Evaluation of Th-1 and Th-2 immune responses in the skin lesions of patients with Blau syndrome.

Blau syndrome is an autosomal dominant syndrome characterized by arthritis, uveitis, skin rash, granuloma, and camptodactyly. It has overlapping symptoms with sarcoidosis and rheumatoid arthritis. Our study was directed toward determining the role of cytokines in granuloma formation in Blau syndrome. Antigenic stimulation usually follows two pathways: Th-1, which activates macrophages and cytotoxic T-lymphocytes and produces interleukin (IL)-2, IL-3, interferon gamma, and tumor necrosis factor alpha, and Th-2, which activates the humoral immune system and produces IL-4, IL-5, and IL-10. The development of cytokine profiles may shed some light on our understanding of this illness. Therefore, we studied the relative roles of two opposing lymphocytes, Th-1 and Th-2, by analyzing their relative expression in the skin lesions of patients with Blau syndrome, using the in situ reverse transcription-polymerase chain reaction technique. Our data revealed a significant upregulation of IL-2, an event that appears to play an important role in the formation of granuloma and in the pathogenesis of Blau syndrome. Expression of IL-10, however, was downregulated, and this may have an inhibitory role in the development of the disease. Further studies would be necessary to confirm the presence of other cytokines and to establish the regulatory roles of Th-1 and Th-2 lymphocytes in the pathogenesis of Blau syndrome.