Component C3 of the complement

General Information

Complement component C3 represents almost 70% of the proteins of the complement system. It participates in the activation of the complement system in both classical and alternative ways.

Complement component C3 is synthesized in the liver, macrophages, skin and lymphoid tissues. Along with other components of the complement system, C3 is used in immunological reactions.

Hereditary deficiency of complement component C3 is a rare anomaly, transmitted in an autosomal recessive manner, clinically occurring with recurrent infectious processes - both gram-negative and gram-positive bacteria.

When is the survey conducted?

• Suspicion of congenital or acquired deficiency of complement component C3 (immune processes that occur with increased consumption of proteins of the complement system: systemic lupus erythematosus, active chronic hepatitis, membranoproliferative and poststreptococcal glomerulonephritis, other chronic infections)
• Assessment of disease activity in systemic lupus erythematosus

Preparation of the patient:  The study is conducted on an empty stomach

Material for examination: Venous blood

Interpretation of results

Some medications also cause changes in the concentration of the C3 component of complement:

• Decreases: cimetidine, cyclophosphamide, oral contraceptives
• Increases: danazol, hydralazine, methyldopa, phenytoin.