Vitamin B12 and the megaloblastic development.

In patients with vitamin B(12) deficiency, phytohemagglutinin-stimulated cultured lymphocytes had little or no thymidylate synthetase activity. Ample activity was found in such lymphocytes from normal individuals and patients with folic acid deficiency or pernicious anemia in remission. It therefore appears that the megaloblastosis that is associated with vitamin B(12) deficiency is related to low thymidylate synthetase activity.

Hyperhomocysteinemia due to pernicious anemia leading to pulmonary thromboembolism in a heterozygous mutation carrier.

Pulmonary thromboembolism is a life-threatening condition resulting mostly from lower extremity deep-vein or pelvic-vein thrombosis. A 46-year-old woman was admitted to hospital with pain on the right side of the chest and hemoptysis. On laboratory analysis, D-dimer level was elevated. Computed tomographic pulmonary angiography revealed intravascular filling defects due to thrombi in right lower lobe pulmonary segmental arteries. Screening for thrombophilic states was normal except for heterozygous mutations of both prothrombin and methylene tetrahydrofolate reductase (MTHFR 677) genes. Homocysteine level was high, and vitamin B12 level and serum ferritin level were reduced. Serum antiparietal antibody was positive, and therefore, pernicious anemia was diagnosed along with iron-deficiency anemia. After the diagnoses were established, enoxaparin followed by warfarin was started in addition to oral vitamin B12, pyridoxine, thiamine, folic acid, and ferroglycine sulfate supplementation. At the end of 8 weeks of the replacement therapy, vitamin B12, folate, and homocysteine levels and red cell volume were found to be normal, with complete resolution of the thrombus confirmed by repeat computed tomographic pulmonary angiography. We conclude that hyperhomocysteinemia due to vitamin B12 deficiency associated with pernicious anemia might have decreased the threshold for thrombosis. In addition, the presence of heterozygous prothrombin and methylene tetrahydrofolate reductase mutations might serve as synergistic cofactors triggering pulmonary thromboembolism.

Nonspecific esterase activity in pernicious anemia and chronic erythremic myelosis: a cytochemical and electrophoretic study.

Cytochemically, nonspecific esterase activity was detected in megaloblasts from three patients with severe untreated pernicious anemia, in megaloblastoid erythroblasts from five patients with chronic erythremic myelosis (DiGuglielmo syndrome), and in normoblasts from a patient with severe untreated iron-deficiency anemia. Nonspecific esterase activity in all of these erythroblasts was inhibited by sodium fluoride. Enzymatic activity could not be detected in normoblasts from normal marrows. Electrophoretically, three bands of nonspecific esterase activity could be visualized in marrow sonicates from the anemic patients and normal persons. All of these bands were inhibited by sodium fluoride. The results demonstrate that electrophoretically and in terms of fluoride inhibition, nonspecific esterases obtained primarily from erythroid precursors in various types of anemias are similar to nonspecific esterases found in normal marrows presumably containing a more heterogeneous population of cells.

Phosphorylase activity in chronic erythremic myelosis.

Phosphorylase activity was detected in the cytoplasm of erythroid precursors of 6 of 7 patients with chronic erythremic myelosis (Di Guglielmo syndrome), in proerythroblasts and megaloblasts from 3 patients with pernicious anemia and in 2 patients with severe folate deficiency in neoplastic lymphocytes from 2 patients with acute lymphoblastic leukemia, and in 1 patient with leukemic lymphosarcoma. In all of these patients, most of the erythroid precursors and/or neoplastic lymphocytes contained increased amounts of glycogen when stained with the PAS reagent. Phosphorylase activity was not detected in erythroid precursors obtained from 6 presumed normal individuals or from 3 of 7 patients with a variety of other types of anemia in which the erythroid precursors were PAS-negative. Similarly, phosphorylase activity was absent in lymphocytes obtained from presumed normal individuals. Although the mechanisms responsible for the pathogenesis of PAS positivity are unclear, it is possible that the increased phosphorylase activity found in cells that are PAS-positive may reflect a disorder in the biosynthetic pathway of glycogen.

