The prevalence of human T-cell leukemia virus in blood donors in China.

BACKGROUND: China has not yet incorporated routine human T-lymphotropic virus (HTLV)-1/2 blood donor screening, even though HTLV has been reported in the southeastern coastal region. This study was conducted to investigate the prevalence of HTLV in five major regions across of China. METHODS: From January 2016 to December 2017, blood samples were collected in 20 blood centers located in different regions of China. These samples were screened for HTLV-1/2 antibodies using enzyme-linked immunosorbent assay (ELISA). If the test samples were reactive, the samples were confirmed with a western blot (WB) assay. If the results of WB were indeterminate, the donor was interviewed after a minimum lapse of 8 weeks. All follow-up samples from donors were tested for anti-HTLV-1/2 with ELISA and WB. RESULTS: There were 875,453 donor samples tested for anti-HTLV-1/2 by ELISA. In all, 365 samples tested negative, 22 samples tested positive by WB, and 14 samples with HTLV status undetermined due to being lost to follow-up. The prevalences were 11.09, 5.96, 3.16, 2.88 and 0.98 per 100,000 in Xiamen, Changsha, Beijing, Shenzhen, and Nanjing blood center, respectively. The prevalences were 0 per 100,000 for all 15 other blood centers. There was significant differences in the prevalence of HTLV in different regions of China (p = 0.0011). CONCLUSION: In China, HTLV-1 confirmed positive donors are mainly from southeastern coastal areas. It may be necessary to conduct HTLV screening in these areas to reduce the risk of transfusion-transmitted HTLV.

Relationship between HLA-DPA1 mRNA expression and susceptibility to hepatitis B.

Chronic hepatitis B virus (HBV) infection is influenced by both viral and host factors. In genome-wide association studies, the human leucocyte antigen HLA-DPA1 and related polymorphism rs3077 were found to be associated with susceptibility to and spontaneous clearance of HBV infection. Here, we evaluated the association between HLA-DPA1 mRNA expression and the risk of HBV infection. HLA-DPA1 and rs3077 polymorphisms were investigated in 169 patients with chronic HBV and 217 healthy controls (HCs) from Sichuan Han blood donors using sequence-based typing and meta-analysis for HLA-DPA1 alleles. HLA-DPA1 mRNA levels were measured by real-time polymerase chain reaction. The results showed that HLA-DPA1 and rs3077 were associated with HBV infection in the Sichuan population. Rs3077T and DPA1*01:03 played protective roles in HBV infection, and rs3077C and DPA1*02:02 increased susceptibility to HBV infection. We found that the HLA-DPA1 mRNA expression was decreased in the CHB group; in particular, the 3077CT, 3077TT, DPA1*01:03 and DPA1*02:01 alleles showed a significant decrease. Our results demonstrated, for the first time, that expression of HLA-DPA1 alleles and rs3077 affected the risk of HBV infection. Genotypes with lower HLA-DPA1 expression had a greater susceptibility to HBV infection. Thus, further independent studies are needed to strengthen the associations of these polymorphisms with susceptibility to and clearance of HBV infection in Chinese populations.

Prevalence of hepatitis E virus in Chinese blood donors.

OBJECTIVE: To investigate the prevalence of hepatitis E virus (HEV) antibodies and RNA in voluntary blood donors, in China. METHODS: Serum samples from blood donors were collected sequentially at six blood donation centres in five geographical regions of China. Donors were stratified between two groups according to their serum alanine aminotransferase (ALT) concentration (≤ 40 U/l and >40 U/l. Enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction were used to quantify anti-HEV antibodies and RNA, respectively. RESULTS: In total, 21.1% (172/816) of donors were positive for anti-HEV immunoglobulin (Ig) G (elevated ALT samples group 18.9% [85/450]; normal ALT group 23.8% [87/366]), and 0.5% (four of 816) donors were positive for anti-HEV IgM (elevated ALT group 0.9% [four of 450]; normal ALT group 0% [none of 366]). The rate of anti-HEV IgG seropositivity was significantly higher in male than in female donors. No serum sample tested positive for HEV RNA. CONCLUSION: The prevalence of anti-HEV antibodies in blood donors in China is high, regardless of ALT concentration.