INTRODUCTIONRheumatoid arthritis (RA) is a chronic, deforming arthritis that can lead to disabilities and poor quality of life. Cytokines are protein mediators of inflammation and are produced as a result of the activation of various cellular reactions. They are the final mediators and/or regulators of the inflammatory process.

MATERIALS AND METHODSThe sera from 64 RA patients were assayed for both Th-1 and Th-2 related cytokines and soluble TNF-alpha receptors (IFN-gamma, TGF-beta, TNF-alpha, IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, sTNF-R1 and sTNFR2) using ELISA.

RESULTSThe pro-inflammatory cytokines (IL-1, IL-6, IL-8, IL-18 and TNF- alpha) were significantly elevated in RA patients, while TGF-beta, an immunomodulatory cytokine, was elevated in control individuals. When the RA patients were categorised as active or inactive based on DAS scores, similar cytokines profiles were observed in both RA sub-groups. However, assays of sTNF-R1 and sTNFR-2 were noted to be significantly elevated in inactive RA patients when compared to active patients.

CONCLUSIONOur findings indicate that local production of cytokine inhibitors is capable of diminishing disease activity and cytokine activity.

Adult ; Aged ; Arthritis, Rheumatoid ; blood ; pathology ; Cell Differentiation ; Cytokines ; blood ; Female ; Humans ; Male ; Middle Aged ; Receptors, Tumor Necrosis Factor, Type I ; chemistry ; Receptors, Tumor Necrosis Factor, Type II ; chemistry ; Transforming Growth Factor beta ; chemistry

INTRODUCTIONInterleukin-18 (IL-18) is a Th1 cytokine, which is postulated to play a role in systemic lupus erythematosus (SLE). Two single nucleotide polymorphisms (SNPs) in the IL-18 promoter gene region were found to influence the quantitative expression of the IL-18 protein. The aim of this study was to determine whether IL-18 promoter gene polymorphisms are associated with SLE.

MATERIALS AND METHODSOne hundred and thirteen Chinese SLE patients and 218 Chinese healthy individuals were recruited. Genomic DNA was extracted from peripheral venous blood. Sequence-specific primer PCR and restriction fragment length polymorphism (RFLP) analysis were used to genotype the DNA samples for SNP-137 and SNP- 607. The following genotypes were obtained: SNP(-607) AA, AC, CC and SNP(-137) GG, GC, CC. Plasma IL-18 concentrations of patients and control subjects were measured by enzyme-linked immunosorbent assay.

RESULTSthe frequency of SNP-607/CC genotype was significantly higher in SLE patients (Pc < 0.05) while genotype SNP-607/AC was significantly decreased in SLE patients compared to the control group (Pc <0.05). Plasma IL-18 concentrations were significantly higher in SLE patients than in control subjects (P <0.05). Both patients and control subjects with CC and AC genotypes have significantly higher IL-18 concentrations than those with AA genotype.

CONCLUSIONThe IL-18 promoter gene polymorphism SNP-607 C allele is associated with SLE and may result in the enhanced production of IL-18 protein in SLE and normal individuals.

Adolescent ; Adult ; Aged ; Asian Continental Ancestry Group ; genetics ; Female ; Gene Frequency ; Genotype ; Humans ; Interleukin-18 ; genetics ; Lupus Erythematosus, Systemic ; genetics ; Male ; Middle Aged ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length ; Polymorphism, Single Nucleotide