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Biomedical subjects

D Isenberg

Publications and source records attributed to D Isenberg.

At least 91 records · Page 5Linked to original sources

Crosscultural validation and reliability of 3 disease activity indices in systemic lupus erythematosus.

Rheumatologists from 4 countries, representing 8 rheumatology centers, tested 3 systemic lupus erythematosus (SLE) disease activity indices: the SLE Disease Activity Index (SLEDAI) from Toronto; the Systemic Lupus Activity Measure (SLAM) from Boston and the British Isles Lupus Assessment Group (BILAG) for their reproducibility and validity in the assessment of real patients. Seven patients representing a spectrum of disease manifestations and activity were each examined by 4 of 7 observers from all centers except Toronto, using a Youden square design. Each observer completed all 3 indices and a category rating scale for disease activity on each of the 4 patients seen. All 3 indices detected differences among patients. There was no detectable observer effect among the 7 observers with each of the 3 indices. There was a detectable order effect with the SLAM. The 3 indices are comparable and reproducible for evaluating disease activity in SLE.

Boston↗

Agalactosyl IgG: an aid to differential diagnosis in early synovitis.

Sixty consecutive patients presenting with early-onset synovitis were studied by measuring rheumatoid factor (RF) titers and the percentage of oligosaccharide chains attached to the C gamma 2 domain of IgG that lack galactose (GAL[0]). After 2 years of followup, 39 patients (65%) had developed rheumatoid arthritis (RA), and 21 had developed a variety of other inflammatory joint diseases. A combination of RF positivity and GAL(0) levels above the age-corrected mean gave a positive predictive value for a diagnosis of RA in 94% of these patients. These observations may well have clinical utility.

Adult↗

Changes in IgG glycoform levels are associated with remission of arthritis during pregnancy.

It was found that the percentage of IgG-associated agalactosyl N-linked oligosaccharides (G0) falls during normal human pregnancy and rises to values higher than before conception following delivery (n = 10, 39-55 days after delivery). Serial bleeds from a normal pregnant woman showed a fall in the percentage G0 during gestation and a rapid rise post-partum. A similar study on a pregnant arthritic woman with a pathologically elevated percentage G0 also showed a fall in percentage G0 during pregnancy and a rapid rise post-partum. The changes in IgG glycosylation in the pregnant arthritic woman occurred simultaneously with the pregnancy-induced remission and post-partum recurrence of disease. A further seven pregnant women with rheumatoid arthritis were studied and analysis of their G0 values pre- and post-partum confirmed the result. In a further series of experiments using an animal model of rheumatoid arthritis, DBA/1 mice with collagen-induced arthritis were found to have elevated G0 levels compared with control mice. The percentage G0 was found to fall simultaneously with pregnancy-induced remission to the same value as non-arthritic pregnant mice. Post-partum recurrence of arthritis in these mice was also accompanied by a simultaneous and rapid rise in percentage G0. Pseudopregnancy did not result in a change in the percentage G0, confirming the effect of true pregnancy. Since the proportion of agalactosyl IgG is abnormally high in the serum of patients with rheumatoid arthritis these changes in IgG glycoform levels, or the factors which control them, may be related to the mechanisms underlying remission of arthritis in humans during pregnancy.

Acetylglucosamine↗

Autoimmunity associated with infection: leprosy, acute rheumatic fever and Lyme disease.

This review examines the links between autoimmunity and three common infectious diseases. These disorders are associated with a variety of clinical and serological autoimmune phenomena. In addition they might conceivably trigger autoimmune diseases themselves. Mechanisms that may be responsible for these links, including molecular mimicry, are explored.

Acute Disease↗

Insidious loss of renal function in patients with anticardiolipin antibodies and absence of overt nephritis.

Circulating anticardiolipin antibodies are associated with recurrent thrombosis, fetal loss and thrombocytopenia. We have identified four patients with SLE or lupus-like disease who have high circulating levels of ACLA, repeated thrombosis and evidence of renal disease. Their clinical signs and symptoms of lupus activity were minimal, yet all had renal insufficiency with GFR 50 ml/min or less despite no history nor evidence of overt nephritis (proteinuria less than 0.5 g/day and no haematuria). Renal biopsy specimens showed focal ischaemic lesions with no evidence of active lupus nephritis. We describe a new lesion of renal ischaemia secondary to non-inflammatory vascular pathology associated with circulating ACLA.

Adult↗

T cell receptor expression in Sjögren's syndrome.

