Recent in vitro studies have shown that interleukin 4 (IL-4) induces and gamma interferon (IFN-γ) inhibits collagen production. To define the TH1(IFN-γ) and TH2(IL-4) cytokine profiles in systemic sclerosis (Sscl), a disease characterized by widespread fibrosis, we investigated IL-4 and IFN-γ transcripts in peripheral blood mononuclear cells and plasma protein levels in 13 patients with Sscl. Two previously identified IL-4 transcripts, a full-length transcript and an alternatively spliced (truncated) transcript (designated IL-4δ2), were identified in patients and normal controls. Significantly increased levels of total IL-4 transcripts (full-length plus IL-4δ2 transcripts) were found in patients with Sscl in comparison to those found in healthy controls (P = 0.003), and this increase was primarily due to an increase in the level of the alternatively spliced IL-4δ2 form. The IL-4δ2/full-length-IL-4 transcript ratio was significantly increased in Sscl patients (P < 0.0001, versus healthy controls). Sequencing analysis revealed that the frequency of IL-4 clones carrying the IL-4δ2 transcript was also substantially increased in patients with Sscl. Plasma IL-4 protein levels were increased in Sscl patients compared to those in healthy controls (P = 0.001) and correlated with total IL-4 transcript levels. The up-regulation of the fibrogenic IL-4 (a TH2 cytokine) in Sscl suggests a pathogenic role for IL-4 in this disease.
Giant synovial cysts (GSC) are large, well-defined cavities, containing synovial fluid and lined by a synovium-like membrane, which extend for a variable distance outside the joint cavity. We are reporting 15 cases of GSC of various joints. Rheumatoid arthritis is the most common disease process reported in association with GSC. We suggest that trauma may be a more important cause of GSC than has previously been described. Arthrography and ultrasonography are both helpful in diagnosing these large cysts, especially in the knee to aid in differentiating GSC from thrombophlebitis.
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