[Analysis of the tandem-repeat polymorphisms in DC-SIGNR alleles among drug users population with or without HIV/HCV infection].

Objective: To study the distribution of DC-SIGN/DC-SIGNR alleles among drug user (DUs) populations with or without HIV/HCV infection in Shenzhen, and to evaluate the role of these alleles in the construction of genetic resistance to HIV or HCV and screen out the anti-HIV/HCV gene in Shenzhen.

Methods: All 500 DU blood samples were collected from Shenzhen Detoxification Center, including 313 from injected drug users (IDUs). All samples were screened for HIV and HCV antibody by means of ELISA. The genomic DNA were extracted and amplified by PCR. The neck domain repeat regions of DC-SIGN/DC-SIGNR were sequenced directly from the PCR products to confirm the amplification for some samples and all positive PCR products were analyzed by agarose gel electrophoresis.

Results: Of 500 samples, 97 were found HIV positive, all of which were IDUs and HCV positive. The total positive rate of HCV among all HIV negative DU was 57.57% (232/403), and it was 63.89% (138/216) among IDUs; in comparing to the 50.26% (94/187) of DUs with other manners there showed significant difference (chi(2) = 7.61, P = 0.0058). Among HIV + DUs, there was a higher proportion of patient with the DC-SIGNR 5/6 and 5/8 (Fisher's exact, P = 0.043 and P = 0.034) with statistical significance; there was no statistically significant difference between HCV + and HCV-DUs and no significant difference between IDUs and other DUs for the DC-SIGNR polymorphism.

Conclusion: The results might indicate that DC-SIGN/DC-SIGNR polymorphism might not influence the susceptibility to HCV. Genotype 5/6 might probably have a relation with HIV infection, but still need further investigation for the low frequency.