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Biomedical subjects

S Whittingham

Publications and source records attributed to S Whittingham.

At least 19 recordsLinked to original sources
PubMed1994

Fibromyalgia syndrome and disease activity in systemic lupus erythematosus.

To study the effect of fibromyalgia syndrome (FS) on the expression of systemic lupus erythematosus (SLE) and on the measurement of disease activity, we performed a cross-sectional study of subjects with SLE. Eighty-seven subjects were studied and 22 (25.3%), all female, had FS (Yunus' criteria). Disease activity and organ system involvement were assessed using the systemic lupus activity measure (SLAM) and using 10 cm visual analogue scales (VAS) completed by both physician and patient. No significant difference between FS and non-FS groups in the objective measurement of disease activity was present, median (range) SLAM scores being 5 (0-18) and 6 (0-24), respectively (NS). Similarly, expression of SLE, as measured by the prevalence of specific organ system involvement, was similar in the two groups. In contrast the prevalence of glucocorticoid use, antibodies to DSDNA and fulfilling four ACR criteria was higher in the non-FS group. The rating of SLE disease activity was affected by concomitant FS. Physician and patient disease activity VAS correlated significantly with SLAM scores in non-FS subjects (P < 0.001, Spearman analysis), whereas in FS subjects, neither physician nor patient VAS correlated with SLAM scores. We conclude that FS is prevalent in individuals with SLE and does not affect disease expression but may interfere with the rating of disease activity.

Adult↗
PubMed1993

Cytokine production in response to Epstein-Barr virus infection of peripheral blood mononuclear cells in vitro.

To obtain a better understanding of the immune response to Epstein-Barr virus (EBV), we measured the cytokines tumour necrosis factor (TNF)-alpha/beta, interleukin-2 (IL-2), interferon-gamma (IFN-gamma), IL-6 and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the conditioned medium of peripheral blood mononuclear cells from 10 healthy adults before and at 48 h and at 1, 2, 3 and 4 weeks following infection in vitro with EBV. Cultures were examined for regression of outgrowths of nascent virus-transformed B cells, and populations of cells in the cultures were analysed by flow cytometry. TNF-alpha/beta was not detected in infected or non-infected cultures. In infected cultures assayed at the nominated times, the highest levels of IL-2 were detected at 48 hours, IFN-gamma at 1 week, IL-6 at 2 weeks and GM-CSF between 2 and 4 weeks. IL-6 and GM-CSF, but not IL-2 or IFN-gamma, were detected in non-infected cultures but at lower levels than in infected cultures. Nine of the 10 healthy adults showed regression of outgrowths of virus-transformed B cells and, of these, seven had antibodies to the EBV capsid antigen (VCA). Strong regression was associated with sequential increases in IL-2, IFN-gamma, and low levels of IL-6 and GM-CSF. Absent or weak regression was associated with an undetectable level of IL-2, a low level of IFN-gamma, high levels of IL-6 and GM-CSF and an increased frequency of cells bearing the phenotype CD20 and HLA-DR in the final weeks of culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Definition of a discontinuous immunodominant epitope at the NH2 terminus of the La/SS-B ribonucleoprotein autoantigen.

High-titer IgG autoantibodies to the La/SS-B ribonucleoprotein (RNP) are a hallmark of patients with primary Sjogren's syndrome. Anti-La/SS-B-positive human sera bind to multiple epitopes on recombinant La/SS-B, although the initial response is against an immunodominant epitope within the first 107 NH2-terminal amino acids (aa). Sequence analysis has identified a striking homology between aa 88-101 in this NH2-terminal region of La/SS-B and a feline retroviral gag polypeptide suggesting the anti-La/SS-B response may be initiated by cross-reactivity with an exogenous agent. In the present study, detailed mapping of this NH2-terminal epitope, using recombinant La/SS-B purified from the expression of overlapping DNA fragments spanning aa 1-107, has shown that this immunodominant epitope is a complex conformational or discontinuous epitope dependent upon both aa 12-28 and 82-99 for expression, even though these regions share no homology with each other. This requirement questions the significance of the homology between La/SS-B and a retroviral gag polypeptide in the generation of the B cell response to La/SS-B and is in accord with the general concept that B cells recognize conformational epitopes on antigens rather than small linear peptide sequences. The finding also reinforces the notion that native autoantigen could be the initiator of the autoimmune response.

