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Biomedical subjects

R Coppo

Publications and source records attributed to R Coppo.

At least 55 records · Page 3Linked to original sources
PubMed1995

Report on intensive treatment of extracapillary glomerulonephritis with focus on crescentic IgA nephropathy.

UNLABELLED: PURPOSE AND DESIGN OF STUDY: In this retrospective analysis the effects of combined treatment with steroid pulses, cyclophosphamide and plasma exchange on six crescentic IgA glomerulonephritis (IgAGN) patients, selected on a histological basis, were examined. The histological criteria included involvement of more than 40% of glomeruli by cellular crescents. The effects of this treatment were compared to those observed in three untreated crescentic IgAGN patients and 12 treated patients who had extracapillary glomerulonephritis of different origins, i.e. ANCA-associated systemic or renal-limited vasculitis. All patients, except the three crescentic untreated IgAGN patients, received the same 2-month treatment according to a standardized protocol: steroid boli 15 mg/kg methylprednisolone for 3 consecutive days by intravenous infusion, followed by prednisone per os (1 mg/kg/day for 4 weeks, 0.75 mg/kg/day for 4 more weeks), cyclophosphamide per os 2.5 mg/kg/day for 8 weeks, and plasma exchange. RESULTS: After this 2-month course of therapy, substantial clinical improvement was observed in both IgAGN and vasculitis patients. However, a second biopsy revealed that florid crescents persisted in IgAGN patients and, unlike the vasculitis group, during the long-term the initial clinical amelioration disappeared in one-half of the treated IgAGN cases. Nevertheless, even in the progressive cases, intensive treatment seemed to substantially delay the onset of dialysis. CONCLUSIONS: Despite some clinical benefits of therapy, short-term reversal of active crescents appears less likely to occur in crescentic IgAGN than in vasculitis-associated crescentic GN. Intensive treatment seems sufficient to arrest, but inadequate to reverse, phlogistic lesions in IgAGN before development of chronic changes.

Adolescent↗
PubMed1994

Functional consequences of the binding of gliadin to cultured rat mesangial cells: bridging immunoglobulin A to cells and modulation of eicosanoid synthesis and altered cytokine production.

Oral immunization with gliadin (GLI) can induce immunoglobulin A mesangial deposits (IgA nephropathy [IgAN]) in mice. A role for GLI in human IgAN has been inferred from an association with celiac disease, increased serum anti-GLI IgA in patients with IgAN, and benefit from a gluten-free diet observed in some IgAN patients. These effects might be due to the antigenic or lectinic properties of GLI. The aim of our study was to investigate whether GLI binding to glycosylated residues (ie, lectinic activity) favors binding of GLI to cultured rat mesangial cells, bridging IgA macromolecules. We also sought to determine whether GLI binding alters mesangial cell function. Gliadin binds to rat mesangial cells in the third and fourth passages, as determined by immunofluorescence. Gliadin binding is inhibited by co-incubation with 1 mol/L N-acetyl-D-glucosamine and 1 mol/L alpha-D-mannose, sugars competitive for this lectinic bond. Quantification by biotinylated GLI revealed a significant dose-dependent binding of GLI (P < 0.001) inhibited by N-acetyl-D-glucosamine (P < 0.05). Some saccharolytic enzymes, like invertase, modify the cell surface to decrease GLI binding (P < 0.02). In addition, GLI promoted the binding of purified mouse polymeric IgA to mesangial cells. The binding of GLI to mesangial cells modulates arachidonic acid metabolism by cultured mesangial cells, significantly inhibiting prostaglandin E2 production (P < 0.02), increasing synthesis of thromboxane B2 (P < 0.01) and tumor necrosis factor (P < 0.001), but not interleukin-1 beta. These responses were abrogated by co-incubation with N-acetyl-D-glucosamine and/or pretreatment with invertase. Non-immune binding of an environmental alimentary lectin, GLI, to mesangial cells in culture might favor the binding of IgA and IgAIC to mesangial cells, enhancing both IgA mesangial trapping and in situ IgA deposit formation. This could occur via GLI-specific antibodies or by virtue of the binding of nonspecific IgA on a lectinic basis, or both. Moreover, related changes in eicosanoid synthesis might stimulate mesangial cell growth and mesangial matrix production, together with mesangial cell contraction, contributing to the pathogenesis of IgAN.

