Objective To investigate the role of activated T lymphocytes in the pathogenesis and effect of CD95 and bcl 2 expression on the development of alopecia areata. Methods The lymphocytes were isolated from the peripheral blood of the patients. Then CD4 +, CD8 +,and/or CD95 and bcl 2 positive lymphocytes were sorted out by flow cytometry . Results In the active stage of the disease, CD4 + lymphocytes decreased while CD8 + lymphocytes increased significantly. At the same time, the expression of bcl 2 was much more frequently detected in CD8 + lymphocytes than in CD4 +lymphocytes. CD95 expression was also increased markedly in T lymphocytes. Conclusions Down regulation of bcl 2 leads to the decrease in number of CD4 + lymphocytes. Meanwhile, CD8 + lymphocytes increased duo to the over expression of bcl 2. As a result , the ratio of CD4 + to CD8 +lymphocytes has dropped markedly and the cytotoxic effect of CD8 +lymphocytes on the hair follicles is enhanced. On the other hand, over expression of CD95 in T lymphocytes triggers cell apoptosis in the hair follicles. Both effects promote the development of alopecia areata . [

OBJECTIVE To explore the genetic basis for a family affected with Peutz-Jeghers syndrome (PJS). METHODS Genomic DNA was extracted from peripheral blood and oral swab samples from the patient and her relatives. Next-generation sequencing (NGS) was used to analyze 106 target genes by capturing the exons and adjacent intronic regions. Suspected pathogenic mutation was verified by NGS. RESULTS A missense STK11 mutation was detected in the proband, which was not reported previously. The mutation has caused substitution of Leucine by Proline. NGS has detected the same mutation in the mother but not among other relatives. CONCLUSION This hereditary case of PJS may be attributed to the missense mutation of the STK11 gene.