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D A Isenberg

Publications and source records attributed to D A Isenberg.

At least 379 records · Page 21Linked to original sources

Disease activity in systemic lupus erythematosus related to a range of antibodies binding DNA and synthetic polynucleotides.

Antibodies to dDNA, nDNA, Z-DNA, poly(dT), poly(I), poly(dG.dC), poly(dA.dT), and total IgG and IgM were measured in five serial bleeds from 39 patients with systemic lupus erythematosus (SLE). The main findings were that those patients with renal disease form a distinct subset whose antibody levels correlate well with disease activity; anti-poly(dT) antibodies showed the best overall correlation with disease activity; and discriminant functional analysis demonstrated a major improvement in correlation of disease activity with combinations of antibodies to dDNA/nDNA/Z-DNA/poly(dT) (generally 50% or more were correctly classified) than with dDNA or nDNA alone (generally less than 25% correct). Serum IgG (but not IgM) correlated significantly (p less than 0.01) with six antibodies, suggesting that polyclonal activation plays a part in the development of these antibodies, though antibody cross reactivity is not excluded.

Antibodies↗

An analysis of autoimmunity through studies of DNA antibody idiotypes.

The existence of idiotypic networks, first postulated over 12 years ago, is now widely recognised. Idiotypic analyses of autoantibodies have been reported among both hybridoma-derived and naturally occurring immunoglobulins. In this review the many studies of idiotypes detected on anti-DNA antibodies, notably one designated 16/6, are analysed to see what clues they offer to our understanding of autoimmunity. The links between infection and autoimmunity are emphasised by this analysis. It is also obvious that idiotypes first identified an autoantibodies are not confined to these immunoglobulins. Thus, the 16/6 idiotype originally described on a hybridoma-derived monoclonal anti-DNA antibody has also been identified on naturally occurring antibodies binding the Klebsiella polysaccharide K30.

Antibodies, Antinuclear↗

B lymphocyte activation in systemic lupus erythematosus: spontaneous production of IgG antibodies to DNA and environmental antigens in cultures of blood mononuclear cells.

IgG antibodies to DNA, influenza virus haemagglutinin (HA), adenovirus hexon (HX) and mannan from Candida albicans (MN) have been determined in supernatants from 2-day unstimulated cultures of peripheral blood mononuclear cells from SLE patients and controls. Mean values were much higher in the SLE group, with from 20% (MN) to 85% (DNA) of patients giving values above the normal range. Although a significant correlation was observed between anti-DNA and anti-HA production, anti-HX and anti-MN showed no such correlations. The specificity of the ELISA assays was demonstrated by inhibition tests. It is concluded that a selective form of polyclonal activation in SLE results in the production of antibodies to foreign as well as to self antigens.

Antibodies, Antinuclear↗

Development and assessment of a computerized index of clinical disease activity in systemic lupus erythematosus. Members of the British Isles Lupus Assessment Group (BILAG).

Five centres in Great Britain and the Republic of Ireland have collaborated to produce a computerized index of clinical disease activity in systemic lupus erythematosus, based on the principle of the physician's intention to treat. The index assesses separately eight organ-based systems. The index has proved quick and easy to use despite a comprehensive database and compares favourably with two other indices of disease activity. It has great potential for use in multicentre studies of disease outcome and new therapies in systemic lupus erythematosus.

Humans↗

Human monoclonal antibodies to phenolic glycolipid-I derived from patients with leprosy, and production of specific anti-idiotypes.

Human monoclonal antibodies (mAb) were produced by hybridomas derived from fusion of the GM4672 lymphoblastoid cell line and peripheral blood mononuclear cells from leprosy patients. Hybridoma supernatants were screened for immunoglobulin (Ig) secretion, binding to Mycobacterium leprae, phenolic glycolipid-I (Phen GL-I), the unique M. leprae glycolipid and single-stranded(ss)DNA by ELISA. On the basis of direct-binding ELISAs, two IgMk mAb (PR4 and TH3) were selected for characterization. PR4 and TH3 bound to M. leprae, Phen GL-I and ssDNA; PR4 also bound to M. avium and M. kansasii and TH3 to M. kansasii. Inhibition assays demonstrated that these antibodies did not bind to the terminal disaccharide of Phen GL-I. In addition, both PR4 and TH3 bound to several autoantigens: ssDNA, double-stranded(ds)DNA and poly(ADP-ribose) but not RNA. PR4 and TH3 were used for preparation of rabbit anti-idiotype antisera. Inhibition studies demonstrated that the affinity purified rabbit anti-idiotype antisera were specific for their respective idiotype and that both Phen GL-I and ssDNA inhibited binding of idiotype to its anti-idiotype. PR4, but not TH3, was found to be similar but not identical to the 16/6 idiotype originally identified on a human monoclonal anti-DNA antibody derived from a patient with systemic lupus erythematosus (SLE).

