Immunohistochemical findings in the pancreatic islets of a patient with transfusional iron overload and diabetes : case report

Excessive iron storage sometimes causes diabetes in patients with hemochromatosis,
a disease caused by iron overloading. We performed an immunohistochemical
analysis to study an autopsy case of aplastic anemia and diabetic hemochromatosis caused
by frequent blood transfusions, and extensive hemosiderin deposition was observed in
the liver and pancreas. The pancreatic islets of the patient and a control subject were
stained to detect glucagon, insulin, and proinsulin. Significantly lower levels of immunoreactivity
with both insulin antibodies and proinsulin antibodies, but not with glucagon
antibodies, was observed in the islet cells in the patient’s tissue than in the islet cells of
the control. Hemosiderin deposition in the islets is known to be exclusively distributed
in the β-cells, thus, selective iron-induced damage to the β-cells may have affected insulin
synthesis and secretion and led to glucose intolerance in the patient.

The journal of medical investigation : http://medical.med.tokushima-u.ac.jp/jmi/index.html