Measurement of T-cell markers in rheumatoid arthritis patients on monoclonal antibody therapy

Abstract

Rheumatoid Arthritis forms part of the autoimmune diseases spectrum as antibodies are directed to oneself. The exact cause of this disease is still unknown; however, it is thought that both genetic and environmental factors play a role in the development of this disease. The abnormal functions of CD4+ and CD8+ cells play a key role in the autoimmune process leading to the development of Rheumatoid Arthritis. With that being said, there is still lack of research on how therapy affects these T-cells. Monoclonal antibody (MAB) therapy (Rx) and/or Disease Modifying anti-Rheumatic Drugs (DMARDs) are two types of therapies that are prescribed to RA patients. Ten patients who were administered MAB were recruited and a further 10 patients who were administered DMARD therapy were also recruited. The CD3+, CD4+ and CD8+ counts and percentages of each patient were obtained by performing flow cytometry using BD FACSCANTOII, after staining the cells with a combination of fluorochrome conjugated monoclonal antibodies. The means CD3+, CD4+ and CD8+ counts and percentages of the different Rx groups were compared to the means of normal healthy controls, where CD3+ counts and percentages were significantly lower than normal healthy controls but CD4+ and CD8+ counts and percentages were not significantly lower. As for patients who were administered DMARD therapy, all variables except CD3% were significantly lower than normal healthy controls, however when the same means were compared among the therapy groups no significant difference was observed. As for the correlation between the Rheumatoid factor (RF) value and the CD3+, CD4+ and CD8+ counts of the different Rx groups, different relationships were established. CD3+ and CD4+ counts in MAB Rx-treated patients showed a positive correlation, while CD8+ showed a negative correlation. As for patients who were administered DMARD therapy, a negative correlation was observed in all the three variables.