lactoferrin and Leukemia--Lymphoid

Lactoferrin (Lf) in lymphocytes was assessed with immunofluorescence/flow cytometric technique. Surface Lf was detected primarily among B-cell-enriched preparations. Tonsillar B-cells of different densities expressed surface Lf similarly. Very small percentages of CALLA+ ALL, HCL, or EBV-transformed B-cells expressed surface Lf, whereas B-CLL lymphocytes had the highest percentages of surface Lf positivity. Few resting, cultured, or neoplastic T-lymphocytes expressed Lf. The pattern of immunofluorescence and analyses of surface and total cellular immunoreactive Lf indicated that Lf is associated primarily with the lymphocyte surface. The percentage and/or intensity of surface Lf-specific fluorescence were not significantly altered in B- or T-cells by incubation with physiologic concentrations of differric Lf, and the percentages of Lf-positive cells detected in respective subjects remained stable over time. Surface Lf positivity was unrelated to the expression of other surface antigens (except those marking B- or T-cell lineage) or cell cycle. Expression and/or binding of Lf in B-lymphocytes may become increased during certain stages of cell maturation.

Topics: B-Lymphocytes; Cell Membrane; Cells, Cultured; Flow Cytometry; Fluorescent Antibody Technique; Humans; Lactoferrin; Lactoglobulins; Leukemia, Lymphocytic, Chronic, B-Cell; Leukemia, Lymphoid; Lymphocyte Activation; Lymphocytes; T-Lymphocytes

A solid-phase, one-step radioimmunoassay was developed for the determination of plasma lactoferrin concentration. The detection limit of the assay is 150 micrograms/l. Leakage of cellular lactoferrin was minimal when EDTA was used as anticoagulant, while results obtained from serum and from heparinized plasma were not reproducible. The plasma lactoferrin concentration of 35 female and 44 male healthy adults was measured in order to determine normal values. The geometric mean of lactoferrin levels in men is about 10% higher than in women: 483 (200-1500) micrograms/l in men and 446 (200-870) micrograms/l in women. Patients with acute and chronic leukaemias were also studied. In 38 patients with chronic myeloid leukaemia plasma lactoferrin levels were increased by three times while the neutrophil count was ten times higher than normal. Normal lactoferrin concentrations were measured in plasma samples from 15 patients with chronic lymphocytic leukaemia in incomplete remission while no detectable lactoferrin was found in samples from those in relapse (10 patients). In the untreated patients or those in relapse (19 cases) of both acute lymphocytic and myeloid leukaemias, plasma lactoferrin concentrations were undetectable while they seemed to return to normal during remission (3 cases). The data obtained indicate that the determination of plasma lactoferrin concentration might play an important role in facilitating the assessment of total blood granulocyte pool (TBGP).

Topics: Blood Cell Count; Female; Humans; Lactoferrin; Lactoglobulins; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid; Male; Neutrophils; Prognosis; Radioimmunoassay; Reference Values

This study describes an ELISA technique with high specificity, sensitivity, accuracy and reproducibility for measurements of plasma lactoferrin. The detection limit was 0.001 microgram/ml and the median value obtained in EDTA plasma from 47 healthy adults was 0.100 microgram/ml (0.05 fractile: 0.046 microgram/ml, 0.95 fractile: 0.257 microgram/ml). The lactoferrin concentration in serum was on the average 2 1/2 times higher than in plasma. The ambient temperature did not influence the plasma concentration during the first 6 h from blood sampling to separation of plasma from the cells. In 8 patients with untreated acute leukaemia plasma lactoferrin was positively correlated to the peripheral neutrophil count. An almost parallel course in plasma lactoferrin and peripheral neutrophil number was observed in 4 patients with AML during chemotherapy. In 2 patients achieving complete remission, plasma lactoferrin increased about 6 d before the concomitant increase in neutrophil count, suggesting plasma lactoferrin as an early predictor of bone marrow regeneration.

Topics: Adolescent; Adult; Aged; Bone Marrow; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immune Sera; Kinetics; Lactoferrin; Lactoglobulins; Leukemia, Lymphoid; Leukemia, Myeloid, Acute; Leukocyte Count; Male; Middle Aged; Neutrophils; Temperature

Topics: Child; Granulocytes; Hematopoietic Stem Cells; Humans; Lactoferrin; Lactoglobulins; Leukemia, Lymphoid; Leukemia, Myeloid, Acute; Peroxidase; Peroxidases; Reference Values