Study of human leukocyte antigen class I phenotypes in Moroccan patients with nasopharyngeal carcinoma

Previous reports demonstrated an association between the human leukocyte antigen (HLA) and risk for nasopharyngeal carcinoma (NPC) among the Chinese in Singapore, a population with a high incidence of this malignancy. In our study, we assess the association between HLA and NPC in Morocco, a median‐prevalence area for this cancer, where NPC presents the particularity of also affecting young individuals. Using the standard microlympho‐cytotoxicity test, we typed a total of 154 Moroccan NPC patients and 257 unrelated healthy controls for their HLA‐A and B antigens. The results of these analyses show that the frequencies of HLA‐A10, HLA‐B13 and HLA‐B18 were found to be higher in the NPC group than in the control group, whereas HLA‐A9 was associated with a decreased risk. After correction for the number of specificities tested, these differences were statistically significant only for HLA‐B18 (corrected p value [pc] < 0.023, relative risk [RR] = 4.14) and HLA‐A9 (pc < 0.023, RR = 0.45). The comparison of the distribution of the HLA antigens in younger and older cohorts of patients shows that the incidence of HLA‐A10 and HLA‐ B18 was higher in the older group, whereas the frequencies of HLA‐A19 and HLA‐B13 were significantly higher in younger patients compared with controls. The presence of both HLA‐A19 and HLA‐B13 phenotypes correlated with an increased risk of developing NPC among overall patients compared with controls. According to the sex distribution, increased frequency of HLA‐B18 was found in male and female NPC patients compared with controls, whereas the frequency of HLA‐A10 was higher only in male NPC patients compared with controls. © 2001 Wiley‐Liss, Inc.