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At least 415 records · Page 23Linked to original sources
PubMed1998

IgA nephropathy complicating diabetic glomerulosclerosis.

A retrospective study was done on 66 diabetic patients who had renal biopsies performed during 1979-1994. This review shows 10 patients who presented IgA nephropathy associated with diabetic nephropathy. Six patients had insulin-dependent diabetes mellitus and 4 patients non-insulin-dependent diabetes mellitus. All patients presented with proteinuria and 7 had hematuria. Four patients presented with renal impairment. Histologic evaluation disclosed the presence of thickened glomerular basement membranes and increased mesangial matrix in all cases, associated with nodular sclerosis in 8 cases. By immunofluorescence, diffuse mesangial IgA deposits were observed in all cases. The high incidence of the coexistence of IgA nephropathy and diabetes seems not merely coincidental. Structural and/or functional abnormalities of the glomerular basement membranes might facilitate the development of immune complex glomerular diseases. In patients with diabetes, the appearance of urinary abnormalities and/or deterioration in renal function altered the clinical history of diabetic nephropathy. The disorders are clinically suggestive of the presence of nondiabetic renal disease and raised the possibility of another pathogenetic mechanism.

Adult↗
PubMed2006

Role of complement and other innate immune mechanisms in the removal of apoptotic cells.

The complement system is regarded as an ancient host defense mechanism that helps to promote phagocytosis and/or killing of foreign microorganisms. Less well known is the facilitatory role that complement and other closely related molecules of the innate immune system play in the removal of dying cells. In this chapter, we review the complement system and the mechanisms of complement activation that include natural antibodies and acute phase proteins. The effects of spontaneous and genetically engineered mutations on function of these proteins and their relationship to autoimmune diseases such as lupus are discussed. We also review the known function of non-complement receptors and their roles in recognition and removal of dying cells in normal cellular homeostasis and in inflammation.

Acute-Phase Reaction↗
PubMedDate not supplied

Circulating immune complexes in patients with uncomplicated group A streptococcal pharyngitis and patients with acute poststreptococcal glomerulonephritis.

To investigate the role of circulating immune complexes (CIC) in the pathogenesis of acute poststreptococcal glomerulonephritis (AGN), sera were obtained serially from 13 patients with biopsy-proven AGN, 16 patients with group A streptococcal infection, and 20 age- and sex-matched controls. Samples were analysed for Clq-binding activity (Clq-BA), levels of IgG, IgA, IgM, C3 and C4, and antibody titres to streptococcal enzymes. Significant elevation of Clq-BA was observed in 11 patients (84.5%) with AGN and 7 patients (44%) with streptococcal infection alone. The data suggest that CIC do not necessarily cause glomerular damage, but rather represent a systemic inflammatory response in patients with group A streptococcal infection.

Adolescent↗
PubMed1990

Glomerulonephritis with organized deposits: a new clinicopathological entity? Light-, electron-microscopic and immunofluorescence study of 12 cases.

Twelve cases of glomerulonephritis in patients without systemic diseases, displaying organized glomerular deposits, were reported. Microfibrils (11-30 nm diameter) were found in 9 patients and microtubules (20-35 nm diameter) in the other 3. Histochemical stainings for amyloid were always negative. By light microscopy, mesangial proliferative, membranous and membranoproliferative patterns were seen in 5, 3 and 4 patients, respectively. By immunofluorescence, granular deposits, mainly of IgG and C3, were found in all cases, either in the mesangium or in the mesangium and in the capillary walls. A second biopsy was performed in 2 patients. The number of hyaline glomeruli was increased, but the general pattern of glomerular changes remained unchanged. The commonest clinical findings were hypertension, microhematuria and proteinuria, often of nephrotic range. At variance to what is reported in the literature, 2 pediatric cases were found as well, and the overall prognosis (mean follow-up 54.3 months) was mostly favorable. The diagnostic relevance of these findings is pointed out, but further investigations are needed, before suggesting a new clinicopathological entity.

Actin Cytoskeleton↗
PubMed1992

Comparative study of IgA nephropathy with acute and insidious onset. Clinical, laboratory and pathological findings.

