Secondary Organising Pneumonia Caused by Denosumab

INTRODUCTION: Organising pneumonia belongs to diffuse interstitial lung diseases; we distinguish the cryptogenic organising pneumonia, which is idiopathic, from the secondary organising pneumonia caused by drugs or a defined cause. Denosumab is a human monoclonal antibody, rarely inducing adverse pulmonary effects. CASE DESCRIPTION: A 57-year-old female patient was admitted to our chest clinic for acute respiratory distress. She was treated with denosumab for severe osteoporosis. The patient described a dry cough and dyspnoea over the previous four months, increased after the last injection of denosumab. A high-resolution computed tomography scan showed bilateral basal parenchymal condensations. The aetiological investigation did not reveal any infectious or immunological origin. The favourable computed tomography imaging and clinical evolution after corticosteroid therapy led to the diagnosis of drug-induced organising pneumonia. CONCLUSION: Denosumab could induce organising pneumonia. Therefore, clinicians should be aware of this pulmonary toxicity. LEARNING POINTS: To the best of our knowledge denosumab, a human monoclonal antibody, may rarely induce organising pneumonia. Despite this, we advocate that clinicians be aware that exposure to this drug can cause pulmonary toxicity. The taking of denosumab by our patient does not in any way prove the causal link.