Relationship between serum interleukin–18 level and natural killer cell number in RA

الملخص EN

Objective : the aim of this study was to assess peripheral blood natural killer cells (NK) number and serum IL-18 level in rheumatoid arthritis (RA) and to find out the correlation between them and their possible role in the pathogenesis and activity of RA.

Methods : Thirty serum samples from RA patients who were diagnosed according to American College of Rheumatology (ACR) revised criteria were enrolled in this study.

They were tested along with 10 serum samples from apparently healthy subjects.

Peripheral blood NK cell number was assessed using flow cytometer and serum IL-18 level was assessed using ELISA.

Modified Disease Activity Score (DAS) was used as a measure of disease activity.

Results : peripheral blood NK cell number was significantly lower in RA patients than in the control group and serum IL-18 level was significantly higher in RA than in the control group.

Also, a negative correlation was found between NK cell number and serum IL-18 level.

Conclusion : NK cell number may play a role in inducing remission of active RA.

Also, IL-18 being high in active RA and negatively correlated with NK cell number may play a role in inhibiting innate immunity and reducing NK cells number.