T-lymphocyte subsets, thymic size and breastfeeding in infancy

Area of Science:

• Immunology
• Pediatrics
• Human Development

Background:

• The thymus plays a crucial role in T-cell maturation.
• Previous research suggests a link between breastfeeding and increased thymus size in infants.
• The impact of breastfeeding on specific T-lymphocyte subsets (CD4+ and CD8+) requires further investigation.

Purpose of the Study:

• To investigate the association between breastfeeding and the concentrations of CD4+ and CD8+ T-lymphocyte subsets in infants.
• To examine the relationship between thymus size and T-lymphocyte subset concentrations during infancy.
• To explore the current and long-term immune-modulating effects of breastfeeding on the developing cellular immune system.

Main Methods:

• Longitudinal study tracking T-lymphocyte subsets (CD4+, CD8+) and thymus size in infants from birth to 1 year.
• Comparison of two infant groups: variable breastfeeding duration (Group I) and long-term breastfeeding (Group II).
• Statistical analysis to determine correlations between breastfeeding, thymus size, and T-lymphocyte counts at various time points (4, 8, and 10 months).

Main Results:

• A correlation was observed between CD8+ cells and thymic index at 10 months in both groups.
• Infants breastfed at 8 months had higher CD8% compared to formula-fed infants (p=0.05).
• Breastfeeding at 4 months correlated with higher CD4% at 10 months (p=0.03).
• Long-term breastfed infants (Group II) showed increased absolute CD4+ and CD8+ cell counts from 8 to 10 months.
• Higher frequency of daily breastfeeding at 8 months positively correlated with increased CD4+ cells from 8 to 10 months (p<0.01).

Conclusions:

• A significant correlation exists between thymus size and CD8+ T-lymphocyte cell counts in infants.
• Breastfeeding demonstrates a potential for both immediate and lasting immune-modulating effects.
• These findings highlight the importance of breastfeeding for the development of the infant cellular immune system.