Abstract
In our previous reports 2 cases with insulin-autoimmune syndrome showed severe hypoglycemic attacks. This paper deals with another case with insulin-autoimmune phenomenon.
The third case was a 67-year-old female showing a mild hypoglycemic symptom and a diabetic pattern in the glucose tolerance test. She was admitted as a diabetic patient in May, 1971. No insulinoma was suggested because her hypoglycemic symptom was so mild.
Existence of insulin-binding antibodies in the serum was proved with a gel filtration method which separated 131I-insulin-antibody complex from free 131-insulin. Also, 125I-insulin-antibody complex was precipitated with anti-IgG serum. The binding capacity of the antibodies of the third case with human insulin seemed stronger than with pork insulin, whereas the serum proteins of other patients treated with exogenous insulin bound with pork insulin much strongly than with human insulin.
The fasting serum insulin level of this case increased about 100 times of the normal concentration of insulin, and it increased significantly after glucose administration. The extracted insulin from her serum showed the immunological characteristics of human insulin or pork insulin, but not of beef insulin, in the systems of radioimmunoassay of insulin.
