Cytokine concentration in foals’ serum pre- and post suckling

Reasons for performing study:

Colostrum acts as a source of immunomodulatory molecules for the neonate. Little information is available about the transfer of cytokines via colostrum in the foal. Objectives: To investigate the transfer via colostrum of IL-4, IL-13, IL-8 and IFN-γ.

Study design:

Prospective observational study.

Methods:

Jugular venous blood pre- (T0) and post suckling (T24) and colostrum were collected from 14 healthy foals and their dams. The cytokines’ concentration was measured with an ELISA test. Serum IgG concentration was measured in foals at T24 with an immunoturbidimetric assay. Since data were not normally distributed, nonparametric tests for statistical analysis were used. The Wilcoxon t test evaluated the difference in each cytokine concentration between T0 and T24. Spearman rank correlation tested the association between cytokines’ concentration in T24 serum and in colostrum, between T24–T0 (ΔT) serum concentration and colostrum concentration, and between cytokines serum concentration at T24 and IgG concentration.

Results:

All the foals had a complete transfer of passive immunity. A statistically significant difference was found between serum IL-4 concentration at T0 and at T24. The significant correlations found were: serum IL-4 concentration at T24 with IL-4 concentration in colostrum, serum IL-13 concentration at T24 with IgG serum concentration, and IL-4 concentration in colostrum with ΔT serum IL-4 concentration.

Conclusions:

The results support the hypothesis that IL-4 is transferred via colostrum to the foal, as reported for TNF-α [1]. The presence of IL-8 in the foal’s serum at T0 suggests an endogenous production. The IL-13 concentration is close to zero for the major part of serum and colostrum samples suggesting a subject-dependent immunologic response. The IFN-γ is present both in colostrum and in T0 serum suggesting that foals are not deficient at birth