Background and Importance Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with wide-ranging pleuropulmonary manifestations. Acute lupus pneumonitis (ALP) is one of its uncommon complications. Systemic steroids associated with immunosuppressive therapy (cyclophosphamide, rituximab, hydroxychloroquine and intravenous immunoglobulin) are the mainstream treatment of ALP.

Aim and Objectives To describe the case of a patient with ALP treated with intravenous cyclophosphamide as well as to evaluate the effectiveness and safety of this treatment.

Material and Methods We report the case of a 67-year-old woman with a medical history of breast cancer and polymyalgia rheumatica treated with corticosteroids. She was referred to the emergency department due to intermittent fever, fatigue, generalised myalgia and arthralgia, mild dyspnoea and dry cough with sputum for the past 3 weeks. Multiple and bilateral lung opacities were present on chest X-ray so she was diagnosed with community-acquired pneumonia. The woman presented slight improvement despite empirical antibiotic and antifungal coverage. Subsequently, laboratory findings showed leukopenia and positive anti-double-stranded-DNA antibodies so the final diagnosis was ALP secondary to SLE. Systemic steroid treatment was initiated with a high-dose of methylprednisolone and hydroxychloroquine. Due to the severity of the pulmonary involvement, it was requested to start treatment with intravenous cyclophosphamide.

Results The patient received a total of three doses (600 mg/m2) of intravenous cyclophosphamide. MESNA, ondansetron and oral hydration were prescribed as supportive treatment. Despite the decrease in inflammatory analytical parameters, the woman presented modest reduction of lung injury and symptoms. She reported high-grade myalgia and vomiting after first infusion, which was successfully treated with paracetamol and metoclopramide. Sequential therapy with oral cyclophosphamide was considered, but because it is not funded for ALP and its adverse effect profile, treatment with methotrexate was started. Currently, the patient continues treatment with methotrexate, hydroxychloroquine and oral steroids. Computed tomography, performed 3 months after ending intravenous cyclophosphamide, showed stability of the disease.

Conclusion and Relevance Treatment with intravenous cyclophosphamide has not shown promising results in our patient although its safety profile is good. Because the therapeutic alternatives in patients with ALP are limited, it would have been interesting to verify that sequential therapy with oral cyclophosphamide improves the signs and symptoms of the disease, and long-term adverse effects could also be analysed.

Conflict of Interest No conflict of interest.