Louis R. Wasserman

Increased Incidence of Acute Leukemia in Polycythemia Vera Associated with Chlorambucil Therapy

In studies to determine the optimal treatment for polycythemia vera, 431 previously untreated patients whose disease met established diagnostic criteria were entered into a prospective, randomized controlled trial between 1967 and 1974. Three treatment regimens were used: phlebotomy alone, chlorambucil supplemented by phlebotomy, or radioactive phosphorus supplemented by phlebotomy. Despite minor differences in age and sex, the three groups were comparable in initial hematocrit, white-cell and platelet counts, and disease-related symptoms. The median duration of follow-up is now more than 6 1/2 years. As of February 15, 1980, there were no statistically significant differences in survival among the groups. However, the risk of acute leukemia in patients given chlorambucil was 2.3 times that in patients given radioactive phosphorus and 13 times that in patients treated with phlebotomy alone. The increased incidence of leukemia during chlorambucil treatment is statistically significant (P less than or equal to 0.002); accordingly, the Polycythemia Vera Study Group has discontinued the use of chlorambucil in the treatment of polycythemia vera.

Suppression of Erythroid-Colony Formation by Lymphocytes from Patients with Aplastic Anemia

To explore the possible role of cell-mediated suppression of erythropoiesis in acquired aplastic anemia, we studied the effect of peripheral blood lymphocytes from seven patients with aplastic anemia on erythroid-colony formation by normal human bone marrow in an in vitro plasma clot-culture system. Varying numbers of peripheral blood lymphocytes (0.5 to 6 X 10(5) cells) were cocultured with 6 X 10(5) normal bone-marrow cells in the presence of 2 IU of erythropoietin for seven days. Peripheral blood lymphocytes from five of the seven patients with aplastic anemia caused a 79 to 94 per cent reduction of erythroid-colony formation. Thus, at a peripheral blood lymphocyte concentration of 2 X 10(5) cells, the numbers of erythroid colonies formed (control vs. experimental) were 374 +/- 16 (S.E.M.) vs. 22 +/- 6, 48 +/- 4, 50 +/- 16, 80 +/- 4 and 27 +/- 3. These results suggest that some patients with aplastic anemia possess a population of lymphocytes capable of suppressing in vitro erythropoiesis.

Erythroid colony formation by polycythemia vera bone marrow in vitro. Dependence on erythropoietin.

In the plasma clot culture system both normal and polycythemia vera (PV) bone marrow cells respond to erythropoietin (Ep), giving rise to large numbers of colonies of erythroid cells. In PV, but not in normal individuals, the marrow produced endogenous erythroid colonies (EED) in the absence of exogenous Ep. The number of EEC formed varied from patient to patient comprising anywhere from 6 to 29% of the total number of colonies formed in the presence of Ep. Exposure, before use in culture, of fetal calf serum and citrated bovine plasma to the gammaglobulin fraction of rabbit anti-Ep serum followed by treatment with goat anti-rabbit gamma-globulin re sulted in a significant decrease in EEC formation. Addition of anti-Ep directly to the culture medium produced similar results. In addition, the production of EEC in response to added Ep was inhibited in the presence of anti-Ep. Addition of very small doses of highly purified Ep to anti-Ep-treated cultures resulted in the reappearance of a significantnumber of EEC formation in PV may be due to a population of erythroid-committed precursors that are abnormally sensitive to small concentrations of Ep which may be present in fetal calf serum and citrated plasma. Although the mechanism of formation of these cells is not known, it appears that the final steps in the formation of red cells derived from this clone of precursors is subject to the usual Ep control.

ISOAGGLUTININS ASSOCIATED WITH ABO ERYTHROBLASTOSIS

The occurrence and severity of erythroblastosis fetalis, due to maternal Rh isoimmunization, can be predicted through simple prenatal serological tests (1, 2). If Rh isoagglutinins are present in maternal serum, and if the incompatible Rh antigen is transmitted from the father, the newborn will have hemolytic disease, the severity of which is often proportional to the titer of the mothers serum Rh isoagglutinins (1, 2). In the event that the isoimmunized Rh negative mother delivers an Rh negative infant, the titer of Rh antibodies in the cord serum, except for saline agglutinins, is generally equal to the titer obtained in the maternal serum (3). For practical purposes, almost all maternal Rh isoagglutinins seem to cross the placental barrier freely, and their titration value affords guidance toward the effective management of hemolytic disease of the newborn. This has not been the case for erythroblastosis fetalis due to ABOincompatibility (1, 2). ABO erythroblastosis of sufficient severity to warrant exchange transfusion therapy for the control of hyperbilirubinemia, has a frequency equal to that of erythroblastosis due to Rh incompatibility (2, 4), and yet prenatal tests have been of little value thus far in identifying those mothers who may deliver affected infants (4). Since ABO erythroblastosis occurs often in the first incompatible pregnancy (5, 6), a reliable prenatal test would be of extreme importance in anticipating the occurrence of this disease for intelligent management. A varying proportion of maternal anti-A (a) and anti-B (,/) isoagglutinins can be demonstrated in the serum of the newborn (7, 8). Most ABO isoagglutinins cannot cross the placenta and therefore play no role in the pathogenesis of erythroblastosis. Fudenberg, Kunkel and Franklin (9)

