Haptocorrin human milk

Adkins, Y., and Lonnerdal, B. (2003). Potential host-defense role of a human milk vitamin B-12-binding protein, haptocorrin, in the gastrointestinal tract of breastfed infants, as assessed with porcine haptocorrin in vitro. Am. ]. Clin. Nutr. 77,1234—1240. 

Three Automated Platforms Reacts Differently Towards Changes in Sample Type. This section describes the design of assays for cobalamin from the three main players in automated cobalamin analysis on human serum (Abbott, Bayer Diagnostics and Roche) and demonstrates how these assays react if employed for the measurement of cobalamin in human milk. Human milk contains up to 200-fold more haptocorrin than serum and most of it is unsaturated with cobalamin. If haptocorrin is insufficiently denatured, it can interfere in the assays (Lildballe et al. 2009). 

We discovered these analytical problems when seeking to analyse the content of cobalamin in human milk (Lildballe et al. 2009). However, we encountered the same problem for serum samples with a high content of unsaturated haptocorrin (Lildballe et al. 2011). Once such a problem is realized, it is possible to... 

False levels of cobalamin may be encountered if the concentration of cobalamin unsaturated haptocorrin is high as observed in human milk. 

Lildballe, D.L., Hardlei, T.F., Allen, L.H., and Nexo, E., 2009. High concentrations of haptocorrin interfere with routine measurement of cobalamins in human serum and milk. A problem and its solution. Clinical Chemistry and Laboratory Medicine. 47 182-187. 

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