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1.
Int J Infect Dis ; 91: 101-103, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31759170

ABSTRACT

We describe a symptomatic Plasmodium falciparum infection in a 29-year-old Guinean man receiving Infliximab for one year and without recent travel. The reactivation of submicroscopic malaria following the inhibition of TNF-alpha by infliximab is suspected.


Subject(s)
Infliximab/adverse effects , Malaria, Falciparum/etiology , Adult , Humans , Inflammatory Bowel Diseases/complications , Inflammatory Bowel Diseases/drug therapy , Infliximab/therapeutic use , Male , Plasmodium falciparum , Tumor Necrosis Factor-alpha/antagonists & inhibitors
2.
Rev Med Brux ; 36(4): 237-47, 2015 Sep.
Article in French | MEDLINE | ID: mdl-26591307

ABSTRACT

Malignant lymphoma and other lymphoproliferative disorders represent a group of malignant hemopathies where immunotherapy has allowed spectacular progresses over the last ten years. The recent W.H.O. classification, based upon tumor immunology, and cytogenetical anomalies, allows a better identification of each lymphoma and the comparison of homogeneous populations within various clinical studies. The increase in the incidence of non-Hodgkin lymphoma is related to the aging of the population as well as to other factors that are still to be analysed - a real challenge for the future. We have tried to offer an overview of the latest therapeutical advances while focusing on the major role of general practitioner. The most frequency askeed questions will be discussed.


Subject(s)
Drugs, Investigational/therapeutic use , General Practitioners , Lymphoma/therapy , Physician's Role , Humans , Lymphoma/pathology , Practice Patterns, Physicians' , Therapies, Investigational/methods
4.
Acta Clin Belg ; 69(6): 433-8, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25103595

ABSTRACT

OBJECTIVES: The aim of our study was to evaluate the clinical values of anti-beta2 glycoprotein I antibodies (anti-beta2GPI) IgG and IgM comparing with lupus anticoagulant (LA), anticardiolipin antibodies (aCL) in the two clinical groups of antiphospholipid syndrome (APS), vascular thrombosis (VT) and pregnancy morbidity (PM). METHODS: Eighty patients who fulfilled the APS clinical criteria, VT n = 34; PM n = 40, both VT and PM n = 6 were included. LA, aCL and three anti-beta2GPI ELISA kits were tested. RESULTS: Sensitivities of LA, aCL and anti-beta2GPI assays were found respectively 62, 26 and 41% in VT, and 28, 28 and 30% in PM. The sensitivity for the APS diagnosis could reach to 63% using triple tests. The presence of LA (P<0·01, OR = 4·3) or anti-beta2GPI IgG alone (P<0·05, OR = 8·4) was significantly associated with VT. IgM isotype was found more frequent in PM (92%) than in VT (57%) among all positive anti-beta2GPI cases. CONCLUSION: Both IgG and IgM anti-beta2GPI assays were useful when clinical features of APS presented, even its standardization is ongoing. A decreased by half sensitivity of LA in PM compared with that in VT underlines the importance of adding anti-beta2GPI in PM of APS, especially IgM isotype although recent review questioned its significance.


Subject(s)
Antiphospholipid Syndrome/diagnosis , Immunoglobulin G/blood , Immunoglobulin M/blood , Pregnancy Complications/diagnosis , Thrombosis/diagnosis , beta 2-Glycoprotein I/immunology , Adult , Antibodies, Anticardiolipin/blood , Antiphospholipid Syndrome/blood , Antiphospholipid Syndrome/immunology , Biomarkers/blood , Female , Humans , Lupus Coagulation Inhibitor/blood , Male , Predictive Value of Tests , Pregnancy , Pregnancy Complications/blood , Pregnancy Complications/immunology , Thrombosis/blood , Thrombosis/immunology
5.
Rev Med Brux ; 26(5): 445-50, 2005.
Article in French | MEDLINE | ID: mdl-16318098

ABSTRACT

This case report describes the evolution of a mycosis fungoides into a Sézary syndrome. The originality of the case consists in the appearance of ascitis with Sézary cells during the leukemic phase. It is the second report of a such case. Mycosis fungoides and its leukemic variant, the Sézary syndrome, are primary cutaneous T-cell lymphomas. Their incidence is low. The treatments are topical in the early stages and systemic during the advanced stages. New immunomodulating treatments are in development. The existing therapeutic agents unfortunately do not improve the prognosis of the disease today.


