John B. Winfield

The American College of Rheumatology Preliminary Diagnostic Criteria for Fibromyalgia and Measurement of Symptom Severity

To develop simple, practical criteria for clinical diagnosis of fibromyalgia that are suitable for use in primary and specialty care and that do not require a tender point examination, and to provide a severity scale for characteristic fibromyalgia symptoms.

Fibromyalgia Criteria and Severity Scales for Clinical and Epidemiological Studies: A Modification of the ACR Preliminary Diagnostic Criteria for Fibromyalgia

Objective. To develop a fibromyalgia (FM) survey questionnaire for epidemiologic and clinical studies using a modification of the 2010 American College of Rheumatology Preliminary Diagnostic Criteria for Fibromyalgia (ACR 2010). We also created a new FM symptom scale to further characterize FM severity. Methods. The ACR 2010 consists of 2 scales, the Widespread Pain Index (WPI) and the Symptom Severity (SS) scale. We modified these ACR 2010 criteria by eliminating the physician’s estimate of the extent of somatic symptoms and substituting the sum of 3 specific self-reported symptoms. We also created a 0–31 FM Symptom scale (FS) by adding the WPI to the modified SS scale. We administered the questionnaire to 729 patients previously diagnosed with FM, 845 with osteoarthritis (OA) or with other noninflammatory rheumatic conditions, 439 with systemic lupus erythematosus (SLE), and 5210 with rheumatoid arthritis (RA). Results. The modified ACR 2010 criteria were satisfied by 60% with a prior diagnosis of FM, 21.1% with RA, 16.8% with OA, and 36.7% with SLE. The criteria properly identified diagnostic groups based on FM severity variables. An FS score ≥ 13 best separated criteria+ and criteria− patients, classifying 93.0% correctly, with a sensitivity of 96.6% and a specificity of 91.8% in the study population. Conclusion. A modification to the ACR 2010 criteria will allow their use in epidemiologic and clinical studies without the requirement for an examiner. The criteria are simple to use and administer, but they are not to be used for self-diagnosis. The FS may have wide utility beyond the bounds of FM, including substitution for widespread pain in epidemiological studies.

Lupus anticoagulant activity of autoimmune antiphospholipid antibodies is dependent upon beta 2-glycoprotein I.

It has been reported that antiphospholipid autoantibodies do not recognize phospholipid alone, but rather the plasma protein beta 2-glycoprotein I (beta 2GPI), or a beta 2GPI-phospholipid complex. In vitro beta 2GPI binds to anionic phospholipids and inhibits the prothrombinase activity of procoagulant membranes. In light of the fact that lupus anticoagulants, a type of antiphospholipid antibody, have similar anticoagulant properties, the relationship of beta 2GPI to lupus anticoagulant activity was investigated. IgG from patients with autoimmune diseases or syphilis were tested for anticardiolipin reactivity and lupus anticoagulant activity in the presence and absence of beta 2GPI. As expected, anti-cardiolipin reactivity associated with autoimmune disease was beta 2GPI dependent. In contrast, IgG from a patient with syphilis recognized cardiolipin alone and binding was inhibited by beta 2GPI. Autoimmune antiphospholipid antibodies prolonged the dilute Russell viper venom time of normal plasma, but had no effect on beta 2GPI-depleted plasma. Antiphospholipid antibodies associated with syphilis had no anticoagulant effect. RP-1, an anti-beta 2GPI mAb, had anticoagulant effects similar to those of autoimmune antiphospholipid antibodies. These data demonstrate that antiphospholipid autoantibodies exert lupus anticoagulant activity via an interaction with beta 2GPI. These antibodies and RP-1 appear to amplify the anticoagulant effect of beta 2GPI itself.

THE 8.5-KB PSTI ALLELE OF THE STRESS PROTEIN GENE, HSP70-2 : AN INDEPENDENT RISK FACTOR FOR SYSTEMIC LUPUS ERYTHEMATOSUS IN AFRICAN AMERICANS ?

