Idiopathic nodular glomerulosclerosis: a clinicopathologic study of 15 cases

Idiopathic nodular glomerulosclerosis is an enigmatic condition closely resembling diabetic nodular glomerulosclerosis without evidence of diabetic mellitus or other specific disease. Idiopathic nodular glomerulosclerosis remains a rare disease entity with an unclear pathogenesis. Clinicopathologic features of 15 patients with idiopathic nodular glomerulosclerosis were evaluated in a retrospective review of renal biopsies between 1998 and 2007. Our study cohort consisted predominantly of older (mean age, 64.2 years) white (73%) women (67%). Fourteen patients (93%) had a history of hypertension, and 10 (67%) were active smokers at the time of biopsy. Nine patients (60%) were obese (body mass index, >30 kg/m²) and 4 (27%) were overweight (body mass index, 25-29.9 kg/m²). Fourteen patients (93%) presented with renal insufficiency with mean serum creatinine level of 2.8 mg/dL. All 15 patients presented with proteinuria (mean urinary protein excretion, 5.6 g/24 h). Eleven patients (73%) presented with nephrotic-range proteinuria and 8 (53%) with nephrotic syndrome. Histopathologic findings showed nodular glomerulosclerosis (100%), moderate to severe arterio-arteriolosclerosis (100%), and glomerular basement membrane thickening (100%). Immunofluorescence and electron microscopy studies had no other specific findings. Our results confirm previous studies of a close association of hypertension and smoking with idiopathic nodular glomerulosclerosis. A significantly higher incidence of obesity and overweight in patients with idiopathic nodular glomerulosclerosis suggests that increased body mass index may also contribute to the development and progression of idiopathic nodular glomerulosclerosis.     

Kappa light chain nodular glomerulosclerosis with conspicuous crescent formation and tubulointerstitial injury. Report of a case.

We describe a 39-year-old man who developed kappa light chain nodular glomerulosclerosis with superimposed conspicuous crescent formation and extensive tubulointerstitial injury. The clinical picture was characterized by nephrotic syndrome and rapidly progressive glomerulonephritis. Incessantly progressive loss of renal function culminated in irreversible renal failure 7 weeks after initial manifestations of renal insufficiency. The patient has since been maintained on thrice weekly hemodialysis with chemotherapy for five years. At the time of pathologic diagnosis by renal biopsy, there was no evidence of multiple myeloma, and no serum M-component or Bence-Jones proteinuria was detected. An initial bone marrow aspirate revealed the presence of 0.6% atypical lymphocytes as the sole abnormality, although these were later identified as atypical plasma cells. These cells had also infiltrated the renal interstitium. Crescentic kappa light chain nodular glomerulosclerosis lacking evidence of plasma cell dyscrasia should be included in the differential diagnosis of rapidly progressive glomerulonephritis.     

Essential mixed cryoglobulinemic glomerulonephritis associated with diabetic glomerulosclerosis. Light, immunofluorescence, and ultrastructural study of two cases

The association of cryoglobulinemic glomerulonephritis with diabetic glomerulosclerosis is reported in two patients. Renal pathology was investigated by light and electron microscopy and by immunofluorescence on biopsy material from both patients and on autopsy material (obtained a few hours after death) from one patient. Glomerular involvement due to cryoglobulins preceded the development of diabetic glomerulosclerosis in one patient. This contrasts with what has been reported in the literature, where various types of glomerular lesions are reported to be superimposed on overt and often long-lasting diabetic glomerulopathy. Though the association may be coincidental, the immune complexes (cryoglobulins) may have accelerated the formation of the nodular hyaline diabetic lesions in the mesangium through a mesangiolytic process.     

Idiopathic nodular glomerulosclerosis is a distinct clinicopathologic entity linked to hypertension and smoking

