The effect of BCG-PSN on T-cell subsets and cytokines in vernal conjunctivitis.

The effects of BCG-PSN on T-cell subsets and cytokines in vernal conjunctivitis were observed. The level of total IgE was quantitatively determined before and after treatment with BCG-PSN by allergen diagnostic instrument in vitro. The content of T-cell subsets of peripheral blood and cytokine were determined by using indirect immune fluorescence method, and IL-4 and INF-gamma were quantified by ELISA. The results showed that the level of total IgE was substantially reduced (P < 0.01) after treatment in the BCG-PSN group. Meanwhile, CD8+ was decreased, CD4+ and CD4+/CD8+ ratio elevated with significant differences (P < 0.05) as compared with pre-treatment results. The changes in total IgE, CD8+, CD4+ and CD4+/CD8+ ratio after treatment also presented significant differences (P < 0.05) between BCG-PSN group and routine treatment group. The level of IL-4 in serum declined (P < 0.05) after treatment in the BCG-PSN group, and INF-gamma went up (P < 0.05). IL-4 and INF-gamma in serum showed significant differences (P < 0.05) between two groups after treatment. It is concluded that BCG-PSN has a bi-directional immunoregulating effect. It can bring CD4+ and CD8+ into homeostasis, thereby preventing the occurrence of anaphylaxis. At the same time, BCG-PSN can restrain Th2, decrease the synthesis of IL-4, switch the balance of Th1/Th2 to Th1 side, boost up the predominance of Th1 relatively, which is propitious to perennial stabilization and recovery of vernal conjunctivitis.