Measuring Trace Immune Factors in Human Milk

There is increasing interest in measuring cytokines and other trace immune factors in human milk in order to understand different aspects of the impact of breast-feeding on maternal and infant health. Results generated from different laboratories are often difficult to compare because of variations in methods or lack of sufficient explanation of methods. The research areas using the information are varied and include investigation of how breast-milk protects infants from infection, how it promotes infant gut and immune system development, how breast-feeding may influence the development of allergies, and how breast-milk immune factors protect the breast from infection. Research into milk cytokines is not yet as advanced as research into plasma cytokines and it seems important at this stage to consider how researchers into plasma cytokines have proposed standardising and comparing methods across laboratories^1–4 and to see how their ideas can be extrapolated to the measurement of cytokines and other trace immune factors in breast-milk. In the workshop the various issues of concern in measuring milk immune factors were presented and participants discussed their own successes, failures and suggestions in small working groups. This chapter summarises the issues and provides recommendations for validating and reporting laboratory methods in order to permit better interpretation of results on trace immune factors in human milk.