Autoantibodies↗
PubMed1991

Enforced BCL2 expression in B-lymphoid cells prolongs antibody responses and elicits autoimmune disease.

The biological functions of the BCL2 gene were investigated in transgenic mice harboring human BCL2 cDNA under the control of an immunoglobulin heavy chain enhancer (E mu). Mice of a representative transgenic strain, E mu-bcl-2-22, had a great excess of B lymphocytes, immunoglobulin-secreting cells, and serum immunoglobulins, attributable to increased longevity of B-lineage cells. Pre-B and plasma cells as well as B cells exhibited prolonged survival in culture. Immunized animals produced an amplified and protracted antibody response. Within the first year of life, most mice spontaneously produced antibodies to nuclear antigens, and 60% developed kidney disease, diagnosed as immune complex glomerulonephritis. Thus E mu-bcl-2-22 mice constitute a transgenic model for a systemic autoimmune disease resembling the human disorder systemic lupus erythematosus.

Animals↗
PubMed1990

Mapping of multiple B cell epitopes on the 70-kilodalton autoantigen of the U1 ribonucleoprotein complex.

High titer IgG autoantibodies to the 70-kDa polypeptide component (p70) of the U1 ribonucleoprotein (RNP) complex occur in the sera of patients with mixed connective tissue disease, SLE, and related rheumatic diseases. To gain insight into the pathogenesis and diversity of this antibody response we have used recombinant DNA technology to map the linear B cell epitopes on p70. A full length 1.7-kb cDNA clone encoding p70 was isolated from a human placental library and restriction fragments or polymerase chain reaction-generated fragments of the gene subcloned into the bacterial expression vector pGEX. Purified fusion proteins representing specific regions of p70 were immunoblotted with a panel of 70 anti-(U1)RNP+ sera containing anti-p70 antibodies. Six epitopes, four major (A, B, C, and F) and two minor (D and E) were mapped and were located throughout the molecule. The anti-(U1)RNP sera displayed heterogeneity in their pattern of reactivity to the six epitopes although reactivity to epitope C was more frequently associated with SLE rather than mixed connective tissue disease. The identification of multiple B cell epitopes on p70 is consistent with the concept that this self Ag drives the autoantibody response.

Autoantigens↗
PubMed1989

The nucleotide sequence of a human cDNA encoding the highly conserved nucleolar phosphoprotein B23.

A cDNA clone containing the complete coding sequence for the human nucleolar phosphoprotein B23 was isolated from a Burkitt's lymphoma cDNA library by immunoscreening with human autoantibodies. The B23 clone contained a 1.3 kb cDNA insert encoding a polypeptide of 294 amino acids with a predicted molecular mass of 32,539 daltons. The deduced B23 amino acid sequence contained 2 acidic domains rich in aspartic and glutamic acid, a feature shared by a number of nuclear and nucleolar proteins. The human B23 amino acid sequence showed 98% homology with rat B23 and 68% homology with the Xenopus laevis nucleolar phosphoprotein, NO38 showing that the primary structure of B23 is highly conserved among these species.

Amino Acid Sequence↗
PubMed1989

Racial differences in antinuclear antibody patterns and clinical manifestations of scleroderma.

The profile of antinuclear antibodies (ANA) in 49 Thais with scleroderma (systemic sclerosis) was compared with that in 68 white Australians with scleroderma. Forty-eight (98%) of the Thais and all (100%) of the white Australians were positive for ANA, with the majority (100% and 97%, respectively) showing a diffuse speckled pattern of nuclear fluorescence. The distribution of the patterns was different in the 2 races; 35 (71%) of the Thais and 17 (25%) of the Australians showed staining of the nucleolus, and 1 (2%) of the Thais and 35 (51%) of the Australians showed staining of the centromeres. The frequency of precipitating antibodies to extractable nuclear antigens was also strikingly different: 86% in Thais and 26% in Australians (P less than 0.001). Precipitating antibodies to Scl-70 (topoisomerase I), the predominant extractable nuclear antigen in patients with scleroderma, were detected in 37 (76%) of the Thais and 18 (26%) of the Australians, and these were shown by Western blotting to react with the Scl-70 (topoisomerase I)-associated polypeptides. Differences in the frequencies of the ANA specificities in the 2 races were consistent with differences in the clinical manifestations of scleroderma; all of the Thai patients, in contrast to 15% of the Australian patients, had diffuse scleroderma with widespread skin involvement. This suggest that environmental or genetic factors may influence the expression of scleroderma.

