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PubMed1981

Immune complexes in early arthritis. L Detection of immune complexes before rheumatoid arthritis is definite.

Fifty-three patients with early arthritis were studied longitudinally for up to 3 years. During this time, 24 developed sufficient features for definite rheumatoid arthritis (RA) to be diagnosed. The other (arthralgia patients) differed from the RA patients as, in the majority, C-reactive protein and ESR were normal and anti-nuclear antibodies or rheumatoid factors were rarely found. Moreover, in time their signs and symptoms improved or disappeared. Circulating immune complexes were detected in both groups of patients by the platelet aggregation test whereas complexes detected by abnormal Clq-binding activity were found mainly in the RA patients. Platelet-aggregating complexes were usually present in the first samples studied and disappeared in the arthralgia patients with recovery from their symptoms. In the RA patients, Clq-binding complexes appeared simultaneously or later than platelet-aggregating complexes but both tests were positive several months before RA could be diagnosed. These results suggest that immune complexes are one of the first immunological abnormalities to appear in patients with arthritis. Although the constituent antigen and antibody of complexes detected by either test are unknown, their possible nature is discussed.

Adolescent↗
PubMed1982

Isolation of Clq-binding virus-antibody immune complexes from lactic dehydrogenase virus (LDV)-infected mice.

A Sepharose-IgG-Clq sorbent has been successfully used to isolate circulating virus-antibody (virus Ab) complexes from serum of lactic dehydrogenase virus (LDV)-infected mice. The chronological study demonstrated that although circulating LDV in persistently infected mice was complexed with IgG antibody, the virus-Ab complexes bound to the Clq sorbent only early during the infection. Inactivation of these Clq-isolated virus Ab complexes was accomplished with rabbit anti-mouse IgG but not anti-IgM. The critical time period for the demonstration of Clq-binding LDV-Ab complexes in serum was between 10 and 18 days postinoculation. The reasons for the apparent shift from Clq-binding virus-Ab complexes to non-Clq binding are not clear, however, possible explanations and implications in immune complex tissue injury are discussed.

Animals↗
PubMed1982

Immune complex-like activity associated with abnormal serum lipoproteins in systemic erythematosus.

Sera from four patients with systemic lupus erythematosus (SLE) were shown to contain abnormal lipoproteins which behaved as immune complexes (IC). One IC lipoprotein (IC VLDL) had the density in ultracentrifugation of very low density lipoprotein, but a markedly altered electrophoretic mobility. A second IC lipoprotein (IC LDL) had the electrophoretic mobility of very low density lipoprotein but was slightly denser than low density lipoprotein on ultracentrifugation. Both the IC VLDL and IC LDL contained IgG and behaved as IC in the Clq deviation test, platelet aggregation and rheumatoid factor inhibition assays, but not in the conglutinin and Clq binding assays and the Clq solid phase assay. These differences could be due to the low densities of the IC VLDL and IC LDL. The abnormal lipoprotein IC disappeared with clinical remission in two patients and were not present in the sera of other patients with inactive or mild SLE, Type IV hyperlipidaemia, or during prednisone therapy or plasma exchange for other conditions. These IC appeared to be markers of severe and active SLE.

Adolescent↗
PubMedDate not supplied

[Quantitative and qualitative determinations and clinical and histological correlations of cryoglobulins in glomerulonephritis].

The Authors have investigated the presence of cryoglobulins in sera from 91 GN patients, 69 of whom had a renal biopsy. Cryoglobulins have been found in 12.5% of the idiopathic glomerulonephritis (GN), in 22.2% of the ones related to systemic diseases. Also 4 cases of GN with mixed essential cryoglobulinemia have been studied. Quantitative analysis has shown a IgG and IgM prevalence, the last ones of monoclonal type in 77.8% of the cases, with anti IgG activity in 44.4%. Concerning cryoglobulins found in idiopathic GN, the Authors observed a high incidence in the forms with cellular proliferation and glomerular exudation, as rapidly progressing GN, the acute post-infectious GN, and the mesangio-capillary GN. Among the GN related to systemic diseases, high incidence of cryoglobulins has been observed in lupus nephritis and polyartheritis. In both diseases (idiopathic GN and GN related to systemic diseases) a good correlation was found between clinical-ordinary activity and immunological parameters such as circulating immune complexes and complement breakdown products. The correlation between cryoglobulins level and disease activity is less evident in the mixed essential cryoglobulinemia G.N. Furthermore the Authors discuss here the pathogenesis of cryoglobulins in human G.N.

Antigen-Antibody Complex↗
PubMed1980

The interaction of heparin with plasma proteins. Demonstration of different binding sites for antithrombin III complexes and antithrombin III.

