A novel reagent for the screening of haptoglobin-deficient blood donors

Vox Sang. 2023 Dec;118(12):1109-1114. doi: 10.1111/vox.13543. Epub 2023 Oct 5.

Abstract

Background and objectives: In Japan, the prevalence of haptoglobin deficiency is approximately 1 in 4000. Haptoglobin-deficient individuals may produce anti-haptoglobin from allo-immunization, leading to serious transfusion reactions. Therefore, implementation of a consistent supply of haptoglobin-deficient fresh frozen plasma is crucial. We developed a novel reagent to facilitate large-scale identification of haptoglobin-deficient individuals as potential donors of plasma products.

Materials and methods: We established mouse monoclonal anti-haptoglobin-producing cell lines (three clones) using the hybridoma method by immunizing mice with the haptoglobin protein. Purified antibodies were conjugated with carboxylate-modified polystyrene latex beads and used for haptoglobin measurements by the latex agglutination method using an automatic analyser (LABOSPECT008). Samples with low protein concentrations were re-examined by enzyme-linked immunosorbent assay to confirm the results. Additionally, the haptoglobin gene was amplified by polymerase chain reaction to confirm the haptoglobin deletion allele (Hpdel ).

Results: From February to October 2022, 7476 blood donor samples were screened. Two haptoglobin-deficient and 21 low-haptoglobin-expressing individuals were identified. Two haptoglobin-deficient donors were found homozygous for Hpdel , and 19 (90%) of the 21 low-haptoglobin-expressing individuals were heterozygous for Hpdel , which includes the first reported case of heterozygous Hpdel /HpJohnson .

Conclusion: We developed a new reagent for the detection of haptoglobin deficiency, which is automatable and inexpensive and appears useful for large-scale screening of blood donors.

Keywords: haptoglobin-deficient donor; reagent for screening.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / chemistry
  • Blood Donors*
  • Enzyme-Linked Immunosorbent Assay
  • Haptoglobins* / chemistry
  • Haptoglobins* / genetics
  • Heterozygote
  • Humans
  • Mice
  • Polymerase Chain Reaction / methods

Substances

  • Haptoglobins
  • Antibodies, Monoclonal