Subject(s)
Ascites/etiology , Sezary Syndrome/complications , Skin Neoplasms/complications , Administration, Topical , Aged , Aged, 80 and over , Female , Humans , Immunologic Factors/therapeutic use , Prognosis , Sezary Syndrome/drug therapy , Skin Neoplasms/drug therapy
6.
Clin Lab Haematol ; 24(3): 179-82, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12067284

ABSTRACT

Protein aggregates, red cell or white cell fragments are known to interfere with platelet counts in automated blood analysers, both by aperture impedance and optical technologies. When a falsely high value is suspected, interference by pseudo-platelet particles can be confirmed by systematic examination of stained blood films. The method that best avoids these sources of interference is the reference, immunological platelet count. We describe a case of treated malaria with a false normal platelet count. The blood smear revealed small red cells, infected by trophozoites of Plasmodium falciparum, that interfered with the platelet count. The Cell Dyn 4000 shows different patterns of interference by infected red cells in its impedance and optical counts, and thrombocytopenia was suspected immediately. This was confirmed by a phase-contrast microscopic platelet count.


Subject(s)
Malaria/blood , Platelet Count/methods , Adult , Antibodies, Monoclonal/analysis , Blood Platelets/immunology , Erythrocytes/microbiology , Erythrocytes/pathology , False Positive Reactions , Humans , Male , Platelet Count/instrumentation , Platelet Count/standards
8.
Br J Haematol ; 106(3): 756-61, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10468870

ABSTRACT

We have previously shown that polymorphonuclear leucocytes (PMN) harvested from children with cancer and exposed to chemotherapy exhibit defective bactericidal activities against both Gram-positive and Gram-negative microorganisms as well as accelerated apoptosis. In this study, PMN from children with cancer were evaluated to compare in vitro the corrective effects of the two myeloid colony stimulating factors G-CSF and GM-CSF on these defective pathways. Both G-CSF and GM-CSF were able to increase the defective bactericidal activities against S. aureus and E. coli. However, GM-CSF was consistently superior to G-CSF in correcting PMN microbicidal activity; this correction was incomplete since it did not reach the level observed in normal PMN exposed to GM-CSF. The accelerated apoptosis of PMN was not affected by G-CSF. In contrast, GM-CSF significantly prolonged the survival of the PMN although it did not reach the level of survival observed with normal PMN exposed to GM-CSF. These observations were consistent with other studies indicating that in PMN, microbicidal activities and apoptosis are differentially sensitive to the myeloid growth factors G-CSF and GM-CSF.


Subject(s)
Granulocyte Colony-Stimulating Factor/therapeutic use , Granulocyte-Macrophage Colony-Stimulating Factor/therapeutic use , Leukemia/pathology , Neutrophils/physiology , Phagocyte Bactericidal Dysfunction/therapy , Adolescent , Apoptosis , Child , Child, Preschool , Escherichia coli , Humans , Staphylococcus aureus
9.
J Lab Clin Med ; 133(4): 353-61, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10218766

ABSTRACT

Neutrophils (PMNs) from patients with secondary iron overload have an increased iron and ferritin content as well as a phagocytosis defect. Several serum components might be incriminated in the cellular iron accumulation. We therefore compared the effects on the PMN phagocytosis of total serum as well as the ferritin and transferrin fractions of serum derived from patients with thalassemia major and healthy control subjects. An incubation system of PMNs was developed. PMN phagocytosis was measured before and after incubation. Total serum from patients with thalassemia induced a defect that was prevented by co-incubation with deferoxamine (DFO). Gel-filtration chromatography was performed to separate the serum fraction containing transferrin and albumin from that containing ferritin. The transferrin-albumin fraction had no effect on PMN phagocytosis. On the contrary, the ferritin fraction of normal serum was deleterious to PMN phagocytosis, and the same fraction from thalassemic serum decreased PMN phagocytosis even more. Co-incubation with DFO or catalase improved this defect. Moreover, a cellular increase in the L-type subunit of ferritin was observed after the incubation of PMNs with the ferritin-containing fraction from thalassemic serum. In conclusion, serum from patients with thalassemia is toxic to PMNs, and this toxicity is due to ferritin-associated iron.


