Pediatric C3 glomerulopathy: a 12-year single-center experience.

BACKGROUND: Complement component 3 glomerulopathy (C3G) is a disease with limited data in children. We aimed to compare childhood C3G cases with adults. We also studied subgroups of pediatric C3G and predictors of poor outcome. METHODS: This is a 12-year retrospective, single-center cohort, observational study. All cases of C3G were defined based on the 2013 consensus guidelines. RESULTS: C3G was diagnosed in 162 patients (119 adults, 43 pediatric) predominantly affecting males. With varied light microscopic patterns, pediatric C3G cases were categorized as follows: 23 C3 glomerulonephritis (C3GN) and 11 dense deposit disease (DDD) on electron microscopy. The pediatric DDD patients were relatively younger with more severe disease at presentation (more crescents in biopsy) but with lesser chronicity in biopsy compared with pediatric C3GN patients; however, both had a similar outcome. On comparing pediatric and adult C3G cases, adults had lower median eGFR and a higher degree of chronicity in the biopsy. The prognosis of C3G was better in pediatric patients. Predictors of kidney failure in pediatric C3G were low eGFR (HR = 0.82, p = 0.05) and severe interstitial fibrosis/tubular atrophy (HR = 1.05, p = 0.02). CONCLUSIONS: Electron microscopy-based subgroups of pediatric C3G differ in clinical presentation and course of the disease but have similar prognosis and long-term outcomes. Pediatric C3G differs from adult C3G with respect to presentation, laboratory results, biopsy features, treatment, and outcome, and as such, it should be considered as a separate entity rather than a smaller version of adult C3G.

Clinicopathological characteristics and predictors of poor outcome in anti-glomerular basement membrane disease - a fifteen year single center experience.

INTRODUCTION: Anti-glomerular basement membrane (anti-GBM) disease is a small vessel vasculitis affecting the renal and lung capillary beds. We aim to study the clinicopathological characteristics and predictors of poor outcome of this disease in our population. MATERIALS AND METHODS: This is a 15 year retrospective, single center observational study of Indian cohort. Patients with biopsy proven anti-GBM disease were studied. RESULTS: Anti-GBM disease was found in 0.5% of the total cases. The mean age at presentation was 46.7 years. Compared to renal limited disease those with pulmonary-renal syndrome had a higher frequency of hypertension, oliguria, percentage of crescents, interstitial inflammation and glomerulosclerosis. Double positive (anti-GBM and ANCA antibodies) patients showed more of glomerulosclerosis, tubular atrophy/interstitial fibrosis (IFTA) as well as periglomerular granulomas on biopsy. Patient survival at one year was 40.4% and death censored renal survival was 9.7%. Factors affecting the dialysis dependency at presentation were oligoanuria (p = .04), creatinine levels >5.7 mg/dl (p = .003), and high mean anti-GBM titers (p = .008). Atypical cases accounted for 8.3% of these patients. Oligoanuria (HR = 5.0, p = .05), high serum creatinine (HR = 1.55, p = .05), severe glomerulosclerosis (HR = 1.09, p = .03), and IFTA (HR = 2, p = .04) were associated with poor renal outcome. Advanced age (HR = 1.92, p = .03), high serum creatinine (HR = 1.9, p = .04) and high anti-GBM titers (HR = 1.01, p = .03) were associated with poor patient survival. CONCLUSIONS: Anti-GBM is a rare disease with poor prognosis and varied presentations. Patients with pulmonary-renal syndrome showed severe disease whereas double positive had more of chronic changes. The predictors of poor prognosis include advanced age, oliguria, serum anti-GBM levels, serum creatinine levels, degree of glomerulosclerosis and IFTA. Atypical anti-GBM cases should be kept in mind while evaluating renal biopsies.

Pediatric Glomerular Diseases in North India-Epidemiology and Clinicopathologic Correlation.

