Background: Systemic Lupus Erythematosus (SLE) is an inflammatory chronic disease characterized by the presence of autoantibodies, immunocomplex production and organ injury. Several alterations of the immune system have been described, namely of CD4 T cells, with particular focus on regulatory subgroup.
Objective: Quantify peripheral CD4 T cells in a population of patients with SLE and correlate it with lupus activity, affected organs, therapeutics and infections.
Methods: Retrospective study involving all SLE patients seen in the clinical immunology outpatient clinic of the Hospital Geral Santo António, Porto that has done some peripheral blood flow cytometry study.
Results: Twenty-nine patients have been evaluated, 16 were taking glucocorticoids and six immunossupressors. The mean SLEDAI at the study time was nine and the ECLAM was three. Thirty-one percent of the patients had leukopenia, 76% lymphocytopenia and the same number CD4 depletion. Fifty-five percent of the patients had CD4 levels lower than 500/mm3, 31% lower than 200/mm3. All patients with SLEDAI > or = 20 and ECLAM > or = 4 had CD4 counts inferior to 500/mm3 and all patients with inactive disease had CD4 superior to 500/mm3. There have been three opportunistic infections: cryptococcal meningitis, pulmonary aspergilosis, Pneumocystis jirovecii pneumonia, all in patients with CD4 counts lower than 500/mm3.
Conclusion: Decreased CD4 T cells counts have been very common in this study population. There is an inverse relation between CD4 cells counts and disease activity. Opportunistic infections occurred in patients with severe CD4 depletion.