What Can JIA Patients Expect 18 Years In?

Follow-up in a Scandinavian cohort of juvenile idiopathic arthritis (JIA) patients that began in 1997-2000 revealed a number of surprises, a new study indicated.

More than two-thirds of patients were using no drug therapies at year 18, even though only about half were in remission and that latter figure hadn’t changed in the previous 10 years, reported Mia Glerup, MD, PhD, of Aarhus University Hospital in Denmark, and colleagues.

Also, JIA subtype classifications under International League of Associations for Rheumatology (ILAR) criteria had changed for about one-third of patients between initial recruitment and year 18, the researchers wrote in Arthritis Care and Research. The most common reason for reclassification was “updated information” on related rheumatologic conditions affecting a first-degree relative.

One takeaway from these findings, according to an accompanying editorial, is that it appears many JIA patients in young adulthood are willing to live with some disease activity if it means they can forgo medications. (Across the full cohort, 70% at year 18 were taking no medications, even as 48% did not meet criteria for remission.)

“Receiving treatment has a significant psychosocial impact and risks of side effects that decrease quality of life,” noted the editorialists, Jaime Guzman, MD, MSc, and Ross Petty, MD, PhD, both of the University of British Columbia in Vancouver. They conceded that there are other possible explanations for this finding: perhaps remission criteria are “too stringent,” or patients didn’t transition properly to adult care and need to be reconnected.

But the downsides of medical therapy are the “most likely” reason, as patients “may consider minimal disease activity [to be] an acceptable state, preferable to the inconveniences and risks of treatment.”

Study Details

The cohort originally comprised 510 JIA patients (median age 6.6 at enrollment, 67% girls) who were evaluated at year 8 and again at year 18. A total of 422 were available for the final exam, and 373 of these patients had data from year 8 as well.

At baseline, about 53% were classified under ILAR criteria as having “persistent” oligoarthritis; the next most common was polyarticular JIA with negative rheumatoid factor (21%), followed by undifferentiated arthritis (10%).

At year 8, the “persistent” category had been subdivided with a new category called “extended” oligoarthritis alongside “persistent,” with 18% of participants qualifying for this new subtype, and 31% still classified as having “persistent” disease.

This and other alterations in the ILAR classifications prompted Guzman and Petty to list a second takeaway from the study: that changing diagnostic methods will complicate patient management, let alone long-term, longitudinal studies.

“It is important that we classify patients in a uniform way early in the disease to accurately advise patients and families on what to expect,” they pointed out. Of course, some reclassification is inevitable, insofar as the criteria depend on family members’ conditions that are not fixed in stone.

With that in mind, Glerup and colleagues found that, over time, rates of psoriatic arthritis rose from 2% at baseline to nearly 7% at year 18, and 5% of patients changed during follow-up to undifferentiated arthritis from other diagnoses.

As would be expected, medication regimens changed considerably as well. Half of the cohort were receiving nonsteroidal anti-inflammatory drugs at enrollment, which declined to 19% at year 18. Systemic corticosteroid use was almost nonexistent at the last follow-up. About 18% were using biologic therapies, half of whom had them as monotherapy and the rest along with conventional immunomodulators.

Guzman and Petty saw two additional lessons in the study findings. One was that remission rates hardly budged from year 8 (when it was 51%) to year 18. The editorialists’ interpretation was that “long-term prognosis has improved but is not optimal.” Yet, the fact that most patients were not using any medications at year 18 is remarkable, they wrote, noting that “[i]n oncology that would be called a cure.”

Finally, Guzman and Petty commented that patients’ prospects for some JIA subtypes had improved more than others. Specifically, outcomes in systemic arthritis are now the best among all the classifications. Oligoarthritis, meanwhile, has traditionally been considered the “most benign,” yet the 18-year findings demonstrate that “up to 30% of patients [were] not in remission 30 years after onset.”