Dr. Cho requested these labs be drawn: Islet cell autoantibodies screen; TSH; thyroglobulin antibodies; C-peptide; immunoglobulin A level; hemoglobin A1C; and anti-tissue transglutaminase antibodies

Question

Described how each is related to the diagnosis of type 1 diabetes.

Answer 1

• Islet cell autoantibodies: serve as an indicator of the body's self destructive attack against its pancreatic β-cells.
• TSH: diabetic patients are more likely to be affected by thyroid dysfunction and an elevated TSH level may suggest an autoimmune attack against the thyroid gland; 17% to 30% of children with T1DM develop autoimmune thyroid disorders.
• Thyroglobulin antibodies: as discussed above, due to the similarity in the autoimmune etiology of type 1 diabetes and thyroid dysfunction, presence of these antibodies can help diagnose hypothyroidism early.
• C-peptide: C-peptide is cleaved from proinsulin to produce insulin and its presence in the bloodstream is an indirect measure of insulin production/beta cell function.
• Immunoglobulin A: increased levels can be observed during beta-cell destruction seen in type 1 diabetes
• Hemoglobin A1C: is an indicator of average blood glucose level over the previous 2-3 months (RBCs life span is 120 days) as Hgb will have a higher level of glycation with greater blood glucose levels.
• Tissue transglutaminase: This value can allow the physician evaluate the patient for celiac disease as it too is a disease of improper autoimmune assaults and more common in type 1 diabetics; 1%-16% with T1DM develop celiac disease.