Animals↗
PubMed1994

[Optimization of the treatment of idiopathic nephrotic syndrome in children].

From 1981 to 1992, 81 children affected by idiopathic nephrotic syndrome were treated in our Division. The majority were males (74%), with mean age at diagnosis of 4.8 (0-14)) years. They had a mean follow-up of 5.7 (0.5-11) years. The renal function at diagnosis was normal in all cases, proteinuria was selective in 86.4% of the cases. 28 children with somehow atypical behaviour underwent renal biopsy. In this negatively selected group the more frequent histologic forms were focal segmental glomerular sclerosis (33.5%), minimal change disease (37.4%), IgM mesangial glomerulonephritis (16.6%), membranous nephropathy (12.5%). First choice drug was in all cases prednisone. In the last years the trend for steroid therapy was to adopt long protocols (16 weeks), with a total dose of 105-133 mg/kg per therapeutic cycle. About 90% of children had a favourable response to steroids, but half of them were frequent relapser. In these cases the long term stable remission was obtained with steroids alone in 10.8% of the cases, with the association of cyclophosphamide in 62%. In a minor fraction and in the steroid resistant (13.6% of the total cases) levamisol and cyclosporin were also adopted. 2.4% of the cases progressed to end stage chronic renal failure. Most of the steroid sensitive children were in remission after 3-4 years of disease, only 6% relapsed more than 5 years after diagnosis.

Adolescent↗
PubMed1994

[IgA serology in idiopathic IgA deposit nephropathy in children].

It is generally thought that in primary IgA nephropathy (IgAN) an altered immune response favours high levels of serum IgA directed against environmental or mesangial antigens (Ag) leading to circulating IgA containing immune complexes (IgAIC). The aim of this multicenter collaborative study was to evaluate some of the IgA immunologic abnormalities in children with IgAN. We investigated 42 children with biopsy-proved IgAN, 21 children with non-IgA glomerulonephritides (CD) and 15 with previous urologic disorders without any evidence of immunologic disease (U). The following methods were used: detection of macromolecular IgA (IgAIC by the conglutinin solid-phase assay, heavy MW IgA measured in 2.5% polyethylene glycol precipitate, IgA-fibronectin aggregates, mixed IgA-IgGIC); serum levels of IgA to alimentary Ags (gliadin, glyc-gli, ovalbumin, bovine serum albumin) and mesangial Ags (fibronectin, laminin, type IV collagen) and reactivity of IgA with the lectin jacalin. In children affected with IgAN serum levels of macromolecular IgA were significantly higher in comparison to U group (p < 0.05-p < 0.0005). IgA-fibronectin aggregates only were significantly higher also than CD group (p < 0.0005). Mean levels of antigliadin IgA were significantly higher in IgAN than in controls (CD p < 0.01 and U p < 0.03) and similar data were found for IgA to mesangial matrix (laminin and fibronectin), which were significantly greater in IgAN than in CD and U (p < 0.01-p < 0.0002). Serum IgA in children with IgAN showed a greater affinity for both polycations and glycosylated molecules. Children affected by IgAN present abnormalities in serum IgA similar to those observed in adults with the same disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Experimental IgA nephropathy secondary to hepatocellular injury induced by dietary deficiencies and heavy alcohol intake.

