Cytomegalovirus seropositivity is associated with the expansion of CD4+CD28-and CD8+CD28-T cells in rheumatoid arthritis

Objective. Previous researchers have found expansion of CD4+CD28- T cells i n patients with rheumatoid arthritis (RA) compared to age matched controls, and have identified expanded clones of autoreactive cells within this popu lation. We examine the association of prior cytomegalovirus (CMV) infection (positive serum anti-CMV IgG) with the percentage of CD3+CD28- T cells and CD8+CD28- T cells in patients with RA. Methods. A total of 45 patients (36 women, 9 men), mean age of 59 years, wi th definite RA were studied. Results. In this group 28 patients were seropositive for CMV and 17 seroneg ative. Seropositive and seronegative subjects did not differ significantly in age, sex, medication use, or severity of disease. Joint count, Health As sessment Questionnaire, pain score, patient global assessment, physician gl obal assessment, and presence of extraarticular disease served to assess di sease severity. Expression of CD4/CD28/CD57 and CD8/CD28/CD57 on lymphocyte s was determined by 3 color flow cytometry. (CD28 and CD57 are reciprocally related.) CD4+CD28-CD57+ T cells were expanded only in CMV seropositive pa tients. Conclusion. The "carrier" phenotype that has been hypothesized based on a 2 population model for the distribution of CD4+CD28- T cells in RA can be ex plained by prior infection with CMV.