In vitro demonstration of IgE antibody to folate-albumin in anaphylaxis from folic acid.

Abstract

BACKGROUND:

Folic acid (the synthetic form of folate B vitamins in foods) is widely used in vitamin supplements. Anaphylaxis from ingestion or injection of folic acid suggests IgE antibody-mediated mechanisms, but this has not been demonstrated previously in vitro.

OBJECTIVE:

This study was conducted to better define the mechanism of folic acid hypersensitivity and cross-reactivity among folic acid congeners.

METHODS:

Skin testing was performed with folic acid congeners in a woman who developed anaphylaxis after ingestion of 2 different multivitamin preparations containing folic acid. In vitro immunologic serum studies were conducted using a folate-human serum albumin (HSA) conjugate prepared by a novel application of carbodiimide condensation.

RESULTS:

The patient had positive immediate-type skin test reactions to folic acid and several folate analogues including leucovorin (folinic acid). Urticaria developed during graded oral test dosing with leucovorin. Using a dot immunoblot assay or an ELISA for IgE antibody to folate-HSA, results of the patient's serum testing were positive, whereas results of sera from normal control subjects were negative, the first in vitro demonstration of IgE to a folic acid-protein conjugate. By ELISA, the positive result of the patient's serum was inhibited significantly by serum coincubation with folate-HSA, but not HSA or folic acid.

CONCLUSIONS:

Immediate hypersensitivity to folic acid and possibly other vitamins can be mediated by IgE antibody to conjugates formed between vitamins and self-proteins or polypeptides. Leucovorin can have clinically important immunologic cross-reactivity with folic acid. A diet rich in natural folates (pteroylpolyglutamates) appears useful as a management strategy for providing adequate nutrition to patients with folic acid hypersensitivity.

• Authors: M S Dykewicz, N A Orfan, W Sun
• Journal: The Journal of allergy and clinical immunology (J Allergy Clin Immunol) Vol. 106 Issue 2 Pg. 386-9 (Aug 2000) ISSN: 0091-6749 [Print] United States
• PMID: 10932085 (Publication Type: Case Reports, Journal Article)

Chemical References

• Antibodies, Anti-Idiotypic
• Carrier Proteins
• Folate Receptors, GPI-Anchored
• Receptors, Cell Surface
• Serum Albumin
• anti-IgE antibodies
• Immunoglobulin E
• Folic Acid

Topics

• Adult
• Anaphylaxis (chemically induced)
• Antibodies, Anti-Idiotypic (blood)
• Carrier Proteins (immunology)
• Enzyme-Linked Immunosorbent Assay
• Female
• Folate Receptors, GPI-Anchored
• Folic Acid (adverse effects, immunology)
• Humans
• Immunoblotting
• Immunoglobulin E
• Receptors, Cell Surface
• Serum Albumin (immunology)