PP.38.11

Objective: Primary hypertension (PH) is associated with activation of immune system, however, most of the data on immune abnormalities in PH are experimental studies. We hypothesized that PH children (PHC) may present subtle changes in maturation of immune system in comparison with normotensive children (NC) and those immune abnormalities correlate with hypertension severity and target organ damage (TOD). Design and method: 68 PHC in mean age 15.6 ± 2 (59 boys) were included to the study. Control group consisted of 26 (19 boys) NC in mean age 14.8 ± 3.7. In all children the profile of lymphocytes associated with maturation of immune response was analysed with triple-colour flow cytometry. Lymphocyte receptors CD3, CD4, CD8, CD18, CD56, CD45RA, CD45RO in CD4 and CD8 T cells were analyzed. In all PHC left ventricular mass index (LVMi) and carotid intima-media thickness (cIMT) were analysed. Results: PHC and NC didn‘t differ regarding age and gender. PHC presented greater intensity (7.6 ± 3.8 vs 5.4 ± 1,2; p = 0.0001) and percentage of 45RO+ CD4 in comparison with NC (43.6 ± 10.2 vs 38.6 ± 9.9; p = 0.04). CD8 of PHC presented greater percentage of 45RO+ cells (25.0 ± 9.1 vs 19.4 ± 6.9; p = 0.008) than NC. RA+/RO+ of CD4 (1.3 ± 0.5 vs 1.6 ± 0.8; p = 0.04) and CD8 (3.6 ± 2 vs 4.6 ± 1.7; p = 0.03) was lower in PHC. There were no correlations between the expression of maturation markers on lymphocytes and cIMT. PHC with left ventricular hypertrophy had lower percentage of 45RA+CD4 (48.8 ± 9.9), greater percentage of RO+CD4 (50 ± 8.7) and lower ratio of RA+/RO+ CD4 cells (1.0 ± 0.3) in comparison with PHC with normal LVMi (55.2 ± 10.2, p = 0.04; 42 ± 9.9, p = 0.013; 1.4 ± 0.5, p = 0.002; respectively). The percentage of 45RA+CD8 cells steadily decreased from prehypertension (62.1 ± 10.2) to stage 1 (52 ± 8) and stage 2 hypertension (51.2 ± 10) (p < 0.05). Conclusions: PHC present significant alterations of maturation process of peripheral blood lymphocytes indicating faster maturation with decreased number of naïve T lymphocytes and increased of more mature cells. These alterations are associated with hypertension severity and TOD.