Subject(s)
Ferritins/blood , Hemosiderosis/blood , Iron/pharmacology , Neutrophils/drug effects , Phagocytosis/drug effects , beta-Thalassemia/blood , Adolescent , Blood Transfusion , Catalase/pharmacology , Chelating Agents/pharmacology , Child , Child, Preschool , Deferoxamine/pharmacology , Female , Ferritins/pharmacology , Hemosiderosis/etiology , Humans , Iron/blood , Luminescent Measurements , Male , Neutrophils/physiology , Tetradecanoylphorbol Acetate/pharmacology , Transferrin/metabolism
10.
Br J Haematol ; 102(5): 1284-91, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9753058

ABSTRACT

Treatment of average-risk acute lymphoblastic leukaemia (ALL) in children consists of 6 months of intensive chemotherapy followed by 18 months of maintenance therapy. Polymorphonuclear leucocyte (PMN) functions from children with ALL were studied in order to evaluate and compare the toxicity of the initial intensive treatment with the toxicity of the subsequent less intensive maintenance treatment. H2O2 and O2- production, evaluated by chemiluminescence, were significantly decreased during the intensive period but returned to normal values when maintenance therapy began. In contrast, bactericidal activity against Gram-positive and Gram-negative microorganisms remained at low levels throughout the treatment but returned to normal values in patients off chemotherapy. PMN from patients on maintenance therapy exhibited an excess of morphological changes associated with apoptosis. This was confirmed by standard two-colour flow cytometry which revealed an increase in the number of hypodiploid cells, and increased expression of membrane phosphatidylserine together with a drastic reduction in the expression of the Fcgamma receptor IIIB (CD16). These defective PMN were differentially sensitive to the effects of granulocyte colony stimulating factor (G-CSF): G-CSF induced similar increase in chemiluminescence in control and patient PMN; GSF partially corrected the defective bactericidal activity; G-CSF did not affect the accelerated PMN apoptosis. These observations indicate that ALL children undergoing chemotherapy present PMN defective functions which are partially sensitive or even resistant to G-CSF.


Subject(s)
Granulocyte Colony-Stimulating Factor/pharmacology , Neutrophils/immunology , Precursor Cell Lymphoblastic Leukemia-Lymphoma/immunology , Adolescent , Cell Survival , Child , Child, Preschool , Escherichia coli/immunology , Humans , Luminescent Measurements , Neutrophil Activation , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Respiratory Burst , Staphylococcus aureus/immunology
11.
J Infect Dis ; 174(4): 800-5, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8843219

ABSTRACT

Granulocyte colony-stimulating factor (G-CSF) has important direct and priming effects on different functions of normal mature polymorphonuclear leukocytes (PMNL). Previous study has shown an alteration in respiratory burst and bactericidal activities of PMNL harvested from children with cancer treated with chemotherapy. The present study evaluates the possibility that recombinant human (rh) G-CSF could correct these defective functions in vitro. Free radical formation in defective PMNL was enhanced by rhG-CSF to a level similar to that found in normal PMNL primed by rhG-CSF. The defective bactericidal activity against Escherichia coli and Staphylococcus aureus was also corrected. This bactericidal activity was not different from that observed in normal PMNL primed by rhG-CSF. In conclusion, correction of the altered free radical-formation pathway by rhG-CSF in these cells contributed to the restoration of normal bactericidal activity against both gram-positive and gram-negative microorganisms.


Subject(s)
Antineoplastic Agents/adverse effects , Granulocyte Colony-Stimulating Factor/therapeutic use , Neoplasms/drug therapy , Neutrophils/drug effects , Adolescent , Blood Bactericidal Activity/drug effects , Child , Child, Preschool , Escherichia coli/immunology , Female , Granulocyte Colony-Stimulating Factor/pharmacology , Humans , Male , Neoplasms/immunology , Neutrophils/physiology , Recombinant Proteins/therapeutic use , Staphylococcus aureus/immunology
12.
Rev Med Brux ; 17(3): 136-9, 1996 Jun.
Article in French | MEDLINE | ID: mdl-8766585

ABSTRACT

We report the case of a 70 years old woman who developed a thrombotic thrombocytopenic purpura. Despite a treatment with corticoids and high doses IV gammaglobulins, the patient developed seizures. Treatment with plasma exchanges combined with plasma infusions allowed recovery. The authors review the clinical and biological aspects as well as the pathogeny of the disease. The authors insist on the importance of the plasma exchanges in the treatment of this disease.


