Elevated vitamin B₁₂ levels in autoimmune lymphoproliferative syndrome attributable to elevated haptocorrin in lymphocytes

Clin Biochem. 2012 Apr;45(6):490-2. doi: 10.1016/j.clinbiochem.2012.01.016. Epub 2012 Jan 28.

Abstract

Objective: Identify the etiology of elevated B(12) in autoimmune lymphoproliferative syndrome (ALPS).

Design: Peripheral blood of ALPS patients with elevated B(12) and controls were evaluated.

Results: Total and holo-haptocorrin (HC) levels were 26- and 23-fold higher in ALPS patients, respectively. No abnormal B(12)-binding proteins were found. Western blot revealed HC in lymphocyte lysates only from ALPS patients.

Conclusion: Elevated concentrations of B(12) found in ALPS patients were due to increased lymphocyte expression of HC.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autoimmune Lymphoproliferative Syndrome / blood*
  • Autoimmune Lymphoproliferative Syndrome / pathology
  • Case-Control Studies
  • Humans
  • Lymphocytes / metabolism*
  • Protein Binding
  • Transcobalamins / metabolism*
  • Vitamin B 12 / blood*

Substances

  • Transcobalamins
  • Vitamin B 12