Immunochemical cross-reactivity between albumin and solid-phase adsorbed histamine

Area of Science:

• Immunology
• Biochemistry
• Assay Development

Background:

• Development of specific antibodies is crucial for accurate biomolecule detection.
• Histamine antibodies are essential tools in various biological and medical research fields.
• Challenges exist in ensuring antibody specificity and avoiding cross-reactivity with similar molecules.

Purpose of the Study:

• To produce and characterize antibodies against histamine.
• To develop an immunoradiometric assay for histamine antibody testing.
• To investigate potential cross-reactivity issues in histamine antibody production.

Main Methods:

• Antibodies against histamine were produced by immunizing rabbits with histamine coupled to human serum albumin (HSA).
• An immunoradiometric assay was developed using solid-phase bound histamine, antisera, and radiolabeled protein A.
• Inhibition experiments were conducted using free histamine, histamine coupled to other carriers, and HSA.

Main Results:

• The developed assay confirmed that histamine adsorbed onto a solid-phase could bind the antiserum.
• Neither free histamine nor histamine coupled to unrelated carriers inhibited antiserum binding.
• Significant cross-reactivity was observed between HSA and solid-phase bound histamine, as HSA inhibited the assay.
• A commercially available anti-HSA antiserum also bound to solid-phase histamine, confirming unexpected cross-reactivity.

Conclusions:

• The production of antibodies against histamine using HSA as a carrier can lead to unexpected cross-reactivity with HSA.
• Standard immunoradiometric assays may not detect this HSA cross-reactivity.
• It is crucial to test histamine antibody preparations for cross-reactivity with carrier proteins like HSA.