Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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PMID:C1Q nephropathy in children. 1624 48

C1q nephropathy (C1qNP) is a rare cause of childhood nephrotic syndrome (NS). We describe a child with retinoblastoma, lipomyelomeningocele and a chromosome 13 deletion who presented with massive proteinuria due to C1qNP. Despite steroid resistance, successful treatment of the NS was achieved with mycophenolate mofetil.
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PMID:C1q nephropathy in a child with a chromosome 13 deletion. 1652 Sep 46

There have been rare reports of glomerulopathies developing in patients with Bartter syndrome (BS) and its milder variant, Gitelman syndrome (GS). We present the first case of C1q nephropathy (C1qN) in an African American child with GS. This child was diagnosed with GS at 9 years of age and subsequently developed nephrotic range proteinuria 3 years later. Renal biopsy revealed mesangial hypercellularity and focal segmental glomerulosclerosis (FSGS). The segmental lesions were generally located at the vascular pole. Dominant C1q (2+) staining along with IgG (1-2+) was demonstrated in the mesangium, which correlated with scattered electron dense mesangial deposits demonstrated by electron microscopy. Treatment with an angiotensin-converting enzyme inhibitor led to an improvement in proteinuria to near-normal values (urine protein/creatinine ratio down to 0.5), but the creatinine clearance declined to approximately 58 ml/min/1.73 m(2). This case highlights the possible association between the milder hypokalemic tubulopathy, GS, and glomerular disease, including C1qN. Prompt evaluation of proteinuria with renal biopsy in these patients is recommended to detect significant glomerular pathology. Further research is needed to define risk factors for this complication.
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PMID:C1q nephropathy in association with Gitelman syndrome: a case report. 1704 81

C1q nephropathy (C1qNP) is a controversial and uncommon form of glomerulonephritis, characterized by mesangial immunoglobulin and complement deposits, predominantly C1q, with no evidence of systemic lupus erythematosus. Clinically, it may present as nephrotic syndrome and non-nephrotic proteinuria per se or associated with microhematuria, hypertension, or renal insufficiency. We describe two sisters with C1qNP, who presented with steroid-resistant nephrotic syndrome. Both sisters presented before the age of 2 years, and they showed a poor response to other immunosuppressive therapy. Both girls had normal serum complement levels, negative antinuclear antibodies (ANAs) and negative hepatitis B antigen. Renal biopsy in both patients showed histological features of mesangioproliferative glomerulonephritis, with diffuse "full-house" positive immunofluorescence reaction in the mesangial area. The immunofluorescence reaction for C1q was most intense and co-dominant with IgG in both patients. Correspondingly, electron microscopy demonstrated dense deposits mainly in the mesangial areas too. We report on two young sisters with the characteristic features of C1qNP presented in early childhood. To the best of our knowledge, this is the first report of C1qNP in siblings.
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PMID:C1q nephropathy in two young sisters. 1795 93

C1q nephropathy is a proliferative glomerulopathy with extensive mesangial deposition of C1q. A three-year old boy presented with a nephrotic-range proteinuria during an acute phase of Epstein-Barr virus (EBV) infection, and he had a family history of Dent's disease. The renal biopsy findings were compatible with C1q nephropathy. However, EBV in situ hybridization was negative. The CLCN5 gene analysis revealed an R637X hemizygous mutation, which was the same as that detected in his maternal cousin, the proband of the family. The causal relationship between EBV infection and C1q nephropathy remains to be determined. Moreover, the effects of underlying Dent's disease in the process of C1q nephropathy has to be considered.
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PMID:Proteinuria in a boy with infectious mononucleosis, C1q nephropathy, and Dent's disease. 1798 49

