Serum Vitamin B₁₂ Concentrations in Leukaemia and in some other Haematological Conditions

Abstract

THE vitamin B, , concentrations in the serum of normal subjects, of patients with niegaloblastic anaemia due to vitamin B, , deficiency and of patients with various other diseases have been previously reported by us Ross, 1952, 1954). Assays of vitamin B,, were made with Euglena gracilis var. bacillaris as test organism.The total vitamin B, , concentration of the serum of 126 healthy normal subjects aged 15 to 70 years ranged from IOO to 900 wg./ml. with a mean of 362 wg./ml. Almost all the vitamin was in the combined form. The mean serum B,, concentration in each of 190 patients with pernicious anaemia in relapse was much lower than those of the normal subjects, being less than 100 !.wg./ml.; in the majority of patients it was less than 50 wg./ml. In the patients with other blood disorders the serum B,, concentrations were not significantly different from those of normal subjects. This group included some patients with acute and chronic leukaemia (Mollin and Ross, 1952).More detailed studies of the serum B,, concentrations of patients with different types of leukaemia have shown that while the concentrations in chronic lymphocytic leukaemia and in acute undifferentiated leukaemia were normal, those in chronic myelocytic leukaemia were in all cases very much higher. The mean serum B,, concentrations of patients yith certain other conditions have also been found to be significantly higher than normal. The results of our more recent observations are given in this paper, a summary of which was coniniunicated to the Fifth International Congress of Haematology, which was held in Paris in September 1954. The data now presented have been obtained from 56 patients with leukaemias of various types, 32 with polycythaemia rubra Vera, eight with myelosclcrosis, two with leukaemoid reactions, six with myelomatosis, seven with aplastic anaemia, and one with chronic agranulocytosis. Except where stated in the text, the patients were UIItreated at the time when the assays were made. METHODS HaenintologicalThe methods used were those described by Dacie (1950). Needle biopsies of the bonemarrow were made on all patients, a diagnosis of myelosclerosis being supported by histological examination of bone-marrow removed by surgical biopsy. A diagnosis of polycythaemia rubra Vera was based on the demonstration of hyperplasia of the erythropoietic, granulopoietic and platelet-forming tissues of the marrow associated with an increased peripheral red-cell count, leucocyte count and/or platelet count. Differential counts on bonemarrow films were based on counts of at least 500 cells.

The in Vitro Binding of Cobalt60 Labeled Vitamin B1 by Normal and Leukemic Sera

“…The vitamin B12 concentration, UBBC, and TBBC were all greatly elevated in chronic myelogenous leukemia as has been noted by other workers (1)(2)(3). The increase in UBBC was a labile abnormality decreasing rapidly to normal with the onset of treatment in contrast to the gradual decline in serum vitamin B12 levels following treatment.…”

“…Thus, serum vitamin B12 levels were more helpful in distinguishing these patients from those with chronic myelogenous leukemia. However, this was not uniformly so, and Mollin and Ross have reported increased serum vitamin B12 levels in two patients with chronic leukocytoses (2).…”

“…The serum concentration of vitamin B12, the capacity of the serum to bind added cobalt' labeled vitamin B1 and the distribution of the added vitamin B,2 among the serum proteins were determined. Studies were carried out on 13 patients with chronic myelogenous leukemia, 8 patients with other types of leukemias, 8 patients with nonmalignant granulocytic leukocytoses, 2 patients with polycythemia vera and 22 control subjects, the latter group being composed of healthy laboratory personnel or ambulatory hospitalized patients suffering from functional disorders.…”

“…In chronic myelogenous leukemia both the serum concentration of vitamin B12 and the capacity of the serum to bind added vitamin B12 are markedly increased (1)(2)(3), suggesting an abnormality of the serum proteins in this disease. In vitro measurements of vitamin B12 binding capacity employing a microbiological assay method have not demonstrated a qualitative difference between normal and leukemic sera in respect to the binding of added vitamin B12 by the various serum protein fractions (1,4).…”

Co58B12 ABSORPTION, PLASMA TRANSPORT AND EXCRETION IN PATIENTS WITH MYELOPROLIFERATIVE DISORDERS, SOLID TUMORS AND NON-NEOPLASTIC DISEASES*

“…Several investigators have documented the fact that chronic myelocytic leukemia (CML) is associated with increases in serum vitamin B12 concentrations which may be of the order of 20 to 40 times the normal value (1)(2)(3)(4). Less striking and less consistent elevations have been found in other myeloproliferative disorders.…”