Immunologic detection of intracellular and cell-surface lysozyme with human and experimental leukemic leukocytes

Intracytoplasmic Lysozyme in Malignant Hematologic Disorders: An Immunoperoxidase Study

Intracytoplasmic lysozynie was studied by the peroxidase antiperoxidase (PAP) and protein A-peroxidase methods in 130 cases of various myeloproliferative and lymphoproliferative disorders and 21 lymph nodes and bone marrow metastases from solid primary tumors. This marker, which can be identified in formalin or Zenker-fixed tissues, as well as in peripheral blood and bone marrow smears, proved useful to distinguish malignant myeloid and histiocytic tumors from malignant lymphoid and undifferentiated epithelial metastases. The diagnostic application of these findings are discussed.

The expression of lysozyme in multiple myeloma

Lysozyme, a hitherto myelomonocytic marker, has been previously reported as being raised in the sera of some myeloma patients. This fact, and the sporadical observation of a positive immunohistochemical lysozyme staining seen in some myelomas, prompted us to systematically search for an expression of lysozyme in both neoplastic and reactive plasma cells. A total of 74 paraffin-embedded, formalin-fixed, EDTA-decalcified core biopsies of newly diagnosed cases of plasmacytoma were immunohistochemically investigated for lysozyme expression by a modified avidin-biotin immunoperoxidase technique. The myelomas were subclassified according to their nuclear maturity into poorly differentiated plasmacytoma (PDP) (30 cases), moderately differentiated plasmacytoma (MDP) (24 cases), and well differentiated plasmacytoma (WDP) (20 cases). An unexpected lysozyme positivity was seen in 16/74 cases, and was most prevalent in 10/30 cases of PDP. No correlation has been detected between either lysozyme and kappa or lambda light chain expression, or an abnormal activity of chloroacetate esterase sometimes seen in myeloma. Since lysozyme has not been found in normal plasma cells or reactive plasmacytosis, the expression of this antigen in myeloma represents another example of so-called lineage infidelity, and parallels the previously reported abnormal expression of other myelomonocytic markers in some myelomas and a myeloma cell line. Apart from the unsettled prognostic impact, a facultative lysozyme expression in myeloma must be always considered when applying algorhythmic immunohistological strategies in delineating the histogenesis of haematopoietic or lymphatic malignancies.

Diagnostic and prognostic significance of serum measurements of lactoferrin, lysozyme and myeloperoxidase in acute myeloid leukemia (AML): recognition of a new variant, high-lactoferrin AML

92 patients with acute myeloid leukemia were classified according to the FAB classification (M1 n = 20, M2 n = 43, M3 n = 1, M4 n = 19, M5a n = 2, M5b n = 2, and M6 n = 5 patients). Serum measurements of lactoferrin (LF), myeloperoxidase (MPO) and lysozyme (LYS) were performed before the start of treatment. LF was significantly lower in M1 when compared with M2 but not as compared to M4, MPO was significantly higher in M2 and M4 than in M1, but comparable MPO levels were found in M2 and M4. LYS was significantly elevated in M2 in comparison with M1, and in M4 when compared to both M1 and M2. Polymorphonuclear granulocytes (PMNs) in M1 were significantly reduced when compared with M2 and M4, whereas mononuclear cells were significantly increased in M4 in comparison with both M1 and M2. FAB classification did not generate any prognostic information. When the patients were, instead, subdivided according to LF levels were found prognostically significant differences. Of patients below 100 micrograms/l, 44% went into remission as compared to 77% with LF from 101 to 400 micrograms/l. In patients with LF levels above 400 micrograms/l the remission frequency was only 14%. Multivariate statistical analysis on the data further suggested that lactoferrin may be used as an independent prognostic indicator. We conclude that although determination of the serum-levels of lactoferrin, lysozyme and myeloperoxidase in certain cases may be valuable as a supplement to the morphological examination of acute myeloid leukemia, it is evident that none of the three determinations can be used alone to distinguish between the FAB groups.

Leukemic cell lysis pneumonopathy. A complication of treated myeloblastic leukemia

The course of acute noninfectious pulmonary infiltrates in five patients with myeloblastic leukemia was evaluated. All had circulating blast cells (range, 245-192,000/mm3) and recently had received chemotherapeutic drugs for their leukemia. Within four days of the nadir of their leukocyte counts, a patchy, often multilobar pneumonitis developed. Cultures for bacteria, fungi, and viruses were all negative, and no clinical response was observed to broad-spectrum antibiotics. On lung biopsy, pathologic changes were characterized by diffuse alveolar damage with degenerating blast cells in the interstitium and in organizing alveolar exudates. No potential pathogenic organisms were seen on light or electron microscopy of the biopsy samples. In each case the pulmonary infiltrate resolved without specific therapy. We postulate that lysis of leukemic cells, with subsequent release of their enzyme contents, led to the diffuse alveolar damage observed pathologically. Leukemic cell lysis pneumonopathy may be one of the potential causes of pulmonary infiltrates in leukemic patients and can be distinguished pathologically by its distinctive pattern.

