Lysozyme (Muramidase), Plasma
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Lysozyme is a bacteriolytic enzyme that is found in some hematopoietic cells. It is primarily present in granulocytes, monocytes, and histiocytes. The enzyme is present in only minute amounts in lymphocytes; and is not present in myeloblasts, eosinophils, and basophils.
Lysozyme in the plasma comes chiefly from the degradation of granulocytes and monocytes and its concentration reflects the turnover of these cells. Increases are seen in benign (eg, infection, inflammation) and malignant processes(eg, some leukemias). Plasma lysozyme is elevated in patients with acute or chronic granulocytic or monocytic leukemias and falls with successful treatment. Conversely, patients with lymphocytic leukemia may have depressed plasma lysozyme levels.
Patients with renal disorders (including rejection of transplanted kidneys) or Crohn’s disease (regional enteritis) also tend to have elevated levels of plasma lysozyme.
Confirming marked increases in the granulocyte or monocyte pools as in granulocytic or monocytic leukemias, myeloproliferative disorders, and malignant histiocytosis
Following the course of therapy in cases of chronic granulocytic or chronic monocytic leukemias
Levels >200 mcg/mL may be seen in acute nonlymphocytic leukemia (M2, M4, M5) or chronic granulocytic leukemias.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Increased levels may be seen in nonmalignant disorders including infections, Crohn’s disease, kidney transplant rejection, and other renal disorders.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
> or =12 months: 2.7-9.4 mcg/mL
Reference values have not been established for patients who are <12 months of age.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
Catovsky D, Galton DA, Griffin C: The significance of lysozyme estimations in acute myeloid and chronic monocytic leukaemia. Brit J Haematol 1971;21:565-580