Calprotectin (S100A8/A9) and S100A12 are associated with measures of disease activity in a longitudinal study of patients with rheumatoid arthritis treated with infliximab.

OBJECTIVES: The pro-inflammatory proteins calprotectin (a heterocomplex of S100A8/A9) and S100A12 have been associated with disease activity in rheumatoid arthritis (RA). The aim of this study was to compare their potential as biomarkers in a prospective study of RA patients starting with infliximab as their first biological disease-modifying anti-rheumatic drug (DMARD). METHOD: Thirty-nine RA patients were examined and serum samples collected when starting with infliximab and after 3, 6, and 12 months. Calprotectin and S100A12 were analysed by enzyme-linked immunosorbent assays (ELISAs) and, together with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), measured at all time points. A disease activity score of 28 joints (DAS28) was calculated. Radiographs of the hands, wrists, and feet were taken at baseline and after 3 years, and assessed according to the modified Sharp/van der Heijde (SvH) score. Responsiveness was evaluated according to the European League of Associations for Rheumatology (EULAR) response criteria based on 28 joints. RESULTS: Both S100 proteins were significantly higher in seropositive than in seronegative patients (p = 0.01). Calprotectin correlated significantly with CRP (ρ = 0.51-0.75), ESR (ρ = 0.32-0.52), and DAS28 (ρ = 0.32-0.62). S100A12 correlated with calprotectin (ρ = 0.62-0.77) and CRP (ρ = 0.32-0.63). The S100 proteins, and especially calprotectin (ρ = 0.23-0.39), showed weak associations with radiographic progression, unlike CRP/ESR. None of the S100 proteins could predict responsiveness. CONCLUSIONS: Calprotectin showed the strongest correlation with measures of disease activity and may be better than S100A12 when evaluating disease activity in RA patients. More extensive studies are needed to further compare the predictive value of the S100 proteins relative to radiographic progression.

Estimation of the prevalence of primary Sjögren's syndrome in two age-different community-based populations using two sets of classification criteria: the Hordaland Health Study.

OBJECTIVE: To estimate the point prevalence of primary Sjögren's syndrome (pSS) in two populations, aged 40-44 and 71-74 years, using two sets of classification criteria. METHODS: The participating individuals were recruited from the Hordaland Health Study (HUSK) conducted during 1997-99. A total of 18 592 individuals born 1953-57 and 3346 individuals born 1925-27 were sent a questionnaire covering various health-related questions, including four questions about sicca symptoms. Among those answering positive to at least one of the four questions, 99 and 90 individuals born 1953-57 and 1925-27, respectively, were examined further. For diagnosis of pSS two classifications were used, the preliminary European criteria from 1993, and the revised European criteria from 1996. RESULTS: By using the two classification criteria from 1993 and 1996, the point prevalences were 0.44% [95% confidence interval (CI) 0.34-0.57] and 0.22% (95% CI 0.15-0.32), respectively, for the population group born 1953-57. The corresponding estimates were 3.39% (95% CI 2.77-4.14) and 1.40% (95% CI 1.02-1.92) for the population born 1925-27. CONCLUSION: The point prevalence of pSS was approximately seven times higher in the elderly population aged 71-74 years compared to individuals aged 40-44 years, regardless of the classification criteria used.

Associations of MHC class II alleles in Norwegian primary Sjögren's syndrome patients: implications for development of autoantibodies to the Ro52 autoantigen.

Sjögren's syndrome (SS) is a chronic autoimmune disease characterized by dryness of the eyes and mouth. Currently, the highly polymorphic major histocompatibility complex (MHC) genes are the best documented genetic risk factor for the development of autoimmune disease. We examined the MHC class II alleles DRB1, DRB3, DRB4, DRB5, DQA1 and DQB1 in a group of Norwegian pSS patients and compared with a group of healthy controls. Because a number of studies have shown that some of the MHC class II alleles are not associated with the disease as a whole, but rather to the development of autoantibodies, anti-Ro52 autoantibodies in serum were measured and compared to MHC class II allele status. A clear association with pSS was detected for the DRB1*0301 and DRB3*0101 alleles, but these alleles were more closely associated with the presence of anti-Ro52 autoantibodies than with pSS itself. Moreover, the DQA1*0501 and DQB1*0201 alleles were only associated with the presence of anti-Ro52 autoantibodies. This study shows that the production of anti-Ro52 autoantibodies in pSS is associated with the DRB1*0301, DRB3*0101, DQA1*0501 and DQB1*0201 alleles which are in strong linkage disequilibrium.

