Rheumatoid with rheumatoid factor in RA is IgM

Rheumatoid factors are apart of a family of
autoantibodies directed against the Fc portion of Immunoglobulin G (IgG). The
main type of type of immunoglobulin associated with rheumatoid factor in RA is
IgM (Ryo Yamada, 2005).Rheumatoid
factor is produced by B cells in lymphoid
follicles that develop in inflamed synovium. Rheumatoid factors are
produced as an immune response against infections (Song, 2009). Seropositive result reveals the presence of antibodies
that which cause symptoms of rheumatoid arthritis. The normal range
for RF is <15 IU/ml (Richey, 2015).Using RF levels to diagnose RA is inadequate because of the limited specificity, since RF is found in patients with other autoimmune diseases such as Sjögren's syndrome and is found in healthy individuals (Yeong Wook Song, 2010). RF ELISA has a high specificity of 91% (Gerard A. Schellekens, 2000). The enzymatic conversion of arginine to citrulline by the enzyme peptidyl arginine deiminase (PAD) is citrullination. This process occurs during inflammation, apoptosis and keratinization (Mariusz Puszczewicz, 2010).Citrullinated proteins are produced in the area of inflammation, thus it is excepted to be in the synovium (Ryo Yamada, 2005). Vimentin is among the citrullinated proteins associated with RA, citrullinated vimentin is a critical protein for triggering the production of anti-cyclic citrullinated proteins (ACPAs) (Houen, 2016). ELISA technique has been used to detect autoantibodies against citrullinated vimentin and has shown better sensitivity than other citrullinated proteins (Mariusz Puszczewicz, 2010). Anti- CCP has a specificity of 98%, positive predictive values of both RF and anti-ccp is 91% and negative predictive value of 78% (Gerard A. Schellekens, 2000). ACPAs are useful biomarkers for diagnosis during preliminary stages of RA. The normal range of anti-CCP autoantibody(ACPA) <20 U/ml (Richey, 2015). Anti-CCP autoantibody is linked to increased risk of developing RA in healthy individuals, it is also detectable in healthy individuals. Increased levels among individuals with RA is associated with severe symptoms (Mariusz Puszczewicz, 2010). C-reactive protein (CRP) is produced by the liver levels increase as a response to tissue injury and infection  (Bishnu Prasad Devkota, 2014). Measuring the levels of C-reactive protein can help determine progression of RA.  Normal range of CRP is 5-10 mg/L and increases with age, infections and in pregnant women (Aryal, 2015). Decreasing levels of CRP indicate improvement to treatment or reduced inflammation.   Rheumatoid factor test is measured using several methods, an agglutination technique, nephelometry test and ELISA technique. Enzyme-Linked Immunosorbent Assay or ELISA technique is used to detect IgM antibodies to IgG antigen (Mogens Vejtorp, 1979). IgM conjugate is added to micro assay well and binds to rheumatoid factors forming an immune complex, which can be visualized with the addition of Tetramethylbenzidine (TMB) substrate, creating a blue colour as a reaction product. The more intense the colour is the higher the amount of IgM rheumatoid factors in the serum. To stop the reaction sulphuric acid which creates a yellow endpoint colour, absorbance is read at 450 nm (Seymour P. Halbert, 1980).   C-Reactive Protein (CRP) should be measured to check whether treatment is helping the patient (Playfair, 1995). Other tests that can be carried out are the Erythrocyte Sedimentation Rate(ESR) test and the Antinuclear Antibody, however these are non-specific tests and can be carried out for a range of diseases. Liver and kidney function tests should be used to monitor the effects of medication, they can lead to build in the kidneys which requires change in dosage of medication. Patient's symptoms should be assessed in case they indicate other secondary diseases such as osteoarthritis, vasculitis and disease of the lungs and cervical spine (NHS, 2016 ). For long term complications such as carpal tunnel syndrome from compression of the nerves by damaged joints, imminent or actual tendon rupture, stress fracture patients should be offered surgical options before the damage is irreversible (NICE, 2015).