Mass spectra of the IgA1 hinge in serum from the donor and from the recipient before BMT and after BMT.

The distribution of the post-BMT (B) IgA1 peaks shifted to a lower molecular weight than the pre-BMT (A) and donor IgA1 peaks (C), indicating a reduction in sialylation and galactosylation of IgA1 hinge glycopeptides of post-BMT serum (day 300).