The in vitro effect of the thymic factor thymopoietin on a subpopulation of lymphocytes from severely malnourished children.

Several investigators have shown that the proportion of T cell lymphocytes was greatly reduced while that of the B cell lymphocytes was virtually unaffected; thus the relative proportion of null cells was significantly increased in severely malnourished patients. Other studies have demonstrated that extracts of bovine thymus will induce an increase in the proportion of T cell rosettes from patients with various disorders. This study has demonstrated that peripheral blood lymphocytes from severely malnourished patients with secondary infections contain a subpopulation of lymphocytes which will respond in vitro in the presence of thymopoietin by increased numbers of E rosettes. These results also support the concept of a finite population of responder cells and indicate that other thymopoietin insensitive subpopulations of null cells are increased when the proportion of T cells are greatly suppressed. Further characterization of the lymphocyte subpopulation(s) affected by thymopoietin is needed.