We have summarized the latest findings on markers for progression of immunoglobulin A (IgA) nephropathy (IgAN), the most common primary glomerulonephritis with a high prevalence among end-stage renal disease (ESRD) patients. The clinical predictors of renal outcome in IgAN nephropathy, such as proteinuria, hypertension, and decreased estimated glomerular filtration rate (eGFR) at the time of the diagnosis, are well known. The Oxford classification of IgAN identified four types of histological lesions (known as the MEST score) associated with the development of ESRD and/or a 50 % reduction in eGFR. In addition, the role of genetic risk factors associated with IgAN is being elucidated by genome-wide association studies, with multiple risk alleles described. Recently, biomarkers in serum (galactose-deficient IgA1, IgA/IgG autoantibodies against galactose-deficient IgA1, and soluble CD 89-IgA complexes) and urine (soluble transferrin receptor, interleukin-6/epidermal growth factor ratio, fractalkine, laminin G-like 3 peptide, κ light chains, and mannan-binding lectin) have been identified. Some of these biomarkers may represent candidates for the development of noninvasive diagnostic tests, that would be useful for detection of subclinical disease activity, monitoring disease progression, assessment of treatment, and at the same time circumventing the complications associated with renal biopsies. These advances, along with future disease-specific therapy, will be helpful in improving the treatment effectiveness, prognosis, and the quality of life in connection with IgAN.

We describe data on 10,472 renal biopsies gathered by the Czech Registry of Renal Biopsies over a period of 18 years. We assessed the main demographic, clinical and histological data of individuals who underwent renal biopsies of native kidneys in 31 centers in the Czech Republic (population 10.3 million) during the period 1994–2011. We evaluated 10,472 renal biopsies: males 57.8 %, children (≤15 years) 13.6 %, elderly (>60 years) 19.1 %. The most frequent biopsy-proven diseases were primary (55.7 %) and secondary (29.1 %) glomerulonephritides (GN). Tubulointerstitial nephritis (TIN) was observed in 3.4 % and vascular diseases in 4.1 %. The samples were non-diagnostic in 4.2 %. Among primary GN the most frequent diagnoses were IgA nephropathy (IgAN) (37.4 %), membranous GN (MGN) (13 %) and focal segmental glomerulosclerosis (FSGS) (12.6 %). Among secondary GN, systemic lupus erythematosus (SLE) represented 23.2 %, hereditary diseases 19.8 % and necrotizing vasculitis (NV) 19.4 %. Among adults, mild renal insufficiency [serum creatinine (SCr) 111–200 μmol/l] was present in 24.7 %, advanced renal insufficiency (SCr 201–400 μmol/l) in 15.3, and 12.3 % of patients had SCr > 400 μmol/l. The most common diseases in patients with nephrotic proteinuria were minimal change disease (MCD) (39.7 %) among children, IgAN (26.2 %) in adults aged 16–60 years and amyloidosis (42.7 %) among the elderly. The mean annual incidence (per million population) was: primary GN 30.9, secondary GN 18.1, IgAN 11.6, MGN 4.0, SLE 4.0, FSGS 3.9, MCD 3.4, NV 3.2, diabetic nephropathy 2.3, thin basement membrane glomerulopathy 2.0, mesangioproliferative GN 1.9, and TIN 1.9. Ultrasound needle guidance was used in 66.8 %. The frequency of serious complications (symptomatic hematoma, gross hematuria, blood transfusion) was approximately 3.2 %. This report provides representative population-based data on native biopsy-proven renal diseases in the Czech Republic. Over the 18 years of nationwide biopsy survey, we noted an increase of the mean age of renal biopsy cases, an increasing proportion of elderly, and a cardinal change in biopsy technique towards ultrasonography needle guidance.

IgA nephropathy (IgAN), the most common primary glomerulonephritis worldwide, has serious outcomes with end-stage renal disease developing in 30–50% of patients. The diagnosis requires renal biopsy. Due to its inherent risks, non-invasive approaches are needed. We evaluated 91 Czech patients with biopsy-proven IgAN who were assessed at time of diagnosis for estimated glomerular filtration rate (eGFR), proteinuria, microscopic hematuria, and hypertension, and then followed prospectively. Serum samples collected at diagnosis were analyzed for galactose-deficient IgA1 (Gd-IgA1) using new native-IgA1 and established neuraminidase-treated-IgA1 tests, Gd-IgA1-specific IgG autoantibodies, discriminant analysis and logistic regression model assessed correlations with renal function and Oxford classification (MEST score). Serum levels of native (P <0.005) and neuraminidase-treated (P <0.005) Gd-IgA1 were associated with the rate of eGFR decline. A higher relative degree of galactose deficiency in native serum IgA1 predicted a faster eGFR decline and poor renal survival (P <0.005). However, Gd-IgA1 has not differentiated patients with low vs. high baseline eGFR. Furthermore, patients with high baseline eGFR that was maintained during follow-up were characterized by low serum levels of Gd-IgA1-specific IgG autoantibodies (P = 0.003). Including levels of native and neuraminidase-treated Gd-IgA1 and Gd-IgA1-specific autoantibodies at diagnosis may aid in the prognostication of disease progression in Czech patients with IgAN. Future tests will assess utility of these biomarkers in larger patients cohorts from geographically distinct areas.

