The prevalence of HLA-A and B antigen loci in patients with Whipple's disease was determined from data obtained in a review of the literature and from personal communications. Data on the HLA-A and B locus typing of 30 patients were available (with the exception that 1 of the patients was not typed for the HLA-B locus), and for an additional 18 patients, HLA-B27 data were available. Of the 47 patients typed for B27, 13 (28%) were B27 positive. Twelve of the 48 patients had sacroiliitis, and 2 (17%) of them were B27 positive. These data suggest that Whipple's disease may be associated with HLA-B27, even in the absence of concomitant sacroiliitis.