Human leukocyte antigen phenotypes and hepatitis C viral load.

BACKGROUND: After hepatitis C virus (HCV) infection, 55% to 85% of patients become chronic carriers. HCV-RNA could be detected in the sera of these patients though the viral load varies. Various factors may be involved in determining the viral load. OBJECTIVES: In this study, we want to investigate the relationship between human leukocyte antigen phenotypes and hepatitis C viral load. STUDY DESIGN: One hundred and sixty HCV-RNA positive subjects were investigated in this study. RESULTS: We have analyzed 160 HCV-RNA positive subjects and found that lower HCV viral load is significantly associated with HBsAg-positivity (P = 0.017) but not age, gender, or mixed infection (infection with different HCV genotypes). One hundred and fifty-four HBsAg-negative subjects were further analyzed to explore the relationship between human leukocyte antigen (HLA) phenotypes and HCV viral load. Subjects with certain HLA alleles (A*34, B*56, DRB1*1502) have significantly lower viral load than those without these alleles (P = 0.0074, 0.0039 and 0.016, respectively) while those with HLA-B*4001 have significantly higher viral load (P = 0.0026). Furthermore, lower viral load was significantly associated with HLA-DRB1 heterozygosity in subjects with HLA-B heterozygosity (P = 0.048). CONCLUSIONS: Our data suggests a role for host immunogenetic factors in determining viral load during HCV infection.

HLA phenotypes and outcomes of hepatitis B virus infection in Taiwan.

The relationship of HLA phenotype and outcome of hepatitis B virus (HBV) infection was studied in two ethnic groups of Taiwan: Han Chinese and Taiwanese Aborigines. In Han Chinese, the study groups consisted of 98 persons who tested both hepatitis B surface antigen (HBsAg) and anti-HBs negative (Uninfected Group), 324 persons who tested HBsAg negative and both anti-HBs and anti-HBc positive (Recovered Group), and 98 patients who tested HBsAg positive for at least 6 months (Chronically Infected Group). In Taiwanese Aborigines, the study groups consisted of 34 persons in Uninfected Group, 229 persons in the Recovered Group, and 138 patients in the Chronically Infected Group. All subjects were tested for HLA (A, B, DRB1) phenotypes by sequence-specific oligonucleotide probe hybridization (SSOPH). HLA-DR*0406 was significantly more frequent in the Recovered Group, compared with the Chronically Infected Group (P < 0.001) in Han Chinese. There was a significant excess of HLA-B*4001 (P = 0.045) in the Recovered Group, compared with the Chronically Infected Group in Taiwanese Aborigines. The observation that different HLA phenotypes associated with recovery from HBV infection in different racial groups implies that various HLA molecules could present different HBV epitopes to induce effective immune responses.

Marrow donor registry and cord blood bank in Taiwan.

Unrelated Bone marrow transplant was initiated thirty years ago. Though there are over millions of donors registered with the bone marrow registries worldwide, Asian patients rarely find a match with all these donors. Tzu Chi Marrow Donor Registry was established to meet this need. It has become the largest Asian marrow donor registry in the world. With the introduction of high technology to test the HLA of the donors and recipients, the success rate of bone marrow transplant is greatly improved among Asian countries. 50% of blood disease Asian patients who cannot find a bone marrow matched donor will be complemented by the establishment of cord blood banks in Taiwan.

Confirmation of a recombinant allele B*5603 and a hypothetical reciprocal hybrid.

From its DNA sequence, B*5603 is thought to be a product of gene conversion. We present here serological evidence of such an event and further speculate on a possible reciprocal hybrid yet to be identified. In addition, we report the allelic frequency of B*5603 in the Taiwanese population and its association with A*1101, Cw*01 and DRB1*1201.