SLE is dramatically more prevalent in persons of African descent than in other populations. Several genes in the class III region of the MHC have been considered as potential susceptibility loci for this disorder, but the primary association(s) remains unknown. The stress protein gene, hsp70-2, is of special interest in this regard because it encodes a protein functionally relevant to antigen processing and presentation and has itself been identified as a putative susceptibility locus in organ-specific autoimmune diseases in Caucasians. To clarify the relationship of the hsp70-2 gene to SLE in African Americans, genomic DNA from 46 patients and 42 appropriately matched control subjects was analyzed for an RFLP of the hsp70-2 gene using the probe pH2.3 and the restriction endonuclease PstI, which identifies alleles of 8.5 and 9.0 kb. The 8.5-kb hsp70-2 allele was associated with SLE in this population (X2 = 8.2473, p = 0.0044). This association was not due to linkage disequilibrium with the C4A deletion or with HLA-DR3, as has been reported in Caucasians with IDDM. These data suggest that the 8.5-kb hsp70-2 allele may be an independent susceptibility marker for SLE in African Americans.

Synthetic Autoantigens of Immunoglobulins and T-Cell Receptors: Their Recognition in Aging, Infection, and Autoimmunity

Abstract Immunoglobulins and their close relatives, the antigen-specific T-cell receptors, are recognition proteins that express structures which readily serve as self-immunogens. Healthy humans can produce antibodies against variable region-defined recognition structures termed idiotypes, as well as against constant region structures, and the levels of these can increase markedly in autoimmune disease; e.g., rheumatoid factors are autoantibodies directed against a conformational determinant of the γ heavy chain. More recent analyses employing synthetic peptide technologies and construction of recombinant T-cell receptors document that autoantibodies directed against both variable and constant region markers of the α/β T-cell receptor occur in healthy individuals. Alterations in levels of antibody, usage of IgM or IgG isotypes, and specificity for particular peptide-defined regions vary with natural physiological processes (aging, pregnancy), with artificial allografting, with retroviral infection, and with the inception and progression of autoimmune disease (e.g., rheumatoid arthritis, systemic lupus erythematosus). Two of the major autoimmunogeneic regions of the Tcr α/β are “constitutive” markers inasmuch as all Individuals tested produce antibodies against these regions. The most frequently observed autoantibodies are against Tcr Vβ CDR1 and Fr3 markers. It is hypothesized that these are normally involved in immunoregulation. Autoantibodies usually are not detected against CDR2 region determinants, or the “private idiotypes” defined by the CDR3 region, or the highly conserved FR4 segment specified by the joining gene segment. However, autoantibodies against the CDR2 of the Tcrα chain occur in some SLE patients, and healthy pregnant women produce antibodies against the common peptide determinant expressed by the joining gene and the beginning of the Cα or Cβ domain. Although the precise role of the naturally occurring autoantibodies in immunoregulation remains to be determined, modification of the course of autoimmune diseases in experimental rodent models (experimental allergic encephalomyelitis) has been successfully carried out by immunization with synthetic peptides corresponding to the CDR2 and Fr3/CDR3 segments, and immunization of humans with synthetic Vβ CDR2 segments may prove helpful in multiple sclerosis.

Expression of the sialosyl-Tn epitope on CD45 derived from activated peripheral blood t cells

The cell surface protein tyrosine phosphatase CD45 is a major target of IgM anti-T cell autoantibodies in systemic lupus erythematosus (SLE). The autoreactive determinants on CD45 are O-linked glycans expressed on activated T cells and certain T cell lines, rather than linear or conformational polypeptide epitopes or N-linked glycans. To identify oligosaccharide structures that may play a role in the functional interactions of CD45 or are candidate target epitopes of SLE anti-CD45 autoantibodies, autoreactive CD45 purified from Jurkat T cells and non-autoreactive CD45 purified from CLL B cells were tested by ELISA for expression of mucin-type O-glycan structures. Monoclonal antibodies (mAbs) directed against blood group A, type 1 H chains, type 2 H chains, T, Le(a), sialylated-Le(a), Le(b), sialylated-Le(c), Le(x), sialylated-Le(x), multi-fucosylated Le(x), Le(y), and sialylated-extended Le(v) failed to react with CD45 from either B cells or T cells. However, mAbs directed against Tn (galNAcalpha1-->O-ser/thr) or sialosyl-Tn (neuNAcalpha2-6gaINAcalpha1-->O-ser/thr) structures reacted with CD45 derived from Jurkat T cells, but not from CLL B cells. Anti-Tn mAbs also reacted in western blotting procedures with CD45 isolated from Jurkat T cells, but did not react with CD45 isolated from CEM, MOLT-3, or PEER T cells; Daudi, Raji, or CLL B cells; or resting or Con A-activated PBL. However, anti-sialosyl-Tn mAbs stained blots of CD45 isolated from Jurkat and CEM T cells and Con A-activated PBL, a pattern of reactivity similar to that of the anti-CD45 autoantibodies. Flow cytometric analyses demonstrated that the sialosyl-Tn epitopes are expressed on a subpopulation of CD4 +/CD8- T cells.

