Abstract: Objective To identify the differentially expressed genes associated with hypersplenism in patients with portal hypertension.Methods The total RNA were extracted from the macrophages isolated from normal spleen and the spleen of patients with portal hypertension and reversely transcribed to cDNA with the incorporation of fluorescent(cy3 and cy5)-labeled dCTP to prepare the hybridization probes.After hybridization of Biostar-H140s chip containing 14 112 spots of cDNAs with the prepared probes,the gene chip was scanned for fluorescence intensity to screen the differently expressed genes.Three gene chips were used for hybridization and only the genes with differential expression in all the three chips were considered to associate with hypersplenism in patients with portal hypertension.Results Totaling 896,1330 and 898 genes were identified to be differentially expressed by the three chips,respectively,and 121 genes(0.86%) showed differential expression in all the three chips,including 21 up-regulated known genes and 73 down-regulated known genes.The differently expressed genes were functionally related with ion channels and transport proteins,cyclins,cytoskeleton,cell receptors,cell signal transduction,metabolism,immunity,and so forth.These genes might be involved in hypersplenism in the condition of portal hypertension.Conclusion cDNA microarray-based screening of differentially expressed genes in the macrophages in the spleen may provide new insights into the pathogenesis of hypersplenism in patients with portal hypertension.