Aggregation of IgG globulin in vivo: I. The hyperviscosity syndrome in multiple myeloma☆

Abstract Two patients with multiple myeloma had, at the onset of their disease, mucous membrane bleeding and retinal vascular disturbances which simulated Waldenstroms macroglobulinemia. This clinical state was related to serum hyperviscosity. Although both paraproteins were shown to be acid-dissociable IgG myeloma globulin aggregates of greater than 7S, they differed in their physicochemical properties and antigenic grouping. Serum viscosity was increased by the presence of these large molecules, not as a result of hypergammaglobulinemia per se . The combination of an expanded plasma volume, distention of vessels and interference with the formation of fibrin was probably responsible for bleeding. This type of myeloma can be distinguished from Waldenstroms macroglobulinemia by means of ultracentrifugation and immunoelectrophoretic analysis, although diagnosis may be difficult on clinical and morphological grounds. Plasmapheresis was an effective method of treatment.

THE RATE OF REMOVAL OF RADIOACTIVE IRON FROM THE PLASMA—AN INDEX OF ERYTHROPOIESIS

Transport iron normally exists in the plasma as ferric beta-l-globulinate. Since in most individuals the greater part of the body iron is incorporated in the hemoglobin of the red blood cells, it is probable that changes in the production and destruction of these erythrocytes will be reflected in the turnover of plasma iron. Radioactive iron of high specific activity is particularly useful for a study of iron metabolism since it can be injected intravenously in tracer amounts without changing the steady state of the organism; the turnover of this radioiron will then mirror the metabolism of the iron in the body.

Association of antibody-coated red blood cells with ulcerative colitis; report of four cases.

Abstract Four cases of ulcerative colitis associated with antibody-coated red cells are presented. The clinical, hematologic and immunologic findings are discussed. One of the patients had overt hemolytic anemia of the acquired autoimmune variety. It was not possible to assess the role played by hemolysis in the anemia presented by the other three patients. The occurrence of antibody-coated red cells in ulcerative colitis appears to be related to the underlying intestinal disorder, and particularly to the presence of diseased bowel, although it is not necessarily related to the clinical activity of the colitis. The possibility of an autoimmune hemolytic process should be considered in the pathogenesis of anemia in ulcerative colitis.

Pool systems in iron metabolism; with special reference to polycythemia vera.

Previous reports( 1 , 2 ) concerning the disappearance of a tracer dose of radioactive iron from the plasma implied a single plasma iron pool with no significant return of radioiron to the plasma during the experimental period of one to 2 hours. Assuming instantaneous mixing following the injection of ferric 59-beta-1 globulinate, as well as a constant relative disappearance rate, the theoretical data could be represented by a single exponential function, i.e., a straight line on semi-log paper. Such a first approximation fitted the experimental data well because of the large errors involved in electroplating( 1 2 3 ) and the relatively insensitive counting technics employed( 1 2 3 ). Two considerations prompted reevaluation of the above concepts. Firstly, utilizing improved counting technics it was noted that the experimental data were no longer approximated by a straight line when plotted on semilog paper. Re-examination of some of the published data in earlier reports reveals similar findings( 1 , 4 ). Secondly, the application of the previous approach to cases of polycythemia vera led to excessively high hemoglobin renewal rates and consequent shortened red cell survival times( 1 ). These findings were not in accord with data obtained by other methods( 5 6 7 ), nor with present basic concepts of the patho-physiology of this disorder( 8 ). It will be demonstrated that the experimental data can be more closely approximated by the sum of 2 exponential functions, thus requiring a more complex system than the one-pool model implied by the single exponential function. Fig. 1a represents experimental data from a case of polycythemia vera plotted on a semilog scale, for the first hour of Fe59 disappearance from the plasma.

Leukocyte Alkaline Phosphatase Activity in Hematopoietic Disorders. A correlative Study by Biochemical and Cytochemical Techniques

Abstract : The principal diagnostic values of this determination in the hematopoietic disorders studied is in the exclusion of chronic myelocytic leukemia. If the alkaline phosphatase activity is high, the diagnosis of chronic myelocytic leukemia would seem unlikely. The cytochemical technique appeared to be more reliable in this exclusion.

Stoichiometric relation between liver-receptor, intrinsic factor and vitamin B12.

Summary “Receptors”for intrinsic factor exist in rat, bull, and rabbit liver homogenate precipitate, and remain intact after lyophilization and acetone-washing of the homogenate. There appears to be a stoichiometric relation between receptors, intrinsic factor, and Vit. B12. Within stated limits, an incubation system of receptors, intrinsic factor, and/or Co60-B12 may prove useful for assay of intrinsic factor, of the quantity of free B12 in biological fluids, and of receptors.