The canine Major Histocompatibility Complex (MHC) contains highly polymorphic genes, many of which are critical in regulating the immune response. We have investigated the MHC class II alleles and haplotypes in a large cohort of 917 dogs with atopic dermatitis collected in Europe, Japan and USA.

MHC alleles and haplotypes were determined by either sequence based typing (SBT) or reference strand-mediated conformation analysis (RSCA). Data was compared with previously characterised control dogs which were supplemented with control dogs from the same country of origin as the cases.

In the total disease cohort, non significant (NS) increases of DLA-DRB1*00101 and DRB1*01201 were observed. The data was also stratified and analysed by breed and country of origin.

Seven breeds had more than 30 cases, see Table 1.

Table 1. DNA Samples Available for this Study

Results

 In the total disease cohort, non significant (NS) increases of DLA-DRB1*00101 and DRB1*01201 were observed.

 The data was stratified and analysed by breed and country of origin.

 German Shepherd cases from the UK showed a strong association with DLA-DRB1*00101 (OR=5.3, p<0.05).

 German Shepherd casesfrom the USA showed no variation.

 Boxer cases from both Sweden and the UK showed a NS increase of DLA-DRB1*00401.

 Labradors from Japan showed a NS increase in DLA-DRB1*00101, while those from the UK showed a NS increase in DLA-DRB1*01201.

 Labradors from the US showed no distortion of DLA-DRB1 allele frequencies.

 DLA-DRB1*00101 was also increased (NS) in Golden retriever cases from the UK and USA, but not from Japan or Sweden.

 Shiba Inu, Shih Tzu and West Highland white terrier cases showed no obvious differences from their controls.

Discussion

These data suggest that DLA-DRB1*00101 may be associated with canine atopy in several breeds.

DLA-DRB1*00101 has been found to be strongly associated with anal furunculosis in German shepherd dogs from UK and Finland. This may represent a marker that is associated with autoimmunity