IgG4-related tubulointerstitial nephritis.

A 67-year-old man was referred to the renal team following an episode of acute kidney injury on a background of chronic kidney disease. He had a 9-year history of steroid-sensitive arthritis, epigastric pain and isolated submandibular gland enlargement. He was noted to have a raised eosinophil count, total serum protein and total immunoglobulin G4 (IgG4) level as well as a serum hypocomplementaemia. A renal biopsy showed a tubulointerstitial nephritis with lymphoplasmacytic infiltrates, fibrosis and IgG4-positive plasma cells on immunohistochemistry. A diagnosis of IgG4-related disease was made based on clinical presentation and pathology. Renal function improved with glucocorticoids and the patient was successfully transitioned to azathioprine as a steroid-sparing agent.

Catching the Worm Early: An Atypical Case of Bancroftian Filarial Nephropathy.

Filarial glomerular disease has been attributed to circulating immune complex deposition. We report here a rare manifestation of filarial nephropathy with microfilariae documented in glomerular capillaries in addition to immune complex glomerulonephritis, thus suggesting that direct toxicity may also contribute to the pathogenesis of this entity.

Crystals, crystals everywhere but not a clue till late Light chain crystalline proximal tubulopathy with concomitant myeloma cast nephropathy.

The renal diseases commonly associated with myeloma include primary amyloidosis, cast nephropathy, and light chain deposition disease. Less frequent forms of renal involvement encountered in the course of myeloma are crystalline and non-crystalline proximal tubulopathies, neoplastic plasma cell infiltration, and immunoglobulin crystallization in interstitial histiocytes and glomerular cells including podocytes. Light chain proximal tubulopathy (LCPT) caused by aggregation of non-crystalline and rarely crystalline deposits of monoclonal light chains in the cytoplasm of proximal tubular epithelial cells, accounts for less than 5% of monoclonal gammopathy-associated kidney diseases. We report the case of a 48-year-old Indian woman with multiple myeloma, who presented with acute kidney injury and nephrotic syndrome, in whom the renal biopsy revealed widespread crystalline inclusions in extraglomerular and glomerular compartments. We present illustrative light microscopic (LM) and diagnostic electron microscopic (EM) findings of this case which enabled a diagnosis of crystalline LCPT, crystal storing histiocytosis, and crystalline podocytopathy occurring synchronously with myeloma cast nephropathy. While documenting this unique juxtapositioning of multicompartmental paraproteinemic renal injury in multiple myeloma, diagnosed after EM analysis of the patient's renal biopsy, we discuss the pathogenetic pathways of this condition along with the clinical implications. Due to intrinsic structural properties of the crystals, they frequently escape detection by routine LM, necessitating EM analysis for their diagnosis. Given the prognostic implications of tubulopathies complicating myeloma, LCPT is a critically important diagnosis, highlighting the need for a comprehensive renal biopsy evaluation inclusive of EM for the practice of precision medicine in such scenarios.

Collagenofibrotic glomerulopathy - A rare disease diagnosed with the aid of transmission electron microscopy.

Collagenofibrotic glomerulopathy (CFG) is a rare idiopathic kidney disease characterized by abnormal deposition of atypical Type III collagen fibers in the glomerulus causing subendothelial and mesangial expansion, manifesting as progressive renal dysfunction accompanied by proteinuria. The majority of CFG cases reported in literature are from Japan where this disease entity was initially recognized. There is an increased awareness and diagnosis of this rare renal disease in India with the recent increase in utilization of electron microscopy (EM) in clinical diagnostic settings. We describe a 28-year-old Bangladeshi woman who presented with hypertension and nephrotic range proteinuria not amenable to treatment with steroids and cyclophosphamide, whose renal biopsy demonstrated diagnostic ultrastructural features of CFG. This illustrative case is presented to highlight the role of EM analysis for diagnostic accuracy in renal biopsy evaluation in addition to demonstrating the unusual renal biopsy findings of this rare entity.

Renal Mucormycosis: A Rare Cause of Urinary Tract Infection Leading to End-stage Renal Disease (ESRD).

Mucormycosis is a rare fungal infection often seen in immunocompromised hosts. Isolated renal mucormycosis may however present in immunocompetent children as renal failure and has a uniformly poor prognosis if not detected and treated early into the course of illness. We present a 3-year-old boy with unrelenting pyelonephritis in whom serial urine cultures done were negative. A final diagnosis of isolated renal mucormycosis was made by magnetic resonance imaging and renal biopsy.

Fibrillary glomerulonephritis in a human immunodeficiency virus-positive, hepatitis C-negative Indian patient: Expanding the profile of renal involvement in human immunodeficiency virus infection.