Subject(s)
Purpura, Thrombotic Thrombocytopenic/therapy , Aged , Blood Cell Count , Drug-Related Side Effects and Adverse Reactions , Female , Humans , Infections/complications , Neoplasms/complications , Plasma Exchange , Purpura, Thrombotic Thrombocytopenic/blood , Purpura, Thrombotic Thrombocytopenic/etiology
13.
Pediatr Res ; 39(5): 835-42, 1996 May.
Article in English | MEDLINE | ID: mdl-8726238

ABSTRACT

To analyze the toxicity associated to chemotherapy upon granulocytes, different functional assays were performed, within days of drug exposure and at time of bone marrow recovery, on polymorphonuclear neutrophils (PMN) from children with cancer. There were no significant postchemotherapy changes in the expression of the different receptors studied nor in the phagocytosis of Staphylococcus aureus 42D. By contrast, a significant decrease was observed in H2O2 production in PMN recently exposed to chemotherapy with both cytofluorometric and chemiluminescence assays. There was also a decrease in the production of O2- and in chemotaxis; finally, the intracellular killing of S. aureus 42D and Escherichia coli was reduced. In patients having recovered from drug-induced bone marrow aplasia, PMN functions were found to be normal except for bactericidal activity which was still defective. The observations indicate that, in patients exposed to chemotherapy, some PMN functions are transiently altered, whereas microorganism cell killing is continuously impaired.


Subject(s)
Antineoplastic Agents/adverse effects , Granulocytes/drug effects , Granulocytes/physiology , Neoplasms/drug therapy , Neoplasms/physiopathology , Adolescent , Blood Bactericidal Activity/drug effects , Bone Marrow/drug effects , Chemotaxis, Leukocyte/drug effects , Child , Child, Preschool , Escherichia coli/immunology , Female , Granulocytes/immunology , Humans , Hydrogen Peroxide/metabolism , In Vitro Techniques , Male , Neoplasms/immunology , Neutrophils/drug effects , Neutrophils/immunology , Neutrophils/physiology , Phagocytosis/drug effects , Receptors, Complement/drug effects , Receptors, Complement/metabolism , Receptors, IgG/drug effects , Receptors, IgG/metabolism , Respiratory Burst/drug effects , Staphylococcus aureus/immunology , Superoxides/metabolism
14.
Clin Exp Allergy ; 25(1): 73-9, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7728626

ABSTRACT

Previously we have reported that in asthmatics an inhalation of 20 micrograms lipopolysaccharide (LPS) produces a bronchial obstruction associated with an inflammatory blood response. The aim of the present study was to evaluate this response in normal subjects. Eight normal non-atopic subjects were challenged by inhalation of a solution containing 20 micrograms LPS (from Escherichia coli 026:B6) a week after bronchial challenge with control solution. The lung function response was evaluated by the changes in forced expiratory volume in one second (FEV1), in specific conductance and in airway resistance while the blood inflammatory response was evaluated by serial measures of total white blood cells (WBC) and polymorphonuclear neutrophils (PMN) count, luminol enhanced-chemiluminescence (luminol-CL, as a marker of the PMN degree of activation), C-reactive protein (CRP), haptoglobin, complement fraction C3, tumour necrosis factor-alpha (TNF-alpha) and adrenocorticotropic hormone (ACTH). No response in lung function was observed for 6 h after the LPS inhalation. The count in WBC and PMN increased 300 (P < 0.01) and 360 (P < 0.01) min after the LPS challenge associated with an increase in the level of luminol-CL (P < 0.001). This rise in luminol-CL level was significant at 120 min (P < 0.05) before any change in the PMN count. After 24 and 48 h the acute-phase protein CRP raised significantly (P < 0.01), the other proteins C3 and haptoglobin being unchanged. A slight increase in ACTH was observed 240 and 360 min (P < 0.05) after the LPS challenge while the TNF alpha detectable level was not modified.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Lung/physiology , Neutrophil Activation , Respiratory Hypersensitivity/physiopathology , Administration, Inhalation , Adrenocorticotropic Hormone/blood , Adult , C-Reactive Protein/metabolism , Endotoxins/administration & dosage , Escherichia coli , Female , Forced Expiratory Volume/physiology , Humans , Leukocyte Count , Lipopolysaccharides , Male , Respiratory Hypersensitivity/etiology , Single-Blind Method
15.
J Trace Elem Electrolytes Health Dis ; 8(3-4): 189-94, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7599511

ABSTRACT

The phagocytosis of blood polymorphonuclear cells (PMNs) was measured by cytofluorometry in 22 patients with inflammatory rheumatic diseases before and after a 60-day treatment with 45 mg zinc daily or a placebo, and the values were compared with those obtained in a group of healthy subjects. Plasma zinc was lower than controls before supplementation and phagocytosis assessed by the percentage of PMNs exhibiting phagocytic activity was significantly impaired. Zinc supplementation increased the percentage of phagocytic PMNs and the mean phagocytic activity, particularly in subjects with initial low phagocytosis. The impairment of PMN phagocytosis could therefore be corrected by zinc supplementation, but the clinical consequence of this stimulant effect remains unknown.


