The measurement of the C3 component of complement in serum is used to screen patients with very low total complement concentration and evaluate disease activity in systemic lupus erythematosus.
More information
Complement is a term that describes 20 specific serum proteins belonging to the globulins that, in combination with antigen-antibody complexes, cause lysis of erythrocytes sensitized to the antibody contained in the complex. The nine main components of the Supplement are named C1 through C9.
Complement component C3 is one of the nine essential components of the complement protein complex and participates in both the classic and alternative pathways of complement activation that function during humoral immune responses. The activation of complement functions occurs during phagocytic activity; microorganisms are destroyed, and an inflammatory response is also observed. This test assesses the integrity of the sequential processes of complement activation, which is increased during acute phase responses and inflammatory processes. Successive determinations of C3 levels may reflect the progress of these processes based on the return of values to normal levels.
Possible Interpretations of Pathological Values
- Increase: Acute phase responses such as infection, dermatomyositis, inflammation, keratoconus, metastatic malignancy, necrotic disorders, rheumatic fever, rheumatoid arthritis
- Decrease: Anemia (malignant due to folic acid deficiency), anorexia nervosa, arthralgias, celiac disease, cirrhosis, congenital C3 deficiency, disseminated intravascular coagulation, glomerulonephritis (acute), hepatitis (chronic active), nephritis, immune complex disease, infection (recurrent pyogenic), liver disease (chronic), malnutrition, multiple myeloma, multiple sclerosis, renal transplant rejection, septicemia (from Gram-negative microbes), serum sickness, subacute bacterial endocarditis, systemic lupus erythematosus (active, with renal involvement), uremia
Important Note
Laboratory test results are the most important parameter for diagnosing and monitoring all pathological conditions. Between 70% and 80% of diagnostic decisions are based on laboratory tests. Correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased."
Laboratory test results should not be interpreted solely based on the numerical result of a single analysis. They should be interpreted in relation to each individual case, family history, clinical findings, and the results of other laboratory tests and information. Your physician should explain the importance of your test results.
At Diagnostiki Athinon, we answer any questions you may have about the test you perform in our laboratory and contact your doctor to ensure you receive the best possible medical care.