Adolescent↗
PubMed1989

Autoantibodies to the major nucleolar phosphoprotein B23 define a novel subset of patients with anticardiolipin antibodies.

Of 164 sera with antinucleolar antibodies, 7 (4.3%) were shown by Western blotting to react with a 37-kd polypeptide in a nuclear extract of HeLa cells and with the recombinant protein expressed by a complementary DNA clone encoding the major nucleolar protein B23. Six of the 7 sera (86%) had antibodies to cardiolipin (aCL), and the sample that was negative for aCL had had lupus anticoagulant on previous testing. All 7 patients had either systemic lupus erythematosus (SLE) or a variant of SLE, suggesting that anti-B23 identifies a subset of patients with SLE associated with a high frequency of aCL.

Adult↗
PubMed1989

Anticardiolipin antibodies in homosexual men: prevalence and lack of association with human immunodeficiency virus (HIV) infection.

Tests for anticardiolipin antibodies (ACL) on sera from 100 male homosexuals and 60 male heterosexuals showed that 57% of the homosexuals, in contrast to none of the heterosexuals, were ACL positive. The ACL were predominantly of the immunoglobulin G isotype and, in a high proportion of cases tested (82%), were reactive with other phospholipids, especially those with a negative charge. ACL were not related to the clinical status of the homosexuals, being evenly distributed among 40 with acquired immunodeficiency syndrome (AIDS), 20 with AIDS-related complex (ARC), 20 with asymptomatic infection with human immunodeficiency virus (HIV) and/or lymphadenopathy syndrome, and 20 who were HIV-antibody negative. Nor were they associated with thrombocytopenia, thrombosis, neurologic disease, a biological false-positive test for syphilis (BFP), or antibodies to DNA. It is concluded that factors other than infection with HIV are responsible for ACL positivity in homosexual males and that the epitopes recognized by ACL in this group are distinct from those associated with thromboembolism or the BFP reaction or cross-reactive with DNA.

AIDS-Related Complex↗
PubMed1989

Autoepitopes reactive with anti-SS-B/La.

Sera from 120 patients with suspected autoimmune rheumatic disease and antinuclear antibodies of anti-SS-B/La specificity were examined by Western blotting for reactivity with the SS-B/La polypeptide of HeLa cells and recombinant SS-B/La derived from a 1.4 kilobase (kb) cDNA encoding approximately 90% of the SS-B/La molecule. All sera reacted with the HeLa cell and the recombinant SS-B/La. One hundred and fourteen (95%) reacted with a set of three Staph. aureus V8 protease-resistant peptides of Mr 30,000, 29,00 and 28,000 from a methionine-rich region of HeLa cell SS-B/La designated the X domain, and 98 (82%) reacted with another set of two protease-resistant peptides of Mr 24,000 and 23,000 from a phosphorylated region of HeLa cell La designated the Y domain. One reacted weakly with the Y domain only. All sera that reacted with X and Y reacted more strongly with X, suggesting that X was the major epitope. Antibodies affinity purified from the X domain reacted strongly with the X peptides but not with the Y peptides and conversely, antibodies affinity purified from the Y domain reacted with the Y peptides but not with the X peptides. Both antibodies reacted with a fusion protein comprising 102 amino acids at the carboxyl terminus of the SS-B/La molecule. This protein contained no methionine, demonstrating that methionines were not involved in the antibody-binding site. Over 80% of patients whose only criteria for selection was the presence of anti-SS-B/La had the clinical, histologic, serologic and phenotypic features of Sjögren's syndrome whilst the remaining 20% had at least two of the features.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Characteristics and epitope mapping of a cloned human autoantigen La.

