Description
Alpha-1-microglobulin (A1M), also called protein HC, is a tubular plasma and tissue protein that belongs to the lipocalin transport protein superfamily for small hydrophobic molecules. It contains 184 amino acids and has a molecular weight of 26 kDa. Mature A1M and bikunin (urinary trypsin inhibitor) result from a common precursor. A1M is found in blood, both in free form and complex-bound to immunoglobulin A (IgA). It is involved in inflammatory and detoxification processes caused by immune system activation and extracellular heme catabolism. While increased excretion is detected in urine or serum shortly after tubular injury, A1M may predict acute kidney injury and the need for renal replacement therapy. Urinary A1M is useful for the early detection of nephropathy in type 2 diabetic subjects