inclusion criteria: - type 1 diabetes treated continuously with insulin from time of diagnosis - age 18-65 - hiv antibody negative - normal cbc - hcg negative (females) - anti-gad positive (except for subjects with c-peptide <10pmol/l) - fasting or stimulated c-peptide between 5-200 pmol/l - participation in protocol #2001p001379, "autoimmunity: in vitro pathogenesis and early detection"

inclusion criteria: - type 1 diabetes treated continuously with insulin from time of diagnosis - age 18-65 - hiv antibody negative - normal cbc - hcg negative (females) - anti-gad positive (except for subjects with c-peptide <10pmol/l) - fasting or stimulated c-peptide between 5-200 pmol/l - participation in protocol #2001p001379, "autoimmunity: in vitro pathogenesis and early detection"