Correlation Between HLA-A, B and DRB1 Alleles and Severe Fever with Thrombocytopenia Syndrome.

OBJECTIVE

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever caused by a tick-borne bunyavirus (SFTSV) in East Asian countries. The role of human leukocyte antigen (HLA) in resistance and susceptibility to SFTSV is not known. We investigated the correlation of HLA locus A, B and DRB1 alleles with the occurrence of SFTS.

METHODS

A total of 84 confirmed SFTS patients (patient group) and 501 unrelated non-SFTS patients (healthy individuals as control group) from Shandong Province were genotyped by PCR-sequence specific oligonucleotide probe (PCR-SSOP) for HLA-A, B and DRB1 loci.Allele frequency was calculated and compared using χ2 test or the Fisher's exact test. A corrected P value was calculated with a bonferronis correction. Odds Ratio (OR) and 95% confidence intervals (CI) were calculated by Woolf's method.

RESULTS

A total of 11 HLA-A, 23 HLA-B and 12 HLA-DRB1 alleles were identified in the patient group, whereas 15 HLA-A, 30 HLA-B and 13 HLA-DRB1 alleles were detected in the control group. The frequencies of A30 and B13 in the SFTS patient group were lower than that in the control group (P = 0.0341 and 0.0085, Pc = 0.5115 and 0.252). The ORs of A30 and B13 in the SFTS patient group were 0.54 and 0.49, respectively. The frequency of two-locus haplotype A30-B13 was lower in the patient group than in the control group(5.59% versus 12.27%, P = 0.037,OR = 0.41, 95%CI = 0.18-0.96) without significance(Pc>0.05). A30-B13-DRB107 and A02-B15-DRB104 had strong associations with SFTS resistance and susceptibility respectively (Pc = 0.0412 and 0.0001,OR = 0.43 and 5.07).

CONCLUSION

The host HLA class I polymorphism might play an important role with the occurrence of SFTS. Negative associations were observed with HLA-A30, HLA-B13 and Haplotype A30-B13, although the associations were not statistically significant. A30-B13-DRB107 had negative correlation with the occurrence of SFTS; in contrast, haplotype A02-B15-DRB104 was positively correlated with SFTS.