Subject(s)
Gluconates/therapeutic use , Neutrophils/drug effects , Phagocytosis/drug effects , Rheumatic Diseases/drug therapy , Zinc/therapeutic use , Administration, Oral , Adult , Aged , Arthritis, Rheumatoid/drug therapy , Arthritis, Rheumatoid/immunology , Double-Blind Method , Female , Humans , Lupus Erythematosus, Systemic/drug therapy , Lupus Erythematosus, Systemic/immunology , Male , Middle Aged , Rheumatic Diseases/immunology , Spondylitis, Ankylosing/drug therapy , Spondylitis, Ankylosing/immunology
16.
Eur J Haematol ; 51(3): 161-5, 1993 Sep.
Article in English | MEDLINE | ID: mdl-8405331

ABSTRACT

Secondary haemosiderosis may be accompanied by a decrease in the phagocytic function of neutrophils (PMNs). This dysfunction has been attributed to an exaggerated generation of oxidants induced by intracellular iron. However, an accumulation of iron has so far not been reliably demonstrated in neutrophils harvested from iron-overloaded patients. Six polytransfused haemodialysed patients, with a serum ferritin level higher than 1000 micrograms/l, and 10 healthy controls were investigated. The iron status of PMNs was evaluated by iron determination using atomic absorption spectrometry and by ferritin measurement using radioimmunoassay. The phagocytic performance was measured by cytofluorometry. The results confirm that PMNs from the haemosiderosis patients have a decreased phagocytosis. Moreover, they demonstrate for the first time that these PMNs have an increased cellular iron and ferritin content. Both latter concentrations were 4 to 5 times more elevated in secondary haemosiderosis than in healthy controls. This iron accumulation may be toxic for the PMNs and may, at least partially, explain the three-fold higher risk of bacteraemia which has been reported in those patients.


Subject(s)
Hemosiderosis/blood , Iron/blood , Neutrophils/physiology , Aged , Female , Ferritins/blood , Hemosiderosis/etiology , Humans , Male , Middle Aged , Phagocytosis , Renal Dialysis/adverse effects , Transfusion Reaction
17.
Am J Clin Pathol ; 99(6): 673-6, 1993 Jun.
Article in English | MEDLINE | ID: mdl-8100681

ABSTRACT

In view of the increasing need to assess the proliferative activity of hematologic malignancies, slide-based methods to quantify the proliferating cell nuclear antigen (PCNA) were developed and evaluated. Two techniques to evaluate this antigen were adapted to the infiltration level of the disease. The first one is particularly appropriate to massive invasion and is based on the alkaline phosphatase-antialkaline phosphatase complex (APAAP)method. The second one is reversed for reduced infiltration and uses a double immunofluorescence labeling. One is specific for the target cell to be identified and the other one is specific for the PCNA. These techniques permit an easy and accurate routine evaluation of cell cycle marker expression in hematologic malignancies.


Subject(s)
Antibodies, Monoclonal , Antigens, Neoplasm/analysis , Bone Marrow/pathology , Leukemia/pathology , Multiple Myeloma/pathology , Nuclear Proteins/analysis , Cell Division , Fluorescent Antibody Technique , Humans , Immunoenzyme Techniques , Kinetics , Leukocytes, Mononuclear/pathology , Proliferating Cell Nuclear Antigen
18.
J Clin Invest ; 91(5): 1979-86, 1993 May.
Article in English | MEDLINE | ID: mdl-8486769

