[Idiopathic interstitial pneumonia that responded to intermittent intravenous administration of high-dose cyclophosphamide].

A 78-year-old man was admitted to the hospital with exertional dyspnea and fever. Chronic idiopathic interstitial pneumonia (IIP) had been diagnosed a year before. Follow-up chest X-ray examination showed diffuse reticular shadows and progressive shrinkage of both lower lobes. Chest CT scan revealed honeycomb appearance of both lower lung fields. Moderate hypoxemia was found by arterial blood gas analysis. The patient responded to an orally administered corticosteroid. Because tapering of the medicine caused exacerbation of the hypoxemia, methylprednisolone pulse therapy was given with poor response. Then high-dose (750 mg) of cyclophosphamide (CPM) were given intravenously 6 times, every 3 or 4 weeks. After the second administration of CPM, decreases in hypoxemia and in blood LDH levels were observed. This treatment allowed as to taper the dose of oral corticosteroid from 60 mg/day to 15 mg/day. This case suggests that intravenous administration of high-dose CPM may be effective against IIP.