Immunoglobulins G (IgG) in urine

Norm
IgG 0–9 mg/24 h
Ratio IgG/albumin 0.025–0.035

Urine
Urine container

Immunoglobulin G enters urine quite difficultly. In serum, there are 8000–17000 mg/l of immunoglobulin G, while in urine, only 10 mg/l. Immunoglobulin G is a non-selective indicator of glomerular filtration because it enters the urine ultrafiltrate in cases of glomerular structural changes, as well as decreased overall reabsorption (tubulointerstitial nephropathy) or secretion (bleeding). An increased concentration of immunoglobulin G in urine can only be interpreted when other specific urine proteins are also detected (albumin, β-NAG, α₁-microglobulin). If glomerular proteinuria exceeds 100 mg/l, IgG in urine is less than 20% of the albumin concentration. If the proteinuria is interstitial or postrenal in nature (e.g., bleeding), in this case, IgG in urine is more than 20% of the albumin level.

Source | Handbook of Basic Laboratory Tests | Doctor of Medical Sciences Gintaras Zaleskis