BACKGROUND: In humans, alcoholic liver disease is frequently associated with IgA mesangial deposits, microscopic hematuria and a small amount of proteinuria, identifying a secondary form of IgA nephropathy. Alcoholic liver disease is almost always associated with nutritional deficiencies. EXPERIMENTAL DESIGN: In order to examine the relationship between alcohol intake and/or inadequate diet and IgA nephropathy, groups of 4 week-old-male Lewis rats were maintained on a lipotrope-deficient (LD) diet (N = 20), intragastric infusions of a commercial whiskey (1.5 ml/100 gm body weight) three times a week, and regular chow (N = 23) or both intragastric whiskey infusion and an LD diet (N = 17). A fourth control group (N = 19) was given no whiskey and normal chow. RESULTS: All rats given the LD diet had marked steatosis and elevated "liver" enzymes. Changes were more severe, and with early bridging fibrosis and nodule formation in those also given whiskey, associated with increased hepatic content of mRNA encoding transforming growth factor-beta. A moderate steatosis without alteration in serum enzymes or transforming growth factor-beta expression was found in rats given whiskey (all p < 0.0001) compared with controls. IgA accumulated in hepatic sinusoids instead of in canaliculi and bile ducts, suggesting impaired transport of IgA and IgA immune complexes from blood to bile, in rats given an LD diet and/or whiskey infusion. A moderate increase in mesangial matrix was observed only in rats given both whiskey and an LD diet. Bright granular IgA and mild granular C3 mesangial deposits and electron-dense deposits were evident in 63 to 70% of experimental rats (all p < 0.001) versus only trace deposits in 5 to 11% of controls. Moderate IgG codeposits were present in 34 to 55% of rats given the LD diet and/or whiskey (all p < 0.02), versus trace deposits in 10% of controls. Significant hematuria and proteinuria were observed in rats given the LD diet and/or whiskey (p < 0.0001) versus controls. Intestinal permeability measured by xylose absorption was significantly increased relative to controls only in rats given both whiskey and the LD diet (p < 0.001). Serum IgA specific for selected alimentary antigens was increased relative to controls in 75 to 100% of the experimental rats. CONCLUSIONS: The combination of LD diet and alcohol intake, which mimics the human alcoholic condition, promotes hepatic and renal changes, leading to hepatocellular injury and a secondary form of IgA nephropathy.

Alcoholism↗
PubMed1993

Angiotensin II local hyperreactivity in the progression of IgA nephropathy.

Immunologic and hemodynamic factors are likely to work in synergism in the progression of immunoglobulin A nephropathy (IgAN) toward sclerosis. The local activation of the renin-angiotensin system may be one the most relevant mechanisms. We investigated the hemodynamic effects of the acute administration of angiotensin-converting enzyme inhibitor (ACEI) (captopril 50 mg). The glomerular filtration rate (GFR) and the effective renal plasma flow (ERPF) were measured by 51Cr-EDTA and 125I hippurate clearances. The correspondent filtration fractions (FFs) in basal conditions and after administration of ACEI were calculated, then the changes in FF (delta FF and % delta FF) were determined. We studied 27 IgAN patients. Eighteen patients had normal renal function (GFR, 112 +/- 19 mL/min/1.73 m2) and nine had moderate renal impairment (GFR, 54 +/- 13 mL/min/1.73 m2). Sixteen patients had proteinuria > or = 0.5 g/d. In addition, 12 glomerulonephritis control cases and eight healthy subjects were investigated. After the administration of ACEI in healthy subjects we observed slight modifications in the GFR, a significant increase in the ERPF (P < 0.005), and a significant decrease in FF (P < 0.04). Similarly, in IgAN patients with normal renal function the GFR increased slightly, the ERPF increased significantly (P < 0.01), and there was a decrease in FF (P < 0.01). The delta FF and % delta FF values were not significantly different from those found in the controls. In patients with initial renal failure GFR remained unchanged, ERPF increased significantly (P < 0.005), and FF significantly decreased (P < 0.004). However, the changes in delta FF and % delta FF were significantly greater than those found in healthy controls (P < 0.01) and in IgAN patients with normal renal function (P < 0.001). IgAN patients with proteinuria levels > or = 0.5 g/d showed greater changes in delta FF and % delta FF after the administration of ACEI than patients with proteinuria levels lower than 0.5 g/d (P < 0.003 and P < 0.04, respectively) or proteinuric control cases (P < 0.05 and P < 0.01, respectively). This different response in proteinuric and nonproteinuric patients was evident even when the analysis was limited to the subgroup of IgAN patients with normal renal function. The decrease in FF consequent to an increase in the ERPF after the administration of ACEI suggests a local hyperactivity of the renin-angiotensin system in some cases of IgAN.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

Role of monocytes in cryoglobulinemia-associated nephritis.

