The measurement of the C3 component of the serum complement is used in the control of patients with a very low total complement concentration and in the evaluation of disease activity in systemic lupus erythematosus.
The complement is a term that describes 20 specific serum proteins belonging to the globulins which in combination with the antigen-antibody complexes induce lysate-sensitized red blood cells with the antibody contained in the complex. The nine key components of the complement are named C1 to C9.
Component C3 is one of the nine essential constituents of all complement proteins and is involved in both the classical and alternative pathways of complement activation that function in humoral immune responses. Activation of complement functions occurs during phagocytic activity, destruction of microorganisms, and inflammatory response. This test evaluates the integrity of successive complement activation processes and increases during acute phase responses and in inflammatory processes. Sequential 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, arthralgia, celiac disease, cirrhosis, C3 congenital insufficiency, diffuse intravascular coagulation, glomerulonephritis (acute), hepatitis (chronic), hepatitis (chronic) pyogenic), liver disease (chronic), malnutrition, multiple myeloma, multiple sclerosis, renal transplant rejection, septicemia (from Gram negative microbes), seronegia, subacute bacterial endocarditis (systemic lupus erythematosus), uremia
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-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 from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings and the results of other laboratory tests and information. Your personal 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 we contact your doctor to get the best possible medical care.