Abstract
Mannan-binding lectin (MBL) deficiency is determined by MBL gene polymorphisms and is associated with an increased infection risk. To clarify the role of MBL in Allo-SCT, 131 recipients-donors were analysed. MBL genotypes were determined by PCR and heteroduplex analyses, MBL serum levels by ELISA, and MBL oligomers by western blotting. MBL levels <400 ng/ml were associated with increased susceptibility to fungal pneumonia (7/12 vs 35/111; P=0.04, adjusted P=0.002), HSV/VZV (7/12 vs 26/111; P=0.03), CMV reactivation and acute GVHD. Donor genotypes had no influence. Pre-SCT MBL levels corresponded to recipients' genotypes (P<0.001), changed significantly post-SCT, but were not influenced by donors' genotypes. MBL oligomer profiles were similar pre-/post-SCT. Cultured CD34+ cells were found not to synthesise MBL. In conclusion, low MBL levels pre-transplant predisposed patients to sepsis, fungal and viral infection. Donors' MBL genotypes did not influence infection rates. Prospective studies should clarify the importance of MBL as a prelude for MBL replacement after SCT.