Die identifizierung differentiell exprimierter gene in T- lymphozytensubpopulationen bei diskordanten monozygotischen zwillingen mit rheumatoider arthritis

To perform an objective analysis of gene expression in rheumatoid arthritis (RA) patients we used differential display (DD) technique to screen messenger RNAs that are expressed by CD4⁺ and CD8⁺ peripheral blood lymphocytes. In order to exclude false positives due to polymorphisms and randomly expressed genes only monozygotic twins were included in the study and DDRT-PCR analysis was repeatedly performed with highly specific cellular material collected at two different times. Herein we report the results of the pilot study including 2 pairs of RA-discordant monozygotic twins. Till now DDRT-PCR analysis revealed 7 differences in gene expression between the compared groups. Differentially expressed DDRT-PCR fragments were subjected to sequence analysis and the obtained sequences were compared with the existing databases. In 5 cases no comparable sequences were found in databases. One of the cDNAs detectable only by the healthy persons is 100% homologous to the available sequence with accession no. aa833746 (EMBL-GDB). The other cDNA present only by the RA patient encodes a protein (EMBL-GDB accession no. aa970280) highly homologous to human 60S ribosomal protein L19. Our data demonstrate that DDRT-PCR technique may be successfully used for objective analysis of differences in gene expression between patient groups and provide further evidence for complexity of the aetiological and pathogenetic mechanisms of RA.