1. Serum Albumin
Introduction
Albumin is quantitatively the most important serum protein synthesized by liver.
Indications
Marker of disorders of protein metabolism (e.g. nutritional, decreased synthesis increased loss).
Normal range
3.5 – 5.0 mg/dL
Increased in
Dehydration (relative increase); LV albumin infusion
Decreased in
Same as for total serum proteins.1. Total Serum Proteins
Introductions
Extensive liver injury may lead to decreased blood levels of albumin, prothrombin, fibrinogen and other proteins synthesized exclusively by hepatocytes. Serum protein levels are neither early nor sensitive indicators of liver disease.
Normal range
5.5- 8.5 mg/dL
Indications
Screening for nutritional deficiencies and gammopathies.
Increased in
Hypergammaglobulinemias, hypovolemic states.
Decreased in
Nutritional deficiency (e.g. malabsorption, Kwashiorkor, marasmus); decreased ineffective protein synthesis (e.g. severe liver disease, agammaglobulinemia increased loss (e.g. renal nephrotic syndrome); Gl disease (e.g. Protein losing enteropathies, surgical resection); severe skin disease (e.g. burns, eczema); plasmapheresis, increased catabolism (e.g. fever, inflammation, hyperthyroidism malignancy); dilutional (e.g. IV fluids administration, SIADH water intoxication).Serum Bilirubin
Introduction
Spectrophotometric determinations of serum bilirubin in clinical laboratory measures two pigment fractions: (1) The water soluble conjugated fraction that gives a direct reaction with diazo reagent and consist largely of conjugated bilirubin. (2) The lipid soluble indirect – reaction fraction that represents primarily unconjugated bilirubin.
Indications
Differential diagnosis of disease of hepatobiliary system and pancreas and other
Causes of jaundice.
| Normal levels | |
| Total bilirubin | Direct bilirubin |
| 0.1 – 1.2 mg/dL | 0.03 – 0.5 mg/dL |
Increased in
Direct (conjugated) Bilirubin in
20 -40% of total: more suggestive of hepatic than posthepatic jaundice, 40 -60% of total: occur in either hepatic or posthepatic; > 50% of total: more suggestive of posthepatic than hepatic jaundice; total serum bilirubin > 40mg/dl indicates hepatocellular rather than extrahepatic obstruction.
Conditions
· Hereditary disorders (e.g. Dubin Johnson syndrome, Rotor's syndrome)
· Biliary duct obstruction (extra and intrahepatic)
· Hepatic cellular damage (viral, toxic, alcohol/ drug related)
· Infiltration, space – occupying lesions (e.g. metastatic tumor, abscess, granulomas)
Increased unconjugated (indirect) bilirubin in
Increased bilirubin production; hemolytic diseases (e.g. hemoglobinopathies, RBC enzyme deficiencies, disseminated intravascular coagulation (DIC), autoimmune hemolysis); ineffective erythropoiesis; blood transfusions; hematomas; hereditary disorders (e.g. Gilbert's disease, Crigler – Najjar syndrome); drugs causing hemolysis.
