Identification of new B27 subtypes (B27C and B27D) prevalent in oriental populations.

With the aid of alloreactive cytotoxic T lymphocytes, three subtypes of HLA-B27 can be defined: B27W, B27K, and B27C (non-B27W and non-B27K). The B27C subtype can be distinguished by 1D-IEF, is not recognized by B27W- or B27K-restricted influenza-A-specific cytotoxic T lymphocytes, and is prevalent in Oriental populations. Preliminary data indicate that the various B27 subtypes (W, K, C) are in different linkage disequilibria with HLA-C antigens. A fourth subtype of B27 (non-B27W and non-B27K), designated as B27D, was detected by 1D-IEF. (See accompanying paper by Neefjes et al.) The finding of four B27 subtypes indicates that the serologically defined B27 antigen comprises a family of various, strongly cross-reactive class-I molecules.