OBJECTIVETo investigate the relationship between the expression of host human leukocyte antigen-B mRNA (HLA-B mRNA) and HLA-B antigen in peripheral blood leukocytes (PBLs) and the differentiation and metastasis of gastric carcinoma (GC).

METHODSTo design and screen specific primers of HLA-B gene independently, detect the expression of HLA-B mRNA from 30 GC patients by reverse transcription-PCR and compare with the HLA-B antigen expression measured by flow cytometry.

RESULTSThe expression rate of PBL HLA-B mRNA from GC patients (23. 3% ) was very significantly lower than that of normals (87. 5% ) (P <0. 01) , especially concerning the poorly differentiated GC patients with lymph node metastasis (16. 0% ). Measured by flow cytometry, the expression percentage of HLA-B antigen of well-differentiated GC patients without lymph node metastasis was 88. 2% , an obviously decreasing tendency was showed in comparison with that in the normal group (98. 8% ) , although the difference was not significant (P = 0. 056) , and the expression percentage in poorly differentiated GC patients with lymph node metastasis(73. 3% )was declined significantly (P <0. 05).

CONCLUSIONThe expression of PBL HLA-B mRNA and HLA-B antigen in GC patients is decreased or lost, and correlated with differentiation and metastasis of the cancer. The expression of PBL HLA-B mRNA may more directly reflect its relationship with the tumor differentiation and metastasis than that of HLA-B antigen.