Peripheral blood T lymphocyte subsets in children with congenital asplenia

The aim of the current study was to examine whether a congenital lack of the spleen changes distribution, state of activation and function of peripheral lymphocyte T subsets. Seven children with congenital asplenia (CA) aged 1.5–17 years and seven age-matched controls were tested. By triple-color flow cytometry we examined: (1) the expression of CD3⁺, CD4⁺, CD8⁺, CD19⁺, and CD56⁺ on lymphocytes; (2) the distribution of CD45RA⁺ and CD45RO⁺ in CD4⁺ and CD8⁺; (3) the expression of CD27⁺ in the CD4⁺ and CD8⁺ T-cell-bearing CD45RA⁺, CD45RO⁺, or CD45RB⁺. Lymphocyte proliferative responses and cytokines production (IFN-gamma, IL-6, TNF-alfa, and IL-10) in anti-CD3-induced peripheral blood mononuclear cells were tested. The results indicate (1) a normal distribution of the basic lymphocyte subsets, (2) low CD3⁺/CD8⁺ percentage but expressing CD8^+high and non-significantly elevated CD4⁺/CD8⁺ ratio, (3) CD45RA^+high and CD27^+high in the CD4⁺ and CD8⁺ T cell, and (4) CD45RB^+high in the CD4⁺ and CD45RO^+high in the CD8⁺. The distribution of CD27⁺ in the CD45RA⁺ and CD45RO⁺ CD4⁺ T cells remained unchanged. However, the percentage of CD8⁺/CD45RO⁺/CD27⁺ T cells tended to be elevated. Altogether, these data indicate that CA is connected with (1) the presence CD4⁺ T cells expressing the “naive” phenotype (CD45RA^+high RB^+high and CD27^+high), (2) high numbers of activated CD8⁺ T cells shifted toward the memory phenotype (CD45RO^+high) but still showing high CD27⁺ expression, which may indicate failure in T CD8⁺ cytotoxic effectors differentiation, and (3) a tendency to the rather pro-inflammatory status of cells, low IL-10 expression, and suboptimal lymphocytes responses to mitogenic stimulation.