Joseph F. Merola, MD, MMSc, on Overcoming the Challenges in Psoriatic Arthritis Diagnosis and Treatment

Interdisciplinary collaboration optimizes outcomes for patients with psoriatic arthritis (PsA), and the growing array of therapeutic options makes possible the treatment of PsA’s many different domains, according to Joseph Merola, MD, MMSc, who spoke at the Interdisciplinary Autoimmune Summit (IAS) meeting on April 22.

Dr Merola is the director of the Center for Skin and Related Musculoskeletal Diseases at Brigham and Women’s Hospital in Boston, and an associate professor with Harvard Medical School.

“Psoriatic arthritis is characterized by diverse clinical features, including peripheral arthritis, axial disease, enthesitis, dactylitis, and skin and nail symptoms,” he explained. “Skin disease precedes joint involvement by as much as 10 years in 85% of cases.” About 30% of patients with psoriasis (PsO) develop PsA, he noted.

Patients with scalp, nail and inverse PsO are at higher risk of developing PsA, as are those with first-degree relatives with PsA, severe PsO, obesity, subclinical musculoskeletal inflammation and certain serum biomarkers, Dr Merola said.

Typically, PsA is diagnosed when 3 or more of the following points occur in the presence of inflammatory articular disease:

• Current psoriasis, or personal or family history of psoriasis
• Psoriatic skin or scalp disease confirmed by a dermatologist
• Psoriatic nail dystrophy on current physical exam, including onycholysis, pitting, and hyperkeratosis
• Negative for rheumatoid factor (RF)
• Current dactylitis or history of dactylitis documented by a rheumatologist
• Radiographic evidence of juxta-articular new bone formation

In 40% to 50% of diagnosed cases of PsA, patients will present with dactylitis and/or enthesitis, and approximately 20% present with axial spondylitis. “Patients may exhibit any combination of manifestations, and these may vary over time and overlap,” Dr Merola stated.

While PsA remains a clinical diagnosis, he said, certain markers can be useful in refining the diagnosis. Approximately 40% of patients with PsA will show elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). These elevations correlate with disease severity, erosion, and progression, Dr Merola said.

Treatment options for PsA today include traditional disease-modifying antirheumatic drugs (DMARDs) such as methotrexate and sulfasalazine; tumor necrosis factor alpha inhibitors, including adalimumab and infliximab; interleukin (IL)-17A inhibitors including secukinumab and ixekizumab; IL-12/23 inhibitors such as ustekinumab; IL-23 inhibitors such as guselkumab and risankizumab; the Janus-kinase inhibitors (JAK) tofacitinib and upadacitinib; and several others, such as abatacept, apremilast, corticosteroids, and nonsteroidal anti-inflammatory drugs. He also discussed a number of new therapies in development, such as IL-17A/F inhibitors bimekizumab and sonelokimab, IL-17R inhibitor brodalumab, IL-23 inhibitor tildrakizumab, and the TYK2 inhibitor deucravacitinib.

He reviewed a number of trials and studies, including the head-to-head comparisons of ixekizumab and adalimumab in the SPIRIT trial, reviewing efficacy of these therapeutics as measured by American College of Rheumatology (ACR) 20, 50, and 70 scores and the Psorisis Area and Severity Index (PASI) scores, revealing significant improvements in these measures with several of the current available agents.

The choice of which of these therapies to use requires careful consideration of comorbidities and coprevalent disease as well as domains of disease within PsA, which range from uveitis and sleep apnea to metabolic syndrome, diabetes, and gout, Dr Merola explained. He presented an algorithm from the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) detailing recommendations for therapeutic agents based on these factors.

Shared decision-making with patients around treatment goals; patient preferences for topical, oral, injectable, or infusion administration; and access to therapies according to health insurance policies, are all important issues to be considered when choosing treatment for PsA, he said.

Clinical trials and real-world practice are informing the treat-to-target approach for PsA, Dr Merola noted. He reviewed the use of composite measures to assess disease activity in PsA, such as the Disease Activity in Psoriatic Arthritis (DAPSA) score, low disease activity (LDA), very low disease activity (VLDA), along with traditional measures such as tender joint count and swollen joint count. By using these measures along with levels of CRP and patient reports on pain and functioning, clinicians can determine if progress is being made toward the chosen target, whether LDA or remission, and adapt therapies according to the level of disease activity, he explained.

Clinicians must also keep in mind that patients place very high priority on their skin condition. “Patients want to be clear,” he said. “Skin matters.”

Dr Merola stressed that “tight control of PsA is associated with significantly greater improvements in signs and symptoms of disease.” Achieving that tight control in turn requires a team of clinicians to address the various domains of disease and coprevalent conditions, including dermatologists, gastroenterologists, primary care physicians, endocrinologists, cardiologists as needed, and mental health professionals to provide support and treatment for depression and anxiety.

“Interdisciplinary collaboration optimizes outcomes for patients with psoriatic disease,” Dr Merola stated.

Reference:
Merola, JF. Overcoming the Challenges in Psoriatic Arthritis Diagnosis and Treatment. Presented at: Interdisciplinary Autoimmune Summit. April 22, 2022. Virtual.