To the Editor. —The CASE REPORT by Roifman et al 1 regarding the use of immune serum globulin in the treatment of chronic polymyositis requires clarification. The authors describe a patient with "normal immunity," but they did not provide any information regarding what this means. We need to know what immunologic studies were performed (eg, measurement of immunoglobulin, complement, and rheumatoid factor levels and antibody titers) and the results of those studies if we are going to understand what the authors mean by normal immunity. This knowledge is important because the intravenous infusion of γ-globulin has been associated with the death of a patient with abnormal immunoglobulins. 2 If there is the slightest doubt regarding the patient's immunologic status, the prudent course is to begin with a test dose of immune globulin before proceeding to a therapeutic regimen. Finally, since spontaneous remission is possible in polymyositis, it is difficult to