Question

Relate the clinical significanc of total urine proteins, micro albumin, myoglobin clearance, serum Beta2-microglobulin, and cystatin C.

Answer 1

Relate the clinical significance of total urine proteins, micro albumin, myoglobin clearance, serum Beta2-microglobulin, and cystatin C.

The significance of presence of protein in urine implies the state of kidney health. An increased protein level in urine indicates the underlying kidney disease. Proteinuria is the condition of excess protein is excreted in urine may be a warning of impending kidney involvement and severe kidney damage. This arises due to the over production of proteins by the body or might be due to damaged filters causes leakage of proteins such as albumin from blood into the urine. The glomerular damage can be arised from effect of toxins or lupus erythematosus resulted immune complexes or streptococcal glomerulonephritis. The clinical significance of elevated protein level in urine is the kidney disease. Glomerular damage might elevate the level of protein upto 10-40 mg/dL and even higher during tubular reabsorption disorder.

The level of microalbuminuria signifies the endothelial dysfunction indicates the elevated urinary excretion of albumin in urine. Microalbuminuria indicates abnormally increased excretion rate of albumin ranges from 30–299 mg/g creatinine. It increases the risk of morbidity and mortality especially with diabetes and hypertensive individuals.

Myoglobin is a muscle protein which contains iron aids in reccieving oxygen from RBCs and also helps to transport the oxygen to mitochondria where the cellular respiration occurs. Circulating myoglobin is critical which has be cleared by kidney. Normal level of myoglobin is less than 90 mcg/L and higher level indicates the muscle damage. The level of myoglobin clearence is critical incase of rhabdomyolysis and acute kidney injury and the clearence needs continuous venous-venous haemofiltration.

The beta-2 microglobulin (B2M) acts as a tumor marker for blood cancers. The level associated with the amount of cancer present. Higher level of B2M indicates the excessive progression of cancer. B2M is esmitated not only in urine and also in blood and CSF to get the details of the stage of metastasis. The normal range of B2M in urine is 0-0.3 µg/mL and in plasma it varies upto 0-3 µg/mL.

The glomerular filteration rate is estimated to analyse the kidney function and the GFR is in turn estimated based on measurement of endogenous blood substances, and serum creatinine (SCr). Serum cystatin C has been proved as an alternative marker for estimating GFR. Higher serum cystatin C implies a decreased glomerular filtration rate and hence to kidney dysfunction. The condition such as diabetes, cancer, HIV, hyperthyroidism, or hypothyroidism might also contribute for the elevation of cystatin C.