Defective phagocytosis due to deficiencies involving the tetrapeptide tuftsin

A description of the symptoms and causes of tuftsin deficiency is presented. Two major causes which give rise to a deficiency of the tetrapeptide (thr-lys-pro-arg) are discussed. One is familial tuftsin deficiency syndrome that results from an inherited mutation involving the tetrapeptide. All patients give a history of repeated infection with variable severity. One parent, father or mother, is deficient and occasionally other siblings may have the disease. The other type of deficiency is the result of loss of splenic function whether it is due to surgical removal of the spleen and to infarction or infiltration of the organ. A method for the assay of tuftsin activity is described.