Feeding of the infection prone preterm neonate with concentrated immunologically active ingredients in the form of colostrum may have even more significant clinical implications than in the full term infants. The scarcity of knowledge on anti-infective factors in colostrum of mothers delivering prematurely prompted us to carry out this study. Colostrum was collected and analysed from 25 mothers delivering prematurely (Study group) and 10 delivering at term (Control group). Major anti-infective factors namely IgA, IgG, IgM, lactoferrin and lysozyme were quantitated and total cell, macrophage, lymphocyte and neutrophil counts were performed. The mean concentrations of IgA, lysozyme and lactoferrin of preterm colostrum were significantly higher than in full term colostrum (p less than 0.001). IgG and IgM were found to be similar in both groups. The absolute counts of total cells, macrophages, lymphocytes and neutrophils were found to be significantly higher in the preterm colostrum as compared to the full term colostrum (p less than 0.001). Though in both the groups IgA was the predominant immunoglobulin, the mean percentage of IgA in the study group was significantly higher as compared to the control group. Degree of prematurity did not have any influence on the anti-infective protein levels in colostrum. However total cells and macrophages were significantly higher in colostrum of mothers delivering severely preterm babies.

The cellular composition of colostrum (within 72 hours post partum) and mature milk samples (5th-7th day post partum) from 20 mothers delivering preterm babies and 20 mothers delivering full term babies was examined. Lymphocyte subsets including T cells, B cells, T4 and T8 cells were quantitated by indirect immunoperoxidase staining using specific monoclonal antibodies. The mean total cell count in preterm colostrum (9,338/mm3) was significantly higher than in full term colostrum (5,594/mm3). Similarly, counts for macrophages, neutrophils and lymphocytes were significantly higher in preterm colostrum and milk as compared to full term colostrum and milk. B and T lymphocytes including T4 and T8 cells were identified in both preterm and full term breast milk. The absolute count of T, B, T4 and T8 cells was significantly higher in preterm colostrum compared to term colostrum, though the relative percentage distribution of lymphocyte subsets showed no significant difference between the two groups. T and B cells constituted about 74% and 26% of total lymphocytes, respectively in preterm as well as full term colostrum and about 69% and 31% in preterm and full term milk. The mean T4/T8 ratio was higher in preterm colostrum than term colostrum, being 1.82 and 1.60 respectively. However, this difference was not significant statistically and did not change statistically in the milk sample.