Superimposition of poststreptococcal acute glomerulonephritis on the course of IgA nephropathy

A 17-year-old male with poststreptococcal acute glomerulonephritis (PSAGN) superimposed on the course of IgA nephropathy is presented. The histological findings of the first renal biopsy showed mild IgA nephropathy with a mesangial deposition of IgA and C3. Eighteen months later, acute nephritic syndrome with hypocomplementemia and rising antihyaluronidase titer occurred 10 days following the onset of an upper respiratory infection. The second renal biopsy revealed severe diffuse endocapillary proliferative and exudative glomerulonephritis with cellular crescents in 70% of the glomeruli. Immunofluorescence showed granular staining of C3 alone along the capillary walls. The pre-existing IgA deposits had disappeared. Typical 'humps' were observed by electron microscopy. The symptoms were gradually resolved by intensive steroid and anticoagulant therapy. Five months after the episode of acute nephritic syndrome, the patient was clear of symptoms except for mild proteinuria and hematuria. The third renal biopsy at that time showed morphologic changes similar to those of the first renal biopsy with mild mesangial IgA deposits.     

Acute poststreptococcal glomerulonephritis superimposed on IgA nephropathy

Superimposition of poststreptococcal glomerulonephritis (PSGN) on the course of IgA nephropathy (IgAN) is uncommon. A case of PSGN during IgA nephropathy is presented. A 30-year-old man who had alternating gross and microscopic hematuria for 7 months underwent a renal biopsy. The first renal biopsy revealed IgAN with mesangial deposits of IgA and C3. Two months later, the patient suffered generalized edema, proteinuria, hematuria, an increased ASO titer and a decreased C3 level. A second renal biopsy revealed diffuse endocapillary proliferative glomerulonephritis with epimembranous hump-like electron-dense deposits of C3, but the original mesangial IgA deposits had disappeared. A diagnosis of acute PSGN was indicated. Two months after the onset of acute nephritic syndrome, the patient remained asymptomatic, except for microscopic hematuria and proteinuria. Some cases with persistent proteinuria or hematuria after PSGN are probably related to preexisting IgAN.     

Histology and immunohistology of IgA nephropathy

IgA nephropathy is a histologically diverse glomerular disease characterized by mesangial or mesangial plus peripheral glomerular capillary immune complex deposits that contain IgA as the dominant or co-dominant immunoglobulin type. The most common histologic manifestation of IgA nephropathy is mesangial proliferative glomerulonephritis (GN), most often focal but not infrequently diffuse. However, the light microscopic appearance of IgA nephropathy spans the entire range from histologically normal to diffuse proliferative and crescentic glomerulonephritis, much as is the case with lupus nephritis. This review examines the histologic diversity as well as the immunohistologic features of IgA nephropathy.     

Lupus-like nephritis in an HIV-positive patient: report of a case and review of the literature

The most common manifestation of HIV/AIDS in the kidney is the collapsing variant of focal segmental glomerular sclerosis, HIV-associated nephropathy (HIVAN). Other forms of renal disease in HIV-infected patients include mesangial proliferative glomerulonephritis (GN), membranoproliferative GN, IgA nephropathy, minimal change disease and proliferative immune-complex GN. We present the case of a 42-year-old Caucasian male with HIV infection, treatment associated peripheral neuropathy, nephrotic syndrome and progressive renal failure. The initial and subsequent kidney biopsies showed diffuse proliferative glomerulonephritis resembling diffuse proliferative (WHO class IV) lupus nephritis. There was no clinical or serological evidence of systemic lupus erythematosus (SLE). Proteinuria improved with ACE-inhibitors, and renal function remained relatively stable while receiving highly active antiretroviral therapy (HAART). A precipitous decline in renal function to end-stage renal disease followed a brief period of withdrawal from potent antiretroviral therapy during which the viral load rebounded. Considering previously reported cases, it appears that lupus-like nephritis is a rare but well-defined pattern of immune-complex-induced renal injury seen in HIV-infected patients. It appears to be markedly responsive to HAART.     

