P35, an opsonic lectin of the ficolin family, in human blood from neonates, normal adults, and recurrent miscarriage patients

P35 (L-ficolin) is a novel calcium-dependent lectin which may have a role i n innate immunity. The concentration range of P35 in blood donor sera was f ound to be 1.1-12.8 (median 3.7) mu g/ml, with most values below 6.0 mu g/m l. Sera from women with recurrent miscarriage were found to have a generall y similar distribution of concentrations, but 3 (4%) had values lower than the Lower limit of normal defined by the blood donor sera. Cord blood sampl es had significantly lower levels of P35 (median 2.5 mu g/ml) than adults, and cord P35 concentrations correlated with gestational age. During ethanol fractionation of plasma, P35 was enriched in Cohn Fraction III, but did no t bind to mannan immobilised on 3M-Emphaze. P35 thus has some similarities to, and some differences from, mannan binding lectin. (C) 1999 Elsevier Sci ence B.V. All rights reserved.