Background: Nephritis is a common manifestation of IgA vasculitis and is morphologically indistinguishable from IgA nephropathy. While MEST-C scores are predictive of kidney outcomes in IgA nephropathy, their value in IgA vasculitis nephritis has not been investigated in large multiethnic cohorts. Methods: Biopsies from 262 children and 99 adults with IgA vasculitis nephritis ( N =361) from 23 centers in North America, Europe, and Asia were independently scored by three pathologists. MEST-C scores were assessed for correlation with eGFR/proteinuria at biopsy. Because most patients ( N =309, 86%) received immunosuppression, risk factors for outcomes were evaluated in this group using latent class mixed models to identify classes of eGFR trajectories over a median follow-up of 2.7 years (interquartile range, 1.2–5.1). Clinical and histologic parameters associated with each class were determined using logistic regression. Results: M, E, T, and C scores were correlated with either eGFR or proteinuria at biopsy. Two classes were identified by latent class mixed model, one with initial improvement in eGFR followed by a late decline (class 1, N =91) and another with stable eGFR (class 2, N =218). Class 1 was associated with a higher risk of an established kidney outcome (time to ≥30% decline in eGFR or kidney failure; hazard ratio, 5.84; 95% confidence interval, 2.37 to 14.4). Among MEST-C scores, only E1 was associated with class 1 by multivariable analysis. Other factors associated with class 1 were age 18 years and younger, male sex, lower eGFR at biopsy, and extrarenal noncutaneous disease. Fibrous crescents without active changes were associated with class 2. Conclusions: Kidney outcome in patients with biopsied IgA vasculitis nephritis treated with immunosuppression was determined by clinical risk factors and endocapillary hypercellularity (E1) and fibrous crescents, which are features that are not part of the International Study of Diseases of Children classification.

IgA nephropathy is the most common primary glomerulonephritis with potentially serious outcome leading to end stage renal disease in 30 to 50% of patients within 20 to 30 years. Renal biopsy, which might be associated with risks of complications (bleeding and others), still remains the only reliable diagnostic tool for IgA nephropathy. Therefore, the search for non-invasive diagnostic and prognostic markers for detection of subclinical types of IgA nephropathy, evaluation of disease activity, and assessment of treatment effectiveness, is of utmost importance. In this review, we summarize treatment options for patients with IgA nephropathy including the drugs currently under evaluation in randomized control trials. An early initiation of immunosupressive regimens in patients with IgA nephropathy at risk of progression should result in the slowing down of the progression of renal function to end stage renal disease.

Background. The aim of our study was to retrospectively analyse the clinical data and the histological findings of 343 patients (pts) followed up with IgA nephropathy (IgAN) in our department of nephrology. We have assessed the main demographic, clinical and histological data, and the medical treatment of IgAN pts. Methods. Multivariate analysis was used to evaluate the effect of different variables on ≥ 50% increase of plasma creatinine level from baseline during a median follow-up of 4 years. Results. In our group of IgAN pts, the male gender (68%) predominated over female gender (32%). At the time of renal biopsy, the median age of IgAN pts was 32.3 (18–90) years, the median level of serum creatinine was 119 μmol/L and the median level of proteinuria was 1.8 g/day. Most of the pts were found to have arterial hypertension (56.7%). The majority of the pts with arterial hypertension were treated with inhibitors of angiotensin-converting enzyme (80.4%) and the remaining pts (42.6%) were treated with angiotensin II receptor blockers. Fifty per cent of the pts (170 pts) were treated of corticosteroids, 21% of the pts (71 pts) used a combined immunosuppressive treatment of corticosteroids and cyclophosphamide, 8% of the pts (27 pts) took azathioprine, 1.5% of the pts (5 pts) took cyclosporine and 1.5% of the pts (5 pts) were given mycophenolate mofetil. Hypertension at presentation, fibrointimal proliferation of arterial vessels, interstitial fibrosis and interstitial inflammation were shown to be associated with ≥50% increase of plasma creatinine level from baseline in univariate analysis (P < 0.05 for hypertension and fibrointimal proliferation; P < 0.01 for interstitial fibrosis and inflammation). Using stepwise logistic regression presenting proteinuria >2 g/day [odds ratio (OR) = 2.24, P < 0.01], tubular atrophy (OR = 4.97, P < 0.01) and damage of tubular epithelium (OR = 1.78, P < 0.05) were found as risk factors for ≥50% increase of plasma creatinine level from baseline. Conclusion. Our retrospective analysis found valuable information not only about the clinical, laboratory and histological findings in IgAN pts but also information about the risk factors influencing the progression of renal insufficiency.