Characterization of a monoclonal IgMK (IgMGAS) anti-Gd cold agglutinin (CA). Its coexistence with a monoclonal IgG3K (IgGGAS) without CA activity that might be clonally related to IgMGAS.

摘要: A monoclonal IgMK (IgMGAS) cold agglutinin (CA) of the infrequent anti- Gd specificity, found in a patient with Waldenstrom macroglobulinemia, has been characterized. IgMGAS uses VH gene homologous (93.7%) to reported VH251 germ-line, one two functional genes VH5 family, differences both framework regions and complementary determining (CDR). The VL is 15AVK1 germ-line gene, recently described an anti-i CA, mostly clustered CDR. In patient's serum, coexisted IgG3K (IgGGAS) that lacked CA activity but expressed private idiotopes on IgMGAS. Both Ig reactivity antibodies detecting VH1 or VHIII VKIII subgroup VH4–21 product by anti-I/i CAs. K chains from Igs showed same isoelectrical mobility. Moreover, k serum N-terminal amino acid sequence. This sequence was identical predicted nucleotide VK1GAS segment, including discrepancy at position 15 (Ile for Val) respect consensus VK1 regions. Although these data do not exclude possible independent clonal origin, they are consistent notion IgGGAS might be clonally related