Clinical experience with antilymphocyte serum

Many different antilymphocytic antisera have been used clinically, and the properties of any particular type of ALS are not necessarily identical to those of any other type. Nevertheless, it is possible to draw certain general conclusions about the effects of ALS in human subjects. ALS administration has often been shown to reduce the number of circulating E-rosette-positive lymphocytes, although the precise mechanisms by which this reduction occurs are not known. Using a combined technique of E-rosette formation and immunofluorescence, heterologous immunoglobulin has been demonstrated on T and non-T lymphocytes from patients receiving non-selective ALS. Fifteen years' experience has failed to provide convincing support for the view that ALS (including immunoglobulin prepared from the whole antiserum) prolongs human renal allograft survival. It is not yet known whether ALS is a useful immunosuppressive agent in cardiac transplantation. One observation of possible clinical interest is that bone marrow regeneration has occurred in a number of patients with aplastic anemia who have been treated with ALS. No satisfactory method has been developed for monitoring the dose of ALS in human subjects. Appropriate studies may determine whether monoclonal antilymphocytic antibodies are clinically useful, for example in prolonging the survival of transplanted organs, in preventing or treating graft-versus-host disease, or in treating lymphoma, leukemia, or aplastic anemia.