New Findings on Rheumatic Drug Therapies among Patients with Ankylosing Spondylitis, Gout, SLE

A study shows no increased risk of chronic kidney disease from allopurinol use in newly diagnosed gout patients who start out with normal or near-normal kidney function.
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WASHINGTON, D.C.—Taking high-dose non-steroidal anti-inflammatory drugs (NSAIDs) with a TNF inhibitor as an ankylosing spondylitis (AS) patient is linked with a 61% decrease in the chances your disease will progress, suggesting there may be a synergy when the drugs are used together, according to a longitudinal observational study from researchers at the University of California, San Francisco (UCSF).

The findings were highlighted at the 2016 ACR/ARHP Annual Meeting in a Discovery abstract session that also included findings on allopurinol and chronic kidney disease in gout patients and the effects of poverty on SLE damage.¹

NSAIDs & AS

TNF inhibitors and NSAIDs have shown mixed results in preventing AS progression. Researchers set out to gauge the benefit seen in those taking TNF inhibitors and NSAIDs together. They looked at 538 patients in the Prospective Study of Outcomes in Ankylosing Spondylitis, with patients followed for at least two years and a median of four. X-rays were collected every two years, with a determination of progression by mSASSS, the modified Stoke Ankylosing Spondylitis Spinal Score.

Among patients not exposed to NSAIDs or exposed only to low doses, there was no benefit in taking TNF inhibitors alone.

But there was a significant benefit observed for those taking a high-dose NSAID along with an anti-TNF over those taking a high-dose NSAID but not an anti-TNF. The odds of progression were decreased by 61% for those taking both an anti-TNF and high-dose NSAIDs (P=0.04). Researchers found an interaction between the NSAID and TNF inhibitor use after adjusting propensity scores to address confounders introduced by the drugs’ indications.

“Another way to look at the estimated probability of progression by treatment group is to stratify it by TNF inhibitor use,” said Lianne Gensler, MD, director of the Ankylosing Spondylitis Clinic at UCSF. “When you look at the patients with high-dose NSAIDs, you can see that their estimated probability of progression is significantly lower when using TNF inhibitors—almost a 50% reduction in fact.”

‘Therapy for gout with allopurinol does not appear to have a harmful effect on renal function,’ Dr. Vargas-Santos said.

She said that this suggests a “synergistic effect” not seen when the therapies are used separately.

“I want to be clear that this is a longitudinal observational study and it does not prove causality,” Dr. Gensler said. “There are still unmeasured confounders that may possibly be playing a role.”