[Heredity and immunology in Sjogren's syndrome]. / Arvelighet og immunologi ved Sjögrens syndrom.

BACKGROUND: Over the next 3-5 years, the rapid progress in genomic research will enable the discovery of many genes associated with the more common diseases. An example of such a common disease is the rheumatic disorder Sjögren's syndrome, an autoimmune disease. A more precise genetic explanation of the mechanism leading to Sjögren's syndrome remains to be given. MATERIAL AND METHODS: One way of investigating the disease related genes in such complex polygenic diseases is to perform linkage studies in families with two or more affected. Another possibility is to conduct association studies on trios (parents and affected child), case control studies, or other experimental designs. In association studies one is testing if an allele is significantly elevated among patients compared to controls, while in linkage analyses one finds subchromosomal regions that are significantly more often inherited by patients than by healthy family members. RESULTS: The most well defined genetic association in Sjögren's syndrome is currently related to different HLA alleles and their association with anti-Ro/SSA and anti-La/SSB autoantibodies. Additional genetic studies focusing on non-HLA regions are under way. INTERPRETATION: Increased genetic knowledge would allow optimisation of the diagnostic criteria as well as development of new and more effective treatment for Sjögren's syndrome, which causes substantial suffering for a large group of patients.

Isotype distribution of anti-Ro/SS-A and anti-La/SS-B antibodies in plasma and saliva of patients with Sjögren's syndrome.

In this study an ELISA assay was used to quantify the levels of antibodies against the recombinant Ro 52 kD, Ro 60 kD, and La 48 kD proteins in plasma and saliva of 17 Sjögren's syndrome patients. The levels of total IgG, IgA, and IgM were also quantified. About one third of the patients had salivary enrichment of IgA and IgM against the Ro 52 kD, Ro 60 kD, and La 48 kD antigens and IgG against La 48 kD, while no enrichment of IgG against Ro 52 kD and Ro 60 kD was found. Most correlations between plasma and saliva levels of antigen specific antibodies were highly significant, as were most correlations between focus score and levels of antigen specific antibodies in plasma and saliva. In total, the results support the hypothesis that autoantibodies are produced in the salivary glands. The strong correlation between focus score and plasma and saliva levels of autoantibodies, indicates that the local autoantibody production is a consequence of local inflammation.

Detection of anti-Ro/SSA and anti-La/SSB autoantibody-producing cells in salivary glands from patients with Sjögren's syndrome.

OBJECTIVE: To investigate and identify the presence of cells producing anti-Ro/SSA and anti-La/SSB autoantibodies in salivary glands from patients with Sjögren's syndrome (SS). METHODS: Submucosal salivary gland biopsy samples from 10 SS patients (8 with and 2 without circulating Ro and La autoantibodies) and 14 control subjects were evaluated. Frozen tissue sections were immunostained by an avidin-biotin complex technique, using biotinylated recombinant Ro and La proteins as detection reagents. Autoantibody levels in SS patient sera were analyzed by enzyme-linked immunosorbent assay. RESULTS: Cells producing autoantibodies to the Ro 52-kd, Ro 60-kd, and La proteins were recorded in 8, 6, and 7 of the 10 SS patient biopsy samples, respectively. Samples from the 2 SS patients without circulating Ro and La autoantibodies were negative for these autoantibody-producing cells, as were all control biopsy samples. A strong positive correlation between the presence of autoantibodies in sera and the presence of autoantibody-producing cells in glandular biopsy tissues was evident. The number of autoantibody-producing cells and the serum autoantibody levels were also correlated (r(s)=0.94, P < 0.0001). CONCLUSION: Using a novel technique, we have demonstrated the presence of Ro and La autoantibody-producing cells in salivary gland biopsy tissues from patients with SS. These findings indicate that anti-Ro/ SSA and anti-La/SSB autoantibodies are produced and are present at sites of inflammation and indicate their potential involvement in the autoimmune exocrinopathy of this disease.

Differential immunological aberrations in patients with primary and secondary Sjögren's syndrome.

