Prolonged but reversible neutrophil dysfunctions differentially sensitive to granulocyte colony-stimulating factor in children with acute lymphoblastic leukaemia

Amoeboid neutrophils with few granules in childhood acute precursor B cell leukemia

BACKGROUND

We sometimes treat children with acute lymphoblastic leukemia in whom neutrophil function is impaired at diagnosis. Transmission electron microscopy enables more accurate assessment by providing greater morphological detail. Using transmission electron microscopy, we have found 2 types of neutrophils in the peripheral blood of children: 1) amoeboid neutrophils, which are characterized as amoeboid cells with pseudopodia and few granules, and 2) round neutrophils with many granules at different stages and glycogen particles.

AIM

To assess the pathological role of amoeboid neutrophils, we investigated amoeboid neutrophils in the peripheral blood of children with leukemia.

METHODS

Amoeboid neutrophils were examined in peripheral blood from 12 children with acute B-cell precursor lymphoblastic leukemia (BCP-ALL). Eight children with short stature served as healthy control subjects.

RESULTS

The percentage of amoeboid neutrophils (per total neutrophil count) at onset or relapse of BCP-ALL was significantly higher than at remission. Children with short stature showed a lower percentage of amoeboid neutrophils than did children with acute leukemia.

CONCLUSION

The presence of fewer intracellular granules in amoeboid neutrophils suggests lower neutrophil activity. These results indicate that amoeboid neutrophils in patients with BCP-ALL have lower function at onset and relapse.

Effects of malnutrition on oxidative burst functions and infection episodes in children with acute lymphoblastic leukemia

INTRODUCTION

The aim of this study was to determine the effect of malnutrition on oxidative burst functions (OBF) of neutrophils in children with acute lymphoblastic leukemia (ALL).

MATERIALS AND METHODS

Twenty-eight patients with ALL and thirty healthy controls were enrolled to the study. Thirteen patients with ALL were found to have malnutrition. While neutrophil OBF of ALL patients without malnutrition were studied both before induction chemotherapy and 3 months after, the same functions in ALL patients with malnutrition were studied both before induction chemotherapy and when the nutritional status improved. Control group were studied at admission and 3 months later.

RESULTS

The OBF of ALL patients with and without malnutrition before induction chemotherapy were found to be significantly lower than the control group (P = 0.009), whereas the OBF were found to be similar in both patient groups with ALL (P = 0.27). The median infection episode rate and the duration of antibiotics therapy during the study period were similar in both patient groups with ALL. The repeated OBF of both patient groups with ALL were shown to increase to similar values with the control group in the third month of chemotherapy (P = 0.002). The median infection episode rate during the first month of chemotherapy was shown to decrease significantly during the third month of chemotherapy in both patient with ALL groups (P < 0.001).

CONCLUSIONS

We have not been able to demonstrate an overt effect of malnutrition on OBF. However, our results still need to be verified via further larger scaled studies of OBF in leukemic children with and without malnutrition.

Maitake beta-glucan promotes recovery of leukocytes and myeloid cell function in peripheral blood from paclitaxel hematotoxicity

Bone marrow myelotoxicity is a major limitation of chemotherapy. While granulocyte colony stimulating factor (G-CSF) treatment is effective, alternative approaches to support hematopoietic recovery are sought. We previously found that a beta-glucan extract from maitake mushroom Grifola frondosa (MBG) enhanced colony forming unit-granulocyte monocyte (CFU-GM) activity of mouse bone marrow and human hematopoietic progenitor cells (HPC), stimulated G-CSF production and spared HPC from doxorubicin toxicity in vitro. This investigation assessed the effects of MBG on leukocyte recovery and granulocyte/monocyte function in vivo after dose intensive paclitaxel (Ptx) in a normal mouse. After a cumulative dose of Ptx (90-120 mg/kg) given to B6D2F1mice, daily oral MBG (4 or 6 mg/kg), intravenous G-CSF (80 microg/kg) or Ptx alone were compared for effects on the dynamics of leukocyte recovery in blood, CFU-GM activity in bone marrow and spleen, and granulocyte/monocyte production of reactive oxygen species (ROS). Leukocyte counts declined less in Ptx + MBG mice compared to Ptx-alone (p = 0.024) or Ptx + G-CSF treatment (p = 0.031). Lymphocyte levels were higher after Ptx + MBG but not Ptx + G-CSF treatment compared to Ptx alone (p < 0.01). MBG increased CFU-GM activity in bone marrow and spleen (p < 0.001, p = 0.002) 2 days after Ptx. After two additional days (Ptx post-day 4), MBG restored granulocyte/monocyte ROS response to normal levels compared to Ptx-alone and increased ROS response compared to Ptx-alone or Ptx + G-CSF (p < 0.01, both). The studies indicate that oral MBG promoted maturation of HPC to become functionally active myeloid cells and enhanced peripheral blood leukocyte recovery after chemotoxic bone marrow injury.

Clinical pathological and epidemiological assessment of morphologically and immunologically confirmed canine leukaemia

Traditionally, classification of leukaemia in dogs has relied on morphological examination and cytochemical staining patterns, but aberrant cellular morphology and stain uptake often curtails accurate categorization, and historical data based on this classification may be unreliable. Immunophenotyping is now the gold standard for classification of leukaemias. The purpose of this prospective study was to assess the clinical pathological and epidemiological features of a population of dogs with morphologically and immunologically confirmed leukaemia and to compare them within categories: acute and chronic lymphoid leukaemia (ALL and CLL), and acute and chronic myeloid leukaemia (AML and CML). There were 64 cases of morphologically and immunologically confirmed leukaemia: 25 cases of ALL, 17 cases of CLL and 22 cases of AML. Prevalence of B and T immunophenotypes in ALL and CLL was not statistically different. Dogs with AML were significantly younger than those with ALL at presentation (P = 0.04). Golden Retriever dogs in the study population were overrepresented in comparison with a control population of dogs (6/25 ALL cases, 8/64 leukaemia cases). No sex was overrepresented. Dogs with ALL had significantly more severe neutropenia (P = 0.001) and thrombocytopenia (P = 0.002) than those with CLL and had significantly more cytopenias. The severity and numbers of cytopenias seen in ALL and AML were not significantly different. