CD95 and BCL-2 expression as apoptotic markers in rheumatoid arthritis patients

ABSTRACT

Dysregulation of apoptosis of the different immune cells including the peripheral blood mononuclea, cells [PBMNC], lymphocytes have been incriminated as a pathogenetic factor in rheumatoid arthrjts [RA]. CD95 [Fas] as a death receptor and Bcl-2 as an antiapoptotic protein are among the important factors responsible for controlling lymphocytes apoptosis. To assess the expression of CD95 and Bcl-2 as apoptotic markers in PBMNs in RA patients and correlate them with RA activity and functional capacity of RA patients. Twenty RA patients and 10 healthy controls were included in this study. All patients were maintained on 7.5 mg methotrexate /week and concomitant NSAIDs. All patients were examined clinically and disease activity measures including Ritchie articular index [RAI] and the number of swollen joints [SW44] were assessed and disease activity score [DAS] was calculated for each patient. Health assessment questionnaire [HAQ] was also determined. CD95 and Bcl-2 expression on the PBMNC were assessed in serum samples by flow cytometry in patients and controls, in addition to complete blood count, Rose Waaler test and ESR. Plain X-ray for both hands was also performed for all patients to detect joint erosions. The mean CD95 expression on PBMNC was significantly higher in RA patients compared to healthy controls [t=3.222, P= 0.004]. CD95 was also significantly and positively correlated with RAI, [DAS] and [ESR] [r=0.463, r=0.736, r=0.542 respectively and P<0.05 for all]. There was no statistically significant difference regarding the mean expression of Bcl-2 in RA patients and controls [t=0.122, P>0.05]. It did not also correlate with any of the studied variables. Increased CD95 expression on PBMNC in RA patients seems to be related to the inflammatory process [disease activity] in rheumatoid disease rather than to the apoptotic process as it is correlated with disease activity measures of the studied patients. Moreover, the normal expression of Bcl-2 in PBMNC indicated that the possibility of dysregulation of apoptosis in this study is unlikely