The aim of the present study was to analyse possible differences in immunological features between patients with primary and secondary Sjögren's syndrome (SS). Ten patients with primary SS and 10 patients with secondary SS also suffering from rheumatoid arthritis, were identified according to established criteria for SS. Ten healthy, age-matched women served as controls. The authors analysed the phenotypic characteristics of lymphocytes in peripheral blood as well as in focal inflammatory infiltrates of minor salivary gland biopsies. Functional analyses of T lymphocytes were performed after stimulation with mitogens and antigen. B cell activity was determined at the single cell level by spontaneous and mitogen induced immunoglobulin production. Serum levels of IL-4, IL-6 and IFN-gamma were also analysed. Patients with primary SS displayed a significantly higher degree of salivary gland inflammation and reduced salivary flow than did patients with secondary SS. Decreased in vitro T cell responses to antigen and mitogens were evident in both patient groups. The CD4/CD8 ratios in both peripheral blood and salivary gland lesions were significantly lower in primary SS compared with secondary SS patients. Polyclonal B cell activation, measured as the frequency of spontaneous immunoglobulin producing cells, was most prominent in primary SS, whereas a diminished response to poke-weed mitogen (PWM), a T cell dependent B cell mitogen, was more pronounced in secondary SS. The results reveal certain immunological aberrations in the whole group of patients with SS. In addition, the authors demonstrated distinct differences in immune dysfunction between patients with primary and secondary SS, indicating that they may constitute separate entities.

Indicators of salivary gland inflammation in primary Sjogren's syndrome.

The aim of this study was to establish additional indicators in saliva and plasma which are associated with salivary gland inflammation in patients with primary Sjögren's syndrome (SS). ELISA assays were used to determine the concentrations of sICAM-1, sVCAM-1, sIL-2R alpha, IgA, IgG, calprotectin and albumin in parotid saliva, whole saliva and plasma samples. Soluble ICAM-1 was present in whole and parotid saliva samples from primary SS patients. Soluble VCAM-1 and sIL-2R alpha could not be detected in salivary samples from either primary SS or control subjects. IgA, IgG, calprotectin and albumin concentrations were higher in both whole and parotid saliva in the patient group compared with the control group. The results showed increased levels of calprotectin in all saliva samples compared to plasma, suggesting that calprotectin may be locally produced. Increased plasma values of sICAM-1, sVCAM-1, sIL-2R alpha, IgA, IgG and calprotectin were detected in primary SS patients when compared to controls. The output/min of IgA, IgG, calprotectin and albumin was decreased in SS patients. Plasma levels of various proteins could offer information concerning glandular and extraglandular inflammatory processes. However, salivary levels of these proteins (particularly sICAM-1) tend to reflect more the local inflammatory activity, providing a convenient and non-invasive tool for diagnosis.

Peripheral blood in Sjögren's syndrome does not contain increased levels of T lymphocytes reactive with the recombinant Ro/SS-A 52 kD and La/SS-B 48 kD autoantigens.

Patients with Sjögren's syndrome (SS) frequently have anti-Ro/SS-A and anti-La/SS-B autoantibodies. The aim of this study was to investigate if these patients have peripheral blood lymphocytes (PBL) secreting IFN-gamma after short-term cultivation in the presence of Ro/SS-A and La/SS-B antigens. The frequency of PBL secreting IFN-gamma was examined in 12 SS patients and 11 healthy controls. The enzyme-linked immunospot (ELISPOT) assay was performed after 48 hours cultivation of PBL in the presence of recombinant Ro 52 kD protein or recombinant La 48 kD protein. The number of unstimulated IFN-gamma secreting cells in the SS patient group was not significantly different from that of the control group. Moreover, no increase in the number of IFN-gamma secreting cells after Ro/SS-A and La/SS-B stimulation was detected in the two groups. Thus, T cells reactive with the recombinant Ro 52 kD and La 48 kD proteins do not occur with any increased frequency in peripheral blood of SS patients.

Serum antibodies from patients with primary Sjögren's syndrome and systemic lupus erythematosus recognize multiple epitopes on the La(SS-B) autoantigen resembling viral protein sequences.

The aim of this study was to investigate the epitope recognition pattern of La(SS-B) autoantibodies in sera from patients with Sjögren's syndrome (SS) and systemic lupus erythematosus (SLE) using overlapping synthetic decapeptides on solid phase. Eighty different decapeptides with five amino acids overlap from the human La(SS-B) autoantigen were synthesized on cellulose paper using F-moc chemistry. Tests were performed with 14 SS and six SLE sera. The results showed that the immune response to the La(SS-B) oligopeptides was restricted and unique for each individual with no particular pattern typical for each of the two diseases, apart from the fact that SLE sera gave positive reaction with fewer peptides. Regions within the N- and C-termini harboured most of the positive sequences. The authors specifically addressed the possibility of a viral aetiology for disease development or autoantibody generation. In this context the most frequently recognized linear epitopes on the La(SS-B) autoantigen showed sequence similarities with proteins from a range of ubiquitous human viruses, in particular from the herpes virus group. The La(SS-B) autoantibodies may thus be generated through molecular mimicry.