Idiopathic nodular glomerulosclerosis (ING) is an enigmatic condition that resembles nodular diabetic glomerulosclerosis but occurs in nondiabetic patients. We reviewed clinicopathologic features, immunohistochemical profiles, and outcomes in 23 patients with ING diagnosed from among 5,073 native renal biopsy samples (0.45%) at Columbia University from January 1996 to March 2001. This cohort, in which diabetes mellitus was excluded, consisted predominantly of older (mean age, 68.2 years) white (73.9%) men (78.3%). Clinical findings at presentation included renal insufficiency in 82.6% (mean serum creatinine = 2.4 mg/dL), proteinuria (> 3 g/d in 69.6%; mean 24-hour urine protein = 4.7 g/d), and-less frequently-full nephrotic syndrome (21.7%). There was a high prevalence of hypertension (95.7%; mean = 15.1 +/- 3.4 years), smoking (91.3%; mean = 52.9 +/- 6.9 pack-years), hypercholesterolemia (90%), and extrarenal vascular disease (43.5%). All 23 patients had prominent diffuse and nodular mesangial sclerosis, glomerular basement membrane thickening, arteriosclerosis, and arteriolosclerosis. Immunohistochemical staining for CD34, a marker of endothelial cells, showed an increased number of vascular channels within ING glomeruli compared with normal controls. Follow-up data were available for 17 patients, 6 of whom reached end-stage renal disease (ESRD) (35.3%). By Kaplan-Meier estimates, the median time after biopsy to ESRD was 26 months. Predictors of progression to ESRD included continuation of smoking (P =.0165), lack of angiotensin II blockade (P =.0007), degree of tubular atrophy and interstitial fibrosis (P =.0517), and degree of arteriosclerosis (P =.0096). In conclusion, ING is a progressive vasculopathic lesion linked to hypertension and cigarette smoking.     

NPHS2 gene, nephrotic syndrome and focal segmental glomerulosclerosis: a HuGE review.

Nephrotic syndrome, characterized by edema, proteinuria, hyperlipidemia and low serum albumin, is a manifestation of kidney disease involving the glomeruli. Nephrotic syndrome may be caused by primary kidney disease such as focal segmental glomerulosclerosis. Mutations in the podocin gene, NPHS2, have been shown in familial and sporadic forms of steroid-resistant nephrotic syndrome, including focal segmental glomerulosclerosis. Podocin is an integral membrane protein located at the slit diaphragm of the glomerular permeability barrier. Complete information is lacking for the population frequency of some NPHS2 variants for all racial and ethnic groups. The most frequently reported variant, R229Q, is more common among European-derived populations than African-derived populations. We calculated crude odds ratios and 95% confidence intervals of childhood nephrotic syndrome and focal segmental glomerulosclerosis associated with R229Q heterozygosity using data from five studies. The R229Q variant is not associated with focal segmental glomerulosclerosis in the US population of African descent. In contrast, the R229Q variant is associated with a trend toward increased focal segmental glomerulosclerosis risk in European-derived populations, with an estimated increased risk of 20-40%. Our insight into the association between NPHS2 variants and nephrotic disease is hampered by the limitations of the existing studies, including small numbers of affected individuals and suboptimal control groups. Nevertheless, the available data suggest that large epidemiological case-control studies to examine the association between NPHS2 variants and nephrotic syndrome are warranted.     

Kappa Light Chain Nodular Glomerulosclerosis with Conspicuous Crescent Formation and Tubulointerstitial Injury

We describe a 39-year-old man who developed kappa light chain nodular glomerulosclerosis with superimposed conspicuous crescent formation and extensive tubulointerstitial injury. The clinical picture was characterized by nephrotic syndrome and rapidly progressive glomerulonephritis. Incessantly progressive loss of renal function culminated in irreversible renal failure 7 weeks after initial manifestation of renal insufficiency. The patient has since been maintained on thrice weekly hemodialysis with chemotherapy for five years. At the time of pathologic diagnosis by renal biopsy, there was no evidence of multiple myeloma, and no serum M-component or Bence-Jones proteinuria was detected. An initial bone marrow aspirate revealed the presence of 0.6% atypical lymphocytes as the sole abnormality, although these were later identified as atypical plasma cells. These cells had also infiltrated the renal interstitium. Crescentic kappa light chain nodular glomerulosclerosis lacking evidence of plasma cell dyscrasia should be included in the differential diagnosis of rapidly progressive glomerulonephritis.     

Case report: IgM type of membranous glomerulopathy in a diabetic patient

We report the case of a 46-yr-old man with a 16-yr history of type I diabetes mellitus who developed rapid onset of nephrotic syndrome. Renal biopsy revealed diabetic nephropathy, characterized by thickened glomerular basement membranes (GBM), mild nodular glomerulosclerosis, and focal arteriolar hyalinization. Immunofluorescent (IF) studies showed strong granular IgM staining along glomerular loops, with subepithelial and intramembranous immune complex deposits along glomerular capillary loops demonstrated by electron microscopy (EM). These findings are consistent with membranous glomerulopathy with IgM as the predominant immunoglobulin. In addition, there were large aggregates of electron-dense material composed of numerous ring or spherical particles, ranging from 200 to 400 nm, in Bowman's space, which corresponded to eosinophilic aggregates on light microscopy (LM) and strong IgM stained materials by IF studies.     

