AGE-ASSOCIATED B CELLS (ABCs) AND AUTOIMMUNITY AMONG EGYPTIAN FEMALES

Background: A particu¬lar population of B cells, named age-associated B cells (ABCs), was found at a higher frequency in healthy autoimmune-prone mice and in elderly women with rheumatoid arthritis. Aim: We aimed at estimating the percentage of ABCs in females with 2 autoimmune disorders in comparison to healthy females and males. We also aimed at identifying any increase in their percentage with age, gender or disease activity. Materials and Methods: Our study included 45 females having systemic lupus erythematosus (SLE) and 30 females having rheumatoid arthritis (RA). 63 healthy females and 60 males, served as control groups. Flowcytometric analysis was done to estimate the percentage of ABCs positive for CD19, CD11b and CD11c collectively, using MACSQuant Analyzer 10. Results: The percentage of ABCs in SLE patients (mean ± SD = 0.22% ± 0.33) was significantly higher than that in RA patients (mean ± SD = 0.06 ± 0.13) and both healthy females (mean ± SD = 0.06% ± 0.1) and males (mean ± SD = 0.07% ± 0.1) with p values of 0.033, 0.021 and 0.011 respectively. However, their percentage was comparable between healthy females and healthy males, with p value = 0.818. Moreover, their percentage was found to increase with age, showing a statistically significant positive correlation, p <0.001. Conclusion: ABCs were found to be significantly higher among SLE patients, but not RA patients, increasing with age in both healthy and autoimmune patients, but without sex predilection. Their percentage correlates positively but insignificantly with disease activity and damage indices.