Investigators found that patients who were not treated with biologic medications were at a significantly increased risk of developing psoriatic arthritis.
A recent case study from India found that patients with psoriasis who received biologic medications had statistically and clinically significant lower risk of developing psoriatic arthritis.
The results suggested considering treatment with biologic medications in patients with significant risk factors for prostatic arthritis at earlier stages of treatment.
Investigators led by Yael Shalev Rosenthal, MPH, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv noted that in recent years psoriasis had affected around 2.5% of the total population.
Previous studies found high levels of osteoclast precursors and other inflammatory properties in patients with psoriatic arthritis. Though multiple biologics and DMARDs have been recommended as therapies for this disease, they are often not used as first line therapy in moderate to severe psoriasis due to their high cost.
Rosenthal and colleagues also mentioned that up to 30% of patients suffering from psoriasis would eventually develop psoriatic arthritis in a meantime of 10 years.
This prompted them to investigate the effect of biological treatments for psoriasis on the incidence of psoriatic arthritis.
The team extracted data of patients who had received biological treatment (adalimumab, etanercept, infliximab, ustekinumab, secukinumab, ixekizumab, guselkumab) for psoriasis from Maccabe Healthcare Services, the second largest health maintenance organization in Israel.
None of the patients were diagnosed with psoriatic arthritis before or at the time of biologic treatment initiation.
Altogether, the study included 687 patients that had received biological treatment and 2,278 patients that had not.
The study groups were compared using Chi-square test (or Fisher's exact test) for categorical variables and T-test (or Wilcoxon two-sample test) for continuous variables.
Time to event analysis was performed using Kaplan-Meier curve.
The follow-up time for the study was 10 years, and propensity score matching was implemented as the groups in the study were different in most characteristics (age at diagnosis, gender, time until treatment initiation, etc.)
Rosenthal and colleagues found a significant increased risk for psoriatic arthritis in 10 years following non-biological treatments as compared to biological treatments.
The Kaplan-Meier curve for the matched groups reflected a statistically significant increased risk for PsA among the control group compared to the biological treatment group (Log-rank test P- value = 0.025).
The study also found that women were at a higher risk of developing psoriatic arthritis, though most studies did not find any significant differences between the sexes.
Rosenthal and investigators noted that the association between disease severity and the onset of arthritis is controversial, but that the association had been previously reported.
The recent study suggested that biologic therapies might delay the risk of developing psoriatic arthritis. Though biologic agents had been used for the treatment of psoriasis for decades, their high prices likely contributed to the allocation of the drugs necessary for treatment.
Investigators recommended further research on the relationship between biologic medications and psoriatic arthritis but considered their own study to be substantial.
“The results of the present study show a statistically and clinically significant lower risk for developing PsA among patients receiving biologic medications for psoriasis treatment,” the team wrote. “These results may support initiation of treatment with biologic medications at an earlier stage in patients that present with significant risk factors for PsA.”
The study, “Psoriatic arthritis incidence among patients receiving biologic medications for psoriasis: A nested case control study,” was published online in Arthritis and Rheumatology.