Strong association between IgA nephropathy and hepatitis B surface antigenemia in endemic areas

The frequency of hepatitis B surface antigen (HBsAg) was studied in the sera of 122 patients with primary IgA nephropathy. Hepatitis B surface (HBs) antigenemia was detected in 21 patients (17.2%) and this was significantly higher than the prevalence of HBsAg carrier in the general population (p less than 0.01). These patients had no clinical or laboratory findings to suggest acute or chronic liver diseases. Two glomerulopathic entities: mesangial proliferative glomerulonephritis with predominant mesangial IgA deposits and a mixed picture of membranous nephropathy with capillary IgG deposits and mesangial proliferative glomerulonephritis with mesangial IgA deposits, were observed in this group of patients. Glomerular deposits of HBsAg, hepatitis B core antigen (HBcAg), and both HBsAg and HBcAg were detected in three, five and four renal biopsy specimens respectively. Replication of hepatitis B virus (HBV) was suggested in two of the six renal biopsy specimens examined by HBV DNA gene probe. During the mean study period of 40 months (range 12-84), 19% of these patients with hepatitis B virus-associated IgA nephropathy developed progressive renal deterioration and one required maintenance dialysis therapy. Our study suggests that hepatitis B virus antigenemia may play a significant pathogenetic role in the development of IgA nephropathy in areas of high HBV endemicity and these HBV-associated IgA nephropathies can run an indolent but relentless slowly progressive clinical course.     

IgA nephropathy presenting clinical features of poststreptococcal glomerulonephritis

IgA nephropathy and poststreptococcal glomerulonephritis are common forms of primary glomerulonephritis in children. This paper reports a 5-year-old Omani boy who had a chance occurrence of these two different glomerular diseases. Our patient presented with clinical features of poststreptococcal glomerulonephritis and then developed recurrent macroscopic hematuria, polyarthritis, bloody diarrhea, and erythematous swelling of the penis. Renal biopsy revealed diffuse mesangial hypercellularity, with focal glomerular sclerosis, fibrous crescents, and mesangial IgA and C3 deposits, consistent with IgA nephropathy. The clinical features and differential diagnosis are outlined.     

Dense intramembranous deposit disease: new pathologic features

The pathologic and clinical features of 16 patients with dense intramembranous deposit disease are described. By light microscopy nine patients had membranoproliferative glomerulonephritis, five had focal segmental necrotizing glomerulonephritis with segmental epithelial crescents, four of whom also had a prominent tubulointerstitial nephritis, and two had focal segmental mesangial proliferative glomerulonephritis. The patients with membranoproliferative glomerulonephritis and one with focal segmental mesangial proliferative glomerulonephritis had easily recognizable dense intramembranous deposits by optical microscopy. The patients with focal segmental necrotizing glomerulonephritis and one with focal segmental mesangial proliferative glomerulonephritis did not have recognizable peripheral loop dense intramembranous deposits even under oil immersion. In patients with membranoproliferative glomerulonephritis ultrastructural examination revealed extensive capillary wall dense intramembranous deposits. Immunofluorescence revealed diffuse double linear staining along the capillary walls and "mesangial rings" of C3. In the patients with focal segmental necrotizing glomerulonephritis and one with focal segmental mesangial proliferative glomerulonephritis the immunofluorescence study suggested a diagnosis of dense intramembranous deposit disease because of the segmental double linear staining of the capillary walls and "mesangial rings" of C3, but the diagnosis was only established by fine structural analysis where occasional peripheral loop and prominent paramesangial basement membrane dense intramembranous deposits and mesangial nodular deposits were identified. Clinical features prior to biopsy included nephrotic syndrome in eight patients, an acute nephritic syndrome in six patients, and asymptomatic proteinuria and hematuria in two patients. Five of six patients with an acute nephritic presentation had focal segmental necrotizing glomerulonephritis. The acute renal insufficiency in these patients was transitory and appeared to be related to a prominent acute tubulointerstitial nephritis present in four of the biopsy specimens. Depressed serum C3 levels were present in patients with membranoproliferative glomerulonephritis; patients with focal segmental lesions were normocomplementemic. Because of the "atypical" light microscopic features in six of our patients, we support the suggestion that membranoproliferative glomerulonephritis, type II be replaced by the term 'dense intramembranous deposit disease' for this glomerulopathy with variable clinical and histologic features.     

