Unreliability of IgE/IgG4 antibody testing as a diagnostic tool in food intolerance

Clin Exp Allergy. 1998 Dec;28(12):1526-9. doi: 10.1046/j.1365-2222.1998.00367.x.


Background: Some clinicians link chronic disease in certain patients to 'food intolerance'. This is currently diagnosed by exclusion dieting, a time-consuming and tedious technique. It has been claimed that IgE/IgG4 antibody testing is a rapid and valid method of determining food intolerance.

Objective: To determine the test/retest reliability of IgE/IgG4 antibody testing as a diagnostic tool.

Methods: Blinded testing of duplicate blood samples from nine patients with suspected food intolerance was undertaken by tertiary referral centre using the services of a commercial laboratory. The proportions of consistent and inconsistent results for tests of 95 different foods were analysed.

Results: Test/retest reliability was low. Even though the study method systematically overestimated kappa, this value never exceeded 0.51, regardless of the statistical model used. All but one patient had a greater number of inconsistent results than had been prespecified as an unacceptable level of disagreement. In one case, 50 out of 95 test results were inconsistent on retest.

Conclusions: We found no evidence that IgE/IgG4 antibody testing as performed by this laboratory is a reliable diagnostic tool.

MeSH terms

  • Allergens / immunology
  • Enzyme-Linked Immunosorbent Assay*
  • Evaluation Studies as Topic
  • Food / adverse effects
  • Food Hypersensitivity / diagnosis*
  • Humans
  • Immunoglobulin E / blood*
  • Immunoglobulin G / blood*
  • Reproducibility of Results


  • Allergens
  • Immunoglobulin G
  • Immunoglobulin E