Quantitative and qualitative evaluation of plasma and urine alpha1-microglobulin in healthy donors and patients with different haemolytic disorders and haemochromatosis

Clin Chim Acta. Nov-Dec 2007;386(1-2):31-7. doi: 10.1016/j.cca.2007.07.017. Epub 2007 Jul 26.

Abstract

Background: The haem-binding protein alpha(1)-microglobulin (alpha(1)m) is involved in protection against oxidative damage induced by extracellular haem/haemoglobin. A carboxy-terminally truncated form of alpha(1)m (t-alpha(1)m), formed by reactions with haemoglobin, degrades haem into a yellow-brown chromophore linked to the protein. The aim of this work was to investigate if t-alpha(1)m is present in urine from a large cohort and if urinary and plasma alpha(1)m/t-alpha(1)m concentrations are changed in patients with haemolytic disorders and haemochromatosis.

Methods: Urine and blood from patients (n=20) and a control group (n=22) were investigated for alpha(1)m and t-alpha(1)m by gel electrophoresis, Western blotting and radioimmunoassay. Data were compared to clinical chemistry data and medical records.

Results: Two thirds of all studied subjects displayed t-alpha(1)m in urine but the t-alpha(1)m/alpha(1)m ratio was not increased in patients. Instead, significantly elevated ratios were found in females compared to males. Patients with intravascular or extravascular haemolysis showed higher alpha(1)m, albumin and beta(2)-microglobulin/creatinine ratios in urine indicating glomerulo-tubular dysfunction.

Conclusions: The demonstration of t-alpha(1)m in urine of this cohort may be of importance in quantitative clinical chemistry. Whilst impaired kidney function due to intravascular haemolysis is well-known to occur, it is an unexpected finding in a group of patients with extravascular haemolysis.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alpha-Globulins / analysis
  • Alpha-Globulins / urine*
  • Biomarkers / blood
  • Biomarkers / urine
  • Blotting, Western
  • Case-Control Studies
  • Creatinine / blood
  • Creatinine / urine
  • Electrophoresis, Polyacrylamide Gel
  • Female
  • Hematologic Diseases / diagnosis*
  • Hemochromatosis / diagnosis*
  • Humans
  • Kidney Glomerulus / pathology
  • Male
  • Radioimmunoassay
  • beta 2-Microglobulin / blood
  • beta 2-Microglobulin / urine

Substances

  • Alpha-Globulins
  • Biomarkers
  • alpha-1-microglobulin
  • beta 2-Microglobulin
  • Creatinine