[Two cases of pneumonia caused by Sho-saiko-to]

We describe two cases of pneumonia caused by Sho-saiko-to. Patient 1 was a 61-year-old man with type-C liver cirrhosis. About 50 days after starting to take Sho-saiko-to, he complained of fever and diarrhea, and progressive dyspnea developed. Analysis of arterial blood obtained in the emergency room showed severe hypoxemia:, PaO2 26 Torr. A chest radiograph and a CT scan showed bilateral diffuse fine granular and ground-glass opacities predominantly in the upper lung fields. Despite repeated pulse therapy with methylprednisolone and aggressive medical treatment including mechanical ventilation, the patient remained in respiratory distress, which was later complicated by gastrointestinal bleeding. He died on the 45th hospital day. The bronchoalveolar lavage contained abnormally high fluid percents of lymphocytes and neutrophils. Postmortem examination of the lungs revealed alveolar septal thickening, marked hyperplasia of type 2 pneumocytes, and no hyaline membrane formation. Patient 2 was a 68-year-old man. Eighty days after he began taking Sho-saiko-to, he presented with a 4-day history of shortness of breath accompanied by fewer and progressive coughing. On arrival of the hospital, arterial blood gas analysis showed mild hypoxemia (PaO2, 61 Torr) and a chest radiograph revealed bilateral irregular infiltrates in the lower lung fields. Analysis of bronchoalveolar lavage fluid showed an abnormally high percent of lymphocytes (especially CD8 + lymphocytes), and examination of a biopsy specimen revealed exudates of fibrin and neutrophils in the alveolar spaces and patechy intraluminal organization. The response to prednisolone was good and he was discharged on the 40th hospital day in stable condition. Drug lymphocyte stimulation tests of peripheral blood to Sho-saiko-to were positive in both patients. Patients 2 was though to have a typical case of Sho-saiko-to-induced pneumonia, patient 1 was thought to have fulminating variant of this disease.