Role of natural killer and activating receptors in rheumatoid arthritis / Iman Sami AbouBakr Elbayoumi ; Supervised Shereen Mahmoud Shawky , Mariam Onsy Farag , Hala Ahmed Raafat

Thesis (Ph.D.) - Cairo University - Faculty of Medicine - Department of Clinical and Chemical Pathology

Introduction: Rheumatoid arthritis (RA) is a common chronic autoimmune disease (AID). The impaired activity of the effector lymphocytes: NK cells, T cells and NKT cells, has been detected in RA. Dysregulation of Natural Killer Receptors (NKRs) in patients with RA has been shown. In Egypt, the prevalence rate of HCV (genotype 4) reaches 20%. Because of the high prevalence of the two diseases, HCV-infected patients having arthritis, and classical RA with concomitant HCV, pose a diagnostic problem for rheumatologists. Objectives: In the present work we aimed to study the characterization: The count and the NKRs (CD16 and CD244) expression on the three types of effector lymphocytes, in RA patients and in RA patients with concomitant HCV to investigate their role in the pathogenesis of RA and to detect the difference between their character in RA patients and RA with HCV. Patients and methods: The count of NK, T and NKT cells, the expression of CD16 and CD244 on the 3 effector lymphocytes, were evaluated in 20 RA patients, 21 RA patients with HCV and 17 healthy control with flow cytometry. Cytokines influencing NK cell as TNF-Ü and IL-6 were measured by IRMA and by ELISA respectively. Results: Our main finding was the significantly reduced MFI of CD16 and CD244 on NK, T and NKT cells, in the RA patients with HCV and RA without HCV, compared to the control and a significant increase of percentage and absolute NKT cell count, in the RA patients with HCV and RA without HCV compared to the healthy control

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