In patients with seropositive rheumatoid arthritis, seroconversion within the first year of treatment is not associated with long-term sustained drug-free remission (SDFR), according to results of a randomized, treat-to-target study of patients with early RA.
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“The clinical significance of seroconversion in RA and especially its relationship with long-term SDFR, an approximation of disease ‘cure’ of RA, is a topic of major interest,” wrote Emma C. de Moel, of the department of rheumatology at Leiden (Netherlands) University Medical Center, and her coauthors.
“Previous studies found no association of seroconversion with remission or radiographic damage,” the investigators wrote in Annals of the Rheumatic Diseases. “We here investigated the association between seroconversion and ... SDFR and found no association.”
The study involved 381 patients with early RA (less than 2 years) from the IMPROVED trial who were treated with methotrexate and high-dose prednisone. At baseline and 12 months, 14 RA-associated autoantibodies were measured by ELISA, including anti-CCP2 and rheumatoid factor. Patients were monitored for long-term SDFR, defined as remission lasting longer than 1 year, beginning at any time, and persisting until the maximum follow-up of 5 years.
An association between seroconversion and SDFR was not found. At 12 months, 6 of 170 patients (3.5%) had seroconverted all autoantibodies to negative, and 2 of these 6 patients achieved SDFR, compared with 19 of 164 seropositive patients (11.6%) who achieved SDFR without seroconversion (P = .11). Additionally, neither the proportion of autoantibodies converted to negative nor relative decreases in autoantibody levels were associated with SDFR.
“It appears that seroconversion (as measured by current standards) does not identify a group of patients in ... true immunological remission, and is not superior to signals of low inflammatory load (e.g. by DAS 6) for predicting successful drug tapering,” the investigators concluded. “Future studies are needed to identify whether other immunological parameters such as the numbers or phenotype of circulating autoreactive B or T cells might be a better reflection of disease persistence and markers for immunological remission.”
The study was funded by ZonMw (the Netherlands Organization for Health Research and Development)-consortium Molecular Diagnostics in RA (MODIRA).
SOURCE: de Moel EC et al. Ann Rheum Dis. 2018 Jul 25. doi: 10.1136/annrheumdis-2018-213823.