Several monocyte-macrophage functions were found to be defective in cryoglobulinemic patients. Nevertheless, monocytes actively phagocytizing cryoglobulins have been frequently found in kidney specimens from these patients. Whether subsequent degradation of the ingested immune material is effective, however, is still unknown. Monocytes from eight cryoglobulinemic patients (4 with active disease and associated nephritis and 4 inactive cases without nephritis) and eight normal controls of same sex and similar age were analyzed. Monocytes from patients with active cryoglobulinemia and associated nephritis were found to be able to ingest, but unable to catabolize, cryoglobulins, as shown by electron microscopy using gold-labeled goat IgG to human IgG and IgM in 18-hour cultured suspensions. Synthesis and maturation of monocyte cathepsin D, one of the most important lysosomal proteases, were analyzed in the same subjects. Purified monocytes were cultured in presence or absence of cryoglobulins for 18 hours at 37 degrees C in RPMI medium and labeled with 35S-methionine. The various forms of cathepsin D were separated by electrophoresis and visualized by fluorography. Results from cultures of monocytes from clinically active cryoglobulinemic patients with nephritis suggest that intracellular transport of newly synthesized cathepsin D was impaired and the release into the medium of precursor polypeptides of the enzyme enhanced in each experimental condition. Since procathepsin D is susceptible to activation in pathologic conditions lowering local pH (such as in inflamed tissues), these data suggest that monocytes from patients with active cryoglobulinemia and associated nephritis have a propensity to exert phlogistic effects via secretion of procathepsin D in tissues.

Adult↗
PubMed1993

Dose-dependent effects of deflazacort and prednisone on growth and skeletal maturation.

Deflazacort (DFZ), a new glucocorticoid which has recently become available, is expected to have less negative effects on growth and skeletal maturation than conventional steroids, in children treated long term. To verify this hypothesis, a multicentre trial was organized to evaluate the effects of DFZ vs prednisone (PDN) on statural growth and skeletal maturation in a group of prepubertal children requiring glucocorticoid therapy for at least 6 months/year. The results of an analysis of 55 children (aged 3-12 years, 24 with connective tissue disease and 31 with kidney glomerular disorders) treated randomly with either DFZ (31 patients) or PDN (24 patients) and followed for a mean period of about 22 months (16 months under steroid therapy) are presented. The observation period was split up into the following phases according to dose and administration regimen: daily, high-dose therapy; alternate-day, high-dose therapy; low-dose therapy; suspension of treatment. The height, statural age, skeletal age and body weight velocities (i.e. the increase/year) were considered. In spite of large intra-individual and inter-individual variability, the results suggest that DFZ has a lower negative impact on indicators of growth. During high-dose daily administration, the height velocity tended to be lower in the PDN group and the impairment of skeletal maturity was significantly less for DFZ than for PDN. During an alternate-day regimen, height velocity was slightly higher in the PDN group and skeletal age velocity was higher in the DFZ group. It seems that steroid effects on statural growth and bone maturation occur in parallel.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Determination by Skeleton↗
PubMed1993

Removal systems of immunoglobulin A and immunoglobulin A containing complexes in IgA nephropathy and cirrhosis patients. The role of asialoglycoprotein receptors.

