COMPARISON OF SEROLOGIC- AND DNA-BASED TYPING FOR HLA-CW.
D Thomas, P Paul, A Smerglia, P Kawczak, D Good, D Cook and
EJ Ball, Allogen Laboratories, The Cleveland Clinic Foundation, Cleveland,
OH.
Typing of HLA-Cw antigens by serologic methods is very difficult due
to a lack of reagents and lower levels of expression. Others have shown
that DNA-based methods can assign alleles not identified by serology in
many cases. We have evaluated 99 local samples by standard serologic methods
and SSO, SSP and/or SBT DNA methods. In 37 of the individuals tested, a
difference between serologic and DNA-based methods was observed, with a
total of 43 allele discrepancies. The most common finding was a DNA assigned
allele in the face of a serologic blank (84%). Of these, the majority (79%)
involved Cw*12, 14, 15, 16 or 17 for which serologic reagents are not available.
HLA-Cw*08 was involved in 13% , consistent with weak reactivity of our
local Cw8 antisera. In a small number of cases, different alleles were
assigned by serology and DNA suggesting additional reactivity in HLA-C
antisera (more often in Cw6 and Cw7 reagents). Preliminary results have
identified antisera that may be useful for the assignment of HLA-Cw*12,
15 and 17. Thus, we confirm the high discrepancy rate between DNA-based
and serologic methods in identification of HLA-Cw alleles and conclude
that DNA-based methods provide a more accurate assignment of HLA-Cw* alleles
than can currently be accomplished by serology.