3665 – Anti-CCP

Highlights

• Use of synthetic, cyclic, citrullinated peptides
• Ready-to-use (exception: wash buffer), color and barcoded reagents
• Quality assured handling in routine laboratories
• Short incubation times (60 min / 30 min / 15 min) at room temperature
• Quantitative determination of IgG antibodies
• Calibrated using the international reference preparation IS 2723 of the CDC
• Excellent diagnostic sensitivity and specificity
• High precision within the measurement range
• CE certified
• Automatable

Intended Purpose

The Anti-CCP is a quantitative immunoassay for the determination of IgG antibodies against cyclic citrullinated peptides (CCP) in human serum. The Anti-CCP is intended as an aid in the diagnosis of rheumatoid arthritis (RA) in conjunction with other clinical and laboratory findings. The immunoassay is designed for manual professional in vitro diagnostic use.

Diagnotic Relevance

Rheumatoid arthritis is the most common inflammatory joint disease. About 0.5 to 1.0 % of the population is affected worldwide. Painful joints in the fingers or toes are characteristic of rheumatoid arthritis, but knees, shoulders, hips or other joints may be also affected. The pain is often most pronounced in the morning. As the disease progresses, the number of affected joints usually increases. The diagnosis of rheumatoid arthritis is based on the clinical symptoms, imaging methods and laboratory analysis. In routine diagnostic services, the serological determination of rheumatoid factors is one of the classic and most frequently performed analyzes initially. Rheumatoid factors are mostly IgM antibodies directed against IgG antibodies and are detectable in the majority of patients with rheumatoid arthritis. They are therefore considered to be a sensitive marker for laboratory confirmation of rheumatoid arthritis. However, rheumatoid factors also occur in other autoimmune diseases. Their evidence is therefore not considered proof of the disease. In addition, patients with rheumatoid arthritis without detectable rheumatoid factors have also been described.

Recently, the detection of antibodies against cyclic citrullinated proteins (CCP) has become increasingly important for the diagnosis of rheumatoid arthritis. The starting point was the observation that antibodies against filaggrin were frequently observed in patients with rheumatoid arthritis. More detailed investigations into the characterization of the epitopes established that these antibodies are directed in particular against the citrullinated forms of filaggrin. The citrullination of proteins occurs enzymatically by deimination of arginine to citrulline. This modification is associated with a change in the charge state of the protein and thus in its structure and antigenic properties.

Instead of the isolated filaggrin, cyclic citrullinated peptides (CCP) with relevant epitopes are increasingly being used as the basis for immunoassays for the determination of specific IgG antibodies. Through the cyclization of synthetic peptides, the citrulline epitopes are placed in an exposed position, resulting in a significant improvement in the diagnostic properties – especially the specificity – of the test systems. Today, the determination of IgG antibodies against CCP serves as a specific and early marker for rheumatoid arthritis. In addition, the presence of CCP antibodies has a high prognostic value for an erosive course of the disease.