Background: Glomerular diseases vary with age, and it is important to investigate the spectrum of glomerular diseases in pediatric patients to help in a more precise clinical diagnosis and optimize the management of patients. We aimed to study the clinicopathologic pattern of pediatric glomerular diseases in North India. Methods: This is a 5-year retrospective, single-center cohort study. The database was searched to identify all pediatric patients with glomerular diseases in their native kidney biopsies. Results: About 2890 native renal biopsies were studied, of which 409 were pediatric glomerular diseases. The median age was 15 years with a male preponderance. Nephrotic syndrome was the most common presentation (60.8%), followed by non-nephrotic proteinuria with hematuria (18.5%), rapidly proliferative glomerulonephritis (7%), isolated hematuria (5.3%), acute nephritic syndrome (3.4%), non-nephrotic proteinuria (1.9%), and advanced renal failure (0.7%). Minimal change disease (MCD) was the most common histological diagnosis, followed by focal segmental glomerulosclerosis (17.4%), IgA nephropathy (IgAN; 10%), membranous nephropathy (6.6%), lupus nephritis (5.9%), crescentic glomerulonephritis (2.9%), and C3 glomerulopathy (2.9%). Diffuse proliferative glomerulonephritis (DPGN) was the most common histological diagnosis in patients with hematuria and non-nephrotic as well as nephrotic range proteinuria. The most common histological diagnoses for isolated hematuria and acute nephritic syndrome were IgAN and postinfectious glomerulonephritis (PIGN), respectively. Conclusions: MCD and lupus nephritis are the most common pediatric primary and secondary histopathologic diagnoses, respectively. The adolescent-onset glomerular diseases have a higher frequency of IgAN, membranous nephropathy, and DPGN. PIGN is still an important differential in our pediatric patients presenting with acute nephritic syndrome.

Clinicopathological Significance and Renal Outcomes of Light Microscopic Patterns in Complement Component 3 Glomerulopathy.

BACKGROUND: Complement component 3 glomerulopathy (C3G) is a disease diagnosed based on the predominance of C3 immunostaining in glomeruli. The popular electron microscopic subtyping of C3G into dense deposit disease and C3 glomerulonephritis (GN) is not without limitations. We aimed to study the light microscopic (LM) patterns of C3G along with their clinicopathological correlation and treatment outcome. METHODS: C3G biopsies were classified into 4 LM patterns (membranoproliferative GN [MPGN], mesangial proliferative GN [MesPGN], diffuse proliferative GN [DPGN], and crescentic GN [CrGN]). These patterns were compared for clinicopathological profile, treatment outcome, and renal survival. Further, predictors of end-stage renal disease (ESRD) were determined using the Cox proportional hazards model. RESULTS: Of 162 biopsies, there were 83 MPGN, 36 DPGN, 22 MesPGN, and 21 CrGN. Majority of the patients were young, with males being more than females. About half (48%) of the patients received immunosuppression, steroids alone (29%) or steroids with other immunosuppressants (19%). The overall remission rate was 32.7% (median follow-up = 14 months). CKD developed in 46 patients and 31 patients progressed to ESRD. Predictors of progression to ESRD were older age (hazard ratio [HR] = 1.04, p < 0.01), advanced renal failure at presentation (HR = 3.73, p < 0.01), glomerulosclerosis (HR = 5.07, p < 0.01), and severity of interstitial fibrosis and tubular atrophy (HR = 8.25, p = 0.01). CONCLUSIONS: The LM patterns differed in their clinicopathological profiles, without any significant difference in their renal outcomes. Glomerulosclerosis and interstitial fibrosis portend a poor prognosis. Besides CrGN, MesPGN pattern of C3G presented as a severe form of disease.

Simultaneous tubular and glomerular involvement with cryoglobulinemia vasculitis in multiple myeloma.

Renal manifestations in myeloma are varied. Tubulopathic light chains cause cast nephropathy or proximal tubulopathy, usually associated with tubulointerstitial nephritis. Glomerular involvement includes amyloidosis and monoclonal immunoglobulin deposition diseases. We report a case of multiple myeloma with systemic manifestation of Type-1 cryoglobulinemic vasculitis (skin rash and polyarthritis) and unusual renal manifestation with both tubular and glomerular involvement on renal biopsy along with features of cryoglobulinemic renal vasculitis. Renal biopsy showed light chain cast nephropathy and glomerular involvement. Glomeruli displayed membranoproliferative pattern with monoclonal immunoglobulin deposition disease and features of cryoglobuminemia. Immunoflourescence showed Kappa restriction in the tubular casts and glomerular deposits. Serum light chain assay and immunoelectrophoresis revealed IgG Kappa light chain restriction. The exact mechanism of the varied renal manifestations of multiple myeloma in different patients is not known.