Clinical features:
(1) onset of diabetes in an adult
(2) insulin not required at the time of diagnosis
(3) several markers of autoimmune diabetes including any combination of:
(3a) HLA-DR3 or HLA-DR4
(3b) antibodies to islet cells
(3c) antibodies to glutamic acid decarboxylase (GAD)
(4) variable progression to insulin dependence
(5) other endocrine autoantibodies (anti-thyroid, anti-adrenal, etc)
(6) family history of Type I diabetes or autoimmune endocrinopathy
The patient typically has a low body mass index (BMI).
A patient with antibodies to islet cells or GAD are more likely to develop insulin dependence.
A patient with latent autoimmune diabetes may show a defect in maximally stimulated beta-cell capacity. These patients produce enough insulin for usual requirements but do not have much reserve capacity. One test is to measure C-peptide response following administration of glucagon.
Differential diagnosis:
(1) pancreatic destruction in a patient with non-insulin dependent diabetes