JIA patients experienced higher rate of opportunistic infections

WASHINGTON —Children with juvenile idiopathic arthritis had a greater rate of acquiring rare opportunistic infections than children without the disease, according to research presented at the American College of Rheumatology Annual Meeting.

“There’s very little known about opportunistic infections in JIA,” Timothy Beukelman, MD, MSCE, associate professor of pediatrics at the University of Alabama at Birmingham, told Healio.com. “We know in adults with rheumatoid arthritis who take biologic agents, they have an increased rate of some opportunistic infections like tuberculosis, endemic mycoses, Legionella and Listeria, so we were curious about those types of infections and how frequently they occur in children.”

Timothy Beukelman

Researchers evaluated a cohort of 8,503 children with juvenile idiopathic arthritis (JIA; 14,370 person-years of follow-up) using diagnosis codes and medications data from Medicaid claims from 2000 through 2005. A cohort of 360,262 children diagnosed with attention deficit hyperactivity disorder (490,939 person-years of follow-up) was used for comparison. A 3-month baseline period before study follow-up was used to assess prevalent opportunistic infections and current medication exposure.Methotrexate (MTX), tumor necrosis factor (TNF) inhibitors and systemic glucorticocoids (GC) exposure was based on 30 days from last filled prescription. Age, sex and race distribution were used to standardize the comparable cohort with the JIA group. Incidence rates (IR) and incidence rate ratios (IRR) were calculated.

In the JIA cohort, 1,392 patients used TNF inhibitors and 3,491 used MTX.Considered as a single outcome,the JIA cohort had 42 opportunistic infections (IR=300; 95% CI, 216-406 [per 100,000]; IRR=2.4; 95% CI, 1.7-3.3 vs. comparable cohort).

In the children with JIA, there was one infection each of Nocardia, non-tuberculosis mycobacteria, Toxoplasma and Pneumocystis (IR=7 per 100,000). Other infections in the JIA cohort included: Coccidioides (n=3; IR=21 per 100,000; IRR=101 vs. non-JIA patients); Salmonella (n=5; IR=35 per 100,000; IRR=3.8); and herpes zoster (n=32; IR=225 per 100,000; IRR=2.1) (95% CI for all). Herpes zoster was not strongly associated with GC current use (IRR=1.8 vs. no current GC use), MTX (IRR=1.4 vs. no current MTX or TNF inhibitor use) or TNF inhibitors (IRR=2.2 vs. current MTX use without current TNF inhibitor use) among the children with JIA (95% CI for all). Aspergillus, Blastomyces, Histoplasma, Cryptococcus, Legionella, Listeria, JC virus or tuberculosis were not identified in JIA patients.

“Unsurprisingly there were not very many infections because we were looking for rare, opportunistic infections,” Beukelman said. “What we did find was a two- to fourfold increase in the incidence of opportunistic infections among children with JIA compared to children without JIA. … Any evaluation of medications to treat JIA for opportunistic infections needs to carefully consider the fact that JIA itself may predispose to opportunistic infections.”

Disclosure: Dr. Beukelman and other researchers reported numerous financial disclosures.

For more information:

Beukelman T. P763: Incidence of Selected Opportunistic Infections Among Children with Juvenile Idiopathic Arthritis. Presented at: American College of Rheumatology 2012 Annual Meeting; Nov. 10-14, Washington.