Association among size of thymus, anthropometric dimensions and number of lymphocytes in peripheral blood in newborns from Slovakia.

Aims: Thymus is the central lymphatic organ in humans with important endocrine function that is involved in maturation of immunocompetent T-lymphocytes. In our study we investigated the relationship among thymus size and the anthropometric dimensions as well as between thymus size and the number of lymphocytes in peripheral blood in full-term newborns.

Methods: The examined group consisted of 212 full-term newborns from the region of Southern Slovakia. We examined birth weight, birth body length, head circumference and chest circumference. Thymus size was estimated by ultrasonography and it was expressed as Thymic Index. The number of lymphocytes in peripheral blood was determined from the number of total leukocytes and from the leukogram.

Results: We have found a statistically significant positive correlation among thymus size and the body dimensions of newborns. The highest correlation with thymus size was found for birth weight (r = 0.409; P < 0.001) followed by birth body length (r = 0.368; P < 0.001), head circumference (r = 0.365; P < 0.001) and chest circumference (r = 0.340; P < 0.001). We have proven also a statistically significant positive correlation between the number of lymphocytes in peripheral blood and thymus size (r = 0.208; P = 0.039).

Conclusion: Our results confirmed the findings of other authors about a close relationship of Thymic Index and basic body parameters in newborns.