The La (SS-B) polypeptide is a ribonucleoprotein against which high titer antinuclear antibodies (ANA) react in the human autoimmune disease primary Sjögren's syndrome. To identify the autoepitopes with which the ANA anti-La (anti-SS-B) reacts, we isolated a 1.4-kb cDNA clone for La from a lambda gt10 library made from a human Burkitt's cell line. This clone contained an open reading frame of 1065 bp, encoding a 40.1-kDa polypeptide that corresponded to the carboxyl-terminal end of the La protein. The predicted polypeptide sequence of the recombinant protein was highly charged and unrelated to any previously published sequence. We also compared this clone to a previously published cDNA sequence for La and demonstrated significant differences, particularly that the open reading frame in our cDNA continued for 926 additional bases 3' to a putative termination codon in the previously reported sequence. The recombinant La protein was expressed in Escherichia coli and tested for reactivity with 200 sera containing ANA of various specificities. Only the sera containing anti-La antibodies reacted with the cloned La. By expressing subclones of the La cDNA as fusion proteins with beta-galactosidase, we have localized at least one epitope for the binding of anti-La antibodies to the carboxyl-terminal 103 amino acids of the La protein. No anti-La binding could be demonstrated to the region of the La protein that had previously been predicted to contain an autoepitope for the binding of anti-La (SS-B) antibodies. Studies of cloned autoepitopes could provide important clues to the role ANA play in disease and lead to targeted intervention in the treatment of primary Sjögren's syndrome.

Amino Acid Sequence↗
PubMed1988

Antinuclear antibodies as molecular and diagnostic probes.

Much progress has been made in the past decade in defining the specificities of antinuclear antibodies (ANA) that are present in the blood of patients with multi-system autoimmune rheumatic diseases, and ANA now have an important place in diagnostic immunology. Disease-specific ANA have been defined and the intracellular autoantigens against which they react have been characterized. ANA have also established an important place in cell biology. Their use as probes has enabled molecular biologists to isolate, purify and assay the function of the highly conserved molecules with which they react, revealing new insights into the role these molecules play in gene transcription and translation. Cloning of the genes encoding these molecules in addition to providing information on primary structure has also provided human recombinant proteins for use as pure substrates for the development of simple and highly sensitive diagnostic assays in rheumatology. Studies on the epitopes with binding sites for ANA should provide new knowledge on how the immune response to these molecules evolves, how it is maintained and what role ANA play in the pathogenesis of disease.

Antibodies, Antinuclear↗
PubMed1988

Striational autoantibodies: quantitative detection by enzyme immunoassay in myasthenia gravis, thymoma, and recipients of D-penicillamine or allogeneic bone marrow.

Striational autoantibodies (StrAb) are a useful serologic marker of thymoma in patients with myasthenia gravis (MG). We compared a standard immunofluorescence method with a new enzyme immunoassay (EIA) for detection of StrAb. Retrospective testing of 264 stored sera by the two methods yielded well-correlated results (58 sera were positive by both assays; r = 0.8). For 104 patients with spontaneously acquired MG or thymoma, results were 100% concordant, of which 53% were positive. For 34 recipients of D-penicillamine, StrAb were found in 15% by EIA and in 6% by immunofluorescence. StrAb were detected in two of four bone marrow recipients by EIA and in one by immunofluorescence. Prospective testing of 434 fresh sera (of which 49 were positive by the two methods) yielded discordant results in only 4. Serial EIA quantitation of StrAb in two patients with MG and thymoma proved useful in monitoring immunosuppressant therapy and in a third patient predicted recurrence of the tumor. A high prevalence of StrAb was detected by both assays in elderly patients with spontaneous MG, but StrAb were more readily quantifiable by EIA. The EIA method proved to be highly sensitive and specific for detecting StrAb in patients with thymoma with and without MG, in patients treated with D-penicillamine, and in those with graft-versus-host disease after bone marrow transplantation.

Adolescent↗
PubMed1988

Primary structure of the human M2 mitochondrial autoantigen of primary biliary cirrhosis: dihydrolipoamide acetyltransferase.

Primary biliary cirrhosis is a chronic, destructive autoimmune liver disease of humans. Patient sera are characterized by a high frequency (greater than 95%) of autoantibodies to a Mr 70,000 mitochondrial antigen, a component of the M2 antigen complex. We have identified a human cDNA clone encoding the complete amino acid sequence of this autoantigen. The predicted structure has significant similarity with the dihydrolipoamide acetyltransferase (EC 2.3.1.12) of the Escherichia coli pyruvate dehydrogenase multienzyme complex. The human sequence preserves the Glu-Thr-Asp-Lys-Ala motif of the lipoyl-binding site and has two potential binding sites. Expressed fragments of the cDNA react strongly with sera from patients with primary biliary cirrhosis but not with sera from patients with autoimmune chronic active hepatitis or sera from healthy subjects.

Acetyltransferases↗