Cc2

• Prealbumin:

  • Synthesized in the liver & choroid plexus of the CNS
  • Nonglycosylated; rich in tryptophan
  • Binds T3-T4, retinol-binding protein "Transthyretin"
  • Used as a nutritional marker with a short half-life
  • CSF MARKER; Presence in CSF electrophoresis indicates CSF specimen
  • NEGATIVE APP: Decreased in inflammation/malignancy, liver cirrhosis, protein-losing diseases
  • Migrates as a minor band before albumin in SPE
  • Measured using immunoturbidimetric / immunonephelometric methods
  • Reference interval: 20-40 mg/dL
• Albumin:

  • Nonglycosylated, but 25% glycosylated during hyperglycemia
  • Rich in cysteine, highly soluble in water-high charged AAs
  • Major contributor to oncotic pressure
  • General transporter of substances like bilirubin, calcium/magnesium, hormones, drugs
  • Contributes to anion gap
  • Used for short-term glycemic control in DM patients
  • Prognostic marker of cystic fibrosis
  • Decreased in inflammation, hepatic disease, urinary loss
  • Increased in dehydration, prolonged tourniquet time, albumin infusion
  • Thickest band seen in SPE
  • Assayed using dye-binding methods with dyes like bromocresol green
• • Immunoturbidimetry / immunonephelometry for accurate measurement
• Alpha-1 globulins:

  • Alpha 1-antitrypsin (AAT):
  • Highest concentration protease inhibitor in plasma
  • Functions: Inhibits trypsin & other serine proteases, LEUKOCYTE ESTERASE
  • Increased in APR, estrogens; decreased in pulmonary emphysema, NRDS
  • Major constituent of the A1-globulin fraction in SPE
  • Quantified using immunoturbidimetry / immunonephelometry
  • Phenotyped by isoelectric focusing if deficiency is suspected
• Alpha-fetoprotein (AFP):

  • Homologous to albumin, synthesized in utero and by fetal liver
  • Functions: Protects fetus from immunologic attack, used for detection of fetal disorders, tumor markers
  • Increased in neural tube defects: spina bifida, abdominal wall defects, fetal distress
  • Decreased in Trisomy 21 (down’s syndrome) Trisomy 18 (edwards syndrome)
  • Fractionated by affinity electrophoresis into 3 glycoforms: L1, L2, L3 isoforms based on reactivity with lectin culinaris agglutinin (LCA)
  • AFP levels measured in Quadruple screening test for tumor marker detection
• Alpha 1-antichymotrypsin (A1-X):

  • Contains 25% CHO, encoded by SERPINA3 gene also known as SERPINA A3 l, inhibits cathepsin G, mast cell chymase,chymotrypsin. Binds w/ prostate specific antigen (PSA)
  • Increased in APR, decreased in Parkinson's disease, COPD
  • Major constituent of amyloid deposits in Alzheimer's disease, important screening marker for AD
  • Quantified using immunoturbidimetry / immunonephelometry
• Gc-globulin (Gc):

  • Gc stands for “group specific component” Binds and transports vitamin D “vitamin D binding protein”, integral component in actin-scavenger system
  • Decreased in severe liver disease, nephrotic syndrome, trauma pxs (immunophelometry used)
  • Quantified using immunonephelometry
• Haptoglobin (Hp):

  • Binds free Hgb, prevents renal clearance of Hgb 2 ALPHA, 2 BETA CHAINS
  • Decreased in intravascular hemolysis, liver disease
  • Increased in nephrotic syndrome, biliary obstruction
  • Major a2-globulin in SPE
  • Quantified using immunonephelometry / immunoturbidimetry
  • Phenotypes determined using starch gel electrophoresis
• Ceruloplasmin (Cp):

  • Copper-binding protein, binds 90% of copper, 10% albumin, trancuprein —— CATALYSIS OF REDOX RXNS > regulates ionic state of iron
  • Increased in estrogens, decreased in primary and secondary deficiencies
  • decreased in: secondary: common
• High-density lipoprotein (HDL):