ABSTRACT

This study investigates the pathophysiology of mucormycosis caused by Rhizopus, which has been reported in 46 dialysis patients, while treated with deferoxamine (DFO). This drug aggravates mucormycosis, which we experimentally induced in guinea pigs and which lead to a shortened animal survival (P < or = 0.01). The drug's effect on Rhizopus is not mediated through the polymorphonuclear cells. Fe.DFO, the iron chelate of DFO, abolishes the fungistatic effect of serum on Rhizopus and increases the in vitro growth of the fungus (P < or = 0.0001). This effect is present at Fe.DFO concentrations > or = 0.01 microM, at which fungal uptake of radioiron from 55Fe.DFO is observed. A 1,000-fold higher concentration of iron citrate is required to achieve a similar rate of radioiron uptake and of in vitro growth stimulation as observed with Fe.DFO. These in vitro effects of Fe.DFO (1 microM) in serum on radioiron uptake and on growth stimulation are more striking for Rhizopus than for Aspergillus fumigatus and are practically absent for Candida albicans. For these three fungal species, the rates of radioiron uptake from 55Fe.DFO and of growth stimulation in the presence of Fe.DFO in serum are directly related (r = 0.886). These results underscore the major role of Fe.DFO in the pathogenesis of DFO-related mucormycosis. Pharmacokinetic changes in uremia lead to a prolonged accumulation of Fe.DFO after DFO administration, which helps explain the increased sensitivity of dialysis patients to DFO-related mucormycosis.


Subject(s)
Deferoxamine/adverse effects , Deferoxamine/pharmacology , Mucormycosis/etiology , Neutrophils/physiology , Renal Dialysis , Rhizopus/growth & development , Animals , Blood Physiological Phenomena , Candida albicans/drug effects , Candida albicans/growth & development , Candidiasis/physiopathology , Guinea Pigs , Humans , In Vitro Techniques , Mucormycosis/physiopathology , Neutrophils/microbiology , Rhizopus/cytology , Rhizopus/drug effects , Spores, Fungal/physiology
19.
Pathobiology ; 61(2): 95-7, 1993.
Article in English | MEDLINE | ID: mdl-8216831

ABSTRACT

Accurate measurements of bacteria concentrations are required in numerous studies; they raise methodological problems that complicate, for instance, the investigations of polymorphonuclear neutrophil functions. We propose a new flow cytometric method of determining bacteria concentrations by comparison with a standardized fluorescent latex bead solution. Relative counts of beads and bacteria are established in a system using both fluorescence and light scatter for the two types of particles. On the one hand, the latex bead size (0.98 microns in diameter) permits counting on traditional hematological counters and, on the other, a flow cytometric detection with the same conditions for bacteria. The reproducibility of the study of bacteria concentration measurements gave a coefficient of variation of < 5%.


Subject(s)
Bacteria , Neutrophils/physiology , Bacteriological Techniques , Flow Cytometry/methods , Humans , Latex , Microspheres
20.
Am J Hematol ; 35(1): 13-7, 1990 Sep.
Article in English | MEDLINE | ID: mdl-2389765

ABSTRACT

The aims of the present study are: first, to assess the toxic role of serum from thalassemic patients in phagocytosis of PMN from healthy controls, and second, to seek to determine whether serum and cellular disturbances of polymorphonuclear neutrophils (PMN) phagocytosis, observed in thalassemic patients, can be prevented and/or corrected by use of desferrioxamine (DFX). Two kinds of in vitro incubations--without or with DFX--were performed. PMN or serum from thalassemic patients or from healthy controls was used. First, a phagocytosis defect of 3 different bacteria species was induced in PMN from healthy controls by incubation in thalassemic serum. Second, DFX could prevent, already at 1 microM, the phagocytic defect induced in normal PMN by the incubation with thalassemic serum, with disappearance of the toxic role of thalassemic serum at higher concentrations. Third, improvement of the phagocytosis defect of PMN from thalassemic patients was also observed at 1 microM of DFX for the 3 bacteria species. Normalization was obtained at higher concentrations for gram-negative bacteria. In vivo studies revealed, after a 3 hr subcutaneous infusion of DFX into 3 thalassemic patients, an improvement of the phagocytosis results and a decrease of the Prussian Blue reactivity of the PMN. It is concluded first that an iron-mediated defect in phagocytosis can be induced in normal neutrophils by incubation in serum from thalassemic patients, and second that a precautious and intensive chelation therapy seems to be advantageous for increasing PMN defense against infectious agents. Special care must nevertheless be taken in order to detect rapidly opportunistic (such as Yersinia) infections.


Subject(s)
Deferoxamine/pharmacology , Neutrophils/physiology , Phagocytosis/drug effects , Thalassemia/physiopathology , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Male , Neutrophils/drug effects , Phagocyte Bactericidal Dysfunction/etiology , Phagocyte Bactericidal Dysfunction/prevention & control , Thalassemia/blood , Thalassemia/pathology
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