min lasting Cr(cl) (before and during 2 microg/kg b.w./min i.v. dopamine).

RESULTS

The results obtained during follow-up were as follows (baseline vs. after therapy): DIR 14.9 +/- 16.4 vs. 30.3 +/- 14.3% (p < 0.01); urine protein 2.31 +/- 2.01 vs. 1.31 +/- 1.37 g/24 h (p < 0.01); (Cr(cl)) 105.71 +/- 27.3 vs. 103.9 +/- 20.9 ml/min (n.s.); NAG 8.3 +/- 1.8 vs. 6.0 +/- 1.2 U/g(creat) (p < 0.01), and homocysteine 16.2 +/- 3.15 vs. 13.8 +/- 2.6 micromol/l (p < 0.05). The only correlation found was linear correlation between basal DIR and DIR change (r = -0.570; p < 0.010) and basal NAG (r = -0.460; p < 0.50).

CONCLUSIONS

Omega-3 supplementation is associated with the improvement of both renal vascular function and tubule function.

Review Article. Immunosuppressive treatments for immunoglobulin A nephropathy: A meta-analysis of randomized controlled trials

Immunoglobulin A (IgA) nephropathy is a worldwide disease that causes end-stage kidney disease (ESRD) in up to 15-20% of affected patients within 10 years from the apparent onset of disease and in up to 30-40% of individuals within 20 years from diagnosis. No specific treatment has been established and there is wide variation in current practice. This systematic review evaluates the use of immunosuppressive agents to treat patients with IgA nephropathy. The Cochrane Renal Group Specialized Register, Cochrane Controlled Trial Registry, MEDLINE, EMBASE and article reference lists were searched for randomized or quasi randomized trials. Two independent reviewers assessed studies for inclusion criteria (biopsy proven IgA nephropathy, randomized trial, use of immunosuppressive agents) and extracted data regarding the effects of immunosuppressive agents on ESRD, doubling of serum creatinine, glomerular filtration rate, urinary protein excretion and side-effects. Data were analysed with a random effects model. The published trials were few (13 trials, 623 patients) and were generally of poor quality. Compared with placebo, steroids were associated with a lower risk of progression to ESRD (six trials, 341 patients, RR 0.44, 95% CI 0.25-0.80) and lower end-of-trial proteinuria (six trials, 263 patients, weighted mean difference (WMD) -0.49 g/day, 95% CI -0.25 to -0.72). Treatment with alkylating agents significantly reduced end of treatment proteinuria (two trials, 122 patients, WMD -0.94, 95% CI -0.46 to -1.43). Although the optimal management of patients with IgA nephropathy remains uncertain because of limitations with the existing published data, immunosuppressive agents are a promising strategy and should be investigated further.

The role of the vitamin K-dependent growth factor Gas6 in glomerular pathophysiology

PURPOSE OF REVIEW

The product of growth arrest-specific gene 6 (gas6) is a unique vitamin K-dependent growth-potentiating factor for vascular smooth muscle cells, and anticoagulant warfarin inhibits the activation process of the protein. It has been reported that Gas6 is also a mitogen for mesangial cells, and that warfarin inhibits mesangial cell proliferation by blocking the activation of Gas6. A recent series of studies has revealed the in-vivo roles of Gas6 and its receptor Axl in the progression of various kidney diseases. This review summarizes these studies and discusses the possible interventions targeting the Gas6/Axl pathway to prevent the progression of kidney diseases.

RECENT FINDINGS

The expression of Gas6 and Axl is upregulated in an acute model of glomerulonephritis in rats, and the interference of the Gas6/Axl pathway by warfarin or the extracellular domain of Axl inhibits the progression of diseases. Induction of chronic glomerulonephritis in Gas6 mice results in less mortality, proteinuria, and histological changes of kidneys compared to wild-type mice. Administration of recombinant Gas6 reverses these phenotypes. Expression of Gas6 is also upregulated in streptozotocin-induced diabetic nephropathy, and administration of low-dose warfarin decreases albuminuria and hypertrophy of glomeruli. Possible roles of Gas6 are also reported in renal allograft dysfunction of rats and humans.

SUMMARY

The importance of the Gas6/Axl pathway has been implicated in many types of kidney disease. Further investigations on the role of the Gas6/Axl pathway in human kidney diseases and the development of specific antagonists targeting the pathway are warranted.

Treatment of IgA nephropathy with ACE inhibitors: a randomized and controlled trial

Some retrospective studies have suggested a beneficial influence of angiotensin-converting enzyme (ACE) inhibitors on the progression of IgA nephropathy (IgAN), but prospective and controlled studies demonstrating this effect are lacking. Forty-four patients with biopsy-proven IgAN, proteinuria > or = 0.5 g/d, and serum creatinine (SCr) < or = 1.5 mg/dl were randomly assigned either to receive enalapril (n = 23) or to a control group (n = 21) in whom BP was controlled with antihypertensives other than ACE inhibitors. Primary outcome was renal survival estimated by a 50% increase in baseline SCr. Secondary outcomes were the presence of a SCr > 1.5 mg/dl at the last visit and the evolution of proteinuria. Baseline clinical findings were similar at baseline between enalapril-treated and control group, and there were no differences in BP control during follow-up. Mean follow-up was 78 +/- 37 mo in the enalapril group and 74 +/- 36 mo in the control group. Three patients (13%) in the enalapril group and 12 (57%) in the control group reached the primary end point (P < 0.05). Kaplan-Meier renal survival was significantly better in enalapril group than in control group: 100% versus 70% after 4 yr and 92% versus 55% after 7 yr (P < 0.05). Three patients in the enalapril group (13%) and 11 (52%) in the control group showed SCr > 1.5 mg/dl at the last visit (P < 0.05). Proteinuria significantly decreased in the enalapril group, whereas it tended to increase in the control group (P < 0.001 between groups). In conclusion, ACE inhibitors significantly improve renal survival in proteinuric IgAN with normal or moderately reduced renal function.

An "evidence-based" survey of therapeutic options for IgA nephropathy: assessment and criticism

BACKGROUND

Immunoglobulin A (IgA) nephropathy is a worldwide disease that causes end-stage renal failure in 15% to 20% of patients within 10 years of the apparent onset of disease and in 30% to 40% of individuals within 20 years. Severity of renal lesions, serum creatinine level, and severe proteinuria are adverse prognostic indicators. No specific treatment has been established, but several approaches have been experimented.

METHODS

We reviewed the literature and evaluated the quality of published randomized trials using standard methods and the quality of their reporting according to the revised version of the Consolidated Standards for Reporting Trials Statement. Meta-analyses of randomized trials on the efficacy of steroid treatment, cytotoxic agents, and fish oils on the outcome of renal function and daily proteinuria in patients with IgA nephropathy were performed.

RESULTS

Only 10 randomized trials were available and included in the review. Their quality was very poor, and a limited amount of data was reported. Cytotoxic agents seem beneficial on both renal function (relative risk, 0.38; 95% confidence interval [CI], 0.22 to 0.66) and daily proteinuria (weighted mean difference [WMD], -1.16; 95% CI, -2.18 to -0.14) in patients with moderate to severe renal damage, steroids act mainly on proteinuria (WMD, -0.50; 95% CI, -0.78 to -0.21), and fish oils do not imply a particular benefit. This statement is based on the very limited and poor available published evidence.

CONCLUSION

Only a few randomized trials, of low quality and inadequately reported, are available relating to treatment of IgA nephropathy. More properly designed and reported trials are necessary to reach a definitive assessment of this matter.