[IgA nephropathy: histological analysis and clinicomorfological correlation in patients from Minas Gerais State]

Role of Direct Immunofluorescence Microscopy in Spectrum of Diffuse Proliferative Glomerulonephritis: A Single-Center Study

Introduction

Immunofluorescence (IF) microscopy is an essential tool for the analysis of glomerular diseases. In this study, we studied the significance of the IF technique together with light microscopy (LM) and clinical details in the diagnosis of different types of diffuse proliferative glomerulonephritis (GN). We intended to evaluate the spectrum of Diffuse Proliferative Glomerulonephritis (DPGN) in our institute.

Materials and Methods

We evaluated a total of 95 kidney biopsies received in the past 10 years. All biopsies were scrutinized by LM and IF techniques. Clinical details were documented in a predesigned form.

Results

The predominant clinical presentation in this study was nephrotic syndrome (49.4%) followed by systemic lupus erythromatosus with suspected renal involvement (24.2%). On microscopy, lupus nephritis (LN) was the most common DPGN in the study (35.7%), followed by immunoglobulin (Ig) A nephropathy (25.2%) and postinfectious GN (PIGN) (16.8%). The majority of patients were in the <30 years age group (72.6%), with the average age of patients being 24.4 years. The dominant deposit on IF in LN was C3 and IgG (100%). A high deposit of IgA (100%) in IgA nephropathy and of IgG and C3 (100%) in membranoproliferative GN was seen. PIGN showed dominant positive staining of IgG (92.8%).

Conclusion

The predominant clinical presentation was of nephrotic syndrome and on LM LN was the most commonly diagnosed DPGN in this study. Direct IF is vital for classifying DPGN, followed by electron microscopy, which is an essential tool. This article describes a rational evaluation of kidney biopsies with DPGN pattern on LM in a way that guides toward the logical assessment to reach the diagnosis. Using the IF technique and comparing it with LM and clinical details, we evaluated the spectrum DPGN in our center.

Renal Outcomes in Brazilian Patients with Immunoglobulin A Nephropathy and Cellular Crescentic Lesions

BACKGROUND AND AIM

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulopathy. The Oxford classification was recently updated to include crescents as markers of poor prognosis. The aim of this study was to evaluate the impact of cellular crescents on the prognosis of patients with IgAN in Brazil.

METHODS

This was a single-centre retrospective analysis of medical records and renal biopsies in patients with IgAN. The renal biopsy findings were classified according to the revised Oxford classification: mesangial hypercellularity, endocapillary hypercellularity (E), segmental glomerulosclerosis (S), tubular atrophy or interstitial fibrosis (T), and crescent formation (C). We evaluated a composite outcome (progression to end-stage renal disease or creatinine doubling). We performed analyses between the patients with crescents in the renal biopsy specimen (C1/C2 group) and those without such crescents (C0 group).

RESULTS

We evaluated 111 patients, of whom 72 (65.0%) were women, 80 (72.0%) self-identified as White, 73 (65.6%) were hypertensive, and 95 (85.6%) had haematuria. The distribution of patients according to cellular crescentic lesions was: C0, 80 (72%); C1, 27 (24.4%); C2, 4 (3.6%). The composite outcome was observed in 33 (29.72%) of the 111 patients. In comparison with the C0 group, the C1/C2 group had higher proportions of patients with hypertension (p = 0.04), haematuria (p = 0.03), worse serum creatinine (p = 0.0007), and worse estimated glomerular filtration rate (p = 0.0007). The C1/C2 group also had higher proportions of patients in whom the biopsy specimen was classified as E1 (p = 0.009), S1 (p = 0.001), or T1/T2 (p = 0.03), In addition, the mean follow-up period was shorter in the C1/C2 group (p < 0.0001). Furthermore, the composite outcome was observed in a greater proportion of patients and in a shorter length of time in the C1/C2 group than in the C0 group (p = 0.002 and p = 0.0014, respectively). In a Cox regression analysis, the independent risk factors for the composite outcome had Oxford classifications of S1, T1/T2, and C1/C2.

CONCLUSION

Oxford classification findings of S1, T1/T2, or C1/C2 were independent risk factors for the composite outcome, corroborating previous studies.

IgA Nephropathy in Salvador, Brazil. Clinical and laboratory presentation at diagnosis

Introduction:

IgA nephropathy (IgAN) is the most prevalent primary glomerulopathy in the world, but great variation is reported in different countries. In Brazil, the reported prevalence is high in the Southeastern States and low in Salvador, Bahia State, Brazil.

Objectives:

This study investigated the clinical and histological patterns of patients with IgAN in Salvador, Brazil.

Methods:

This is a descriptive study that included all patients with a diagnosis of IgAN performed in native kidney biopsies collected from referral nephrology services of public hospitals in Salvador between 2010 and 2015. Results: Thirty-two cases of IgAN were identified, corresponding to 6% of primary glomerulopathies. There was a slight male predominance (56%) and the median age was 30 [22-40] years. Hematuria was present in 79%, non-nephrotic proteinuria was present in 61%, and hypertension was present in 69% of patients. Segmental sclerosis (S1 lesions) was present in 81% of cases, and chronic tubulo-interstitial lesions (T1 and T2 lesions) were present in 44% of cases. Patients with M1 and T2 MEST-C scores exhibited higher serum urea and creatinine than other patients.

Conclusion:

The prevalence of IgAN was lower in Salvador than other regions of Brazil. Chronic histological lesions and laboratory markers of severe disease were frequent. M1 and T2 MEST-C scores were correlated with markers of renal dysfunction.

IgA nephropathy in Brazil: apropos of 600 cases

IgA nephropathy (IgAN) is th e commonest primary glomerular disease worldwide. Studies on its prevalence in Brazil are however scarce. Databases and clinical records from 10 reference centres were retrospectively reviewed. Clinical and laboratory features at the moment of the biopsy were retrieved (age, gender, presence of hematuria, serum creatinine [mg/dL], proteinuria [g/24 h]). Renal biopsy findings were classified according to Haas single grade classification scheme and the Oxford Classification of IgAN. 600 cases of IgAN were identified, of which 568 (94.7 %) were on native kidneys. Male to female ratio was 1.24:1. Patients averaged 32.76 ± 15.12 years old (range 4–89, median 32). Proteinuria and hematuria were observed, respectively in 56.63 and 72.29 % of patients. The association of both these findings occurred in 37.95 % of the cases. Serum creatinine averaged 1.65 ± 0.67 mg/dL (median 1.5 mg/dL) at diagnosis. Segmental sclerosis and mesangial hypercellularity were the main glomerular findings (47.6 and 46.2 %) The commonest combination by Oxford Classification of IgAN, was M0 E0 S0 T0 (22.4 %). Chronic tubulo-interstitial lesions with an extension wider than 25 % of the renal cortex could be identified in 32.2 % of the cases. Tubular atrophy and interstitial fibrosis were more strongly associated with higher 24-h proteinuria and serum creatinine levels. Segmental sclerosis (S1) showed a stronger tendency of association with the presence of tubulo-interstitial lesions (T1 and T2) than other glomerular variables. To the best of our knowledge this is the largest series of IgAN in Brazil. It depicts the main biopsy findings and their possible clinical correlates. Our set of data is comparable to previous reports.