Autoantibodies to nucleolin cross-react with histone H1 in systemic Lupus erythematosus

IgM autoantibodies to nucleolin and histone H1 are strongly associated in the serum of patients with systemic lupus erythematosus. IgM eluted from immobilized nucleolin specifically stained histone H1 blotted to nitrocellulose; conversely, IgM eluates prepared from immobilized histone H1 stained nucleolin blots. We conclude that the linkage of anti-nucleolin and anti-histone H1 autoantibodies in SLE is due, at least in part, to immunologic cross-reactivity between these two autoantigens, which share certain similar structural features.

Specificity of autoantibodies to histone H1 in SLE: relationship to DNA-binding domains.

Autoantibodies in the sera of patients with systemic lupus erythematosus were examined with respect to their specificity for proteolytic fragments of histone H1 that retain, or do not retain, DNA-binding domains. 16 of 31 sera contained IgG and IgM antibodies to histone H1. IgM antibodies to H1 in 8 sera (50%) were directed at 18 kD and 20 kD alpha-chymotrypic H1 fragments that bore binding sites for DNA, as identified by staining immunoblots containing the fragments with ssDNA plus 6/0, a mouse monoclonal antibody against ssDNA, IgM with this type of histone H1 specificity did not react with comparably-sized V8 protease fragments of H1. IgM antibodies to H1 in the other patients were directed against entirely different epitopes which were preserved in V8 protease digests of H1. In serial studies of three patients during different phase of their SLE, the level of antibodies against the 18 kD and 20 kD histone H1 fragments varied in parallel with the level of anti-ssDNA antibodies in one and varied inversely in the other two. The data suggest that a significant proportion of autoantibodies to histone H1 are directed at a limited number of epitopes localized to H1 fragments containing DNA-binding sites.

Stress Proteins in Autoimmunity

Interest in the idea that stress proteins (also called heat shock proteins) contribute to the development and persistence of autoimmunity derives from five principal observations. First, stress proteins are immunodominant antigens of all prokaryotic infectious microorganisms, many of which have been implicated as inducers of arthritis and autoimmune disease in genetically susceptible individuals. Second, the T-cell repertoire, especially that of T-cells bearing γδ TCRs, appears to be biased toward recognition of microbial stress proteins (and, possibly, host stress proteins as well) as part of an evolutionarily conserved mechanism for host defense against infection and for resolution of tissue inflammation. Third, stress proteins are highly conserved, as would be expected in view of their fundamentally important roles in cell biology. During infection, which entails “stress” for both the microorganism and the host, there is increased synthesis and altered expression of extremely similar sets of autologous and foreign stress proteins. Fourth, the inflammatory response associated with infection up-regulates HLA glycoproteins that present antigen peptides to T-cell receptors. This may amplify recognition signals for conserved stress protein peptides to a degree sufficient for stimulation of autoreactive T-cells that have escaped deletion in the thymus. The various “permissive” genetic effects that underlie autoimmune disease may allow an autoreactive immune response to stress proteins, or to other self-constituents that cross-react with stress proteins, to persist or recur in susceptible individuals. Finally, two animal models of human autoimmune disease, adjuvant arthritis in the rat and spontaneous type-1 diabetes in non-obese mice, have implicated a stress protein, hsp60, as the critical pathogenetic element.

Autoregulation of Tcr V region epitopes in autoimmune disease.

Normal individuals possess low levels of autoantibodies specific for certain peptide defined regions of T-cell receptor (Tcr) variable regions, particularly CDR1 and Fr3. These regions are predicted to be exposed on the surface of the native molecule and, by analogy and comparison with immunoglobulins, correspond to public idiotype determinants. The anti-Tcr idiotype antibodies appear to be ubiquitous and we propose that they play a role in the regulation of T-cell function. To delineate the parameters of expression of these antibodies, we characterized anti-Tcr antibody activity in normal individuals, in those suffering from the autoimmune diseases rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), and in patients with non-autoimmune arthritis (osteoarthritis) as a disease control. There were significant increases in autoantibody levels in the autoimmune patients. There was also variation in isotype and the particular variable regions recognized. IgM autoantibodies directed against a few peptide defined determinants were elevated in RA, whereas SLE patient sera showed high levels of IgG binding to a broad spectrum of Tcr peptides.