Occurrence and patterns of muramidase containing cells in Hodgkin's disease, non-Hodgkin's lymphomas, and reactive hyperplasia

The occurrence and pattern of cytoplasmic muramidase containing histiocytes were studied by the unlabeled antibody peroxidase-antiperoxidase method in biopsy material from patients with Hodgkin's disease, non-Hodgkin's lymphomas, and reactive hyperplasia. The majority of lymph nodes from patients with Hodgkin's disease, nodular lymphoma, and reactive hyperplasia gave positive staining reactions when tested in this manner. Differences in the staining pattern were observed for the different conditions studied. In general, stain positive cells occurred in one of the following four patterns: nodular, dispersed, aggregating without background stain, or aggregating with background stain (mottling pattern). The nodular and aggregating without background stain patterns were not specific and were seen in various conditions. The dispersed pattern, however, was observed only in some cases of non-Hodgkin's diffuse lymphomas, suggesting a subgroup of tumors characterized by active participation of reactive histiocytes. The mottling pattern was virtually limited to Hodgkin's disease. Since the mottling pattern appeared to be produced by virtue of a large amount of extracellular muramidase, the elevation of the serum muramidase level in Hodgkin's disease may be related to enzymatically active secretory histiocytes. Moreover, the mottling staining pattern was observed frequently in the lymphocytic predominance and nodular sclerosis type of Hodgkin's disease, but relatively infrequently in the mixed cellularity or lymphocytic depletion types, suggesting that the variation in histiocytic activity may be related to the course of the disease. The decreased staining reaction observed in the latter two categories could not be accounted for by a decrease in the numbers of histiocytic cells in hematoxylin and eosin stained sections, suggesting that release or synthesis may be defective in those unfavorable types of Hodgkin's disease.

Demonstration of lysozyme, alpha 1-antichymotrypsin, alpha 1-antitrypsin, albumin, and transferrin with the immunoperoxidase method in lymph node cells

The immunoperoxidase method was used to investigate the presence of intracytoplasmic lysozyme, alpha 1-antichymotrypsin (alpha 1-ACT), alpha 1-antitrypsin (alpha 1-AT), transferrin, and albumin in hyperplastic and inflamed human lymph nodes. Lysozyme was demonstrated in eosinophils, neutrophils, histiocytes, in epithelioid cells, mast cells, and some lining cells of lymph node sinuses. alpha 1-ACT was detectable in many, but not all histiocytes that stained for lysozyme, and in sinus histiocytes, epithelioid cells, and mast cells, but not in neutrophils or eosinophils. alpha 1-AT was demonstrable in mast cells, neutrophils, and some epithelioid cells, but not in histiocytes. Transferrin was found in mast cells, but not in any of the other cell types investigated. Albumin was detectable in a few epithelioid cells and giant cells of the Langhans type. Lysozyme, alpha 1-ACT, alpha 1-AT, transferrin, and albumin were never demonstrable in interdigitating reticulum cells, dendritic reticulum cells, or lymphoid cells.

Cell-surface characteristics of hairy cell leukemia in seven patients

Surface marker studies were performed on "hairy cells" from 7 patients with hairy cell leukemia (HCL). Using sensitive analytic techniques including specific antisera and Fluorescence Activated Cell Sorter (FACS-1), further definition of the abnormal cell was achieved. Four different antisera were used in infestigating the cell surface characteristics of these patients: anti-p23,30, an antiserum reactive with B cells and a subset of monocytes, anti-311, which reacts only with T cells, pepsin digested anti-F(ab')2 which reacts with B cells only and pepsin digested anti-lysozyme reactive with monocytes and myeloid cells, but not with B or T cells. In all cases strong reactivity was observed with anti-p23,30 and anti-F(ab')2, but no reactivity with anti-311. Five out of the seven cases were reactive with anti-lysozyme in a pattern similar to normal monocytes. Furthermore, when cells were separated according to binding to anti-p23,30, anti-F(ab')2 and anti-lysozyme and in two cases, according to cell size, the majority of reactivity and large cells were "hairy" when examined under microscopy. In contrast, the small and nonreactive (dull cells) appeared as normal mature lymphocytes. Thus, our data supports the view that HCL cells bear in most cases B cell and monocytic membrane markers.