Histological features of IgA glomerulonephritis as predictors of pregnancy outcome

116 pregnancies undertaken by 70 women with IgA glomerulonephritis and their diagnostic renal biopsies have been reviewed. An IgA diffuse mesangial proliferative lesion with superimposed focal and segmental proliferative lesions (IgA FSP) on diagnostic renal biopsy was associated with a greater incidence of maternal complications than IgA diffuse mesangial proliferative glomerulonephritis with no superimposed lesions (IgA DMP) and IgA diffuse mesangial proliferative glomerulonephritis with superimposed focal and segmental hyalinosis and sclerosis (IgA FSHS) (p less than 0.025). Patients with severe vessel lesions had a significantly greater incidence of fetal loss than those with only mild to moderate lesions (p less than 0.025).     

IgA glomerulonephritis

Renal biopsy specimens from 204 patients with glomerulonephritis or nephrotic syndrome have been studied. In ten of the patients not suffering from acute poststreptococcal glomerulonephritis, systemic lupus erythematosus or Schönlein-Henoch syndrome, diffuse, selective mesangial IgA deposition was observed. Clinically, persistent microscopic haematuria, mild proteinuria and, except in one patient, normal renal function were found. Light microscopically the histological picture was dominated by a diffuse or focal increase in volume of the mesangial matrix, and mild mesangial cell proliferation. Exceptionally, there was also crescent formation. Immunofluorescence revealed large IgA, IgG and C3 deposits, as well as small IgM and fibrinogen deposits in the mesangial glomeruli. The authors' assumption that immunocomplexes containing a secretory component might be implicated in the pathomechanism of Berger's disease, could not be proved.On the basis of a lecture given at the XXIIIrd Itinerary Congress of the Transdanubian Section of the Association of Hungarian Internists, held at Gyr on 18th June, 1976. Supported by the Scientific Research Council, Ministry of Health, Hungary (3-18-0304-03-2/H).     

C1q nephropathy: do C1q deposits have any prognostic significance in the nephrotic syndrome?

C1q deposits are usually found in association with other complement components and immunoglobulins in proliferative glomerulonephritis and may predominate in systemic lupus erythematosus (SLE). We report the clinical outcome of four patients who developed a nephrotic syndrome associated with C1q nephropathy unrelated to SLE. On presentation the mean urinary protein loss was 6.8 g/24 h (range 4-10), and renal function impaired, mean serum creatinine 201 mumol/l (150-400). Over a mean follow up period of 6.5 years (1.7-19), all four patients improved, three spontaneously and one treated with steroids and cyclosporin, to a current urinary protein loss of 0.3 g/24 h (less than 0.2-0.9) and serum creatinine 98 mumol/l (68-115). C1q nephropathy was confirmed in each biopsy by conventional immunohistology. C1q deposits were demonstrated within the glomerular basement membrane of three biopsies and the mesangium in two samples. One patient had been categorized on light- and electron-microscopy as having mesangiocapillary glomerulonephritis, one membranous glomerulonephritis, one proliferative glomerulonephritis with focal segmental glomerulosclerosis, and one diffuse proliferative glomerulonephritis with both subendothelial and mesangial dense deposits. In view of the expected progressive nature of the underlying renal histopathological appearance, the presence of predominant C1q deposits would appear to be associated with a better clinical outcome.     

