Diagnostic Value of Anti-Ra33 Antibody, Antikeratin Antibody, Antiperinuclear Factor and Antinuclear Antibody in Early Rheumatoid Arthritis: Comparison With Rheumatoid Factor

Abstract

The goal of this prospective longitudinal study was to determine the serological profile of early rheumatoid arthritis (RA), and to test whether antikeratin antibody (AKA), antiperinuclear factor (APF), anti-RA33 antibody and antinuclear antibodies (ANA) had an additional diagnostic value when prescribed after rheumatoid factor (RF)-detecting methods. Sixty-nine patients with early polyarthritis suggestive of RA, seen between 1991 and 1993, were included. Five autoantibodies (i.e. RF, AKA, APF, RA33, ANA) were looked for at regular intervals. After 24 months follow-up, patients were classified as having RA (n = 49), unclassified polyarthritis (UP; n = 15) or other rheumatic diseases. Among patients with early RA, the sensitivity of these markers was 40.8% for RF, 36.7% for AKA, 28.6% for APF and 28.6% for anti-RA33. Among RF-negative RA patients, 51.7% were positive for AKA, APF, anti-RA33 antibodies and/or ANA. Positivity of the three recent markers usually persisted throughout follow-up, whereas RF was lost by 58% of patients with early, RF-positive, treated RA. Using multivariate analysis, only latex, RF test and AKA or APF had an independent and statistically significant diagnostic value for early RA. Our data suggest that RF and AKA (or APF) should be concomitantly determined for diagnosis in patients with suspected early RA.

Characterization of Autoreactive T Cells to the Autoantigens Heterogeneous Nuclear Ribonucleoprotein A2 (RA33) and Filaggrin in Patients with Rheumatoid Arthritis

“…Taken together, the frequent presence of A2/RA33-reactive Th1-like cells in the blood of RA patients, their presence in the synovial compartment in conjunction with the observed aberrant expression of A2/RA33 in the inflamed synovium, and the occurrence of Aab to A2/RA33 early in the course of RA (42)(43)(44) suggest that this protein may be an important autoantigen in RA. Moreover, A2/RA33 Aab are among the earliest detectable Aab in MRL/lpr lupus mice (80), which, in addition to anti-DNA and other systemic lupus erythematosus-specific Aab, also produce RF and may develop erosive arthritis (81), and have recently been found to occur also in TNF-␣ transgenic mice (Ref.…”

“…Anti-A2/RA33 and AFA are already present in early stages of the disease (40,(42)(43)(44) and are predominantly of the IgG isotype, which is indicative of T cell-driven processes. To gain more insight into such processes and their potential pathogenetic role, we investigated the spontaneous T cell responses to A2/RA33 and Fil in patients with RA and in control subjects including patients with osteoarthritis (OA) and psoriatic arthritis (PSA) and healthy persons.…”

Consenso da Sociedade Brasileira de Reumatologia 2011 para o diagnóstico e avaliação inicial da artrite reumatoide

“…The objective is to develop methods with sensitivity and specifi city for earlier RA diagnosis, more reliable activity markers, and prognostic indicators. Some of the autoantibodies used in RA investigation are as follows: mutated citrullinated vimentin antibodies (anti-MCV); [49][50][51] antikeratin antibodies (AKA); anti-perinuclear factor (APF); 52 antifi laggrin autoantibodies; 53 anti-human citrullinated fi brinogen antibodies (ACF); 54 anti-heterogeneous nuclear ribonucleoprotein A2 autoantibody (anti-RA33); 52 anti-interleukin 1 antibody (anti-IL1); 55 anti-alpha-enolase antibody; 56 and anti-advanced glycation end-products antibody. 57 These antibodies have, in general, good specifi city, but sensitivity lower than that of anti-CCP for diagnosing RA.…”

Anti-perinuclear Factor as Diagnostic Marker in Rheumatoid Arthritis

“…This AB is independent to the age, sex [11] and the duration of disease [6] and is appeared soon and even may appear before the onset of clinically rheumatoid arthritis [13][14][15] and in relation to the severity of disease. Sensitivity of APF is the same degree of RF and its specificity is more than RF specificity in the diagnosis of RA [9,10] There was no significant relationship between the onset of APF and severity of disease but there was significant relationship between the APF titer and severity of disease (p<0.05).…”