In order to clarify the difference of clinical and pathological features between the IgA nephropathy patients with acute and insidious onset, 427 patients were examined in this study. Seventy-eight patients with acute onset (group 1) were often associated with mucosal system infections at the abrupt onset. This group revealed macroscopic hematuria, more severe microscopic hematuria (more than 20/hpf), higher glomerular filtration rate (p less than 0.01) and lower serum levels of C3 (p less than 0.01). It had also a significantly higher incidence of exudative lesions (p less than 0.001). On the other hand, the onset of 349 patients (group 2) was noticed to be insidious without preceding infections. This group showed a more severe increase in mesangial cells (p less than 0.01) and a significantly higher incidence of adhesion, arterial sclerosis and tubulointerstitial changes. Deposition of Clq, C4 and IgM and detachment of visceral epithelium from the basement membrane were more frequently seen in group 2. Twenty-seven of 345 patients followed for at least 1 year after the biopsy were on maintenance hemodialysis: 1 patient was in group 1 and 26 were in group 2. These results clarified that there was a difference in clinical, laboratory and histopathological findings between the patients with IgA nephropathy with acute and insidious onset.

Acute Disease↗
PubMed1982

Molecular weight of circulating immune complexes in patients with glomerulonephritis.

The Clq-binding test was used to detect circulating immune complexes in 86 patients with glomerulonephritis at the time of renal biopsy. By gel filtration of the sera it was possible to estimate the molecular weight in 24 of these patients. The molecular weight of circulating immune complexes varied from 150,000 to above 1.2 X 10(6) and was not related to the type of glomerulonephritis as defined by light microscopy, renal function, proteinuria, hematuria or antecedent infections. In 8 patients with rheumatoid arthritis and in 5 patients with secondary syphilis and no evidence or renal disease, only circulating immune complexes with a molecular weight below 1.2 X 10(6) were detected. 7 patients with glomerulonephritis had electron-dense deposits in glomeruli on electron microscopy, but the molecular weight of circulating immune complexes was not related to the site of the deposits on either side of the basement membrane.

Adult↗
PubMed1988

Discrepancy between effects of in vivo and in vitro administration of gammaglobulin on phagocytic killing of Streptococcus pneumoniae in an antibody-deficient serum.

Phagocytic killing of Streptococcus pneumoniae serotypes 6A, 14, 18C, 19F and 23F was investigated in the dysgammaglobulinemic serum of a patient with recurrent pneumococcal infections. Previous studies with this serum had established combined IgG2, IgG4 and IgA deficiency, deficiency with regard to specific antipolysaccharide antibodies and essentially normal complement functions. Phagocytic killing of all serotypes was reduced in the patient's serum. Addition of immunoglobulin in vitro enhanced both classical and alternative complement pathway mediated opsonization. In constitution experiments neither purified Clq nor CRP influenced phagocytic killing. Surprisingly, intramuscular administration of a fairly small dose of gammaglobulin to the patient was associated with a rapid increase in the serum opsonic activity for serotype 23F. The increased opsonization occurred before specific anticapsular antibodies were detectable in serum. The findings suggest that the possible effects of gammaglobulin treatment may not exclusively be related to the acquisition of serotype-specific antibodies.

Complement Activating Enzymes↗
PubMed1996

Complement activation by C-reactive protein on the HEp-2 cell substrate.

The complement (C) activation by C-reactive protein (CRP) in acute-phase sera is routinely tested in our laboratory by means of an indirect immunofluorescence method (C3-IFT) on rat kidney sections. This C3-IFT assay is based on the binding of CRP to the renal tissue followed by the fixation of C4 and C3 components to distinct vessel-associated medullary structures as a result of CRP-mediated C activation in vitro. While the activation cascade leading to the deposition of C4 and C3 could previously be deduced experimentally, we were unable as yet to visualize CRP and the components of the C1 complex on kidney sections when testing patients' sera by indirect immunofluorescence. In an attempt to analyze the mechanisms of unexpectedly negative C3-IFT results (e.g. bacterial endocarditis) we employed monolayers of fixed HEp-2 cells which have previously been shown to be a suitable substrate for CRP binding. By incubating purified native CRP supplemented with normal human serum as a source of C we detected the C components Clq, Clr, Cls, C4 and C3 in the same speckled immunofluorescent pattern on HEp-2 cell nuclei as described characteristically for CRP binding. The serial activation steps from CRP up to C3 could also be followed on HEp-2 cells using C3-IFT-positive acute-phase sera. However, certain C3-IFT-negative acute-phase sera showed an arrest between Cls and C4 of the CRP-mediated C activation cascade. HEp-2 cells can thus be used to monitor the process of autologous C activation initiated by endogeneous CRP in patients' sera. In contrast to native CRP, urea-modified CRP (mCRP) did not bind to HEp-2 cell nuclei, but was detected in association with distinct filamentous cytoplasmic structures. Unlike its native counterpart, binding of mCRP was not followed by a deposition of C components.