Antibodies, Antinuclear↗

Reduced B-cell galactosyltransferase activity in rheumatoid arthritis.

Autosensitisation to IgG may be important in the pathogenesis of rheumatoid arthritis and could be related to reduced glycosylation of the oligosaccharides in the C gamma 2 region of serum IgG. The activity of galactosyltransferase, the enzyme that catalyses the addition of galactose to the oligosaccharide chains, was measured in the circulating B cells of seventeen patients with classic rheumatoid arthritis. It was significantly lower than that of a group of eleven controls (p less than 0.001) or of nine age-matched controls (p less than 0.001). In contrast, the enzyme activity of the T cells was within the range of that in nine age-matched controls, and enzyme activity in monocyte-rich mononuclear-cell populations was higher than in controls, possibly reflecting stimulation of the monocytes in rheumatoid arthritis. These findings suggest that galactosyltransferase may regulate the degree of glycosylation during IgG synthesis and could therefore be implicated in the rheumatoid inflammatory process.

Adult↗

Autoantibodies against a specific nuclear RNP protein in sera of patients with autoimmune rheumatic diseases associated with myositis.

Polymyositis is an autoimmune, inflammatory disease affecting human skeletal muscle. In the presence of concomitant vasculitis in the skin, the term dermatomyositis is used. In contrast, systemic lupus erythematosus (SLE) is a multisystem disease in which involvement of the skin, kidneys, joints, brain, and other organs may be found. The clinical manifestations vary according to the organ/system involved. It is clinical and therapeutic importance to define which organ/system is involved during the course of the disease. We approached this problem by studying the specificity of autoantibodies that are generated in patients with SLE and polymyositis/dermatomyositis. Among such antibodies are those directed against nuclear components including a variety of ribonucleoprotein (RNP) complexes. We have utilized mammalian nuclear preparations enriched with RNP particles as the antigenic source for immunoblotting studies to identify specific antigenic polypeptides. In the study reported here, sera from five groups of patients were examined: 10 patients with dermatomyositis/polymyositis; six patients with SLE and myositis; 12 lupus patients with cerebral and/or renal disease; eight patients with SLE but no myositis, renal, or cerebral disease; and 5) 11 patients with muscle weakness or muscle disease not due to myositis. In the first two groups of patients with myositis, antibodies against a nuclear RNP protein of 56 KD was identified in 12 of 16 sera. In contrast, such antibodies were found in the serum of only two of 20 patients with SLE but without muscle involvement (groups 3 and 4), and were not found at all in patients with other muscle diseases. This study has identified a new marker, antibodies against a nuclear RNP protein of 56 KD for detecting muscle involvement among the autoimmune rheumatic diseases.

Animals↗

A common anti-DNA idiotype in sera of patients with active pulmonary tuberculosis.

The sera of 57 patients with active, untreated pulmonary tuberculosis were examined for the presence of a common anti-DNA idiotype, 16/6. Thirty-four of the 57 sera (60%) had an increased level of the idiotype, as measured by enzyme-linked immunosorbent assay using a specific rabbit anti-16/6 serum. Of 28 matched control sera, only 1 (4%) was found to be positive for the idiotype. The sera of patients with tuberculosis also showed increased activity against a variety of antigens with which lupus autoantibodies are known to crossreact (e.g., single-stranded DNA, double-stranded DNA, polynucleotides, and cardiolipin). A correlation was observed between serum IgG and IgM levels and the 16/6 idiotype levels.

Adult↗

Detection of antibodies to total histones and their subfractions in systemic lupus erythematosus patients and their asymptomatic relatives.

