Plus a smaller connection to MM genotype. I'd get his ABO and secretor types done, then get him on the program..

Non-secretors appear to have an increase in the prevalence of a variety of autoimmune diseases including ankylosing spondylitis, reactive arthritis, psoriatic arthropathy, Sjogren's syndrome, multiple schlerosis,and Grave's disease. This susceptibility towards autoimmune problems appears to be most pronounced among the recessive Lewis phenotypes (Le (a-b-)).

Shinebaum R. ABO blood group and secretor status in the spondyloarthropathies. FEMS Microbiol Immunol 1989 Jun;1(6-7):389-95

Among individuals with spondyloarthropathies, non-secretors are reported to make up 47% of the patient population. In the subgroup of these patients suffering from ankylosing spondylitis. non-secretors account for 49% of patients. Since the control population had a prevalence of non-secretors of 27% (consistent with the expected percent in the general population), it appears that in spondyloarthropathies in general, and ankylosing spondylitis specifically, non-secretors are dramatically over represented.

Shinebaum R, Blackwell CC, Forster PJ, et al. Non-secretion of ABO blood group antigens as a host susceptibility factor in the spondyloarthropathies. Br Med J (Clin Res Ed) 1987 Jan 24;294(6566):208-10

Among individuals with primary Sjogren's syndrome, Lewis blood group frequency differs from that of the general population, due mainly to an increased Lewis negative phenotype (Le (a-b-)) frequency.

Manthorpe R, Staub Nielsen L, et al. Lewis blood type frequency in patients with primary Sjogren's syndrome. A prospective study including analyses for A1A2BO, Secretor, MNSs, P, Duffy, Kell, Lutheran and rhesus blood groups. Scand J Rheumatol 1985;14(2):159-62

Among individuals with multiple sclerosis, a similar trend for over representation of the non-secretor phenotype also occurs.

Markovic S, Bozicevic D, Simic D, Brzovic Z. Genetic markers in the blood of multiple sclerosis patients. Neurol Croat 1991;41(1-2):3-12

The inability to secrete the water soluble glycoprotein form of the ABO blood group antigens into saliva is significantly more common in patients with Graves' disease than control subjects (40% vs 27%: P less than 0.025) but not among those with Hashimoto's thyroiditis or spontaneous primary atrophic hypothyroidism. Non-secretors with Grave's disease were found to produce higher levels of antitubulin antibodies, while levels of other antibodies were similar to secretors.