Background Chronic immune activation may induce an increase of memory CD4+ T-cells and a decrease of naive CD4+ T-cells. In SLE patients this chronic adaptive immune activation profile could induce cardiovascular morbidity, including the MetS.
Objectives The aim of this study was to determine whether the naive and memory CD4+ T-cell proportions or the memory/naive CD4+ T-cells ratio are associated with the MetS in SLE patients after considering other possible factors.
Methods This cross-sectional study was conducted in consecutive SLE patients seen in our Rheumatology Department from September 2013 to January 2014. SLE was defined using the ACR criteria. The MetS was defined according to the 2009 consensus statement of the International Diabetes Foundation. Disease activity was ascertained using the SLEDAI and disease damage with the SLICC/ACR damage index (SDI). Use of prednisone was recorded as current dose and total time of exposure. Use of antimalarials and of immunosuppressives was recorded as current, past or never. Naive CD4+ T cells were defined as CD3+CD4+CD45RA+CD45RO- whereas memory CD4+ T cells were defined as CD3+CD4+CD45RO+CD45RA-. Naive and memory T-cells frequencies were analyzed by flow-cytometry. The association of the MetS and CD4+ T-cells subpopulations was examined by Mann-Withney U test. This was followed by multivariable analysis adjusted for age, gender, disease duration, SLEDAI, SDI, use of prednisone, antimalarials and immunosuppressive drugs.
Results Ninety eight patients were evaluated; their median (IQR) age was 42.3 (36.6-50.2) years, 92 (93.9%) were female; almost all patients were mestizo (mixed Caucasian and Amerindian ancestry). Forty or 40.8% patients presented the MetS. Disease duration was 5.7 (2.5-11.7) years. The SLEDAI was 4.0 (2.0-8.0) and the SDI 0.0 (0.0-1.0). The percentage of naive CD4+ T-cells was 25.0 (16.7-33.1), of memory CD4+ T-cells was 66.5 (57.6-76.0) and the memory/naive CD4+ T-cells ratio was 2.8 (1.8-4.6). Patients with the MetS had a lower percentage of naive CD4+ T-cells (21.7 vs 27.8; p=0.03) but the percentage of memory CD4+ T-cells was comparable among those with and without the MetS (68.8 vs 64.5; p=0.13). Finally, memory/naive CD4+ T-cells ratio was higher among those patients with the MetS than among those without it (5.7 vs 3.1; p=0.02). In the multivariable analysis, the percentage of naive CD4+ T-cells was negatively associated with the presence of MetS (OR: 0.955, 95% CI: 0.914-0,998, p=0.04) whereas the memory/naive CD4+ T-cells ratio was positively associated with its presence (OR 1.231, 95%CI: 1.008-1.504, p=0.04).
Conclusions In SLE patients, a lower percentage of naive CD4+ T-cells and a higher memory/naive CD4+ T-cells ratio were independently associated with the presence of the MetS. This association could reflect the impact of immunosenescence among those SLE patients with cardiovascular morbidity.
Disclosure of Interest None declared