BACKGROUND: Whereas the complex removal routes hypothesized for IgA containing immune complexes (IC) and macromolecules can be adequately analyzed by a recently proposed IgA1-IgG aggregate probe (Lab Invest, 66: 86-95), the relative significance of the asialoglycoprotein receptors in IgAIC clearance is still uncertain. EXPERIMENTAL DESIGN: The removal kinetics of 99mTc diethylenetriamine-pentaacetic acid-conjugated asialo alpha 1 acid glycoprotein (AAGP) and 123I-labeled IgA1-IgG aggregate were analyzed in 11 cirrhosis patients and 13 IgAN patients of comparable age. RESULTS: IgA1-IgG aggregate mean plasma clearance rate was delayed in IgA neuropathy (IgAN) patients (slope 0.038 minutes-1, range 0.027 to 0.053) compared with normals (0.047 minutes-1, range 0.038 to 0.053, p = 0.05). The liver was the main organ involved in the IgA1-IgG removal. When compared with normals, (34.3 minutes, range 29.8 to 42.2), the liver mean transit time (MTT) was significantly (p < 0.02) prolonged in IgAN patients (41.3 minutes, 33.6 to 52.3). Participation of spleen in clearance was observed in some patients and was almost invariably concurrent with normal clearance parameters. Conversely, 9 out of 11 cirrhosis patients had a remarkable splenic uptake, but the blood clearance rate was invariably delayed (0.022 minutes-1, 0.014 to 0.028, p < 0.003) and liver MTT extremely prolonged (122.4 minutes, 52.4 to 400, p < 0.003). In IgAN patients with delayed clearance of the IgA1-IgG aggregate, a distinct trend of progression towards renal failure was noted. AAGP clearance was also delayed in cirrhosis patients: slope = 0.166 minutes-1, 0.108 to 0.247, p = 0.05 as compared with both normals (0.230, 0.173 to 0.289) and IgAN patients (0.250, 0.184 to 0.254). Liver MTT in cirrhosis patients was extremely prolonged: 240.6 minutes, 132.5 to 400 minutes, p < 0.007 compared with both normals (90.0 minutes, 82.7 to 96.6) and IgA patients (92.2 minutes, 70.3 to 107.1). AAGP clearance parameters in normals and IgAN patients were not statistically different. MTT values of AAGP and IgA1-IgG aggregate were strictly related (p = 0.008), suggesting that asialoglycoprotein receptors are partially involved in the clearance of the IgA1-IgG aggregate probe. CONCLUSIONS: Some patients with IgAN have a prolonged circulation of an IgAIC miming probe, probably due to an impaired macrophage function. Other possibilities of prolonged circulation of IgAIC in these patients should imply an abnormal IgA glycosylation pattern that allows IC to escape from an effective asialoglycoprotein receptor system. In cirrhosis patients, all of the removal routes of IgA and IgA containing IC are greatly altered suggesting a causative role in the development of an associated, often clinically inapparent, glomerular disease.

Adult↗
PubMed1993

Glomerular permselectivity to macromolecules in reflux nephropathy: microalbuminuria during acute hyperfiltration due to aminoacid infusion.

Reflux nephropathy is an important cause of chronic renal failure in children. After the parenchymal scar, the progression is thought to be mediated by glomerular hypertension in remnant nephrons resulting in modifications in permselectivity to macromolecules. Proteinuria correlates with a progressive course. The glomerular permselectivity to macromolecules in basal conditions and after acute hemodynamic stress was investigated in 28 children whose bilateral vesico-ureteric reflux (VUR) had been previously surgically corrected (meanly 5.6 years before) and with normal creatinine clearance (CrCl). Bilateral renal scarring (0 to 8 scale for both kidneys) was 4.3 +/- 1.6. Albuminuria (UAE) was evaluated in basal conditions and under acute hyperfiltration induced by amino acid (Aa) infusion. After isotonic saline at 310 ml/hour/1.73 m2, 6 mg/kg/min of Aa were infused for 2 hrs. UAE was significantly higher than controls in basal conditions (p < 0.01), and further increased after Aa infusion (p < 0.02). Microalbuminuria was detectable in 53.5% of the children in basal conditions and in 64.3% after Aa. Also urinary beta 2 microglobulin significantly increased at the end of the test (p < 0.001). CrCl significantly increased at the first hour (p < 0.05). Children with severe renal parenchymal scarring had greater UAE (p < 0.01) and beta 2M (p < 0.02) values after provocative test than those with mild renal damage. In 8 children GFR and ERPF were measured by means of inulin and p-hippurate clearance respectively. The variations in UAE during Aa infusion were significantly correlated with GFR dynamics (p < 0.05) while they were not influenced by ERPF modifications.(ABSTRACT TRUNCATED AT 250 WORDS)

Albuminuria↗
PubMed1993

Cytokine mRNA expression by cultured rat mesangial cells after contact with environmental lectins.