Digital subtraction venography in the diagnosis of renal vein thrombosis.

Fifteen cases of renal vein thrombosis were seen in patients with nephrotic syndrome, both adult and pediatric, and all had kidney biopsies. Six patients were found to have membranoproliferative glomerulonephritis, 3 membranous nephropathy, 2 focal segmental glomerulosclerosis, 2 renal amyloidosis and one each minimal change disease and diffuse mesangial proliferative glomerulonephritis. The diagnosis of renal vein thrombosis was made in all patients by utilizing digital subtraction venography. This method is simple, safe, noninvasive and quite efficient.     

强直性脊柱炎肾损害的临床病理特点

目的探讨强直性脊柱炎（AS）合并肾损害的临床及病理特点。方法回顾性分析18例经肾脏活体组织检查的AS患者的临床及肾脏病理表现。结果18例患者中,9例呈隐匿性肾小球肾炎表现,5例呈慢性肾小球肾炎表现,1例呈肾病综合征表现,3例为慢性肾功能不全;4例血压增高,14例血压正常。24h尿蛋白定量平均为（1．17±1．39）g。15例肾功能正常,3例肾功能异常患者血肌酐平均为（153．2±36．8）umol／L。8例患者血清IgA水平升高,10例c反应蛋白升高,13例红细胞沉降率（EsR）增快,且血清IgA水平和C反应蛋白呈正相关（r=0．707,P=0．001）,血清IgA水平和ESR呈正相关（r=0．858,P〈0．001）。病理检查结果发现15例为IgA肾病（其中10例为轻度系膜增生性肾炎,1例为轻度系膜增生性肾炎并慢性肾小管间质肾病,2例为局灶增生性肾炎,1例为局灶增生坏死性肾炎,1例为局灶节段性肾小球硬化症）,1例为膜性肾病,1例为局灶增生性肾炎伴慢性肾小管间质肾病,1例为慢性。肾小管间质肾病。有慢性肾小管间质肾病者均有服中药史。结论AS相关性肾损伤的病理改变多样,但主要为IgA肾病,也可表现为膜性肾病、局灶增生性肾炎和慢性肾小管间质。肾病,其肾损伤可能与AS疾病本身和（或）治疗用药相关。     

Histologically confirmed superimposition of post-streptococcal acute glomerulonephritis during IgA nephropathy

We describe a 39-year-old Japanese man with post-streptococcal acute glomerulonephritis (PSAGN) super-imposed on long-term immunoglobulin A nephropathy (IgA-N). The histological findings of the first renal biopsy, done at 21 years of age, revealed mild mesangial proliferative glomerulonephritis with mesangial IgA deposition. Nineteen years later, acute nephritic syndrome with hypocomplementemia and an increasing anti-streptolysin O (ASO) titer developed 2 weeks after the onset of an upper respiratory infection. A second renal biopsy revealed severe segmental endocapillary proliferative and exudative glomerulonephritis, with fibrocellular crescents in about 40% of the glomeruli. Immunofluorescence showed that more C3 than IgA was deposited in the mesangium and that the IgA deposits had decreased. Electron microscopy revealed hump electron-dense deposits on the epithelial side of the glomerular basement membrane. These features were consistent with PSAGN superimposed on IgA-N. After 2 weeks of observation, blood pressure, C3 level, and ASO titer had returned to normal, although the persisting nephritic syndrome necessitated steroid therapy. Six months after the onset of the acute nephritic syndrome, the patient remained asymptomatic, except for microhematuria.     

Postinfectious diffuse proliferative glomerulonephritis and acute renal failure in an HIV patient

Postinfectious proliferative glomerulonephritis may occur in HIV-infected patients, although it is not a common cause of severe acute renal failure in them. We report a woman with HIV infection, who developed hypocomplementemic acute nephritic syndrome 10 days after an upper respiratory infection. Systemic diseases were excluded. The serum creatinine level increased to 6.6 mg/dl. Renal biopsy showed diffuse endocapillary proliferative glomerulonephritis, with mesangial and capillary walls, granular deposits of IgG and C3 by immunofluorescence. She was given corticosteroids with progressive normalization of her renal function. No opportunistic infections have occurred during 1-year follow-up.     