Animals↗
PubMed1988

Role of EAC1q4 in C1a transfer reaction (C1aTR) and further information on the nature of the EAC1q4 site.

The complement intermediates EAC1, EAC4, and EAC1q4 were prepared with guinea pig, porcine, as well as human complement. EAC4 and EAC1q4 were made from EC4 and EAC14 respectively. The C1a transfer reaction (C1aTR), the second step of Borsos' C1a fixation and transfer test, was carried out with various combinations of these intermediates. It was found that the EAC1q4, instead of the EAC4, was the C1a acceptor, and the C1rs subcomponents rather than the whole C1 molecule should have to transfer in the C1aTR. The EAC41 derived from EC4 generated no EAC1q4 in EDTA medium as the EAC14 did. This presented evidence for the joining of C4 to A in the EAC1q4 site.

Animals↗
PubMed1994

The synthesis of a water soluble complement activating polyacrylic acid-IgG polymer.

Polyacrylic acid-IgG polymer (PAA-IgG) activates the classical and alternative pathway of complement as shown by specific Clq-(IgG-PAA) interaction and the generation of C4d, Bb, C3b, C3a and C5a. This water soluble and stable PAA-IgG polymer represents a model substance for the study of humoral and cellular inflammatory mechanisms, mediated by the complement system.

Acrylic Resins↗
PubMed1982

Immune complexes in coccidioidomycosis. Correlation with disease involvement.

Circulating immune complexes were quantitated by Clq-binding assays of serum from 73 patients with active coccidioidomycosis, 5 patients with inactive disease, and 34 healthy subjects. Immune complexes were detected in serums of 8 (44%) of 18 patients with active pulmonary disease only and 22 (40%) of 55 patients with active disseminated disease. Results in none of 5 patients with inactive disease and in only 2 (9%) of 34 healthy subjects were positive by the Clq-binding assay. Immune complex levels did not differ in patients with pulmonary disease versus those with disseminated disease. However, immune complexes did correlate with disease involvement. Of 57 patients with coccidioidomycosis involving a single organ system (pulmonary or extrapulmonary), 19 (33%) had immune complexes compared with 6 (67%) of 9 patients with disease involving 2 organ systems, and 5 (71%) of 7 patients with disease of 3 or more organ systems. Immune complex levels correlated with serum IgG, but did not correlate with serum complement-fixing antibody titers to coccidioidin. Rather, the correlation curve between immune complexes and complement-fixing antibody titers yielded a bell-shaped distribution. This distribution pattern suggests that changes in antibody concentration may have effected the size and lattice of immune complexes, resulting in altered detection and/or clearance from the bloodstream.

Antibodies, Fungal↗
PubMed1986

Binding and covalent cross-linking of purified von Willebrand factor to native monomeric collagen.

We have analyzed the interaction of the adhesive glycoprotein, von Willebrand factor (vWF), with native monomeric collagen monolayers by adsorbing acid soluble Types I and III collagen derived from calf skin to polystyrene microtiter wells and incubating the wells with purified human 125I-vWF. The binding of 125I-vWF was saturable, reversible, specific, and was abolished by heat denaturation of the collagen monomers. Binding was half-maximal at 5 micrograms/ml, and, at saturation, 7.5 ng 125I-vWF were bound to each microgram of immobilized collagen. 125I-vWF did not bind to wells coated with other extracellular matrix or plasma proteins such as fibronectin, fibrinogen, gelatin, or the q subunit of the first component of complement (C1q). In addition, bound 125I-vWF could not be displaced from collagen by the addition of either fibronectin or fibrinogen. After incubation with Factor XIIIa, plasma transglutaminase, 125I-vWF bound to collagen could no longer be displaced by vWF, which suggests covalent cross-linking of vWF to collagen monomers. Factor XIIIa-dependent covalent cross-linking of vWF to collagen, but not to fibronectin or laminin, was also demonstrated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate.

Animals↗
PubMed1986

Unusual dermatologic toxicity of long-term therapy with hydroxyurea in chronic myelogenous leukemia.

The unusual appearance of extensive skin ulcerations was observed in 17 patients with chronic myelogenous leukemia on continuous chemotherapy with hydroxyurea. The strict relationship between ulcers and therapy was proved by the complete (14 cases) or almost complete (3 cases) healing of lesions after therapy was discontinued. The possible pathogenetic mechanisms responsible for skin alterations are considered. The particular importance of the continuous hydroxyurea administration modality clearly emerges, suggesting the use of different administration modalities to reduce such serious side effects.

Adult↗