We previously demonstrated that gliadin, a lectinic component of gluten, induces IgA mesangial deposits in orally immunized mice, binds in vitro polymeric IgA and cultured rat mesangial cells modulating their arachidonic acid metabolism. We investigated the effects of gliadin and other environmental lectins on some mesangial cell functions, including synthesis and release of cytokines and lipid mediators. Several lectins, particularly gliadin, affected the mRNA expression of c-myc and c-fos, two proto-oncogenes involved in the transcriptional enhancement of the gene cascade, which are markers of cell growth, differentiation and mitosis. Lectins modulated the ability of cultured rat mesangial cells to express mRNA for cytokines involved in the inflammation and in the regulation of the immune response. TNF-alpha and IL-6 mRNA transcription were enhanced by gliadin and other lectins, and TNF release was variably increased. Conversely, IL-1 production was less affected or slightly depressed. PAF production was not detectable while PGE2 was generally reduced and TXB2 enhanced. Gliadin was one of the lectins most active on the mesangial cells, and its effects were reversed by the addition of N-Acetylglucosamine, a sugar specific for some lectinic bindings, suggesting a carbohydrate interaction. The effects of the various lectins were distinct and only partially convergent, ruling out an aspecific mesangial cell activation. These data suggest that lectins might interfere with mesangial cell functions and modify the mesangial cell homeostasis.

Animals↗
PubMed1992

Do IgA antigliadin and IgA antiendomysium antibodies show there is latent coeliac disease in primary IgA nephropathy?

The finding in primary IgA nephropathy of increased levels of IgA to food antigens and particularly to gliadin prompted the hypothesis that a subgroup of these patients may have latent coeliac disease. The observation that gliadin may experimentally induce IgA mesangial deposits supported this hypothesis. We evaluated specific immunological markers of coeliac disease (antiendomysium antibodies) which parallel histological changes of gluten sensitive enteropathy, and an IgA immunofluorescent test for antigliadin antibodies in 18 patients with IgA nephropathy, in 56 untreated coeliac disease patients, in 254 controls (58 healthy and 196 disease controls). Antiendomysium antibodies were positive in 89.28% of coeliac patients, but negative in all IgA nephropathies and controls. IgA immunofluorescent test for antigliadin antibodies, negative in all IgA nephropathy patients, was positive in 76.78% of coeliac patients and in 4.91% of controls. ELISA IgA antigliadin antibodies were negative in controls, but positive in 22.22% of IgA nephropathy patients and in 60.71% of coeliac patients. Our data would suggest that in most patients with IgA nephropathy there is no evidence of latent coeliac disease.

Adult↗
PubMed1992

Macromolecular properties that promote mesangial binding and mesangiopathic nephritis.

The hydrodynamic size, electrostatic charge, and specificity are established determinants of the site of glomerular localization of macromolecules. Larger macromolecules or aggregates and anionic charge are associated with mesangial deposits, despite the fact that the mesangial matrix bears a negative charge similar to that of the capillary wall. Antigens such as Sendai virus, a model infectious pathogen, gliadin, a model dietary/environmental agent and fibronectin, a model endogenous macromolecule, bind to mesangial cells in vitro on the basis of cell surface glycoconjugates. Nonantibody immunoglobulin A, which does not bind to cells directly, binds to these elements via different carbohydrate specificities (simple sugar inhibition). Such binding promotes or augments macromolecular deposition in the mesangium. More significantly, mesangial deposits per se are not pathogenic, because normal renal function can be observed with florid deposits. Pathogenic deposits must have properties that alter mesangial cell metabolism or interaction with the matrix. Although complement activation is well recognized, complement-independent mechanisms related to cell surface modulation are being recognized. In vitro, antigen/immunoglobulin A aggregates alter mesangial cell eicosanoid synthesis. In vivo, large-lattice cross-linking by particulate antigen promotes hematuria. We conclude that the binding of macromolecules to cells and the cross-linking of cell surface molecules cause alterations in the mesangial cells and therefore in glomerular function. The mesangial cell, rather than a passive respondent, is an active participant in the genesis of glomerulonephritis.

Animals↗
PubMed1992

Dietary antigens and primary immunoglobulin A nephropathy.

