MLAB 2401: Clinical Chemistry Keri Brophy-Martinez Assessment of Proteins

Total Protein  Specimen Collection ◦ Serum ◦ Avoid hemolysis and lipemia  Reference Range ◦ 6.4-8.3 g/dL

Methods for Total Protein Determination

Albumin Determination

A/G Ratio   ◦ Globulin concentration can be calculated by subtracting the albumin from total protein. Globulin = Total Protein (g/dL) – Albumin (g/dL) The A/G ratio can then be determined by dividing the albumin concentration by the calculated globulin.

Urinary Protein   Sources ◦ Blood ◦ Kidney, urinary tract, vagina and prostate When proteins appear in the urine, they have not been reabsorbed by the renal tubules ◦ Screen: urine dipstick ◦ Quantitative: 12 or 24 hour urine

Urine Protein Methods

Urinary Protein: Significance

Physiological Causes (transient proteinuria)

Exercise (causes renal vasoconstruction) Emotional stress Exposure to heat or cold Fever

Pathologic Causes

Glomerular nephritis Pyelonephritis Malignant hypertension Increased permeability of glomerulus (toxins, SLE, infections, diabetes) Pregnancy Orthostatic/Postural (common in teens when rapid growth is occurring) Disturbance of reabsorption Others: Systemic disorders, drugs, chemicals, myeloma-type disease (Bence-Jones protein)

CSF proteins  Reference range ◦ 15-45 mg/dL ◦ Increased total CSF proteins     Bacterial, viral, fungal meningitis Traumatic tap Multiple sclerosis neoplasm

References   Bishop, M., Fody, E., & Schoeff, l. (2010). Clinical Chemistry: Techniques, principles, Correlations. Baltimore: Wolters Kluwer Lippincott Williams & Wilkins.

Sunheimer, R., & Graves, L. (2010). Clinical Laboratory Chemistry. Upper Saddle River: Pearson .