Ro-positive interstitial lung disease treated with cyclophosphamide.

Interstitial lung disease (ILD) comprises a spectrum of conditions involving inflammation and/or fibrosis of the alveolar wall causing limitation in gaseous exchange. Treatment varies depending on the underlying ILD. We describe the case of a woman presenting with a productive cough who was diagnosed with community-acquired pneumonia. While on the ward she developed type-1 respiratory failure requiring continuous positive airway pressure and intensive care unit admission. Failing to respond to targeted antimicrobials she was investigated by chest high-resolution CT and autoantibody screen to identify non-infective causes of her respiratory signs and symptoms. These demonstrated diffuse ground-glass change with peripheral honeycombing in keeping with fibrosis and alveolitis alongside high titres of anti-SS-A/Ro antibodies. She was managed with reducing course of steroids and immunosuppression with cyclophosphamide. The rational of long-term immunosuppression was based on a presumed diagnosis of lung-dominant connective tissue disease, a disease concept proposed in contemporary medical literature.