Mg. Cavallo et al., CELL-MEDIATED IMMUNE-RESPONSE TO BETA-CASEIN IN RECENT-ONSET INSULIN-DEPENDENT DIABETES - IMPLICATIONS FOR DISEASE PATHOGENESIS, Lancet, 348(9032), 1996, pp. 926-928
Background The cows' milk hypothesis for the cause of insulin-dependen
t diabetes (IDDM) is based on the concept that early consumption of co
ws' milk may expose the immune system to a foreign protein possessing
immunological cross-reactivity with an antigen present on pancreatic b
eta-cells. Methods We measured in-vitro peripheral lymphocyte response
to beta casein, a protein in cows' milk, in 47 patients with recent-o
nset IDDM, in 36 healthy people and, to lest disease specificity, in 1
0 patients with autoimmune thyroid disease. Other antigens tested for
were bovine serum albumin, purified protein derivative, human serum al
bumin, and phytohaemagglutinin. Results Specific proliferation of T ly
mphocytes with bovine beta casein was seen in patients with IDDM (mean
[SD] age 18.7 [9]) with a significant difference in mean stimulation
index (SI) versus healthy people (p<0.00001) or patients with autoimmu
ne thyroid disease (p<0.002). 24 of 47 (51.1%) patients with IDDM vers
us 0/10 patients with thyroid disease and 1/36 (2.7%) healthy people h
ad a positive response to beta casein defined as a SI above the mean v
alue +2 SD of healthy people (p<0.00001). No significant differences w
ere observed between the groups of subjects with respect to other anti
gens tested. Interpretation The association between IDDM and early con
sumption of cows' milk may be explained by the generation of a specifi
c immune response to beta casein. Exposure to cows' milk triggers a ce
llular and humoral anti-beta casein immune response which may cross-re
act with beta-cell antigen. it is of interest that sequence homologies
exist between beta casein and several beta-cell molecules.