Liposomal-encapsulated superoxide dismutase was clinically applied to patient showing an increase in neutrophil active oxygen generation, and those with diseases such as severe rheumatoid arthritis (RA), Crohn's disease and progressive systemic sclerosis (PSS) in which presence of a plasmatic clastogenic factor has been demonstrated. Liposomal SOD injection (2.5 mg twice a week) resulted in marked remission in 12 out of 16 patients with active Behcet's disease. The drug was impressively effective on patients with intestinal Behcet. Remission rates in the other diseases was 7 out of 8 mucocutaneous lymphnode syndrome (MCLS, Kawasaki disease) 3 out of 5 dermatitis herpetiformis, IgA linear bullous dermatosis or severe cement dermatitis, 4 out of 9 active and severe RA, 3 out of 3 PSS, 4 out of 4 Crohn's disease, 3 out of 4 colitis ulcerosa, and 2 out of 2 unresponsive (hemolytic) anemia. To be emphasized was that three severe active RA patients and two terminal-stage PSS patients with dyspnea due to lung fibrosis showed dramatic improvement after administration of liposomal SOD. In addition, in 13 out of 15 malignant neo plastic patients including cancer, malignant lymphoma and leucemia who were receiving radiotherapy (total dose, more than 4000 rads) and chemotherapy including anthracycline analogs (total over 450 mg/m2) and bleomycin, the drug also prevented the appearance of myocardiac injury and fibrosis, sometimes seen as a consequence of chemotherapy. Liposomal SOD, which shows no toxicity, has various advantages compared to free SOD preparations, and is highly and broadly applicable to various clinical disorders.