Association between histocompatability antigens (HLA) and nasal carriage of Staphylococcus aureus.

We investigated the association between phenotypes of histocompatability antigen (HLA) and nasal carriage of Staphylococcus aureus in two populations--healthy laboratory workers and patients attending an outpatients' clinic. When data from the two sources were pooled, it was evident that the presence of HLA-DR3 was associated with carriage, and the presence of HLA-DR2, HLA-DR1 and HLA-Bw35 with lack of carriage. However, since each person may have two antigenic specificities encoded at the HLA-A, the HLA-B, and the HLA-DR loci, the carriage of the organism was analysed for paired combinations of the more frequent phenotypes. For example, the lack of carriage evident with HLA-DR1 was more marked with the DR1-A11 and DR1-B7 combinations while the predisposition towards carriage shown with HLA-DR3 was more marked with the DR3-DR5 combination. The importance of the analysis of antigen combinations is discussed in relation to association of single antigens with carriage of S. aureus.