Plasma Proteins - Specific Protein Abnormalities

Alpha-1-antitrypsin (ATT) Transferrin (TF) Caeruloplasmin (CP) Acute Phase Reactants (APR) C-Reactive Protein Procalcitonin (PCT)

Its 53 kDa big The most important proteinase inhibitor in serum Synthesised by the liver Inactivates several serine proteases by irreversibly forming an inhibitor complex There are various isoforms the most common being PiMM

A proteinase inhibitor in serum Inactivates several serine proteases by irreversibly forming an inhibitor complex

Leukocyte elastase Trypsin Chymotrypsin Collagenase Plasmin Thrombin

It’s an important acute phase reactant which is found elevated in inflammatory processes Elevated levels used to help diagnose inflammation of the liver parenchymal cells -> other acute phase reactants aren’t raised by this Deficiency of AAT is caused by genetics

Inhibits proteases Protects self cells from the work of wbcs during infection

When infection occurs there is no alpha 1 to protect cells -> Elastin in lungs is damaged by chemicals produced by wbcs Some genetic defects result in AAT being unable to get out of the liver -> this results in liver damage

79.6 kDa Transports iron in plasma as ferric ions (Fe3+) Each transferrin molecule binds 2 Fe3+ This protects the body against the toxic effects of free iron Transferrin normally 30% saturated with Fe3+ -> increase or decrease indicates iron overload or deficiency Transferrin is decrease in inflammatory states due to excessive degradation of transferrin Fe3+ complexes

Iron overload

Iron deficiency

In inflammatory states

Due to excessive degradation of transferrin Fe3+ complexes

Transports iron in plasma, and its rate of synthesis in the liver can be altered in accordance with the body’s iron requirements and iron reserves, and by oestrogen (e.g., during pregnancy). Measurement of TF indicates latent and manifest iron deficiency and iron overload. It is also a negative acute phase protein with low concentrations present in inflammatory diseases as well as in protein-losing enteropathy, malnutrition, nephrotic syndrome and in disorders of haemoglobin synthesis

Rate of synthesis in the liver can be altered in accordance with the body’s iron requirements and iron reserves, and by oestrogen (e.g., during pregnancy).

Negative phase protein -> hence low levels in inflammation

Inflammatory diseases Protein-losing enteropathy Malnutrition Nephrotic Syndrome Disorders of haemoglobin synthesis

151 kDa A multifunctional protein synthesised in the liver Very high copper content but is not a copper transporter in circulation It is essential in the regulation of redox potential and utilisation of iron Has an antioxidative action, which prevents the oxidation of lipids in the cell membrane through its ferroxidase activity

It prevents the oxidation of lipids in the cell membrane through its ferroxidase activity

Most cases of Wilson’s disease Low in Menkes’ kinky hair syndrome

Decreased ability to incorporate copper into apoceruloplasmin As a result free copper levels in serum and in tissue especially liver, pancreas and brain are greatly increased

The defect is secondary to poor absorption and utilization of dietary copper, from protein loss in the nephrotic syndrome, protein-losing enteropathy and malabsorption, and from decreased synthesis in advanced liver disease

Regulates oxidation-reduction, transport and utilisation of iron

Active liver disease or tissue damage

Group of proteins which rise significantly (<25%) during acute inflammation Presumed to play a role in complex defensive process of inflammation There are nine acute phase reactants