Israel Medical Association Journal

Background: The presence of anti-cyclic citrullinated peptide autoantibody is highly specific for rheumatoid arthritis. Certain HLA-DR4 (HLA-DRB1*04) alleles, also known as the "shared epitope," are associated with increased susceptibility to RA[1]. In addition, these alleles may also have relevance for disease outcome. Anti-CCP[2] antibody positivity has been associated with the presence of HLA-DR4 alleles in patients with RA. However, there is little information available regarding any relationship between quantitative anti-CCP production (serum anti-CCP concentrations) and the shared epitope.

Objectives: To determine the association between anti-CCP antibody production and various HLA-DRB1 alleles.

Methods: Serum anti-CCP, rheumatoid factor and C-reactive protein levels were assessed in 53 RA patients. All these patients underwent HLA-DRB1 genotyping.

Results: Of the 53 patients 33 (62%) were positive for anti-CCP antibody. We found significant correlations between anti-CCP and RF[3] positivity (chi-square = 6.717, P < 0.01), as well as between anti-CCP and HLA-DRB1*04 positivity (chi-square = 5.828, P < 0.01). There was no correlation between RF positivity and serum levels, CRP[4] serum levels and HLA-DRB1*04 positivity. When quantitatively comparing serum anti-CCP levels with shared epitope positivity, patients carrying one or two copies of HLA-DRB1*04 alleles had significantly higher anti-CCP concentrations (530.0 ± 182.6 U/ml) compared to DRB1*04-negative patients (56.8 ± 27.4 U/ml) (P < 0.01). There was no difference in serum anti-CCP antibody concentrations between patients carrying only one HLA-DRB1*01 allele but no HLA-DRB1*04 allele (12.0 ± 8.6 U/ml) in comparison to SE[5]-negative patients (76.8 ± 56.2 U/ml). Regarding non-SE HLA-DRB1 genotypes, all 6 patients (100%) carrying DRB1*15 alleles and 6 of 7 (85%) patients carrying DRB1*13 were anti-CCP positive. In addition, patients with HLA-DRB1*13 (282.5 ± 23.8 U/ml) and DRB1*15 (398.7 ± 76.2 U/ml) produced significantly more anti-CCP than did any other non-SE HLA-DRB1 subtypes (P < 0.01).

Conclusions: There is significant association between anti-CCP and RF, as well as between anti-CCP and SE positivity in RA. In addition, the presence of one or two copies of HLA-DRB1*04 alleles has been associated with higher serum anti-CCP antibody levels. Thus, patients carrying HLA-DRB1*04 alleles exhibited an overall tenfold increase in serum anti-CCP antibody levels in comparison to HLA-DRB1*04-negative subjects. Increased anti-CCP production may also be associated with other non-SE HLA-DRB1 genotypes, such as DRB1*13 or DRB1*15. In reports by other investigators, both anti-CCP concentrations

Among the several mechanisms that play a role in maintaining peripheral self-tolerance is the existence of a unique CD4+CD25+ population of naturally occurring regulatory T cells, which actively prevent both the activation and the effector function of autoreactive T cells that have escaped different mechanisms of tolerance. Many studies have shown the benefit of targeting this cell population by restoring self-tolerance. Therapies that could possibly increase the suppressive ability of T regulatory cells were proven to improve the course of autoimmune diseases.

Klinefelter's syndrome, which occurs in males, is not a rare gonosomal aberration. The disorder is characterized by micro-orchidism.

Diffuse idiopathic skeletal hyperostosis is often incorporated into osteoarthritis. Although DISH[1] often coexists with OA, patients affected by this disorder differ from patients with primary OA in several aspects: prevalence in the general population, gender distribution, anatomic site of primary involvement, magnitude and distribution in the spine and the peripheral joints. DISH is a distinct clinical entity. Its recognition as such should stimulate clinicians and researchers to focus on its pathogenesis, treatment and prevention.

Matrix metalloproteinases are a family of enzymes that degrade different components of extracellular matrix. They play an important role in normal physiologic processes of maintaining tissue integrity and remodeling, as in wound healing, processes of development, and regeneration. However, excessive expression of MMP[1] has been observed in many disease states, including rheumatoid arthritis and osteoarthritis, vascular remodeling in atherosclerosis and aortic aneurysm formation, neoplastic processes, macular degeneration and many others.

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