Tumor necrosis factor receptor 2 polymorphism in systemic lupus erythematosus: no association with disease

Genetic factors and immune dysregulation play important roles in the development of systemic lupus erythematosus (SLE). Tumor necrosis factor receptor 2 (TNFR2) is suggested to be involved in the development of SLE because its genetic locus (1p36) encompasses one of the susceptible loci for SLE and its ligand (TNF) is associated with SLE. To investigate the role of TNFR2 in the pathogenesis of SLE, 139 Korean patients were genotyped with SLE, 137 healthy control subjects were genotyped for TNFR2 196 R/M polymorphism in exon 6 with PCR-SSCP, and the clinical characteristics of SLE were analyzed according to the genotypes. The genotype frequencies of 196 R/R, 196 R/M, and 196 M/M were 3.6%, 30.9%, and 65.5% in SLE patients and 4.4%, 26.3%, and 69.3% in healthy controls (p = 0.676). The allelic frequency of 196 R was 19.1% in SLE patients and 17.5% in healthy controls (p = 0.638, odds ratio = 1.109, and the 95% confidence interval = 0.720-1.708). The clinical characteristics were not different according to the genotypes. In conclusion, no skewed distribution of TNFR2 196 R/M polymorphism was found in Korean patients with SLE compared with healthy controls. Further studies in other populations will be needed to elucidate the role of the TNFR2 polymorphism in the development of SLE.

Localized pigmented villonodular synovitis of the knee: arthroscopic treatment

Pigmented villonodular synovitis (PVNS) is a relatively rare condition. It occurs in two forms: a diffuse form involves the entire synovium and occurs in the majority of cases, and a localized form involves a discrete section of the synovium. The disorder almost always involves a single joint and the knee is most commonly affected. We report on three cases of localized PVNS that involved the patellar fat pad and synovium. Diagnostic and therapeutic arthroscopies were performed, and typical localized PVNS was found. Complete resection of the lesions was performed arthroscopically. Arthroscopy can be used as an effective diagnostic and therapeutic tool for identification and treatment of intra-articular localized PVNS of the knee.