Isolation of human mannan binding lectin, serum amyloid P component and related factors from Cohn fraction III.

Cohn Fraction III, a waste product of plasma fractionation, is a source of several proteins involved in host defence as part of the innate immune system. Here a procedure is described for purifying mannan binding lectin and serum amyloid P component to virtual homogeneity from Cohn Fraction I + III, and their separation from other mannan-binding factors and from C-reactive protein. It is suggested that products derived from Cohn Fraction III could have therapeutic potential, either for specific substitution therapy or as a combined package of innate immune factors.