VH subgroup restriction in human erythrocyte antibodies: Studies of anti-A, anti-B, and anti-Duffy antibodies.

IgG from 13 anti-A, 26 anti-B, and 10 anti-Duffy antisera were used to coat human erythrocytes. With antisera specific for each of the three VH subgroups, VHI, VHII, and VHIII, a clear VH subgroup restriction was shown in these antibody preparations. Of the 26 IgG anti-B-coated cell preparations, 21 were agglutinated exclusively by the anti-VHIII antiserum, and 5 were agglutinated mainly by the anti-VHIII antiserum but showed also some reactions using anti-VHI or anti-VHII antiserum, or both. Similarly, 11 out of the 13 IgG anti-A antibodies belonged to VHI, and only 2 to VHIII. The 6 IgG anti-Fy(a) antibodies were restricted to subgroups VHI and VHII, and of the 4 IgG anti-Fy(b) antibodies, 3 belonged to subgroup VHIII and one to VHII. Additional experiments indicated that IgM anti-A and IgM anti-B antibodies showed the same type of restriction to VH subgroups as the corresponding IgG antibody preparations.