Paulista Registry of glomerulonephritis: 5-year data report.

BACKGROUND: The Paulista Registry of Glomerulopathies was created in May 1999 and comprises several centres of S?o Paulo, the most populous Brazilian State, that concentrates people from all regions of the country who look for health care. METHODS: This report includes data from 2086 patients from Brazil submitted to renal biopsy due to the presumed diagnosis of glomerular diseases, registered prospectively since May 1999 until January 2005. Data were collected by the integrants of the 11 centres involved, utilizing a standardized questionnaire. RESULTS: The mean age of the patients was 34.5+/-14.6 years. Primary glomerular diseases were more frequent in males (55.1%) than in females; on the other hand, secondary glomerular diseases were more frequent in females (71.8%). The most common clinical presentation was nephrotic syndrome and the frequency of hypertension, at this time, was 55.5%. There was a predominance of indication of biopsies in the third, fourth and fifth decades of life. The most common primary glomerular diseases were focal and segmental glomerulosclerosis (29.7%), followed by membranous nephropathy (20.7%), IgA nephropathy (17.8%), minimal change disease (9.1%), membranoproliferative glomerulonephritis (7%), crescentic glomerulonephritis (4.1%), advanced chronic glomerulopathy (4%), non-IgA mesangial glomerulonephritis (3.8%), diffuse proliferative glomerulonephritis (2.5%), focal segmental proliferative glomerulonephritis (1%) and others (0.3%). The most frequent secondary glomerular disease was lupus nephritis, corresponding to 66.2% of the cases, followed by post-infectious glomerulonephritis (12.5%), diabetic nephropathy (6.2%), diseases associated to paraproteinaemia (4.9%), hereditary diseases (4.6%), vasculitis (3.2%), malignancies (0.9.%), secondary focal segmental glomerulosclerosis (0.6%) and others (0.9%). CONCLUSION: Focal segmental glomerulosclerosis was the most frequent primary glomerular disease, followed by membranous nephropathy and IgA nephropathy. Lupus nephritis predominated over all the other secondary glomerular diseases.     

C1Q nephropathy in children

C1q nephropathy (C1qNP) is a peculiar form of glomerulonephritis characterized by mesangial immunoglobulin and complement deposits, predominantly C1q, with no evidence of systemic lupus erythematosus. We describe the incidence, manifestation, histopathologic findings, follow-up, treatment and outcome of C1qNP. Twelve C1qNP patients were identified among 131 children who had undergone renal biopsy, accounting for a 9.16% incidence of C1qNP. Light microscopy examination showed focal segmental glomerulosclerosis (FSGS) with or without diffuse mesangial proliferation (n=6), minimal change disease (MCD) (n=4) or focal glomerulonephritis (n=2). C1q deposits were found in all, while electron microscopy revealed visible deposits in nine cases. Eight children presented with nephrotic syndrome, while one had nephrotic proteinuria and renal insufficiency that progressed to end-stage renal failure. The remaining three patients presented with nonnephrotic proteinuria associated with microhematuria, hypertension or renal insufficiency. Only one nephrotic syndrome patient responded excellently to corticosteroids, while four became corticosteroid dependent, and three were corticosteroid resistant, showing a very poor response to other immunosuppressive therapy as well. Patients with non-nephrotic proteinuria demonstrated fixed laboratory findings. Most C1qNP patients had FSGS or MCD, the majority of them presenting with corticosteroid-dependent or corticosteroid-resistant nephrotic syndrome. The latter showed a very poor response to any immunosuppressive therapy and high risk for progressive renal insufficiency.     

