1. The history, morphology and technics of counting of basophils have been briefly reviewed.
2. A marked relative and absolute increase of basophils was always found in chronic myelogenous leukemia. Moderate relative and absolute increases of basophils usually occurred in myeloid metaplasias (including polycythemia vera with leukocytosis). In some cases of iron-deficiency, hemolytic and toxic anemias of long standing there may be moderate increases of blood basophils.
3. Marked relative and absolute decreases of basophils occurred in almost all cases of neutrophilic leukocytosis or leukemoid reaction, associated with infection, neoplasia, tissue necrosis or acute anemia. Patients with chronic lymphatic leukemia, monocytic leukemia or acute leukemia almost always have relative and absolute decreases of circulating basophils.
4. In our experience there is no evidence that basophils possess any peculiar radioresistant qualities. In general, the basophils fall proportionately with the decline of leukocyte counts during Myleran, P32 and x-ray therapy of chronic myelogenous leukemia and myeloid metaplasia. The suppressing action of these therapeutic agents seems to be on the proliferating blast cell.
5. The function of the basophils is not known, but it has been postulated that they might act as "heparinocytes," inhibiting clotting and stasis of blood and lymph in areas of inflammation.
6. There is suggestive evidence that the basophilopenia in cases of infection, neoplasia, tissue necrosis and acute anemia is analogous to the eosinophilopenia of the "stress reaction" mediated via the adrenal glands; however, it must be admitted that this has not been unequivocally established, and other mechanisms may play a role in controlling the levels of circulating basophils.