(DMARDs), in a single center retrospective analysis in Argentina that followed patients for almost 2 decades.
About 30%-40% of patients with psoriasis go on to develop psoriatic arthritis (PsA), usually on average about 10 years after the onset of psoriasis. One potential mechanism of PsA onset is through enthesitis, which has been described at subclinical levels in psoriasis.
“It could be speculated that treatment with biologics in patients with psoriasis could prevent the development of psoriatic arthritis, perhaps by inhibiting the subclinical development of enthesitis,” Luciano Lo Giudice, MD, a rheumatology fellow at Hospital Italiano de Buenos Aires, said during his presentation at the virtual annual meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis.
Although these results do not prove that treatment of the underlying disease delays progression to PsA, it is suggestive, and highlights an emerging field of research, according to, professor of medicine at University Hospital Schleswig-Holstein, Germany, who led a live discussion following a prerecorded presentation of the results. “We’re going in this direction – how can we prevent psoriatic arthritis, how can we delay it. We are just starting to think about this,” Dr. Thaçi said in an interview.
The researchers examined medical records of 1,626 patients with psoriasis treated at their center between 2000 and 2019, with a total of 15,152 years of follow-up. Of these patients, 1,293 were treated with topical medication, 229 with conventional DMARDs (methotrexate in 77%, cyclosporine in 13%, and both in 10%), and 104 with biologics, including etanercept (34%), secukinumab (20%), adalimumab (20%), ustekinumab (12%), ixekizumab (9%), and infliximab (5%).
They found that 11% in the topical treatment group developed PsA, as did 3.5% in the conventional DMARD group, 1.9% in the biologics group, and 9.1% overall. Treatment with biologics was associated with a significantly lower odds of developing PsA compared with treatment with conventional DMARDs (3 versus 17.2 per 1,000 patient-years; incidence rate ratio [IRR], 0.17; P = .0177). There was a trend toward reduced odds of developing PsA among those on biologic therapy compared with those on topicals (3 versus 9.8 per 1,000 patient-years; IRR, 0.3; P = .0588).
The researchers confirmed all medical encounters using electronic medical records and the study had a long follow-up time, but was limited by the single center and its retrospective nature. It also could not associate reduced risk with specific biologics.
The findings probably reflect the presence of subclinical PsA that many clinicians don’t see, according to Dr. Thaçi. While a dermatology practice might find PsA in 2% or 3%, or at most, 10% of patients with psoriasis, “in our department it’s about 50 to 60 percent of patients who have psoriatic arthritis, because we diagnose it early,” he said.
He found the results of the study encouraging. “It looks like some of the biologics, for example IL [interleukin]-17 or even IL-23 [blockers] may have an influence on occurrence or delay the occurrence of psoriatic arthritis.”
Dr. Thaçi noted that early treatment of skin lesions can increase the probability of longer remissions, especially with IL-23 blockers. Still, that’s no guarantee the same would hold true for PsA risk. “Skin is skin and joints are joints,” Dr. Thaçi said.
Dr. Thaçi and Dr. Lo Giudice had no relevant financial disclosures.