Changes in T lymphocyte subsets in preterm infants with intrauterine growth retardation

Abstract:

Objective To study changes in T lymphocyte subsets in preterm infants with intrauterine growth retardation (IUGR). Methods The study enrolled 29 IUGR preterm infants, 38 preterm infants born appropriate for gestational age (AGA), and 20 healthy full-term infants. Peripheral blood was sampled during the first 24 hours of life, and again at a corrected age of 38 weeks of the preterm infants. T lymphocyte subsets were analyzed by flow cytometry, and absolute counts of leukocytes, total lymphocytes, and T lymphocytes were determined with an automated hematology analyzer. Results Within the first 24 hours of life, percentages of CD3⁺ and CD4⁺ were lower in IUGR preterm infants than in AGA preterm infants and full-term infants (P<0.05), percentages of CD8⁺ and CD4⁺/CD8⁺ ratio were lower in IUGR preterm infants than in full-term infants (P<0.05), and percentages of CD3⁺, CD4⁺ and CD4⁺/CD8⁺ ratio were lower in AGA preterm infants than in full-term infants (P<0.05). Moreover, the absolute counts of total lymphocytes were lower in IUGR preterm infants than in full-term infants (P<0.05); the absolute counts of T lymphocytes were lower in preterm infants, regardless of IUGR, than in full-term infants (P<0.05), and lower in IUGR infants than in AGA infants (P<0.05). At the corrected age of 38 weeks, percentages of CD3⁺, CD4⁺ and CD4⁺/CD8⁺ ratio were increased in both IUGR and AGA infants as compared to the measurements within the first 24 hours of life (P<0.05), and percentages of CD3⁺, CD4⁺, CD8⁺ and CD4⁺/CD8⁺ ratio were lower in IUGR infants than in AGA infants (P<0.05), whereas there were no significant differences in counts of leukocytes, total lymphocytes and T lymphocytes between IUGR and AGA infants (P >0.05). Conclusions There may be a certain degree of compromise in cell-mediated immunity in preterm infants with IUGR and this compromise may last to 38 weeks after birth.