Distinguishing diabetic nephropathy from other causes of glomerulosclerosis: an update

Diabetic nephropathy is a common cause of end-stage renal disease worldwide. It is characterised by diffuse or nodular glomerulosclerosis, afferent and efferent hyaline arteriolosclerosis, and tubulointerstitial fibrosis and atrophy. Diffuse and nodular diabetic glomerulosclerosis share similar histological features with other clinical conditions. Immunofluorescence and electron microscopy studies, and clinicopathological correlation are essential to differentiate diabetic nephropathy from other conditions that result in diffuse and nodular glomerulosclerosis.     

Light-chain Deposition Disease of the Kidney: A Case Report

A 41-year-old man was admitted for evaluation of nephrotic syndrome associated with microhematuria, hypertension, and moderate renal failure. In serum and urine samples, monoclonal IgG-lambda was detected. Bone marrow examination showed normal representation of all cell lines with normal range of plasma cells. Renal biopsy demonstrated diabetes-like nodular glomerulosclerosis. Immunofluorescence failed to demonstrate the presence of kappa or lambda light chains in the kidney. Electron microcopy showed granular electron-dense deposits along the glomerular basement membranes and in the mesangial nodules. The patient was diagnosed as having light-chain deposition disease (LCDD) without evidence of plasma cell dyscrasia. This report was designed to stress the significant challenges that remain in the diagnosis of LCDD-related glomerulopathy. The salient morphological features that help in making an accurate diagnosis are discussed.     

Light-chain deposition disease of the kidney: a case report

A 41-year-old man was admitted for evaluation of nephrotic syndrome associated with microhematuria, hypertension, and moderate renal failure. In serum and urine samples, monoclonal IgG-lambda was detected. Bone marrow examination showed normal representation of all cell lines with normal range of plasma cells. Renal biopsy demonstrated diabetes-like nodular glomerulosclerosis. Immunofluorescence failed to demonstrate the presence of kappa or lambda light chains in the kidney. Electron microcopy showed granular electron-dense deposits along the glomerular basement membranes and in the mesangial nodules. The patient was diagnosed as having light-chain deposition disease (LCDD) without evidence of plasma cell dyscrasia. This report was designed to stress the significant challenges that remain in the diagnosis of LCDD-related glomerulopathy. The salient morphological features that help in making an accurate diagnosis are discussed.     

Clinicopathological characteristics of obesity-associated focal segmental glomerulosclerosis

Obesity-related glomerulopathy (ORG) is a secondary form of focal segmental glomerulosclerosis (FSGS) occurring in obese patients with a body-mass index higher than 30?kg/m(2). It is typically manifested by nephrotic-range proteinuria without full nephrotic syndrome, and progressive renal insufficiency. Characteristic morphologic features include the consistent presence of glomerulomegaly, predominance of perihilar variant of FSGS, and the relatively mild fusion of visceral epithelial cell foot processes. The concept of podocyte depletion as a driver of the glomerular scarring in obesity-associated FSGS is well documented. The underlying mechanisms are likely to be related in part to the oxidative stress and the impairment of the integrity of the slit diaphragm and cell adhesion resulting mainly from angiotensin II and transforming growth factor-β. These proapoptotic cytokines are upregulated in obesity in response to insulin resistance, compensatory hyperinsulinemia and glomerular hyperfiltration-hypertension mediated mechanical stress. This review is designed to discuss the clinicopathologic features of obesity-associated FSGS, with a focus on the podocyte injury, which is involved in the onset and progression of the glomerulosclerotic process. Ultrastructural glomerular lesions are documented.     

Focal segmental glomerulosclerosis: a diagnostic problem

Focal segmental glomerulosclerosis (FSGS) is an important clinical problem as it leads to end-stage renal disease. Clinicians have long been able to treat patients with FSGS. Therefore, the demands the clinicians make on pathomorphologists, which include the diagnosis of FSGS at a possibly early stage, are justifiable. However, early diagnosis of FSGS is difficult. The analysis involved 150 cases of FSGS diagnosed between 2003 and 2008. These constitute 14.53% of renal biopsy material of that period. The test material comes from 138 adults and 12 children. The adult group mostly included patients with albuminuria (58 patients) and nephrotic syndrome (36 patients). Smaller groups included patients with albuminuria and hypertension, erythrocyturia and albuminuria, isolated erythrocyturia. The children group mostly included patients with the nephrotic syndrome. Individual patients suffered from isolated albuminuria and erythrocyturia. In both groups, FSGS NOS lesions prevailed. However, FSGS hilar and FSGS tip lesions, as well as completely sclerotized glomeruli were also present. Diverse symptoms of diseases may pose specific difficulties in clinical diagnosis. Similarly, determination of FSGS lesion type may be difficult due to simultaneous presence of different subtypes in the same punctate.     

