ABSTRACT
Myelofibrosis (MF) has a close pathogenic relationship to polycythemia vera (PV), chronic myelongenous leukemia (CML) and primary thrombocythemia (PT). Sometimes, clinical, hematological and radioisotopic studies in these patients cannot give a definite diagnosis. As serum vitamin B12 and vitamin B12 binding proteins in patients with PV and CML show their own specific pattern. It would be of interest to see whether these determinations could separate MF from PV and CML. Serum vitamin B12 and vitamin B12 binding proteins were determined on 6 patients with MF. It was found that serum vitamin B12, UBBC and TBBC levels were elevated. Both TCI and TCIII were increased while TCII decreased. A shift to the left of the increased granulocytes in MFR resulted in an increased TCI synthesized by the myelocytes and metamyelocytes while in PV, the increased number of granulocytes, most of which are mature granulocytes is characterized by increased serum TCII resulting in a reverse ratio of TCI/TCIII. In CML, serum vitamin B12, UBBC, TCI and TCII are much more sharply elevated than those of MF. Therefore determination of serum vitamin B12 and vitamin B12 binding proteins with other hematological, bone marrow and clinical studies could be used for a differential diagnosis of MF from PV or CML.