Rheumatoid factor (RF)

Rheumatoid factor is an autoantibody against human denatured immunoglobulin that appears in the serum of patients with rheumatoid arthritis and other diseases. Rheumatoid factor (RF) can be divided into IgM, IgA, IgG, IgD, IgE type 5 (Note: described in clinical internal medicine as type IV, no IgD type; but described in laboratory diagnostics as type 5 It is a kind of autoantibodies against the epitopes on IgGFC fragments in rheumatoid arthritis serum. Rheumatoid factor-positive patients are more often associated with extra-articular manifestations, such as subcutaneous nodules and vasculitis. The IgM type RF positive rate was 60%-78%. Basic Information Specialist classification: growth and development check classification: immunological examination Applicable gender: whether men and women apply fasting: fasting Tips: Light diet and control sorghum diet such as animal viscera spinach. Normal value Enzyme-linked immunosorbent assay (ELISA) 1 ~ 4 ku / L or negative. The nephelometric method is <30 IU/mL. Latex agglutination is negative (or titer <1:20). (Note the specific reference value depends on each laboratory.) Clinical significance Increase: Found in rheumatoid arthritis, systemic lupus erythematosus and other connective tissue diseases (such as Sjogren's syndrome, scleroderma, polymyositis); chronic hepatitis patients and the elderly are also increased. Positive results may be diseases: chills, arthritis, occupational scleroderma, pediatric double lip syndrome, joint pain, phlegm syndrome, inflammatory bowel disease associated scleritis, nodular polyarteritis in children, gout Arthritis, attention to matters Inappropriate people: generally no special population. Taboo before the test: light diet and control sorghum diet such as animal viscera spinach. Requirements for examination: Sometimes the lumps will be a little stiff and painful! So pay attention to the doctor when checking. Inspection process 1. Inactivated at 56 ° C for 30 minutes (inactivate C1q to prevent false positive agglutination). The serum to be tested was diluted 1:20 with 0.1 mol/LPH 8.2 glycine buffered saline (0.05 ml of serum was added to 1 ml of physiological saline). 2. Take 1 drop of this diluted serum (about 0.05ml), add it to the square of the black square glass slide, add 1 drop of latex RF reagent, shake the reaction plate for 3 minutes, mix it fully, and shoot it in direct light. Under observation. Positive and negative controls were set up for each test. Not suitable for the crowd There are no special taboos. Adverse reactions and risks There are no related complications and hazards.

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