Pattern of glomerulonephritis in Hong Kong

A retrospective analysis of all renal biopsies (961) performed in two regional hospitals in Hong Kong during 1977-1985 revealed that IgA nephropathy was the most frequently encountered glomerulopathy. Lipoid nephrosis (minimal change nephrotic syndrome) remained the commonest cause of nephrotic syndrome in children. The frequencies of mesangiocapillary glomerulonephritis, focal glomerulosclerosis, and idiopathic membranous nephropathy were lower than in other populations. Membranous nephropathy was frequently associated with hepatitis B virus antigenemia, especially in children. Other chronic infections did not have a significant pathogenetic role in glomerular diseases. Lupus nephritis was the commonest secondary glomerular disease in our study, and over seventy percent of the renal biopsies showed advanced pathologies with either diffuse proliferative glomerulonephritis or membranous nephropathy.     

Novel homoplasmic mutation in the mitochondrial tRNATyr gene associated with atypical mitochondrial cytopathy presenting with focal segmental glomerulosclerosis

We report a 9-year-old girl with a mitochondrial cytopathy preceded by steroid-resistant focal segmental glomerulosclerosis (FSGS). The proband presented at the age of 2 years with steroid-resistant nephrotic syndrome caused by FSGS. Her renal function progressively deteriorated and a dilated cardiomyopathy developed at the age of 7 years. A skeletal muscle biopsy showed a combined respiratory chain (RC) defect and a partial deficiency of coenzyme Q(10). A novel mutation in the evolutionary highly conserved region of the mitochondrial tRNA(Tyr) gene was found in homoplasmic state in skeletal muscle, blood, and renal tissue. The mutation was also found in homoplasmic state in her mildly symptomatic mother. No other maternal family members were available for testing. The present case of mitochondrial cytopathy initially presenting with steroid-resistant nephrotic syndrome, unusual biochemical and renal findings associated with a novel tRNA point mutation suggests that steroid-resistant FSGS can predate other features of mitochondrial disease for a prolonged period of time and that the progressive glomerulopathy associated with combined mitochondrial RC defects is genetically heterogeneous.     

Etiologic variability of nephropathy in juvenile diabetes mellitus

Clinicopathologic studies of four patients with juvenile diabetes mellitus and renal disease demonstrated the pathogenetic variability of nephropathy in diabetic patients. Only in one patient was the clinical nephropathy associated with the typical diabetic glomerulosclerosis. Another patient had steroid responsive nephrotic syndrome superimposed on minimal diabetic glomerulosclerosis. A third patient had steroid resistant nephrotic syndrome associated with mild diabetic glomerulosclerosis and with later appearance of Grave's disease. The fourth patient, in addition to moderate diabetic glomerulosclerosis had prominent tubulointerstitial nephritis, the latter probably being responsible for the rapidly declining renal function. The poor prognosis associated with diabetic nephropathy warrants a careful search for other potentially treatable causes of nephropathy in patients with juvenile diabetes mellitus.     

The pathogenesis of chronic renal failure in diabetic nephropathy. Investigation of 488 cases of diabetic glomerulosclerosis

Investigation of renal biopsy specimens from 488 patients with diabetic glomerulosclerosis (DGS) of varying severity revealed the following: 1) The severity of DGS increases with the duration of the diabetes. 2) As the severity of DGS increases, it is complicated with increasing frequency by exudative changes, which correspond in detail to hyperperfusion lesions described in the literature. 3) As the severity of DGS increases, the severity of arteriolosclerosis and the incidence of nephrotic syndrome increase significantly. 4) The 5- and 10-year renal survival rates are highest for those diabetic patients in whom the tubules and renal cortical interstitium are of normal appearance. These survival rates are diminished if any of the following are present at the time of biopsy: a) interstitial fibrosis; b) hyperperfusion lesions; c) nephrotic syndrome; d) elevation of the serum creatinine concentration to more than 1.3 mg%. 5) No significant correlation was found between renal survival rate and age, sex, or type of diabetes. 6) The inflammation of the renal interstitium seen in diabetes does not differ from that seen in chronic glomerulonephritis. Monocytes, macrophages, T lymphocytes, fibroblasts and fibrocytes play the major role in this inflammation. This inflammatory process is considered to represent not pyelonephritis, but rather an auto-immune process. In other words, it is proposed that the diabetic kidney fails not only as a result of non-specific glomerular lesions (hyperperfusion lesions) but also because of non-specific tubulointerstitial changes, whereas diabetic glomerulosclerosis alone does not lead to chronic renal failure.     

