Intended use

The EDIA? anti-CCP test kit is an enzyme-linked immunosorbent assay (ELISA) for detection and semi-quantitation of IgG antibodies to Cyclic Citrullinated Peptides (CCP) in human serum or plasma. The assay is used to detect antibodies in a single specimen. The results of the assay are to be used as an aid to the diagnosis of Rheumatoid Arthritis (RA), in conjunction with other laboratory and clinical findings. The analysis should be performed by trained laboratory professionals. For in vitro diagnostic use.

Background

Rheumatoid Arthritis (RA) is one of the most common systemic autoimmune diseases.

The aetiology of the disease, which affects up to 1-2% of the world population, is unknown. The diagnosis of RA depends primarily on clinical manifestation of the disease. The only serological test routinely used is the determination of the presence of rheumatoid factors (RF) in the serum. RF are antibodies directed to the constant region of immunoglobulins of the IgG class. However, these antibodies are also present in relatively high percentages in other autoimmune diseases, infections and in up to 15% of healthy individuals.

Antibodies of a more specific nature have also been found in sera of RA patients. Anti-perinuclear factor (APF) antibodies are reported to be present in around 50% of RA patients with a specificity of over 70%. A number of cyclic synthetic peptides not related to filaggrin or other known proteins have been described which are specifically recognized by autoantibodies in sera from RA patients. These peptides were subsequently used in an ELISA for the detection of RA-specific autoantibodies. Clinical evaluation studies showed that the ELISA was positive in a significant number of well-defined RA patient sera with a high specificity against disease controls. A diagnostic and prognostic value for the measurement of the anti Cyclic Citrullinated Peptides (anti-CCP) antibodies was found in relation to joint involvement and radiological damage in early RA. The EDIA? anti-CCP assay offered by Euro-Diagnostica is based on highly purified synthetic peptides containing citrulline residues and is an additional tool in the diagnosis of RA. This anti-CCP kit contains improved synthetic peptides selected on the basis of performance in the detection of RA autoantibodies. The sensitivity of the test has been shown to be 76%. The specificity was 98% with diseased non-RA patients and 99% with apparently healthy individuals.

Technical information

The EDIA? anti-CCP antibody kit is based on an ELISA method. The test utilizes microtitre wells coated with citrullinated synthetic peptides (antigen). Diluted patient serum or plasma is applied to the wells and incubated. If specific antibodies are present, they will bind to the antigen in the wells. Unbound material is washed away and any bound antibody is detected by adding alkaline phosphatase labelled antibodies to human IgG, followed by a second washing step and incubation with a chromogenic substrate.

The presence of reacting antibodies will result in the development of colour, which is proportional to the quantity of bound antibody, and this is determined photometrically.