“It works two ways: A microRNA can also promote inflammation, or rather its absence may be allowing inflammation,” Dr. McInnes said.
Juvenile Idiopathic Arthritis
Albert Martini, MD, professor of Pediatrics at the University of Genova in Italy, spent much of his talk reviewing the latest on juvenile idiopathic arthritis (JIA). There’s a need to identify early predictors of outcome more effectively, he said, pointing to a study of 440 Nordic cases of JIA. In cases with the last follow-up visit at least seven years after onset of disease, 48.7% of the patients were still not in remission, and 22.9% had sustained damage as a result of the disease.7
A study comparing groups of methotrexate users, with withdrawal of the drug at either six or 12 months after remission, found no difference in relapse rate, but higher concentrations of myeloid-related protein 8/14 was found to be linked with a higher risk of relapse after methotrexate was stopped.8
In a subsequent study, it was found that serum levels of myeloid-related protein 8/14 greater than 740 ng/ml predicted disease flares accurately.9
Dr. Martini noted one study that illuminated the high rate of intolerance to methotrexate among JIA patients. A 297-patient cohort study found that 44.5% of those on oral methotrexate, and 67.5% of those on parenteral doses, experienced methotrexate intolerance.10
“Classic conditioning plays an important role in methotrexate intolerance,” Dr. Martini said.
TNF blockers have produced very good results. A study using the Dutch Register found that, out of 262 biological treatment–naive patients, 32% had an excellent response to etanercept, while 36% had an intermediate response, and 32% had a poor response.11 Excellent responses were linked with low baseline disability scores, few disease-modifying antirheumatic drugs used before starting etanercept, and young age at JIA onset. Poor responses were linked with system JIA and female gender.
There are some concerns about the safety of TNF blockers in children, though how serious they are remains unclear.
A U.S. Food and Drug Administration report said that 48 children with JIA had developed malignancies after taking TNF blockers, but the cases were confounded by the potential risk of malignancy associated with underlying illnesses and by the use of concomitant immunosuppression.12
A subsequent study, using U.S. Medicaid data from 2000 to 2005, found that children with JIA appear to have an increased risk of malignancy, but that treatment, including TNF blockers, was not significantly associated with that malignancy risk.13