Coincident idiopathic focal segmental glomerulosclerosis collapsing variant and diabetic nephropathy in an African American homozygous for MYH9 risk variants

Familial clustering of disparate kidney diseases including clinically diagnosed hypertensive and diabetic nephropathy, idiopathic focal segmental glomerulosclerosis, and HIV-associated nephropathy are often observed in African Americans. Admixture mapping recently identified the nonmuscle myosin heavy chain 9 gene (MYH9) as a susceptibility factor strongly associated with several nondiabetic etiologies of end-stage renal disease in African Americans, less strongly with diabetes-associated end-stage renal disease. MYH9-associated nephropathies reside in the spectrum of focal segmental glomerulosclerosis/focal global glomerulosclerosis. The renal histology in proteinuric African Americans homozygous for MYH9 risk variants with longstanding type 2 diabetes mellitus is unknown. We report a case of coincident idiopathic focal segmental glomerulosclerosis collapsing variant and diabetic nephropathy in an African American homozygous for the MYH9 E1 risk haplotype. This case demonstrates that diabetic African Americans with overt proteinuria can have mixed renal lesions, including those in the spectrum of MYH9-associated nephropathy. Careful interpretation of kidney biopsies in proteinuric African Americans with diabetes is necessary to exclude coincident nondiabetic forms of nephropathy, precisely define etiologies of kidney disease, and determine the natural history and treatment response in mixed lesions of diabetes-associated and MYH9-associated kidney disease.     

Focal glomerular sclerosis and sarcoidosis

Idiopathic nephrotic syndrome occurred in a patient with sarcoidosis. Typical features of focal segmental glomerulosclerosis were present on kidney biopsy. A unique finding was the occurrence of IgA in blood vessels of the skin and lymph node. Whereas the sarcoid hilar adenopathy responded to steroid therapy, the nephrotic syndrome was resistant to steroids and immunosuppression. Evaluation of humoral and cellular immune responsiveness showed no abnormalities except cutaneous anergy. Glomerulonephritis is uncommon in sarcoidosis, and a brief outline of this association is included. This patient is of importance in view of the unexplained relationship between idiopathic nephrotic syndrome and T lymphocyte abnormalities.     

Collapsing glomerulopathy in Galloway-Mowat syndrome: a case report and review of the literature

The Galloway–Mowat syndrome (GMS) (MIM251300) is described as an autosomal recessive disorder, the gene of which has not yet been identified. We report the case of a boy presenting with an early nephrotic syndrome, microcephaly, seizures, and psychomotor retardation. He died at 3 years and 11 months in a context of end-stage renal function consistent with a GMS. He was the second child of a non-consanguineous marriage. There was no family history of nephrotic syndrome or end-stage renal failure, but his mother had a moderate mental retardation complicated by seizures. He presented dysmorphologic features, including micrognathia and large and floppy ears. Renal biopsy showed a focal segmental glomerulosclerosis with a collapsing glomerulopathy and abundant visceral epithelial cell proliferation. The majority of the glomeruli were sclerotic. We report the first case of GMS associated with a collapsing glomerulopathy.     

Glomerular podocyte vacuolation in focal segmental glomerulosclerosis

An electron microscopic study of the nonsclerotic glomeruli or nonsclerosed segments of affected glomeruli was made in 34 children with nephrotic syndrome and focal segmental glomerulosclerosis (FSGS) and in 34 children with minimal-change nephrotic syndrome. Particular attention was paid to alterations of glomerular epithelium. The most striking glomerular change in FSGS was vacuolation of the epithelial cell. Glomerular epithelial vacuolation was found in 21 of the 34 patients with FSGS. Eleven of these 21 patients with vacuoles developed chronic renal failure, while only one of the 13 patients without vacuoles developed renal failure. In minimal-change nephrotic syndrome only five of the 34 patients showed mild epithelial vacuolation. These observations are consistent with glomerular epithelial vacuolation contributing to the development and progression of the glomerular lesion in FSGS.