, a new study finds. However, overall rates of reported disease are very low, and there’s no confirmation of a connection.
“People with MS and comorbid psoriasis – or those at a known high-risk for developing psoriasis – may benefit from a careful consideration of disease-modifying therapy (DMT), specifically when B cell-depleting therapies are considered,” study coauthor and Medical College of Wisconsin neurologist Ahmed Obeidat, MD, PhD, said in an interview. The findings were presented at the 2021 Annual Meeting of the Consortium of Multiple Sclerosis Centers (CMSC).
Dr. Obeidat and colleagues launched the study after noticing cases of psoriasis that developed months to years after patients started taking ocrelizumab, a B cell-depleting therapy. “We referred to the published literature and only found very scant reports of MS, psoriasis, and B cell-depleting therapy use,” he said. “Thus we decided to pursue an investigation of a large [Food and Drug Administration] database to examine for possible out-of-proportion reports for psoriasis in patients with MS who were receiving B cell-depleting therapy.”
The researchers tracked case reports of psoriasis in patients with MS on DMTs from 2009 to 2020 via the FDA Adverse Event Reporting System. They found 517 psoriasis reports among 45,547 reports of skin/cutaneous conditions. The reports were linked to interferon beta 1a (136 reports, 26% of total), natalizumab (107, 21%), fingolimod (75, 15%), dimethyl fumarate (64, 12%), ocrelizumab (49, 10%), teriflunomide (28, 5%), interferon beta 1b (22, 4%), glatiramer acetate (12, 2%), rituximab (10, 2%), and alemtuzumab (9, 2%).
The total numbers of cases is low, but this may reflect underreporting due to the assumption that “autoimmunity begets autoimmunity” and therefore cases of psoriasis in MS are not alarming, medical student Mokshal H. Porwal, the study lead author, said in an interview.
The average age of patients – 48-51 – was similar for all of the drugs except alemtuzumab (mean age 41), which had a very small number of cases. The percentage of cases in females was 71%-77% for most of the drugs, with a few exceptions: rituximab (60%), ocrelizumab (63%), and alemtuzumab (33%).
Other drugs – cladribine, siponimod, and ozanimod – had 1, 1, and 0 reports, respectively, and were not included in the age and gender analyses.
The researchers also found that psoriasis made up about 65% of all skin/cutaneous adverse reports for rituximab, the highest number among DMTs. By comparison, that number was about 30% for ocrelizumab and under 1% for dimethyl fumarate and alemtuzumab.
Links between psoriasis and MS are murky, Dr. Obeidat said. “Some studies consider the presence of psoriasis as a possible indicator of increased future risk for MS, but there’s no clear association between the two conditions,” he said.
As for DMTs, “a few case reports of psoriasis in association with interferon-beta and rare case reports in association with ocrelizumab therapy have been published. However, the possible association between certain DMTs and psoriasis remains unclear,” he said.
Going forward, “we advise that patients with psoriasis on B cell-depleting agents are monitored more closely,” Dr. Obeidat said. “If the psoriasis worsens, it may be beneficial to think about potential alternative therapies.”
No study funding is reported. Dr. Obeidat reports various disclosures; the other authors report no disclosures.