Bone marrow phagocytic activity was studied in 40 patients with Brucella melitensis infection and 35 patients with a variety of medical conditions. Evidence of erythrophagocytosis was found in 14 of the 40 patients with B melitensis infection and in 15 of the 35 control cases; this was taken as baseline bone marrow phagocytic activity. Considerably increased erythrophagocytosis or phagocytosis of all blood elements by increased number of histiocytes was found in one and seven patients, respectively, in the brucellosis group. All but one patient with increased phagocytic activity had splenomegaly. These findings may reflect an intense host response in some patients with B melitensis infection.
Adult Aged