Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

According to criteria established by the French-American-British (FAB) classification, a diagnosis of acute myelomonoblastic leukemia (FAB M4) is based on the presence of 20% bone marrow monocytes or a serum lysozyme level that exceeds the reference value by three times. Reported here is a case of acute myelogenous leukemia with eosinophilia and a cytogenetic inversion of chromosome 16 (inv 16) that lacks morphologic, cytochemical, and immunophenotypic features of monocytic differentiation, but which is associated with an elevated serum lysozyme value. The authors used an immunoelectron microscope to localize lysozyme to both normal and abnormal eosinophil granules, in addition to the secondary granules of myeloid precursors and monocytes. This enzyme could not be demonstrated within the myeloblasts of the patient studied. Postfixation with osmium tetroxide greatly reduced the staining intensity within the crystalloids of normal eosinophils, but only minimally affected that of monocytes, neutrophils, normal eosinophil granule matrix, and the abnormal granules of the leukemic eosinophils. These results demonstrate that lysozyme is present in both normal and leukemic eosinophils and that elevation of serum lysozyme in patients with acute myelogenous leukemia with eosinophilia is not a reliable indicator of monocytic differentiation. Furthermore, an occasional case of acute leukemia with inv 16 is classifiable as acute myelogenous leukemia with differentiation (FAB M2).
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PMID:The significance of an elevated serum lysozyme value in acute myelogenous leukemia with eosinophilia. 154 87

The bone marrow biopsy specimens of 35 patients with benign and malignant erythroid hyperplasias were examined for the presence of hemoglobin A, hemoglobin F, muramidase (lysozyme), and transferrin, using an indirect immunoperoxidase method (PAP) on Zenker's-fixed paraffin-embedded bone marrow biopsy specimens and particles. Five cases of each of the following entities were studied: erythroleukemia and erythremic myelosis, acute granulocytic leukemia with maturation (FAB M2), polycythemia rubra vera, myeloproliferative syndrome in childhood, megaloblastic anemia (B12 and folate deficiency), erythroid hyperplasia (regenerating bone marrow and hemolytic anemia), and Ph' chromosome positive chronic granulocytic leukemia. Hemoglobin A was present in both the early and late erythroid precursors in all conditions. Hemoglobin F was the predominant hemoglobin in early erythroblasts of pernicious anemia and in both early and late erythroid elements in erythroleukemia and erythremic myelosis. Small quantities of hemoglobin F were present in a few isolated clusters in other conditions. Staining for hemoglobin F may be useful in identifying immature erythroid precursors and in distinguishing some cases of dysplastic erythroid hyperplasia from neoplasia. Additionally, these findings suggest that the maturational switch in hemoglobin synthesis operates with distinct pathways under different conditions.
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PMID:An immunohistochemical study of hemoglobin A, hemoglobin F, muramidase, and transferrin in erythroid hyperplasia and neoplasia. 619 99

The revised French-American-British (FAB) classification system for acute myeloid leukemia (AML) recommends the determination of serum lysozyme (SL) or urine lysozyme (UL) levels as an aid in distinguishing acute myeloblastic leukemia with maturation (FAB M2) from acute myelomonocytic leukemia (M4). We reviewed retrospectively 208 cases of adult leukemia in which SL and/or UL were obtained. Elevated lysozyme levels were not found in any of the M0, M3, or M7 cases, but were increased (false positive) in three (14%) M1 cases, 18 (19%) M2 cases and one (20%) M6 case. Although a UL value in excess of 3x normal was found in most cases of AML M4 and M5, only five (11%) M4 cases and three (20%) M5 cases had SL elevations of this magnitude. Lysozyme levels need to be interpreted in conjunction with other parameters for FAB classification.
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PMID:Usefulness and limitations of serum and urine lysozyme levels in the classification of acute myeloid leukemia: an analysis of 208 cases. 870 18