C1q nephropathy is an uncommon glomerular disease with characteristic features on immunofluorescence microscopy. In this report, clinicopathologic correlations and outcomes are presented for 72 patients with C1q nephropathy. The study comprised 82 kidney biopsies from 28 children and 54 adults with male preponderance (68%). Immunofluorescence microscopy showed dominant or co-dominant staining for C1q in the mesangium and occasional glomerular capillary walls. Electron-dense deposits were observed in 48 of 53 cases. Light microscopy revealed no lesions (n = 27), focal segmental glomerulosclerosis (FSGS; n = 11), proliferative glomerulonephritis (n = 20), or various other lesions (n = 14). Clinical presentations in the patients who had no lesions histology were normal urine examination (7%), asymptomatic hematuria and/or proteinuria (22%), and nephrotic syndrome (minimal change-like lesion; 63%), which frequently relapsed. All patients with FSGS presented with nephrotic syndrome. Those with proliferative glomerulonephritis usually presented with chronic kidney disease (75%) or asymptomatic urine abnormalities (20%). Of the patients with sufficient follow-up data, complete remission of the nephrotic syndrome occurred in 77% of those with a minimal change-like lesion, progression to end-stage renal disease occurred in 33% of those with FSGS, and renal disease remained stable in 57% of those with proliferative glomerulonephritis. In conclusion, this study identified two predominant clinicopathologic subsets of C1q nephropathy: (1) Podocytopathy with a minimal change-like lesion or FSGS, which typically presents with nephrotic syndrome, and (2) a typical immune complex-mediated glomerular disease that varies from no glomerular lesions to diverse forms of glomerular proliferation, which typically presents as chronic kidney disease. Clinical presentation, histology, outcomes, and presumably pathogenesis of C1q nephropathy are heterogeneous.
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PMID:Pathology, clinical presentations, and outcomes of C1q nephropathy. 1865 Apr 84

C1q nephropathy, first proposed by Jennette and Hipp [Am J Clin Pathol 83:415-420, 1985; Am J Kidney Dis 6:103-110, 1985], was described as a distinct glomerular disease entity characterized by extensive mesangial deposition of C1q, with associated mesangial immune complexes, and the absence of any clinical and laboratory evidence of systemic lupus erythematosus. Now, 20 years since the first report, the disease entity is gradually attaining recognition, particularly in the field of pediatrics. C1q is the subcomponent of C1 in the classical pathway of complement activation. Generally, C1q deposition is caused by the activation of C1 by immunoglobulin G (IgG) and IgM; therefore, C1q nephropathy is considered as an immune complex glomerulonephritis. However, in C1q nephropathy, it remains unclear whether the deposition of C1q in the glomeruli is in response to the deposition of immunoglobulin or immune complex, or whether deposition is non-specific trapping that accompanies increased glomerular protein trafficking associated with proteinuria. Since not only the pathogenesis of C1q deposition in glomeruli but also its significance are still uncertain, it has not yet been established as an independent disease. From recent publications of the clinical and pathological characterizations, C1q nephropathy has been thought to be a subgroup of primary focal segmental glomerular sclerosis. However, many reports describe different symptoms, histopathologies, therapeutic responses and prognoses, suggesting that C1q nephropathy is not a single disease entity, but that it may be a combination of several disease groups. There are many uncertain areas requiring further investigation, though it is hoped that a detailed examination of future cases will clarify the subgroups making up C1q nephropathy and their clinicopathological characteristics, and will lead to the establishment of C1q nephropathy as an independent disease entity.
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PMID:Current status and issues of C1q nephropathy. 1937 20

C1q nephropathy is a rare glomerular disease characterized by mesangial immune deposits with dominant or codominant staining for C1q. The exact pathogenesis leading to the mesangial immune deposits of C1q remains unknown. C1q nephropathy often presents with proteinuria in the nephrotic range, with an unpredictable or poor response to corticosteroid therapy. It is seen more commonly in older children and young adults and is more common in African Americans compared with Caucasians. We present a 4-year-old African American girl who presented with recurrent gross hematuria in the absence of proteinuria or hypertension and whose renal biopsy demonstrated dominant mesangial deposits of C1q. We conclude that C1q nephropathy should be considered in patients who present with recurrent gross hematuria.
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PMID:C1q nephropathy in a child presenting with recurrent gross hematuria. 1966 67

