Rheumatoid factors, anti-filaggrin antibodies and low in vitro interleukin-2 and interferon-gamma production are useful immunological markers for early diagnosis of community cases of rheumatoid arthritis. A preliminary study.
OBJECTIVE
To determine whether measurements of different autoantibodies (Ab) and cytokines are useful to distinguish very early rheumatoid arthritis (RA) from other inflammatory rheumatisms.


METHODS
From a population-based recruitment, 32 patients with very early polyarthritis (median duration: 4 months) were studied. Evaluations at entry (M0), and at 6 (M6) and 12 months (M12). Ab tested: rheumatoid factors (RF) by agglutination methods and ELISA, antiperinuclear factor (APF), antikeratin Ab (AKA), anti-Sa and antinuclear Ab. Cytokine production (TNFalpha, IL2, IFNgamma, IL1beta, IL10) in whole blood cell culture (WBCC) was determined at M0. At M12, patients were classified as having RA (N = 15) or other rheumatic diseases.


RESULTS
At M0, AKA/APF and anti-Sa Ab frequencies were low, 13% and 7%, respectively. While most Ab detected at M0 persisted, others appeared during follow-up, particularly APF, which rose from 13 to 40% at M12. At M6, IgM-RF was detected in two RA patients exclusively by ELISA. AKA/APF were found to be highly specific markers for RA (100% specificity). At some time during follow-up, two RF-negative RA patients were AKA-positive. In two patients, AKA and APF were present at M0 before they satisfied ACR criteria. IL2 and IFNgamma production was significantly lower (P < 0.05) for RA patients.


CONCLUSIONS
AKA/APF and anti-Sa Ab were detected in community cases of very early RA. AKA/APF and RF detected by ELISA might contribute to an earlier diagnosis of RA. Low production of IFNgamma and IL2 in WBCC constituted a distinct immunopathological feature in very early RA patients.
Vittecoq
O
O
Service de rhumatologie, CHU de Rouen, France.
Jouen-Beades
F
F
Krzanowska
K
K
Bichon-Tauvel
I
I
Ménard
J F
JF
Daragon
A
A
Tron
F
F
Le Loët
X
X
D000974:Antibodies, Antinuclear / Q000097:blood; D000918:Antibody Specificity; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000276:immunology; D015415:Biomarkers; D002478:Cells, Cultured; D003937:Diagnosis, Differential; D000091344:Filaggrin Proteins; D005500:Follow-Up Studies; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis*; D016753:Interleukin-10 / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis*; D007381:Intermediate Filament Proteins / Q000276:immunology*; D007633:Keratins / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D008137:Longitudinal Studies; D010865:Pilot Projects; D011446:Prospective Studies; D012217:Rheumatoid Factor / Q000097:blood*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D000974:Antibodies, Antinuclear; D015415:Biomarkers; C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D007376:Interleukin-2; D007381:Intermediate Filament Proteins; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D007633:Keratins; D007371:Interferon-gamma; D012217:Rheumatoid Factor