Henoch-Sch?nlein purpura and IgA nephropathy in father and son

Considerable controversy exists as to whether Henoch-Sch?nlein purpura and Iga nephropathy are different clinical manifestations of the same disease or if, on the contrary, they are separate entities. We report on the development of Henoch-Sch?nlein purpura and IgA nephropathy in 2 members of the same family. Patient 1, a 63-year-old man, presented with purpura in the legs, abdominal pain, hematuria, renal failure and proteinuria. A biopsy of a purpuric skin lesion showed small-vessel vasculitis, and a renal biopsy showed diffuse proliferative glomerulonephritis with prominent IgA deposits, thus making the diagnosis of Henoch-Sch?nlein purpura. Serum IgA was increased. Patient 2, the 30-year-old son of patient 1, underwent renal biopsy for the investigation of microscopic hematuria and proteinuria. There was no history of skin rash, and serum creatinine was normal. A renal biopsy showed expansion of the mesangial matrix and marked IgA deposition. HLA typing confirmed that they shared a haplotype. HLA B35 or DR4 were absent. These results demonstrate that Henoch-Sch?nlein purpura and IgA nephropathy can possibly be genetically related and therefore support the notion that these two diseases probably share a common pathogenesis.     

Membranous nephropathy with crescents

Membranous nephropathy is a common cause of nephrotic syndrome in adults and can be primary or secondary to systemic lupus erythematosus, chronic infection, or drugs. Rapid decline in renal function in patients with membranous nephropathy may be due to renal vein thrombosis, malignant hypertension, or an additional superimposed destructive process involving the renal parenchyma. Crescents are rare in primary membranous nephropathy and thus suggest another underlying disease process, such as combined membranous and focal or diffuse lupus nephritis. However, in some patients with membranous nephropathy and crescents, the crescentic lesion may be due to a distinct, separate disease process, such as anti-glomerular basement membrane antibodies or anti-neutrophil cytoplasmic antibodies-related pauci-immune glomerulonephritis. Here we describe a case with such renal biopsy findings, review previous reported cases, and discuss possible implications for pathogenesis of the coexistence of these lesions.     

IgA nephropathy in patients with familial Mediterranean fever

Two patients with a long-standing history of familial Mediterranean fever were found to have both microscopic hematuria and proteinuria during the acute attacks. Kidney biopsies from both patients revealed diffuse mesangial proliferative glomerulonephritis with intense mesangial IgA and C3 deposits and no evidence of amyloidosis. To our knowledge these are the first 2 cases documenting the presence of mesangial IgA nephropathy in patients with familial Mediterranean fever.     

Glomerular disease in cirrhosis of the liver: low frequency of IgA deposits

Twelve HBsAg-negative patients with histologically documented cirrhosis of the liver of either alcoholic (8 of 12) or cryptogenic (4 of 12) origin underwent renal biopsy to investigate proteinuria, hematuria and/or renal failure. Immunofluorescence was positive for IgA in 2 patients with mesangiocapillary glomerulonephritis (MCGN) and could not be performed in 2 additional patients with the same diagnosis. However, in the remaining 8 patients, immunofluorescence was negative for IgA and frequently positive for C3, IgG, IgM and/or fibrinogen. These 8 patients without IgA were classified as follows: MCGN with subendothelial electron-dense deposits (2 cases), IgM-IgG cryoglobulinemia with diffuse endocapillary glomerulonephritis (1 case), membranous nephropathy (1 case), diffuse endocapillary proliferative glomerulonephritis (1 case), vasculitis with focal segmental necrotizing glomerulitis and crescentic glomerulonephritis (2 cases). These results show that cirrhosis of the liver can be associated with a wide variety of glomerular disorders. Contrary to previous belief, IgA is absent in two thirds of patients with cirrhosis and glomerulopathy. Therefore, the pathogenetic importance of IgA in the development of glomerular disease in such patients is doubtful.