Steroid resistant nephrotic syndrome (SRNS) remains a challenge facing pediatric nephrologists. The underlying histopathology usually affects the course of the disease and the response to treatment. We studied the pattern of histopathology in children with SRNS who presented to the King Abdul Aziz University Hospital (KAUH), Jeddah, Saudi Arabia. The records of all children with primary SRNS, who were seen between 2002 and 2007 were reviewed. Only patients who had undergone a renal biopsy were included in the study. The histopathology slides were reviewed by two renal pathologists independently. Patients with congenital nephrotic syndrome, lupus or sickle cell disease, were excluded from the study. Thirty-six children fulfilled the inclusion criteria, and included 25 girls and 11 boys with female to male ratio of 2.3:1. Fifty percent of the children (n=18) were Saudi and the remaining 50% were from various other racial backgrounds (9 Asians, 4 Arabs, 2 Africans and 3 from the Far East). Their mean age at presentation was 4.3 +/- 3.0 years (range 1-12 years). The mean serum albumin at presentation was 15.6 +/- 7.1 g/L and all of them had 4+ proteinuria on urinalysis. Five children had elevated serum creatinine at presentation while the mean serum creatinine was 50.4 +/- 45.6 micromol/L. Three children had low serum complement levels at presentation and none were positive for hepatitis B surface antigen or antinuclear antibody (ANA). The renal histopathology was compatible with focal and segmental glomerulosclerosis (FSGS) in 39% (n=14), IgM nephro-pathy in 28% (n=10), mesengioproliferative glomerulonephritis (MesPGN) in 17% (n=6), mini-mal change disease (MCD) and C1q nephropathy (C1qNP) in 8% each (n=3 + 3) and IgA nephro-pathy in 3% (n=1). Our retrospective review shows that FSGS was the commonest underlying histopathology in children who presented with SRNS followed by IgM nephropathy and other variants of MCD such as MesPGN. C1qNP was the underlying cause in some children.
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PMID:Pattern of steroid resistant nephrotic syndrome in children living in the kingdom of Saudi Arabia: a single center study. 1973 91

C1q nephropathy is an uncommon glomerular disease characterized by dominant or codominant mesangial staining for C1q in the absence of systemic lupus erythematosus. There are no series in the literature addressing the significance of C1q deposition in the renal allograft. We retrospectively analyzed 24 patients, most of whom were white (83%) and male (63%), with a mean age at transplant of 31 years. None of the patients were diagnosed with C1q nephropathy in the native kidney or had any features of systemic lupus erythematosus. The mean time from transplant to detection of mesangial C1q deposits was 37 months (>12 months in 71% of cases). Half of the patients had a preceding infection. The indication for biopsy was surveillance (63%) or graft dysfunction (37%). At biopsy, 52% had proteinuria (>1g/day in only 17%). The mean creatinine was 1.8 mg per 100 ml. Only 9% developed hematuria and none had hypoalbuminemia. The glomerular pattern on light microscopy was mesangial hypercellularity (46%), focal segmental glomerulosclerosis (21%), or no lesions (33%). All cases showed intense (>or=2+) dominant (67%) or codominant (33%) mesangial staining for C1q on immunofluorescence. Mesangial electron-dense deposits were seen in 82% of cases. On follow-up (mean 1 year) of the 10 patients without rejection, most had stable creatinine with no or stable proteinuria, and none lost their graft. We conclude that C1q-dominant mesangial deposition in the renal allograft is a morphological pattern with no apparent clinical significance in the majority of patients. It is usually detected after the first year. The rate of preceding infection and the prevalence of proteinuria seem to be similar to the renal transplant recipients in general. Most cases show mesangial hypercellularity or no glomerular changes on light microscopy.
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PMID:C1q deposition in the renal allograft: a report of 24 cases. 2047 74


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