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Published on: August 12, 2020
Preterm neonates show marked leukopenia and lymphopenia that are associated with increased regulatory T-cell values
Rafael Correa-Rocha1, Alicia Pérez, Raquel Lorente
1Laboratorio de Inmunobiología Molecular, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
Insights
Preterm infants have lower immune cell counts, but regulatory T cells (Tregs) are surprisingly higher. This finding may explain leukopenia and guide immune therapies to reduce neonatal mortality.
Area of Science:
- Neonatal immunology
- Perinatal health
Background:
- Neonatal survival has improved, but preterm infants face higher infection risks and mortality.
- Infections are a major cause of death in preterm neonates.
Purpose of the Study:
- To investigate the immune status of preterm neonates.
- To analyze immune cell populations in cord blood from preterm and full-term infants.
Main Methods:
- Analysis of immune cell frequencies and counts in 211 cord blood samples.
- Comparison of immune subsets between preterm and full-term neonates.
Main Results:
- Preterm infants showed lower absolute counts of monocytes, granulocytes, B cells, NK cells, CD4(+), and CD8(+) T cells.
- Regulatory T cells (Tregs) were the only subset with increased frequency in preterm infants.
- Decreased plasma levels of interleukin-7 (IL-7) and its receptor frequency were observed in preterm infants.
Conclusions:
- The elevated frequency of Tregs in preterm infants may contribute to observed leukopenia.
- Findings suggest potential targets for immune therapies to reduce preterm infant mortality.
- Further research into IL-7 pathways could inform therapeutic strategies.
Introduction:
Current advances in neonatology have improved survival among preterm and low-birth-weight infants. However, the risk of neonatal death in preterm infants is much greater than in full-term neonates and is frequently associated with infections.
Methods:
Little is known about the immune status of preterm neonates; therefore, we analyzed the frequency and absolute counts of different immune populations in 211 cord blood samples taken from very-preterm to full-term neonates.
Results:
We found that absolute counts of all the immune subsets analyzed (i.e., monocytes, granulocytes, B cells, natural killer (NK) cells, CD4(+), and CD8(+) T cells) were markedly lower in preterm infants than in full-term infants. Surprisingly, we observed that regulatory T cells (Tregs) were the only cell subset that did not decrease in preterm infants, and their frequency was even higher than in full-term infants.
Discussion:
Tregs are crucial to maternal-fetal tolerance, but their suppressive role could be also implicated in the leukopenia observed in preterm infants. We did not observe differences in thymic function, but we found that plasma levels of interleukin (IL)-7 and the frequency of its receptor were significantly decreased in preterm infants. Our results could help to identify leukopenia and to implement immune therapies that significantly diminish mortality in preterm neonates.
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