Search

Objective: The precipitating event(s) that triggers Wegener's granulomatosis (WG) is unknown. Cytokines, costimulatory molecules, and counterregulatory molecules control the quality and intensity of immune responses. Thus, they are relevant candidates for genetic studies of immune dysregulation in WG, the pathogenesis of which may be facilitated by multiple acquired and/or inherited factors. This study was undertaken to investigate possible genetic associations of various proinflammatory cytokines and CTLA-4, a receptor for T cell inhibition, with WG., Methods: Using polymerase chain reaction-based DNA genotyping, we investigated the polymorphisms located in the genes encoding a variety of proinflammatory cytokines and CTLA-4 in 117 American patients with WG and 123 ethnically matched healthy controls., Results: Compared with controls, patients with WG had a significantly lower frequency of homozygosity for the shortest allele (designated allele 86) of the Ctla4 microsatellite polymorphism (AT)n located in the 3'-untranslated region (3'-UTR) of exon 3 (47.0% versus 69.9%; P = 0.0005). Significant differences between patients and controls in the allelic and genotypic frequencies of polymorphisms in the other cytokine and cytokine receptor genes studied (tumor necrosis factor alpha [TNFalpha], TNF receptor I [TNFRI], TNFRII, interleukin-1beta [IL-1beta], IL-6) were not found., Conclusion: The Ctla4 (AT)n 86 allele has been previously demonstrated to be crucial for maintenance of normal levels of CTLA-4 expression and balance between T cell activation and inhibition. Our results in American patients confirm findings from a Scandinavian cohort in which a positive association between WG and longer alleles of (AT)n in the Ctla4 3'-UTR was demonstrated. Diminished frequencies of the most effective allele for CTLA-4 expression may represent a WG-related susceptibility mutation that accounts, in part, for increased T cell activation and clonal expansion in WG. Blockade of T cell costimulation using CTLA-4Ig might be a useful therapeutic intervention, providing an alternative or complementary approach to conventional treatment with immunosuppressive agents.

Objective: Wegener's granulomatosis (WG) is an idiopathic inflammatory condition characterized by upper and lower airway involvement and often renal dysfunction. Sites of tissue injury include pleomorphic cell populations, and classically mononuclear cell infiltrates that may form granulomas. Vascular inflammation (i.e., vasculitis) is often but not always present. Because CCR5 and its ligands influence mononuclear cell trafficking, we sought to identify their expression in pulmonary lesions and to determine whether genetic variations in genes for CCR5 and its ligands influence susceptibility to WG., Methods: Lung biopsies from 4 patients that had classical features of WG were examined for protein expression of CCR5, RANTES, MIP-1alpha and MIP-1beta using immunohistochemistry. One hundred eighteen Caucasian patients with WG and 127 ethnically matched healthy controls were included in the genetic analysis. Genomic DNA samples were amplified by PCR. CCR5 Delta32 and RANTES -28 and -401 polymorphisms were determined by either specific primers or direct sequencing., Results: CCR5+ cells were enriched in lung lesions from patients with WG. Enhanced protein concentrations of RANTES, MIP-1alpha, and MIP-1beta were present in WG lung lesions, indicating redundancy of ligands for CCR5 in affected tissue. Genetic analyses revealed 3 subsets of patients with WG: (1) circulating antineutrophil cytoplasmic antibody (ANCA) positive and CCR5+/+ (58%); (2) CCR5+/+ and ANCA negative (22%); and (3) CCR5 Delta32 and ANCA positive (20%). Among patients in whom ANCA were repeatedly absent, none was found to carry the CCR5 Delta32 allele. Conversely, patients who possessed the CCR5 Delta32 allele were always ANCA positive., Conclusion: CCR5 and its ligands are abundantly present in pulmonary lesions in WG. The absence of a genetic deletion for CCR5 (CCR5 Delta32) in WG patients lacking ANCA suggests that CCR5 may exert a particularly important pathogenetic role in those patients. Another subset of patients (approximately 20%) with WG possessed a genetic deletion for CCR5. That each of these patients was ANCA positive implies that an alternative pathway to CCR5 may exist, for which ANCA may be especially important.

Objective: To analyze the association of Wegener's granulomatosis (WG) with 2 single nucleotide polymorphisms (SNP), a +49 A/G polymorphism in coding sequence (CDS) 1 and a C/T base exchange in the promoter region at position -318., Methods: Restriction enzyme digestion of PCR amplified genomic DNA was used to analyze the CTLA-4 SNP in 32 patients with WG and 100-122 ethnically matched healthy controls., Results: Patients were more often heterozygous for C/T in the promoter region (31% of the patients vs 14% of controls; p < 0.05). Homozygosity for C was less frequent in patients (69% of patients vs 86% of controls; p < 0.05). There was no association with the A/G SNP in CDS 1. There was a linkage disequilibrium between allele A of CDS 1 and the shortest allele, 86 bp, in the (AT)n of the 3' untranslated region in controls but not in patients., Conclusion: The CTLA-4 SNP in the promoter region at position -318 is associated with WG. The loss of linkage disequilibrium between allele A of CDS 1 and the short 86 bp in the (AT)n in patients indicates that the promoter SNP and the (AT)n polymorphism are independent genetic risk factors.

Objective: Wegener's granulomatosis (WG) is a necrotizing vasculitis characterized by clonal expansions of T cells and production of antibodies against proteinase 3. The disease is associated with expanded dinucleotide repeats in the cytotoxic T lymphocyte antigen 4 (CTLA-4) gene, suggesting that genetic variation(s) in T cell related gene(s) could contribute to the T cell hyperactivity in WG. We investigated the polymorphisms in the genes of 2 cytokines, interleukin 4 (IL-4) and IL-10, which are essential for the polarization of T cells towards Th2 development and for the Ig production by B cells., Methods: Polymorphisms in the genes coding for IL-10 and IL-4 were analyzed in 32-36 Swedish Caucasian patients and 109 ethnically matched healthy individuals., Results: There was no association with the IL-4 gene. A CA repeat polymorphism in IL-10 gene, IL-10.G, was associated with the disease. This polymorphism has earlier been associated with high autoantibody production., Conclusion: Our results indicate that the IL-10 gene may influence the disease, perhaps by influencing the production of autoantibodies.