Can’t find a dictionary entry for “immune disease” and I agree 100% with gygis that the preferred term is “immune system disease”.
That said, I think “immune disease(s)” is seen often enough to warrant an entry on the basis of usage:
"Patients Now Surviving Once-Fatal
Immune DiseaseSt. Jude study finds that more than 85% of adults with X-linked agammaglobulinemia work full time or are full-time students."
http://www.docguide.com/news/content.nsf/news..."
Immune disease breakthrough"
http://news.bbc.co.uk/2/hi/health/1082899.stmThe CBR Institute for Biomedical Research has become the “
Immune Disease Institute”
http://www.cbrinstitute.org/and
"New centre to find biomarkers for
immune diseasesA new research institute, which aims to investigate the role of the human immune system in diseases such as AIDS, cancer and multiple sclerosis, has been founded by not-for-profit organisation the Immune Tolerance Institute and biomedical company Beckman Coulter."
http://www.labtechnologist.com/news/ng.asp?n=...