T lymphocytes expressing the gamma/delta T cell receptor and B lymphocytes expressing CD5 are known to occur in expanded numbers in the peripheral blood of patients with primary Sjögren's syndrome. The cellular infiltrates for the surface phenotypic markers for alpha/beta and gamma/delta T cell receptors, CD4, CD8, CD45, and CD5 were examined in lip biopsy specimens from two patients with primary Sjögren's syndrome, six with secondary Sjögren's syndrome, and seven healthy controls. Most of the Sjögren's lip biopsy cellular infiltrates were T lymphocytes of the CD4 subset expressing the alpha/beta T cell receptor (mean 70%). The low prevalence of gamma/delta T cell receptor bearing cells in lip biopsy specimens is maintained in Sjögren's syndrome (mean 1.5%), and thus it seems unlikely that these lymphocytes bearing the gamma/delta T cell receptor have a major role in the immunopathology of Sjögren's syndrome. Over 70% of cells within the lesional infiltrate of primary and secondary Sjögren's syndrome expressed the CD5 and CD45 cell surface molecules.

Antigens, CD↗

Heat shock proteins and systemic lupus erythematosus.

This review briefly defines the heat shock proteins (hsps), their classification and their functions. The hypothesis that links hsps to the development of autoimmunity is explored, together with the rationale for investigation of the relationship between hsps and systemic lupus erythematosus (SLE). Thus, published work on this subject falls into three main categories: the overexpression of hsps in SLE, the development of autoantibodies to hsps in SLE, and the surface expression of hsps in peripheral blood mononuclear cells in SLE. This work is reviewed in detail. In conclusion, we describe areas for further study and outline ways in which this is being approached.

Autoimmunity↗

Expression of a common idiotype PR4 in the sera of patients with leprosy.

The sera of 187 patients from across the leprosy spectrum were screened for the expression of the PR4 idiotype, which was first identified on a human hybridoma-derived monoclonal antibody from a patient with leprosy and found to react with the Mycobacterium leprae phenolic glycolipid and a variety of polynucleotides. Sixty per cent (51 out of 85) of patients with lepromatous leprosy (LL), 66% (33 out of 49) with borderline lepromatous (BL) disease, 47% (14 out of 30) with borderline tuberculoid (BT) leprosy, and 56% (13 out of 23) of tuberculoid (TT) patients were found to have significantly elevated titres of the PR4 idiotype in their sera compared with endemic controls, irrespective of the presence or absence of endemic malaria. Sera from 52 patients with tuberculosis were also screened as a control for mycobacterial infection. The PR4 idiotype was significantly elevated in 37% (19 out of 52) of these patients. No correlation between idiotype and serum immunoglobulins IgG and IgM was found, indicating that the concentrations of idiotype levels in sera were not merely a reflection of changes in serum immunoglobulin levels. It is hypothesized that the expression of the PR4 idiotype is due to certain germline genes preferentially expressed rather than being the result of polyclonal B cell activation.

Animals↗

Comparison of DNA antibody idiotypes in human sera: an international collaborative study of 19 idiotypes from 11 different laboratories.

The distribution of and relationships between 18 anti-DNA antibody idiotypes and one anti-acetylcholine receptor antibody idiotype have been tested in an international collaborative study of human sera from 180 individuals. The main finding is that the serum levels of many of these idiotypes, whether of murine or human origin, show a high degree of statistical correlation. The studies in a wide range of autoimmune rheumatic diseases confirm that none of the idiotypes tested is disease specific, but 13 of 15 (87%) whose levels were recorded as OD units or cpm correlated strongly with anti-ssDNA antibody levels and 11 of 15 (73%) with total serum IgM. Expression of several idiotypes was found to fluctuate in parallel with disease activity in SLE; levels of others were also elevated in the healthy relatives of lupus patients whilst a few were also raised in the spouses of these patients. The data support the notion that there may be only a few groups of related DNA antibody idiotypes. The correlations between the idiotypes with regard to their quantities, association with disease activity, and wide distribution in different diseases and healthy individuals suggest at least two explanations. First, all of these idiotypes may be present in normal immunoglobulin repertoires and simply increase in response to poly- or oligoclonal B-cell activation in autoimmune diseases. Secondly, these idiotypes may be structurally linked to each other, so that their behaviour under conditions of specific antigenic stimulation is similar. Genetic and structural studies will be required to distinguish between these possibilities.

Autoantibodies↗

The antibody repertoire of early human B cells. I. High frequency of autoreactivity and polyreactivity.

