July, 1999

From:
Dr. John Angles
Diplomate ACVIM
Small Animal Clinical Studies
University College Dublin

Re:   Akita MHC study and the “split” debate

Further to several requests and comments received over the last week, the following may help to clarify some points concerning the UC-Davis Akita MHC study:

The Akita MHC study was specifically aimed at understanding the underlying causes for autoimmune disease in the “American” Akita, and 90% of our samples have come from this source. We have been involved with the Finnish Akita club with specific regard to Sebaceous adenitis, and we have a limited number of “Japanese” type Akita DNA samples.  However, the results reported to date are for the “American” Akita.

A separate study is being developed at present to examine the origins of the “American” Akita, and I would be very interested in getting additional samples for the “Japanese” type of Akita. This is an unrelated study to the Akita MHC study, and would not only type the MHC alleles, but also mitochondrial and microsatellite DNA markers. This study is yet to be started.

The Akita MHC study suggests that the “American” Akita has limited variability in the MHC class II genes DRB, DQA and DQB. While other genes involved in the immune response have yet to be looked at, we view the limited variability in these MHC genes as an important finding in light of the high prevalence of autoimmune disease in the “American” Akita (Akita Dog, Summer 1998; p. 48). Research in other animals suggests that decreased variability in the MHC places a species at risk for increased infectious disease, autoimmune disease and cancer.

While I am aware of autoimmune disease occurring in Akitas in both Europe and Japan, we have no data on the prevalence of diseases in these populations. Our studies looking at VKH-like disease and Myasthenia gravis are specifically directed at the “American” Akita population.

To address the issue of the “American” vs. the “Japanese” Akita split will require a broad study examining the differences and similarities in a number of genetic loci. This type of study would involve examining both phenotypic differences between the types (anatomical, hematological, biochemical, etc.), as well as DNA studies.  I am more than willing to answer any specific questions, and hope that some of the above will help to clarify the results of the Akita MHC study.

Sincerely

Dr. John Angles