Tolicizumab: a new option for refractory idiopathic recurrent pericarditis: a case report.

Background: Recurrent pericarditis is the most common and troublesome complication of pericarditis and can be particularly challenging when it becomes refractory to conventional therapies, often resulting in a prolonged disease course. Interleukin-1 (IL-1) inhibitors have transformed the management of such cases; however, not all patients tolerate or respond adequately to these agents. Case summary: We present a 37-year-old man suffering from idiopathic recurrent pericarditis since the age of 25. After failure of standard therapies, he became corticosteroid-dependent, so treatment with anakinra (an IL-1 inhibitor) was attempted twice, but discontinued early due to allergic reactions. As the recurrences were always characterised by an overt inflammatory phenotype (characterised by fever, increased C-reactive protein, and pericardial effusion), we administered off-label tocilizumab (an IL-6 receptor antagonist) as a last treatment option. The patient gained rapid benefit and was able to discontinue steroid therapy during the 6-month follow-up, achieving complete recovery from pericarditis. Discussion: Interleukin-6 is a key cytokine in the pathogenesis of pericarditis, acting synergistically with IL-1 to drive inflammation and acute phase responses. In our patient, blockade of IL-6 with tocilizumab led to the complete resolution of inflammation, suggesting a possible new therapeutic option for refractory cases. This result highlights the potential of IL-6 inhibition as an alternative strategy, when IL-1 blockers are contraindicated or ineffective.