Fig. 4
From: The isotype repertoire of antibodies against novel UH-RA peptides in rheumatoid arthritis
Improved diagnosis of seronegative patients with rheumatoid arthritis (RA) when testing for anti-UH-RA.1 immunoglobulin (Ig) M was added to the original IgG-specific testing for autoantibodies against UH-RA.1 and UH-RA.21. a Testing for novel autoantibodies against UH-RA.1 and UH-RA.21 (combined as UH-RA.PANEL2) was previously shown to reduce the serological gap by 9 %, based on IgG-specific testing. b Inclusion of antibodies against UH-RA.1 of the IgM isotype increases the sensitivity of the novel autoantibodies in patients with seronegative RA, improving the reduction of the serological gap from 9 % to 13 %. ACPA anticitrullinated protein antibodies, RF rheumatoid factor