Polycythemia rubra vera with pernicious anemia. Some observations on vitamin B 12 metabolism.

By ROBERT E. SAGE P ERSISTENT rather than relative and transient polycythemia was first described in 1892 by Vaquez.’ Polycythemia rubra vera is now regarded as one of the myeloproliferative disorders. A slowly progressive neoplasm of unknown etiology involving all cell series of the bone marrow, it is inevitably fatal after a varying period of time.24 The first clinical description of pernicious anemia was that of Addison5 in 1855. Auto-immune phenomena#{176}9 are now recognized as common occurrences in this disorder, which may be under genetic control. The inability to absorb Vitamin B12 is accompanied by achiorhydria and leads to anemia and neurologic disturbances. Whether it is primarily an auto-immune disorder has yet to be resolved.’0 Megaloblastoid changes in the red cell series of the bone marrow occasionally develop in the course of polycythemia rubra vera but true megaloblastic anemia and polycythemia rubra vera in the same patient have been rarely reported. The development of some manifestations suggestive of polycythemia rubra vera after the institution of therapy for pernicious anemia or anemia due to folic acid deficiency has been occasionally reported. 2#{176} Most of these cases were described before the development of the accurate diagnostic radioisotope technics and in these, as in most cases studied since, there is doubt as to the diagnosis of the polycythemia rubra vera or the pernicious anemia. In the following case the pernicious anemia was manifest only after the polycythemia rubra vera was treated, a sequence which has not previously been satisfactorily documented. Strict criteria for both conditions make the diagnoses unequivocal and the results of the first autoantibody studies in this combination are presented. The adequate control of both disorders by adjustment of the parenteral Vitamin B12 dosage is described. The coexistence of these two rare diseases in the same patient is discussed in relationship to coincidence, and to possible etiologic factors. An apparent unavailability of Vitamin B12 for normal tissue metabolism and hemopoiesis is discussed with respect to the high serum levels seen in some of the myeloproliferative disorders. It is suggested that the high levels of Vitamin B12 binding proteins described in these disorders2124 with an added intrinsic qualitative abnormality25’26 are inhibiting the release of the vitaniin at tissue receptor sites.