  • Contains 50% protein, 25% lipid
  • Increased in healthy individuals, decreased in APR
  • Part of the alpha-1 globulins
  • Formerly termed as "alpha-lipoprotein" because of electrophoretic mobility in SPE
  • HDL levels impact the risk for cardiovascular disease
• Wilson disease, also known as "hepatolenticular degeneration," is characterized by toxic deposition of copper in different organs due to deficient ATPase
• In Wilson disease, copper accumulates in hepatic parenchymal cells in the liver, leading to liver dysfunction
• In Wilson disease, copper also accumulates in the brain, resulting in neurological signs
• In Wilson disease, copper deposition in the periphery of the iris leads to the formation of Kayser-Fleischer rings
• Ceruloplasmin (Cp) is a diagnostic marker for Wilson disease, with low levels (0.1 g/L) indicating the disease
• Menkes disease is an X-linked disorder characterized by a dysfunctional copper transporter due to a mutation
• Menkes disease is characterized by "kinky" hair and neurological symptoms, including seizures
• Alpha 2-macroglobulin (AMG) is homologous to C3-C4 and is the largest major non-Ig plasma protein (725 kDa) with 4 subunits
• Alpha 2-macroglobulin functions as a major plasma proteinase inhibitor by entrapping enzymes with a bait region, including serine, cysteine, and metalloproteinases
• Increased estrogen levels lead to higher concentrations of alpha 2-macroglobulin in women compared to men
• Alpha 2-macroglobulin levels are increased during pregnancy (20%), in infants and children, and in nephrotic syndrome (10x)
• Decreased levels of alpha 2-macroglobulin are seen in severe acute pancreatitis and advanced carcinoma of the prostate
• Beta globulins include transferrin (TRF), also known as "siderophilin," which binds and transports iron in a 1:2 ratio
• Increased transferrin levels are associated with iron deficiency anemia, especially during pregnancy
• Decreased transferrin levels are seen in anemia of chronic disease, hemochromatosis (bronze-skin), malnutrition, nephrotic syndrome, inflammation (-APP), and atransferrinemia
• Transferrin is a major component of the beta-1 globulin fraction in serum protein electrophoresis (SPE)
• Carbohydrate-deficient transferrin (CDT) is a highly specific marker for chronic alcohol abuse
• Hemopexin, which has 20% carbohydrates, binds free heme and is involved in conditions such as intravascular hemolysis, urinary loss, liver disease, inflammation, melanomas, and Duchenne muscular dystrophy
• Low-density lipoproteins (LDL) consist of 80% lipid and 20% protein, and they transport cholesterol
• Increased LDL levels are associated with an increased risk of cardiovascular disease (CVD)
• Decreased LDL levels are found in healthy individuals as LDL is considered "bad cholesterol"
• B2-microglobulin (BMG) is the light/beta-chain of HLAs, with high concentrations in lymphocytes, and is involved in MHC 1 function
• Increased B2-microglobulin levels are seen in renal failure, inflammatory diseases (SLE, RA, neuro-behcet syndrome), neoplasms, CLL, and HIV patients
• Fibrinogen is a highly elongated protein and a major contributor to plasma viscosity, playing a role in the coagulation system by forming fibrin
• Decreased fibrinogen levels lead to extensive bleeding and disseminated intravascular coagulation (DIC)
• Increased fibrinogen levels are associated with an increased risk of cardiovascular disease, thrombosis, and elevated erythrocyte sedimentation rate (ESR)
• Complement is a complex system of proteins divided into 5 groups based on function, including the classical pathway, alternative/properdin pathway, lectin pathway, membrane attack complex (MAC), and inhibitors/regulatory proteins
• Complement helps clear pathogens from the body and is involved in the immune response, with C3 being the most abundant complement component and C4 being the second most abundant
• Increased complement levels are seen in acute phase reactions (APR) as weak and late-reacting acute phase proteins (APPs)
• Decreased complement levels can be inherited due to mutations or secondary to consumption in conditions like hereditary angioedema (HAE) and acute poststreptococcal glomerulonephritis