Clinical Challenges: Managing Adult-Onset Still's Disease

— Immunomodulatory agents are shaping up for rare inflammatory disease

MedicalToday

While adult-onset Still's Disease (AOSD) primarily occurs in young or middle-age individuals, it can also present in the elderly.

A rare inflammatory disease of unknown etiology, AOSD manifests with a spiking fever, arthritis, and cutaneous rash. Some patients experience a monocyclic pattern, and some experience a chronic disease course. In either case, while disease impact can be significant, AOSD lacks a specifically designed and validated patient-reported outcome tool that can be used to manage treatment.

Still, insights into the management of AOSD can be gleaned from systemic-onset juvenile idiopathic arthritis (sJIA). Results from a recent study suggest that AOSD and sJIA are the expressed at different age ranges. They parallel each other in clinical course, molecular evidence, cytokine profile, and treatment response.

While AOSD is treatable, it is not curable, noted Nilanjana Bose, MD, MBA, a rheumatologist at Lonestar Rheumatology in Houston. As with other rheumatic diseases, AOSD has its most pronounced effect on physical activity and can cause arthritis involving multiple joints. Moreover, patients with arthritis may be at higher risk of functional disability and may require more careful management.

Unfortunately, according to Christopher R. Morris, MD, a rheumatologist in private practice at Arthritis Associates in Kingsport, Tennessee, patients with AOSD can experience complications in the heart, lungs, and spleen, as well as hepatitis. Some patients with AOSD may also experience macrophage activation syndrome, to devastating ends. For example, a described an elderly patient with severe AOSD complicated by disseminated intravascular coagulation syndrome and macrophage activation syndrome who progressed rapidly to shock, with inflammatory markers reaching 86,700 white blood cells/µL and 252,796 ng/mL ferritin.

"I think it is a reasonably treatable disease if we get on the medications promptly," said Morris, describing a patient with severe AOSD who responded to immunosuppressants and corticosteroids. After 6 months with normalized laboratory results and no symptoms, Morris tapered first the steroids and then the immunosuppression. The patient has been in remission for 7 years, he said.

Even with remission, however, the effects of AOSD can linger. Compared with age- and gender-matched healthy controls in a multicenter cross-sectional , AOSD patients had quality-of-life impairment across a range of measures, including many domains on the 36-Item Short-Form Health Survey (SF-36), as well as impairments on the Health Assessment Questionnaire, Functional Assessment of Chronic Illness Therapy-Fatigue subscale, European Quality of Life Questionnaire, 100 mm-visual analogue scale (VAS) state of health, VAS pain, and VAS fatigue. These impairments occurred despite low or absent clinical expressiveness and were observed in patients with a monocyclic pattern as well as those with a chronic disease course.

Only one drug, the long-acting interleukin (IL)-1β inhibitor canakinumab (Ilaris) has FDA approval for use in the treatment of AOSD. Since not all patients respond to canakinumab, rheumatologists have explored the use of other biologics, one of which is the humanized monoclonal antibody against the IL-6 receptor, tocilizumab (Actemra).

While there are no guideline recommendations for the use of tocilizumab for the treatment of AOSD, an increasing number of reports have suggested that it is effective at treating AOSD. For example, an analysis of real-world data found that tocilizumab can as well as normalize serum inflammatory markers in patients with AOSD. Tocilizumab had the added advantage of being associated with an excellent drug retention rate that could minimize the risk of long-term exposure to corticosteroids.

Likewise, a recent report found that while methotrexate and prednisolone were not enough for disease , combined use of methotrexate, tocilizumab, and prednisolone was effective to achieve remission. Interestingly, the patient's blood IL-6 levels increased after the initiation of tocilizumab, a phenomenon that the authors hypothesized was related to its mechanism in blocking of IL-6 receptors, such that the excess IL-6 could no longer bind to receptors and instead accumulated in the blood.

Rheumatologists continue to search for immunomodulatory agents that can help patients with AOSD who do not respond to canakinumab or tocilizumab. In a review of 29 cases from case reports and case series describing the in these difficult-to-treat patients, complete response was seen in 42% of patients and a partial response was seen in another 42% of patients. Adverse events were rare and included pneumonia and menometrorrhagia.

Disclosures

Morris and Bose reported no relevant conflicts of interest.