Highly active anti retroviral therapy (HAART) has dramatically improved life expectancy of human immunodeficiency virus (HIV) infected patients, converting HIV infection into a chronic illness with associated changes in its attendant renal complications. The past two decades have witnessed a decrease in the prevalence of HIV associated nephropathy (HIVAN), traditionally considered to be the hall mark of renal involvement in HIV infection. Simultaneously a host of other glomerular and tubulo-interstitial diseases have emerged, expanding the spectrum of HIV associated renal diseases, predominant among which is HIV associated immune complex mediated kidney diseases (HIVICK). Of the diverse glomerular diseases constituting HIVICK, fibrillary glomerulonephritis (FGN) remains a rarity, with only two existing reports to date, confined to patients co-infected with Hepatitis C virus (HCV). The pathogenetic role of HIV in these patients remains under a cloud because of previously well established association of HCV infection and FGN. We report a case of FGN in a HIV seropositive, HCV negative Indian patient, highlighting the diagnostic electron microscopy (EM) findings of FGN and strengthening the causal association of HIV with FGN. In view of increasing heterogeneity of renal complications in HIV infection, the diagnostic utility of a comprehensive renal biopsy evaluation inclusive of EM is emphasized for appropriate selection of treatment modalities.

Spectrum of biopsy proven renal disease in South Asian children: Two decades at a tropical tertiary care centre.

AIM: We report findings from a large single centre paediatric renal biopsy cohort in South Asia. METHODS: We analyzed all renal biopsies performed on children aged ≤18 years between 1996 and 2015 at our centre. The clinical characteristics and histological diagnosis pertaining to each case, distribution of renal diseases in children with various clinical presentations, and changes in the pattern of kidney disease during the study period were analyzed. RESULTS: A total of 1740 paediatric kidney biopsies were performed during the study period. The mean age was 12.8 ± 4.9 years (8 months to 18 years) and the male: female ratio was 1.5:1. The most common indication for renal biopsy was nephrotic syndrome (63.2%) followed by acute nephritic syndrome (13%). Minimal change disease was the most common cause of nephrotic syndrome while endocapillary proliferative glomerulonephritis (65.7% infection related), remained the commonest cause of acute nephritic syndrome. IgA nephropathy was the commonest cause of chronic kidney disease. Contrary to trends in European paediatric cohorts, the frequency of lupus nephritis increased over the two decades of the study, while that of endocapillary proliferative glomerulonephritis did not show any appreciable decline. CONCLUSION: This study provides the largest data on biopsy proven renal disease in children from South Asia published till date and highlights important differences in the spectrum and trends of kidney disease compared to data from other regions.

Histopathological analysis of the non - tumour parenchyma following radical nephrectomy: can it predict renal functional outcome?

ABSTRACT Introduction Radical nephrectomy (RN), a recommended treatment option for patients with Renal cell carcinoma (RCC) leads to an inevitable decline in global renal function. Pathological changes in the non-tumour parenchyma of the kidney may help predict the function of the remaining kidney. Materials and Methods Aim of this prospective, observational study was to find histopathological factors in the non-tumor renal parenchyma that could predict the decline in global renal function postoperatively and its association with co-morbidities like diabetes (DM). Data of consecutive patients undergoing RN from December-2013 to January-2015 was collected. Non-tumor parenchyma of the specimen was reported by a dedicated histopathologist. eGFR was calculated using Cockcroft-Gault formula before the surgery and at last follow up of at least 12 months. Results 73 RN specimens were analyzed. Mean follow up was 12.3 months. The mean decrease in eGFR was 22% (p=.0001). Percent decrease in eGFR did not show association with any of the histopathological parameters studied. DM was significantly associated with decrease in percent eGFR (p<0.05) and increase in arteriolar hyalinosis (p=0.004), Glomerulosclerosis (p=0.03) and Interstitial fibrosis/ Tubular atrophy (p=.0001). Maximum size of the tumor showed a negative correlation with percentage change in eGFR (p=.028). Conclusion Histological parameters in the non-tumour portion of the RN specimen may not be able to predict renal function outcome over a short follow up. However, presence of DM was associated with adverse pathological changes and significant decrease in renal function postoperatively.

Histopathological analysis of the non - tumour parenchyma following radical nephrectomy: can it predict renal functional outcome?

INTRODUCTION: Radical nephrectomy (RN), a recommended treatment option for patients with Renal cell carcinoma (RCC) leads to an inevitable decline in global renal function. Pathological changes in the non-tumour parenchyma of the kidney may help predict the function of the remaining kidney. MATERIALS AND METHODS: Aim of this prospective, observational study was to find histopathological factors in the non-tumor renal parenchyma that could predict the decline in global renal function postoperatively and its association with co-morbidities like diabetes (DM). Data of consecutive patients undergoing RN from December-2013 to January-2015 was collected. Non-tumor parenchyma of the specimen was reported by a dedicated histopathologist. eGFR was calculated using Cockcroft-Gault formula before the surgery and at last follow up of at least 12 months. RESULTS: 73 RN specimens were analyzed. Mean follow up was 12.3 months. The mean decrease in eGFR was 22% (p=.0001). Percent decrease in eGFR did not show association with any of the histopathological parameters studied. DM was significantly associated with decrease in percent eGFR (p<0.05) and increase in arteriolar hyalinosis (p=0.004), Glomerulosclerosis (p=0.03) and Interstitial fibrosis/ Tubular atrophy (p=.0001). Maximum size of the tumor showed a negative correlation with percentage change in eGFR (p=0.028). CONCLUSION: Histological parameters in the non-tumour portion of the RN specimen may not be able to predict renal function outcome over a short follow up. However, presence of DM was associated with adverse pathological changes and significant decrease in renal function postoperatively.