ABSTRACT
To study CD34+ stem cells count in the peripheral blood [PB] of patients with rheumatoid arthritis [RA] and to correlate it with the activity and severity of the disease as a preliminary study for their role in the disease pathogenesis. This study was conducted on 20 RA patients in addition to 10 healthy subjects as a control group. All patients were subjected to full history taking and thorough clinical examination. Assessment was done using modified DAS far disease activity, Speed severity index [SSI] for disease severity, and Larsen score for radiological assessment of the plain x-ray findings of both hands. Assessment of CD34+ stem cells count in the PB was done by using fluorescence-activated cell sorting [FACS]. In this study there was a significantly higher count of CD34+ stem cells in the PB of RA patients compared to the controls. Stem cells absolute count and percentage were significantly negatively correlated with modified DAS, SSI and Larsen score. Bone marrow stem cells [CD34 cells] could play a crucial role in RA. Their level is elevated in the PB of RA patients in comparison with controls. It is suggested that the reduced number of CD34[+] cells in the PB of patients with more severely destructed joints is due to their recruitment to sites of inflammation. Studies are required to further investigate the role of the bone marrow and stem cells in the disease pathogenesis of RA. It could be a future target of treatment in these patients