Pseudoinsulinoma in a white man with autoimmune hypoglycemia due to anti-insulin antibodies: value of the free C-Peptide assay

Audrey E. Arzamendi, Uthra Rajamani, Ishwarlal Jialal

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

OBJECTIVES: Insulin autoimmune syndrome (IAS) is an extremely rare cause of hypoglycemia, particularly in non-Asian populations.

METHODS: In this report, we describe a white male patient with elevated total insulin (>100.0 μIU/mL), C-peptide, and proinsulin levels who was diagnosed with IAS due to anti-insulin antibodies. He also had a small IgG κ M-protein.

RESULTS: We show that anti-insulin antibodies and/or the monoclonal protein can significantly interfere with insulin and C-peptide immunoassays and propose polyethylene glycol precipitation to quantitate free C-peptide levels as a useful assay in differentiating IAS due to anti-insulin antibodies from insulinoma.

CONCLUSIONS: In patients presenting with hypoglycemia with excessively high insulin levels, consideration needs to be given to autoimmune hypoglycemia due to anti-insulin antibodies as a cause. Additionally, if total C-peptide levels are increased, free C-peptide needs to be quantitated following polyethylene glycol precipitation.

Original languageEnglish (US)
Pages (from-to)689-693
Number of pages5
JournalAmerican Journal of Clinical Pathology
Volume142
Issue number5
DOIs
StatePublished - Nov 1 2014

Fingerprint

Insulin Antibodies
C-Peptide
Hypoglycemia
Anti-Idiotypic Antibodies
Insulin
Insulinoma
Immunoassay
Proteins
Immunoglobulin G
Population

Keywords

  • Anti-insulin antibodies
  • Autoimmune hypoglycemia syndrome
  • Free C-peptide assay
  • Hirata disease
  • Insulin autoimmune syndrome

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Pseudoinsulinoma in a white man with autoimmune hypoglycemia due to anti-insulin antibodies : value of the free C-Peptide assay. / Arzamendi, Audrey E.; Rajamani, Uthra; Jialal, Ishwarlal.

In: American Journal of Clinical Pathology, Vol. 142, No. 5, 01.11.2014, p. 689-693.

Research output: Contribution to journalArticle

@article{629d4d6157e547c3895e24e7fe602b92,
title = "Pseudoinsulinoma in a white man with autoimmune hypoglycemia due to anti-insulin antibodies: value of the free C-Peptide assay",
abstract = "OBJECTIVES: Insulin autoimmune syndrome (IAS) is an extremely rare cause of hypoglycemia, particularly in non-Asian populations.METHODS: In this report, we describe a white male patient with elevated total insulin (>100.0 μIU/mL), C-peptide, and proinsulin levels who was diagnosed with IAS due to anti-insulin antibodies. He also had a small IgG κ M-protein.RESULTS: We show that anti-insulin antibodies and/or the monoclonal protein can significantly interfere with insulin and C-peptide immunoassays and propose polyethylene glycol precipitation to quantitate free C-peptide levels as a useful assay in differentiating IAS due to anti-insulin antibodies from insulinoma.CONCLUSIONS: In patients presenting with hypoglycemia with excessively high insulin levels, consideration needs to be given to autoimmune hypoglycemia due to anti-insulin antibodies as a cause. Additionally, if total C-peptide levels are increased, free C-peptide needs to be quantitated following polyethylene glycol precipitation.",
keywords = "Anti-insulin antibodies, Autoimmune hypoglycemia syndrome, Free C-peptide assay, Hirata disease, Insulin autoimmune syndrome",
author = "Arzamendi, {Audrey E.} and Uthra Rajamani and Ishwarlal Jialal",
year = "2014",
month = "11",
day = "1",
doi = "10.1309/AJCPX56JQBJHUBGJ",
language = "English (US)",
volume = "142",
pages = "689--693",
journal = "American Journal of Clinical Pathology",
issn = "0002-9173",
publisher = "American Society of Clinical Pathologists",
number = "5",

}

TY - JOUR

T1 - Pseudoinsulinoma in a white man with autoimmune hypoglycemia due to anti-insulin antibodies

T2 - value of the free C-Peptide assay

AU - Arzamendi, Audrey E.

AU - Rajamani, Uthra

AU - Jialal, Ishwarlal

PY - 2014/11/1

Y1 - 2014/11/1

N2 - OBJECTIVES: Insulin autoimmune syndrome (IAS) is an extremely rare cause of hypoglycemia, particularly in non-Asian populations.METHODS: In this report, we describe a white male patient with elevated total insulin (>100.0 μIU/mL), C-peptide, and proinsulin levels who was diagnosed with IAS due to anti-insulin antibodies. He also had a small IgG κ M-protein.RESULTS: We show that anti-insulin antibodies and/or the monoclonal protein can significantly interfere with insulin and C-peptide immunoassays and propose polyethylene glycol precipitation to quantitate free C-peptide levels as a useful assay in differentiating IAS due to anti-insulin antibodies from insulinoma.CONCLUSIONS: In patients presenting with hypoglycemia with excessively high insulin levels, consideration needs to be given to autoimmune hypoglycemia due to anti-insulin antibodies as a cause. Additionally, if total C-peptide levels are increased, free C-peptide needs to be quantitated following polyethylene glycol precipitation.

AB - OBJECTIVES: Insulin autoimmune syndrome (IAS) is an extremely rare cause of hypoglycemia, particularly in non-Asian populations.METHODS: In this report, we describe a white male patient with elevated total insulin (>100.0 μIU/mL), C-peptide, and proinsulin levels who was diagnosed with IAS due to anti-insulin antibodies. He also had a small IgG κ M-protein.RESULTS: We show that anti-insulin antibodies and/or the monoclonal protein can significantly interfere with insulin and C-peptide immunoassays and propose polyethylene glycol precipitation to quantitate free C-peptide levels as a useful assay in differentiating IAS due to anti-insulin antibodies from insulinoma.CONCLUSIONS: In patients presenting with hypoglycemia with excessively high insulin levels, consideration needs to be given to autoimmune hypoglycemia due to anti-insulin antibodies as a cause. Additionally, if total C-peptide levels are increased, free C-peptide needs to be quantitated following polyethylene glycol precipitation.

KW - Anti-insulin antibodies

KW - Autoimmune hypoglycemia syndrome

KW - Free C-peptide assay

KW - Hirata disease

KW - Insulin autoimmune syndrome

UR - http://www.scopus.com/inward/record.url?scp=84922211211&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84922211211&partnerID=8YFLogxK

U2 - 10.1309/AJCPX56JQBJHUBGJ

DO - 10.1309/AJCPX56JQBJHUBGJ

M3 - Article

C2 - 25319986

AN - SCOPUS:84922211211

VL - 142

SP - 689

EP - 693

JO - American Journal of Clinical Pathology

JF - American Journal of Clinical Pathology

SN - 0002-9173

IS - 5

ER -