AMSTERDAM – Patients with rheumatoid arthritis who underwent elective knee or hip arthroplasty had a doubled rate of hospitalization for infection when they averaged more than 10 mg/day oral prednisone during the 3 months before surgery, based on a review of about 11,000 U.S. insurance claims.

“Limiting glucocorticoid exposure before surgery should be a focus of perioperative management,” Michael D. George, MD, said at the European Congress of Rheumatology. “Glucocorticoid use, especially greater than 10 mg/day, is associated with a greater risk of infection and hospital readmission,” said Dr. George, a rheumatologist at the University of Pennsylvania in Philadelphia.

The analysis also showed that treatment with any biologic drug – including abatacept (Orencia), rituximab (Rituxan), tocilizumab (Actemra), and any of several tumor necrosis factor (TNF) inhibitors – had a similar impact on both postsurgical infections requiring hospitalization and 30-day hospital readmissions.

The findings suggest “it’s more important to reduce glucocorticoids than biological drugs,” commented John D. Isaacs, MD, professor of clinical rheumatology at Newcastle University in Newcastle upon Tyne, England. “This is a really important question that has been very difficult to answer.”

Dr. George and his associates used data from patients with rheumatoid arthritis during 2006-2015 who underwent knee or hip arthroplasty and were in databases from Medicare, or MarketScan, which includes commercial insurers. This identified 11,021 RA patients on any of several biologic drugs before their surgery: 16% on abatacept, 4% on rituximab, 4% on tocilizumab, and the remaining 76% on a TNF inhibitor, either adalimumab (Humira), etanercept (Enbrel), or infliximab (Remicade). About 43% of all patients were on a glucocorticoid during the 3 months before surgery. Biologic use was defined as a minimum of one dose within 8 weeks of surgery, and at least three total dosages during the prior year, except for rituximab, which was at least one dose given 16 weeks before surgery and at least two doses during the prior year.

The rate of hospitalized infections ranged from 6.6% to 8.5% depending on the biologic drug used, and 30-day readmissions ranged from 4.8% to 6.8%. A third outcome the analysis assessed was prosthetic joint infection during 1-year follow-up, which was again similar across most of the biologics, except for patients on tocilizumab, who had prosthetic joint infections roughly threefold more often than the other patients. Although this was a statistically significant difference, Dr. George discounted the finding given the very small number of tocilizumab-treated patients who had these infections and said that any conclusion about tocilizumab’s effect on this outcome had to await data from more patients.

The glucocorticoid analysis divided patients into four subgroups: those not on a glucocorticoid, those on an average daily dosage of 5 mg/day prednisone or equivalent or less, patients on 6-10 mg/day prednisone, and those on more than 10 mg/day. In a propensity-weighted analysis, these three escalating levels of glucocorticoid use showed a dose-response relationship to the rates of both hospitalized infections and 30-day readmissions. At the highest level of glucocorticoid use, hospitalized infections occurred twice as often as in patients not on a glucocorticoid, and 30-day readmissions were more than 50% higher than in those not on an oral steroid, both statistically significant differences. For the outcome of 1-year prosthetic joint infections, the analysis again showed a dose-related link among glucocorticoid users, topping out with a greater than 50% increased rate among those on the highest glucocorticoid dosages when compared with nonusers, but this difference was not statistically significant.

The study was partially funded by Bristol-Myers Squibb, the company that markets abatacept. Dr. George has received research funding from Bristol-Myers Squibb, and some of his coauthors on the study are employees of the company.

mzoler@mdedge.com

SOURCE: George MD et al. EULAR 2018. Abstract OP0228.

Glucocorticoids linked with surgical infections in RA patients