Biologic use in psoriasis reduces risk for psoriatic arthrit
The use of biological disease-modifying antirheumatic drugs in patients with psoriasis reduces the risk for psoriatic arthritis, according to data published in the Annals of the Rheumatic Diseases.

To compare the incidence of PsA among patients with psoriasis based on whether they received biological DMARDs for their skin symptoms, Soriano and colleagues conducted a retrospective cohort study of data from a prepaid HMO. According to the researchers, the HMO provides services to approximately 140,000 adults residing primarily in urban areas, with an electronic medial record of all medical appointments, diagnoses and procedures.

Researchers included all adults with cutaneous psoriasis, but without musculoskeletal symptoms or PsA at study entry, who received either biologics — TNF- inhibitors and interleukinIL-12/23 and IL-17 inhibitors — topical therapy, conventional DMARDs or no treatment for skin disease. Non-biologic, conventional DMARDs included methotrexate and cyclosporine. In all, the analysis included 1,719 patients, representing 14,721 patient-years. Among these patients, 1,387 received topical therapy, 229 were treated with conventional DMARDs and 103 received biologics.

Cases of incident PsA were attributed to a specific therapy if they developed during the administration of that treatment. The researchers used a Cox proportional hazards model to examine the adjusted risk for PsA based on treatment group.

According to the researchers, 14% of the overall study population developed PsA during follow-up, including 231 patients who received topical therapy, six who received conventional DMARDs and two in the biologic group. The global incidence of PsA was 1.6 per patient-year. The risk for PsA was “significantly lower” among those who received biological DMARDs, compared with topical therapy, but not compared with conventional DMARDs, the researchers wrote.

The adjusted analysis suggested that male sex, nail involvement and higher BMI were associated with an increased risk for PsA, while the use of biologics was linked to a lower risk.

“We showed that treatment of the skin in psoriasis was associated with a reduced risk of developing psoriatic arthritis,” researchers said. “Although this should be proved with a randomized clinical trial, it is something to take into account when deciding treatment with a patient with psoriasis.”

“Biologics might not only be able to improve the skin, but also prevent the development of psoriatic arthritis, although we would not, at least yet, prescribe biologics for psoriatic arthritis prevention,” he added. “The clinical significance is that it is worth doing a clinical trial to evaluate if biologics given for the skin could prevent development of psoriatic arthritis. In patients with psoriasis and at high-risk of developing psoriatic arthritis — severe skin involvement, subclinical enthesitis and obesity — this knowledge might help to push for earlier biologic treatment.”