To investigate the role of dietary components in immunoglobulin A mesangial nephropathy (IgAGN), this study focused on gliadin, based on the reported association between coeliac disease and IgAGN as well as the pilot observation that a gluten-free diet was able to reduce the levels of circulating IgA immune complexes (IgAIC). IgA mesangial deposits in mice were induced by oral immunization with gliadin and in rats by inducing alcoholic liver cirrhosis, which increased the levels of IgA against dietary antigens (Ag). Gliadin was able to bind to cultured mesangial cells by a lectinic bond, which was reversed by competitive sugars. Binding increased mesangial cell tumor necrosis factor synthesis and decreased prostaglandin E2 production. Several gluten lectinic fractions modulate leukocyte oxidative metabolism, cytotoxicity, and chemotaxis. In IgAGN patients, serum IgA to dietary Ag were sporadically positive and IgAIC containing IgA to dietary components were significantly increased. The affinity of serum IgA to various lectins was increased in some patients. Conversely, no substantial deposition in renal tissue of dietary Ags was observed by immunofluorescence. A gluten-free diet, given to IgAGN patients with high levels of circulating IgAIC and positive antigliadin IgA, was followed by a decrease in the mean levels of both IgAIC and IgA to various dietary Ag, parallel to a reduction in proteinuria. These data suggest that dietary components, such as Ag or lectins, may play a role in IgAGN by promoting IgAIC formation and perhaps favoring mesangial localization via lectinic interactions.

Animals↗
PubMed1992

Kinetics and fate of IgA-IgG aggregates as a model of naturally occurring immune complexes in IgA nephropathy.

The characteristic granular IgA immunofluorescent pattern in the kidneys of IgA nephropathy patients is consistent with immune complex pathogenesis. The possibility of a delayed clearance of IgA-containing immune complexes from circulation in IgA nephropathy patients is still under discussion. Since pure IgA immune complexes are probably nonphlogistic, (in contrast to IgG-containing IgA immune complexes), the in vivo clearance of a mixture of heat-aggregated IgA/G purified from pooled human sera was analyzed. The test probe was efficiently labeled with 123I and the time course of radioactivity was measured by a gamma-camera. Both the liver and the spleen were found to be involved in the disappearance of IgA/G complexes. Liver accumulation, which was markedly predominant, closely approximates a gamma-variate function which allowed determination of a mean transit time of 34.37 minutes, range 29.8 to 42.2, in 8 normal and 37.54 minutes, range 30.9 to 50.7 in 17 patients (p less than 0.04). At 2 hours, segmental gut accumulation was found, which demonstrated removal by hepatobiliary system as well. Compartmental analysis in patients indicated 3 major compartments represented by vascular bed, hepatobiliary and reticuloendothelial systems (including both liver and spleen phagocytes). Blood clearance rate, representing the final result of multiorgan removal of the test probe from the blood stream, was found to be significantly delayed in IgA nephropathy patients with a slope (0.035 min-1, range 0.019 to 0.052) significantly less negative compared with controls (0.047 min-1, range 0.038 to 0.053, p less than 0.01). This test probe was able to reproduce both removal routes (macrophages cells and hepatobiliary system) hypothesized for IgA-containing immune complexes in humans.

Adult↗
PubMed1991

Comparison of growth retarding effects induced by two different glucocorticoids in prepubertal sick children: an interim long-term analysis.

The low interference with growth expected in child for a cortisol analogue, deflazacort (DFZ), prompted us to verify if DFZ could affect growth less than prednisone (PDN). An interim analysis relative to 27 girls and 38 boys (out of 100 expected) aged 3-12 yrs, after a median period of 14 mo.s is reported. Children with connective tissues (CTD) and glomerular disorders (KD) were randomly allocated to DFZ or PDN. Anthropometric measurements and maturity ratings were performed. Mean daily doses of PDN (or DFZ equivalent), from 0.57 to 0.64 mg/kg (DFZ 0.92 to 0.94 mg/kg) to induce control and from 0.19 to 0.39 mg/kg (DFZ 0.34 to 0.36 mg/kg) to maintain disease under control were given in CTD and KD, respectively. The increase in bone age delay over time was significantly greater than for PDN (-4.0 mo/yr) than DFZ (-1.8 mo/yr) in the overall group. The increases in statural age delay and loss over time were significantly greater than for PDN (-5.9 and -5.9 mo/yr) than DFZ (-2.4 and -2.4 mo/yr), only in children with "taller" midparents. Although doses of DFZ 1.1-1.8 times those of PDN were given, growth retardation in PDN-treated children was nevertheless 2.3-2.5 times that in DFZ-ones.

Age Determination by Skeleton↗