Affinity chromatography of plasma and serum with the use of heparin conjugated Sepharose has confirmed the existence of two types of protein binding sites. A minor heparin fraction binds free AT III selectively and firmly but not its protease complexes. The complexes bind less firmly to another, much larger heparin fraction together with a select group of the plasma proteins at physiological pH and ionic strength. These included complement proteins (C1q, C2, factor B, properdin, and beta 1H), protease inhibitors (inter-alpha-trypsin inhibitor and C3b inactivator) and cell surface proteins (protein HC and fibronectin) as well as beta-lipoproteins. The results demonstrate that affinity chromatography with heparin-Sepharose is extremely useful as an early preparative step in the isolation of these minor plasma components. The results also indicate that the said proteins can be linked to cell surfaces carrying heparinoids in the intercellular space.

Antithrombin III↗
PubMed1993

A humanized CD18 antibody can block function without cell destruction.

Leukocyte integrins are intimately involved in transient adherence of leukocytes to endothelium and to each other in the processes of extravasation and cell activation. In this study, seven mAb directed against human CD11a and two mAb directed against human CD18, the alpha- and beta-chains of the leukocyte functional Ag-1 molecule, respectively, were analyzed for their ability to inhibit several leukocyte functional Ag-1-mediated interactions. The best blocking mAb in these studies, a rat anti-human CD18, YFC51.1, was subsequently humanized by complementarily-determining region grafting, associated with human C regions and expressed. The humanized mAb was shown to maintain binding for human CD18. Even though the humanized mAb was an IgG1 isotype it still retained the functional blocking characteristics of the rat mAb while failing to mediate cell killing. The IgG1 mAb was unable to bind human Clq and could block but did not mediate antibody-dependent cellular cytotoxicity.

Animals↗
PubMed1976

Glomerular lesions in asymptomatic microscopic hematuria discovered on routine medical examination.

Renal biopsies from 145 patients with asymptomatic microscopic hematuria were studied with light microscopic, electron microscopic and immunofluorescence antibody techniques. The predominant lesions were a diffuse proliferative glomerulonephritis (mesangial hypercellularity) with focal epithelial crescents and focal segment and/or global sclerosis in many of them; and a minimal lesion with increased mesangial matrix and mild mesangial hypercellularity. Focal and segmental glomerulonephritis, diffuse mesangio-capillary and membranous glomerulonephritis were less common lesions. IgA deposition with other immunoglobulins was seen in over 50% of cases, with an IgA IgG-Beta1C-globulin combination being the common lesion. IgA secretory piece and HBs antigen were not found in the glomeruli and early complement components C1q and C4 were absent. Changes in the mesangium, basement membranes of capillary loops and mesangial osmophilic deposits reflect the pathogenesis of this disease. In addition to the above 145 patients, thirty-five cases of persistent microscopic hematuria classified as symptomatic, with a past history of "acute nephritis", lumbar pain and other complaints; and 11 patients with macroscopic hematuria, painless or associated with "acute nephritis" had similar glomerular lesions. Raised ASOT levels suggest the role of an upper respiratory infection in the exacervation or precipitation of this lesion. The IgA depositon may be associated with deposition of other antibodies in a picture of chronic glomerulonephritis, post-streptococcal or otherwise. 6 of the 145 patients with asymptomatic microscopic hematuria have gone into chronic renal failure in 3.5 years.

Adolescent↗
PubMed1994

Functional properties of antibody insulin-like growth factor fusion proteins.

Genetic engineering and expression techniques have been used to produce antibody growth factor fusion proteins. Insulin-like growth factors (IGFs) 1 and 2 have been fused to mouse-human chimeric IgG3 at the end of CH1, immediately after the hinge, and at the end of CH3. Fusion heavy chains of the expected molecular weight were expressed, assembled with a co-expressed light chain, and secreted. The resulting molecules continued to bind antigen; they also bound the growth factor receptors, albeit with decreased affinity. The molecule with IGF1 attached after CH3 (CH3-IGF1) had reduced ability to carry out complement-mediated cytolysis. In contrast the molecule with IGF2 attached after CH3 (CH3-IGF2) showed an approximately 50-fold increase in its ability to effect complement-mediated cytolysis and so should be an effective cytolytic agent. Both CH3-IGF1 and CH3-IGF2 bound Fc gamma RI with affinity similar to that of IgG3. The growth factor fusion proteins showed small but significant uptake into the brain parenchyma.

Animals↗
PubMed1993

[A case of non-IgA mesangioproliferative glomerulonephritis with huge paramesangial hemispherical deposits].

A 16-year-old female was admitted to our hospital because of chance proteinuria. On admission, mild proteinuria (0.6g/day) was observed, but microhematuria was not detected during the observation period. All the values of the renal function tests were within the normal range. Her renal biopsy demonstrated a prominent increase in the mesangial area by light microscopy and showed marked paramesangial hemispherical deposits by electron microscopy. Though IgM, IgG, Clq, C3, and fibrinogen were localized in the mesangial region, IgA was not detected by immunofluorescence study. It has been reported that paramesangial hemispherical deposits are strongly indicative of IgA glomerulonephritis. We conclude that this patient is a rare case of non-IgA glomerulonephritis with huge paramesangial hemispherical deposits.

Adolescent↗

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