Background: An association of human leukocyte antigen (HLA)-DQw3 alleles with squamous cell carcinoma (SCC) of the cervix has been reported in some European populations, but the significance of HLA-DQw3 has not been examined in other populations to the authors' knowledge. The interaction between HLA-DQw3 and human papillomavirus (HPV) in SCC remains to be clarified.
Methods: To elucidate the association of HLA-DQ alleles with SCC of the cervix, DNA samples extracted from blood lymphocytes of 23 patients with SCC were amplified by the polymerase chain reaction (PCR) using specific primers for the DQB1 genes, and then, each HLA-DQB1 genotype was defined by digestion with restriction enzymes. Human papillomavirus typing also was performed in all cases by PCR, using specific primers for the E6 regions of cancer-associated HPV types (HPV 16, 18 and 33).
Results: Twenty patients (87%) carried a DQB1 gene-encoding HLA-DQw3, compared with 49.4% Japanese control subjects in the International Histocompatibility Workshop panel (P = 0.0003). Human papillomavirus 16 or HPV 18 DNA was detected in 86% of the patients. In 13 of the patients with invasive carcinoma with HPV, a high incidence of not only HLA-DQw3 but also of HLA-DQw1 was observed compared with that in control subjects (P = 0.0019, P = 0.047, respectively). The correlation between DQB1*03 alleles and HPV infection was not statistically significant.
Conclusion: The frequency of HLA-DQw3 alleles was higher in the authors' patient group than in the control group, suggesting that the HLA-DQw3 molecules may influence the development of SCC of the cervix in young Japanese women. In the patients with HPV-positive invasive carcinoma, the association with HLA-DQw1 molecules suggested that it also may influence the progression of SCC.