Sera drawn from 75 patients with systemic lupus erythematosus, 141 healthy relatives (from the families of 51 patients), and 115 healthy control subjects were examined, by enzyme-linked immunosorbent assay, for IgG and IgM antibodies to total histones and their subfractions. Compared with the controls, statistically significant numbers of patients and their relatives had antihistone antibodies of both isotypes. Among the relatives, the sera from females, notably sisters of the patients, contained the highest levels of anti-total histone antibody. Anti-H2A/H2B and H3 antibodies were most prevalent among the lupus patients, but many of the relatives had IgM anti-H4 antibodies. These findings indicate that antihistone antibodies can serve as a genetic marker in patients with systemic lupus erythematosus.

Autoantibodies↗

Common lupus anti-DNA antibody idiotypes in chronic liver diseases.

Chronic liver diseases may be associated with the appearance of antinuclear antibodies. To further analyze the relationship between connective tissue and liver diseases the sera of 88 patients with chronic liver disorders were examined for the presence of common lupus anti-DNA idiotypes (16/6-id, 134-id, and 32/15-id), using an enzyme-linked immunosorbent assay. The 16/6-id was found in 58 (65.9%), the 134-id in 43 (48.9%), and the 32/15-id in 13 (14.8%) of the patients' sera. Distinct diagnostic groups displayed different lupus anti-DNA idiotype profiles. Patients with primary biliary cirrhosis (PBC) and chronic active hepatitis (CAH) had mainly the 16/6 idiotype, while in alcoholic (AC) and in cryptogenic cirrhosis (CC) the 16/6-id and 134-id were the main idiotypes recorded. There was considerable correlation among the different anti-DNA idiotypes but not between any of these idiotypes and an unrelated common anti-HBsAg idiotype. The occurrence of the various idiotypes was not found to be correlated with increased serum immunoglobulin levels. It can be concluded that the similarities between chronic liver diseases and connective tissue diseases are extended also to the presence of specific common anti-DNA antibody idiotypes.

Autoantibodies↗

A study of antipolynucleotide antibodies, anti-Klebsiella (K30) antibodies and anti-DNA antibody idiotypes in ankylosing spondylitis.

Recent studies have indicated that both ankylosing spondylitis and the anti-DNA antibodies found in systemic lupus erythematosus may be related to Klebsiella surface antigens. In order to explore these possible relationships further, the sera of 24 patients with ankylosing spondylitis (AS), and 20 controls, have been examined for binding to a wide range of antipolynucleotide antibodies, antibodies binding to the Klebsiella pneumoniae polysaccharide K30 and two DNA antibody idiotypes designated 16/6 and 134. We report that although 21% of the AS patients had IgG ssDNA antibodies it is evident that the aetiopathogenesis of this disease is not through the mechanism of autoantibodies or the common DNA antibody idiotypes tested.

Antibodies, Antinuclear↗

Renal abnormalities in ankylosing spondylitis.

The incidence of renal abnormalities is increased in patients with ankylosing spondylitis (AS). Possible mechanisms include the effects of nonsteroidal anti-inflammatory drugs (NSAIDs), an increased incidence of glomerulonephritis and the deposition of amyloid. We assessed renal function in 51 patients with AS randomly selected from those attending routine rheumatology clinics. Five patients were found to have a definite renal abnormality and three of them underwent renal biopsy. These showed one case each of IgA glomerulonephritis, focal segmental glomerulosclerosis and nonspecific tubulo-interstitial damage. A sixth patient had recurrent haematuria and borderline renal functional impairment but refused further investigation. The urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) was elevated in four patients; two had other biochemical evidence of renal damage while the other two patients appeared normal, although they had both received spinal irradiation in the past. The finding of a significant renal abnormality in 10% of AS patients suggests that evidence of renal involvement should be actively sought in this disease.

Adult↗

A double blind controlled trial of methylprednisolone infusions in systemic lupus erythematosus using individualised outcome assessment.

Twenty one patients with severe systemic lupus erythematosus (SLE) were treated with three daily infusions of either 100 mg or 1 g of methylprednisolone on a randomised double blind basis. Nine patients with unsatisfactory outcome subsequently received the alternative therapy. Patients were rated for improvement on a four point scale using individualised criteria. On three occasions patients improved to 'ideal', on 12 there was 'useful' improvement, on 11 the patient remained static, and on four occasions there was deterioration. There was no significant difference between the clinical states after the two doses. The results suggest that any additional benefit of 1 g of methylprednisolone over 100 mg by repeated infusion in the treatment of active SLE is probably not enough to justify the potential hazards and cost involved.

Adult↗