Diabetes, Vol 45, Issue 2 178-182, Copyright © 1996 by American Diabetes Association
Cellular immune response to cow's milk beta-lactoglobulin in patients with newly diagnosed IDDM
O Vaarala, P Klemetti, E Savilahti, H Reijonen, J Ilonen and HK Akerblom
Children's Hospital, University of Helsinki, Finland.
Elevated levels of antibodies to cow's milk proteins, i.e.,
beta-lactoglobulin (BLG) and bovine serum albumin (BSA), have been
associated with IDDM. We observed enhanced cellular immune response by a
proliferation test of peripheral blood mononuclear cells to BLG in 22 of 40
(55%) patients with newly diagnosed IDDM compared with 7 of 32 healthy
children (22%) (P = 0.004, chi 2 test). The median stimulation index to BLG
was 3.3 in patients and 1.5 in healthy children (P = 0.003, Mann-Whitney U
test). No difference was found in cellular reactivity to other cow's milk
proteins, such as BSA or alpha-casein, or to a dietary immunogenic protein,
ovalbumin. Cellular responsiveness to BLG was not associated with HLA-DQB1*
risk alleles of IDDM, which suggests that immune response to the protein
does not only reflect the accumulation of these HLA alleles in the patients
with IDDM. We suggest that enhanced cellular immune response to dietary BLG
may reflect a disturbance in the regulation of immune response to oral
antigens in IDDM. This kind of defect may play a fundamental role in the
development of beta-cell autoimmunity in IDDM.