Abstract
Objective:
One of the leading causes of morbidity and mortality among patients with systemic lupus erythematosus (SLE) is infections. The expression of the ectonucleotidase CD38 on the surface of CD8+ T cells has been linked to compromised cytotoxic function. The aim of this prospective study was to assess whether the presence of CD8+CD38+ in the peripheral blood of patients with SLE can serve as a biomarker for infectious complications.
Methods:
A cohort of 80 patients with SLE were recruited over 18 months. The rate of clinically significant infections and presence of CD8+CD38+ T cells in the peripheral blood were monitored at each clinic visit. The patients were classified into high CD38+ and low CD38+ CD8+ T cells using flow cytometry and a previously established cutoff rate of 28.4%.
Results:
A total of 20 infections were registered over the study period. We observed that the patients with an expanded CD8+CD38+ T cell population in the peripheral blood had a higher rate of recurrent infections and a higher likelihood of infection compared with patients with a low CD8+CD38+ T cell population. The levels of CD38 in CD8+ T cells remained stable over time in the studied subjects.
Conclusion:
High levels of CD8+CD38+ T cells in the peripheral blood of patients with SLE identify a subgroup prone to infections for whom proper clinical measures should be applied.