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

Previous reports demonstrated an association between the human leukocyte an tigen (HLA) and risk for nasopharyngeal carcinoma (NPC) among the Chinese i n 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-p revalence area for this cancer, where NPC presents the particularity of als o affecting young individuals. Using the standard microlympho-cytotoxicity test, we typed a total of 154 Moroccan NPC patients and 257 unrelated healt hy controls for their HLA-A and B antigens. The results of these analyses s how that the frequencies of HLA-A10, HLA-B13 and HLA-B18 were found to be h igher in the NPC group than in the control group, whereas HLA-A9 was associ ated with a decreased risk. After correction for the number of specificitie s tested, these differences were statistically significant only for HLA-B18 (corrected p value [pc] < 0.023, relative risk [RR] = 4.14) and HLA-AP (pc < 0.023, RR = 0.45). The comparison of the distribution of the HLA antigen s 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 H LA-A19 and HLA-B13 were significantly higher in younger patients compared w ith controls. The presence of both HLA-A19 and HLA-B13 phenotypes correlate d with an increased risk of developing NPC among overall patients compared with controls. According to the sex distribution, increased frequency of HL A-B18 was found in male and female NPC patients compared with controls, whe reas the frequency of HLA-A10 was higher only in male NPC patients compared with controls. (C) 2001 Wiley-Liss, Inc.