OBJECTIVES. To present three cases of adult-onset still’s disease (AOSD) who was initially refractory to corticosteroid therapy but were successfully treated with an interleukin-6 (IL-6) inhibitor, tocilizumab (TCZ).

BACKGROUND. Adult-onset Still’s Disease (AOSD) is a systemic inflammatory disorder of unknown etiology characterized by quotidian fever, evanescent rash, and arthritis/arthralgia. The pro-inflammatory cytokine interleukin (IL) – 6 has been implicated in its pathogenesis.

CASE PRESENTATION. Three patients (40F, 37F, and 27M) presented with quotidian fever, evanescent maculopapular rash, arthritis, anemia, leukocytosis, elevated acute phase reactants and hyperferritinemia of 3 to 4 months duration. All were diagnosed AOSD by Yamaguchi criteria after extensive work up to exclude other diagnostic possibilities. Each patient received high dose corticosteroids and 2 patients also received methotrexate (MTX) with initial improvement of symptoms. However, there was recurrence and exacerbation of clinical symptoms on tapering of steroid doses. Each patient was then given TCZ at 8 mg/kg. Within a month of the initial dose of TCZ, there was dramatic clinical and laboratory improvement, enabling rapid steroid dose tapering.

CONCLUSION. This series substantiates the role of IL-6 in the pathomechanisms of AOSD and demonstrates use of TCZ in the management of AOSD refractory to corticosteroids.

Keywords: Adult-onset Still’s disease (AOSD), refractory, Interleukin-6 (IL 6), Tocilizumab (TCZ)

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