ABSTRACT: We enrolled 33 patients with COVID-19 (23 men and 10 women; age 59 ± 15; males, n = 23; females, n = 10) admitted to the Department of Infectious Diseases of Grande Ospedale Metropolitano "Bianchi-Melacrino-Morelli" of Reggio Calabria, Italy, between March and May 2020. Whole blood samples were collected before the start of therapeutic treatment using all virus spread containment measures. Sample preparation protocols were designed in order to minimize operators direct specimen's manipulation. On univariate analysis, circulating levels of CRP were strongly and inversely related to CD3+ (rho = -0.77, p < 0.001), CD3+4+ (rho = -0.74, p < 0.001), and CD3+8+ (rho = -0.66, p = 0.001) implying that the shared variances between absolute values T cells and CRP ranged from 44 to 59%. Of note, the strength of these associations was higher in patients with relatively lower (below the median value) white blood cells (WBC) as compared to those with WBC above the median value. CRP also correlated with NK bright (rho = -0.56, p = 0.005) but failed to be related with CD19+ (rho = -0.38, p = 0.07), CD4+/CD8+ ratio (rho = 0.03, p = 0.89), CD16+ CD56+ (rho = -0.18, p = 0.43), and NKdim (rho = -0.15, p = 0.49). Lymphocyte subsets alteration monitoring in COVID-19 positive patients may be a valid aid to control treatment efficacy of therapy and to choose better clinical approach. In particular, the negative correlation between CD3+, CD3+CD4+, CD3+CD8+ T cells values and CRP could be a useful tool to predict patient's response to therapy, particularly in patients with relatively lower WBC.