[LDH isoenzymes and gastrin in achlorhydri (author's transl)]. / LDH-Isoenzyme und Gastrin bei Achlorhydrie

Several haematological findings (especially the values of serum LDH and its isoenzymes) were compared with changes in the gastrin level in pernicious anaemia. While vitamin B12 substitution therapy led to normalization of the anaemia and of the enzyme levels, gastric atrophy and, hence, the elevation in serum gastrin levels remained unchanged. Determination of serum gastrin, therefore, provides a valuable tool for the verification of the diagnosis of pernicious anaemia in treated cases.

Determination of 'total' and 'true' cobalamin with the SimulTRAC Assay.

The determination of 'total' and 'true' cobalamin (the SimulTRAC Assay, Becton Dickinson) has been compared with other laboratory tests and with clinical symptoms typical of cobalamin deficiency. Patient specimens (n = 5709) were analysed for total cobalamin which was measured by its binding to a crude hog intrinsic factor preparation in the radioisotope assay. Specimens with borderline values (150-225 pmol/l) were reanalysed for true cobalamin in order to find out whether there were patients with cobalamin deficiency and a low true cobalamin content in serum. Of 803 patient sera with total cobalamin values between 150-225 pmol/l two patients had low true cobalamin values (less than 110 pmol/l) and typical laboratory and clinical signs of cobalamin deficiency. On the other hand three patients in this range had laboratory and clinical signs of cobalamin deficiency and significantly higher values with true than with total cobalamin. Measurement of true cobalamin is therefore not an unequivocal way to detect patient sera from patients with a cobalamin responsive anaemia. Analysis of true cobalamin does not seem to increase the sensitivity and specificity for cobalamin deficiency.

Application of an in vitro assay for serum thymidine kinase: results on viral disease and malignancies in humans.

An improved method for the detection of deoxythymidine kinase (TK) in human sera is reported. The method which utilizes 125I-iododeoxyuridine (IdUrd) as a substrate was used to measure TK in sera from patients with different diseases. Sera collected during the acute stage of infectious mononucleosis were found to contain elevated levels of TK, in most cases 10-40 times the normal value. The serum TK activity disappeared gradually and reached a normal level within 4 weeks. Sera from patients with other viral infections contained in most cases normal serum TK levels except in connection with measles, rubella, varicella, herpes simplex virus and cytomegalovirus infections. Additional studies revealed that sera from patients with different types of advanced lymphomas, acute leukemias, chronic granulocytic leukemia and lung cancer of the small-cell type with metastases, contained high TK levels which fluctuated in parallel with alterations in activity of the disease. The TK activity in sera from patients with both mononucleosis and tumor disease was characterized by electrophoresis and by its ability to utilize cytidine triphosphate as the phosphate donor. The results showed that the serum TK has the same properties as the human cytosolar TKI, except in connection with varicella.

Platelet peroxidase-like activity detected in mature erythroblasts from a patient with pernicious anemia.

We report a case of pernicious anemia in which the possession of platelet peroxidase (PPO)-like activity was proved in its erythroblasts. PPO-positive cells were found in a distinct minor population of hemoglobinized (as a mean of differentiated) erythroid cells in the bone marrow before treatment, but these cells disappeared following therapy with vitamin B12. The present report is considered to be the first case to identify PPO-like activity in mature erythroblasts from the nonmalignant clone. The existence of PPO in erythroid lineage in cases with pernicious anemia is discussed.

Serum lysozyme in inflammatory gastric and enteric diseases and in functional dyspepsia.

Serum lysozyme was reevaluated in inflammatory bowel disease and other gastrointestinal disorders. A total of 109 patients were divided into six groups: ulcerative colitis (28), Crohn's disease (9), simple atrophic gastritis (16), atrophic gastritis and pernicious anemia (23), functional dyspepsia (17), and controls (16). Elevated levels of lysozyme, compared with control levels, were found not only in ulcerative colitis and Crohn's disease but also in atrophic gastritis with or without pernicious anemia and in functional dyspepsia. The elevation of lysozyme, since it results from the product of granulocytes and macrophages present in increased amounts in the mucosa of inflammatory bowel diseases, is easily explained. The cellular infiltration in atrophic gastritis may also explain the elevated lysozyme levels. The higher lysozyme levels in some patients with functional dyspepsia could possibly reflect an underlying latent inflammatory process.