Israel Medical Association Journal

Autoimmune diseases are classic examples of multifactorial disorders in which a large number of genes interact with environmental factors to form the final phenotype. Identification of the genes involved in these diseases is a daunting challenge. Initially the search involved the candidate approach where polymorphisms in suspected genes were tested for association in large cohorts of patients and controls. Today, the most widely used method is genome-wide association studies (GWAS), a method based on screening large panels of patients and controls with hundreds of thousands of single nucleotide polymorphisms (SNPs), with microarray-based technology. Unique families in which autoimmune diseases are caused by single genes are another alternative. The identification of candidate genes is often followed by studies that provide biologic plausibility for the findings. The widely expanding list of genes involved in autoimmune conditions show that the same genes frequently underlie the pathogenesis of different autoimmune diseases. Despite all available resources, the main void of heritability in autoimmune conditions is yet to be discovered. Identification of these genes will help define new biological pathways and identify novel targets for the development of new therapeutic drugs.

Background: Acute, as opposed to chronic, anterior uveitis is rarely associated with macular or optic nerve  edema. Nevertheless, mild changes may not be visible on examination.

Objectives: To implement non-invasive ocular coherence tomography (OCT) for obtaining quantitative and qualitative data in the assessment of changes in macular morphology and peripapillary retinal nerve fiber layers in eyes with acute anterior uveitis.

Methods: This retrospective case-control study was conducted in patients with unilateral acute anterior uveitis lasting for up to one month. Patients with evidence of other ocular disease or who had undergone intraocular surgery were excluded. We reviewed the charts of 14 consecutive patients who were diagnosed with acute unilateral anterior uveitis between 2007 and 2008 at the Tel Aviv Medical Center. Data on demographic details, ophthalmic examination, macular thickness and peripapillary retinal nerve fiber layer (RNFL) thickness (as demonstrated by OCT) were retrieved. Retinal and RNFL thickness was compared between the healthy fellow eye (control) and the uveitic eye in the central and four perifoveal quadrant regions, and RNFL thickness was compared in the mean and four quadrant values by Student’s t-test.

Results: We evaluated 28 eyes of 7 males and 7 females (mean age 37.7 years, range 20–65). The diagnoses were: idiopathic in five patients, ankylosing spondylitis in five, Crohn’s disease in one patient and reactive arthritis in one. Nine patients were HLA-B27 positive. The retina and the peripapillary NFL in each area were thicker in the uveitic eyes compared to the controls. The difference was statistically significant. There was no correlation between the differences in OCT values and patients’ demographic characteristics.

Conclusions: OCT demonstrated that eyes with acute anterior uveitis had thicker maculae and thicker peripapillary RNFL than controls. This finding suggests that even milder anterior uveitis may be associated with some degree of posterior segment manifestations.

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

Reactive arthritis is a disease affecting mostly young adults. Owing to a greater general awareness the diagnosis has become more common during recent years. It is well established that ReA is caused by an infection, mostly in genetically susceptible individuals. The pathogenetic mechan­isms are still poorly understood, and the treatment rests mainly on anti-inflammatory drugs or steroids. Vigorous and early treatment of the triggering infection may prevent the develop­ment of ReA but this is rarely possible in everyday clinical practice. Despite its name, the disease should be considered as a general disorder that affects not only the joints. The prognosis is not as good as earlier believed, and relapses or chronic development are not unusual.