12. Changes in plasma protein levels. Disturbances in aminoacid metabolism.

CHANGES IN THE PLASMA PROTEINS. DISTURBANCES IN AMINO ACID METABOLISM

• ⭐ Dysproteinemia - change in serum level proteins (except fibrinogen)
• Basic screening examination is the electrophoresis of serum protein
• Normal amount of plasma proteins in blood = 58-80 g/L

Types of plasma proteins

1. Albumins

• Responsible for oncotic pressure → keeps H2O in vessels
• Transport of insoluble molecules
• 65% of all serum proteins
• Hypoproteinemia → decreased concentration of proteins → increased water leaves vessel into interstitium → edema

2. 𝛂1-globulin

• HDL, tyrosine binding protein, acute phase protein

3. 𝛂2-globulin

• 𝛂2-antiplasmin, ceruloplasmin, VLDL, haptoglobin

4. β-globulin

• Transferrin, LDL

5. Ɣ-globulin

• Factor 8

Dysproteinemias

1. Hyperproteinemia

• Increased globulins in the blood due to infection or inflammation
• Paraproteinemia (monoclonal gammopathy) - the presence of increased amounts of paraprotein in the blood
• Caused by leukemia, lymphoma
• Paraprotein (or M-protein) - monoclonal immunoglobulin fragments or intact immunoglobulins produced usually by a malignant cone of plasma cells or B cells

2. Hypoproteinemia

• Decreased amount of serum proteins
• Abnormal loss of proteins from the digestive tract or inability of the GI system to absorb proteins
• Malnutrition → insufficient dietary intake
• Kidney disorders → nephrotic syndrome → loss of proteins in urine (proteinuria)
• Liver dysfunction → cirrhosis, hepatitis
• Increased breakdown of proteins → cancer, higher catabolism
• Disturbances in globulin protein cause:
• Myeloma
• Bone marrow cancer
• Uncontrolled production of defective proteins (paraproteins)
• Overactive immune system
• Acute infection + inflammation