CTLA-4 polymorphisms are not associated with ocular inflammatory disease

A Darwinian View of Behçet's Disease

Behçet's disease (BD) is a multisystem inflammatory disorder of unknown etiology, characterized by oral and genital ulceration, with other complications including eye, skin, joint, and central nervous system (CNS) lesions. Diagnosis is based on clinical findings, which may differ between patients. There is a strong genetic basis for BD; however, only a few genes have been associated with the disease across the geographical spread of BD. In this article, we discuss the history and combination of genes involved in this complex disease in relation to the geographical range and present our view that the disease has developed from a Darwinian perspective, with different gene polymorphisms that affect the same biological pathway. Moreover, these mutations individually are protective mechanisms against the disease relevant to each region, which affected both archaic and modern humans.

Study of association of CTLA4 gene variants to non-anterior uveitis

This study was undertaken to investigate the possible genetic association of functional CTLA4 polymorphisms with susceptibility to non-anterior uveitis. Four hundred and seventeen patients with endogenous non-anterior uveitis and 1517 healthy controls of Spanish Caucasian origin were genotyped for the CTLA4 polymorphisms rs733618, rs5742909 and rs231775, using predesigned TaqMan(©) allele discrimination assays. PLINK software was used for the statistical analyses. No significant associations between the CTLA4 polymorphisms and susceptibility to global non-anterior uveitis were found. It was also the case when the potential association of these genetic variants with the anatomical localization of the disease, such as intermediate, posterior or panuveitis, was assessed. Our results do not support a relevant role of these CTLA4 polymorphisms in the non-anterior uveitis genetic predisposition.

The role of CTLA-4 exon-1 49 A/G polymorphism and soluble CTLA-4 protein level in egyptian patients with Behçet's disease

This study analyzed the association of the A/G SNP at position +49 of exon-1 in the CTLA-4 gene to the susceptibility and clinical manifestations of Behcet's disease (BD). It was performed on 60 Egyptian BD patients and 95 age- and sex-matched healthy controls. The genotypes for the +49 A/G polymorphism of the CTLA-4 gene were determined by PCR-RFLP, while the serum level of CTLA-4 protein was measured by ELISA. CTLA-4 +49 A allele (P < 0.001, OR = 3.084, and CI (95%) = 1.90-4.99) and A/A genotype (P < 0.001, OR = 6.643, and CI (95%) = 2.58-17.10) frequency distribution was significantly more increased in patients than in the controls, with no significant differences between males and females with regard to the genotype or allele frequency distribution. A/A genotype was associated with a more reduced expression of sCTLA-4 protein in patients than in the controls (1.76 ± 0.19 versus 1.91 ± 0.30, resp; P < 0.0007). In addition, it is associated with the occurrence of ocular and vasculitic manifestations of BD in the patient group. The CTLA-4 gene could be considered as a susceptibility and a disease-modifying gene to BD in Egyptian population that needs further confirmatory studies on larger cohorts.

The protein tyrosine phosphatase nonreceptor 22 C1858T polymorphism and vasculitis: a meta-analysis

The aim of this study was to determine whether the functional protein tyrosine phosphatase nonreceptor 22 (PTPN22) C1858T polymorphism (rs2476601) confers susceptibility to vasculitis. A meta-analysis was conducted on the PTPN22 C1858T polymorphism across nine comparative studies containing 1,922 vasculitis patients and 11,505 normal control subjects. Meta-analysis showed no association between the T allele and vasculitis in all subjects [odds ratio (OR) 1.046, 95 % confidence interval (CI) 0.755-1.1.451, p = 0.786], and analysis after stratification by ethnicity indicated that the T allele was not associated with vasculitis in Europeans (OR 1.104, 95 % CI 0.798-1.528, p = 0.551). However, meta-analysis showed a significant association between the T allele and anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) (OR 1.415, 95 % CI 1.228-1.630, p = 1.59 × 10(-6)) and Wegener's granulomatosis (WG) (OR 1.829, 95 % CI 1.377-2.431, p = 3.09 × 10(-5)). In addition, meta-analysis showed an association between the T allele and WG in ANCA-positive subjects (OR 2.042, 95 % CI 1.534-2.719, p = 1.02 × 10(-6)), but not in ANCA-negative WG patients (OR 0.595, 95 % CI 0.199-1.781, p = 0.353). This meta-analysis does not show that the PTPN22 C1858T polymorphism is associated with vasculitis susceptibility, but does show that this polymorphism is associated with susceptibility to AAV, WG, and ANCA status in WG.

Genetics in ocular inflammation--basic principles

The ability to identify individuals at risk of ocular disease, or to determine the potential severity of disease or response to therapy is the current focus of much research. These studies are being led by genetic analysis of individuals to determine associations with alterations in gens that may explain manifestations of particular diseases. In this review we consider the basic principles behind genetic studies in general and of ocular disease in particular. We address the methodologies being utilised, and the results derived so far. The potential and pitfalls of such studies are relevant to the concept of personalised medicine and better defined clinical trials.

Immune response genes in uveitis

Uveitis is defined as an intraocular inflammation induced by different etiologies. Though the precise pathogenesis is still unknown, accumulating evidence shows that both innate and adaptive immune responses may be predominant mechanisms involved in the development of uveitis. Toll-like receptors have been shown to be expressed in the human eye and play an important role in infectious uveitis. The NOD proteins, expressed mainly in the cytosol by APCs, recognize the products of bacteria and participate in the development of uveitis. HLA genes have been associated with some uveitis entities, including acute anterior uveitis (HLA-B27), Behcet disease (HLA-B51), birdshot retinochoroidopathy (HLA-A29), Vogt-Koyanagi-Harada syndrome (HLA-DR4), sarcoidosis, sympathetic ophthalmia, juvenile idiopathic arthritis, tubulointerstitial nephritis and uveitis (TINU) syndrome, and pars planitis (HLA-DR15). The exact mechanism whereby certain HLA genes predispose to a certain uveitis entity has not yet been elucidated. In addition, several studies have demonstrate that polymorphisms in certain immune response genes, such as tumor necrosis factor (TNF), MHC class I polypeptide-related sequence A (MICA), interleukin-1 (IL-1), and some chemokines, may contribute to the development of human uveitis. Polymorphisms in the gene coding for the costimulatory molecule known as cytotoxic T-lymphocyte antigen 4 (CTLA-4) were recently found in Chinese patients with VKH syndrome but not in patients with Behcet disease. Further developments in the unraveling of immune response genes may lead to a better understanding of human uveitis and will hopefully allow the development of novel treatment regimes.