Characterization of insulin autoantibodies in a patient with autoimmune hypoglycemia

A. Di Cerbo, V. Tassi, A. Scillitani, G. Zoppetti, V. De Filippis

Research output: Contribution to journalArticle

Abstract

A 60-year-old man referred because of hypoglycemic bouts was found to have insulin autoantibodies. Total plasma insulin was as high as 1.44 nmol/l. Both plasma free insulin and C-peptide were in the normal range. The indirect immunofluorescence technique showed positivity for antinuclear antibodies. The T-lymphocyte populations in the peripheral blood were normal. When serum binding capacity for pork insulin was measured, antibodies binding pork insulin were not detected. The patient’s serum bound 125l-insulin. The binding protein was identified to be an immunoglobulin G. The kinetics of dissociation, studied by the Scatchard analysis of the autoantibody, showed a curvilinear plot, which was analyzed in two components. Cold human insulin was able to compete with 125l-insulin for the antibody binding site (I.C.50=1.35 nmol/ml). These antibodies were apparently not associated with antibodies directed against the insulin receptor.

Original languageEnglish
Pages (from-to)299-304
Number of pages6
JournalJournal of Endocrinological Investigation
Volume18
Issue number4
DOIs
Publication statusPublished - 1995

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Keywords

  • autoimmunity
  • Hypoglycemia
  • insulin

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism

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