Cord blood and fetal liver B cells were immortalized using Epstein-Barr virus, and IgM antibodies from the resulting lines and clones were examined for their binding to a variety of auto-antigens and micro-organisms by ELISA and fluorescence assays. Auto-antigens tested included Fc of IgG, ssDNA and dsDNA, cardiolipin, histones 1-4, collagens type I and II, thyroglobulin, cytoskeletal components, and a tissue section screen. Of 71 cell lines tested, all but 19 showed some autoreactivity. All 32 fetal liver lines reacted to some self-antigens. In cord blood clones, 16 out of 26 bound to auto-antigens. Many of the clones reacted with more than one auto-antigen and were 'polyreactive'. Some of the cord blood clones bound to extracts of micro-organisms, showing specificity for both endogenous and exogenous antigens. The high frequency of CD5+ B cells in the cord blood (greater than 50%) and fetal liver (greater than 70%) argues for many of these clones being derived from this subset. Therefore, our data support the concept that many 'early' B cells produce polyreactive IgM which can bind to a variety of different auto-antigens and micro-organisms. These IgM antibodies are similar to those described by others as 'natural antibodies'.

Antibody Specificity↗

Autoantibody and idiotype profile of lung involvement in autoimmune rheumatic disease.

Several reports have linked the presence of certain serum autoantibodies with particular clinical manifestations of autoimmune disease. For example, the Jo-1 antibody is now established as a marker for fibrosing alveolitis in polymyositis. To investigate the possible association of further autoantibodies or idiotypes with fibrosing alveolitis in autoimmune rheumatic disease a panel of autoantibodies was measured in serum samples from 28 patients with systemic lupus erythematosus (SLE) (10 with and 18 without lung involvement), 21 patients with scleroderma (12 with fibrosing alveolitis and nine without), and 41 patients with 'lone' fibrosing alveolitis. Antibodies measured were IgM and IgG anti-dsDNA and anti-ssDNA antibody; IgG and IgM anticardiolipin antibody; anti-poly (ADP-ribose) antibody; antibodies to two common idiotypes of anti-DNA antibodies, designated 134 and 16/6; and IgM, IgG, and IgA isotypes of rheumatoid factor. None of these antibodies was specifically associated with lung involvement in SLE or scleroderma, but a trend was found towards an increase in all autoantibodies in association with lung disease in SLE, while the reverse trend was seen in scleroderma.

Antibodies, Antinuclear↗

DNA antibody idiotypes: an analysis of their clinical connections and origins.

Approximately thirty common DNA antibody idiotypes have been described on hybridoma derived or affinity purified DNA-binding antibodies. There are associations between some idiotypes and the clinical manifestations of systemic lupus erythematosus although none are sufficiently firm to be clinically useful in identifying subsets of SLE or in assessing disease activity in individual patients. The expression of these idiotypes is not confined to DNA antibodies in SLE. They may be found in the serum from patients with a range of autoimmune rheumatic disorders, infectious disease and blood dyscrasias. In most cases the antigen binding specificity of the antibody bearing the idiotype is unknown. The precise relationship between the various idiotypes is becoming better understood with increasing availability of genetic and structural data. DNA antibody idiotype manipulation may provide a potential new therapeutic modality in SLE.

Antibodies, Antinuclear↗

Autoantibodies against a nuclear 56 kDa protein: a marker for inflammatory muscle disease.

Antibodies to a 56 kDa nuclear protein have been found in the sera of 85% of patients with myositis using an immunoblotting technique. This auto-antibody appears to be relatively disease-specific though more frequently detectable in both adult and childhood onset dermatomyositis. In adult patients with myositis the anti-56 kDa antibody level reflects disease activity. This antibody is thus much more frequently found than previously described disease-specific autoantibodies in patients with myositis such as the Jo-1 antibody, and may represent a useful diagnostic aid in patients with muscle weakness.

Animals↗

Elevation of the levels of SmB, B' and D proteins but not that of the La (SS-B) antigen during HSV infections.

Three Sm proteins, B, B' and D, which are highly immunoreactive in systemic lupus erythematosus (SLE), increase in abundance in Vero cells infected with laboratory strains and clinical isolates of herpes simplex virus (HSV) types 1 and 2. The autoimmune antigen La (SS-B) does not accumulate in identical infections. The significance of the Sm antigen accumulation is discussed in terms of its possible role in HSV infection and in connection with the origin of autoantibodies in SLE.

Animals↗