Insulin autoimmunity and hypoglycemia in seven white patients.
Endocr Pract
; 11(2): 97-103, 2005.
Article
em En
| MEDLINE
| ID: mdl-15901524
ABSTRACT
OBJECTIVE:
To report the clinical, biochemical, and immunologic characteristics of 7 white patients with the rare disorder of hyperinsulinemic hypoglycemia in association with spontaneously generated high titers of antibodies to human insulin.METHODS:
We reviewed the clinical data, history, and symptoms of the 7 study patients and summarized the biochemical findings during a spontaneous episode of hypoglycemia. Insulin antibody binding was measured in all patients, and antibody affinity, capacity, and clonality were analyzed in 4. A mixed meal study was conducted in 2 patients. A potential mechanism for postprandial hypoglycemia is presented.RESULTS:
In all 7 patients (6 women and 1 man), symptoms were neuroglycopenic, occurring primarily postprandially but during fasting in some patients. During hypoglycemia, concentrations of insulin, proinsulin, and, in most patients, C peptide considerably exceeded those observed in patients with insulinoma. These concentrations were spuriously elevated as a result of interference by the autoantibodies in the immunoassays. No patient had evidence of an insulinoma on various radiologic localization procedures directed at the pancreas. Insulin antibodies showed a high percentage of binding to human insulin--50 to 90%. Heterogeneity of antibodies regarding clonality and antibody binding sites was noted; some patients had polyclonal and some had monoclonal IgG class antibodies. Most patients had two categories of binding sites high affinity/low capacity and low capacity/high affinity. Although the mechanism for postprandial hypoglycemia remains conjectural, prolonged elevations of postprandial concentrations of total and free insulin are consistent with the putative mechanism of a buffering effect of insulin antibodies.CONCLUSION:
Insulin autoimmune hypoglycemia, although rare in any racial group and especially in white subjects, can be readily detected by high titers of insulin antibodies. Such a determination should be done in all patients undergoing evaluation for hypoglycemia.
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Bases de dados:
MEDLINE
Assunto principal:
Autoimunidade
/
População Branca
/
Hiperinsulinismo
/
Hipoglicemia
/
Insulina
Tipo de estudo:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Risk_factors_studies
Limite:
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Endocr Pract
Assunto da revista:
ENDOCRINOLOGIA
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Estados Unidos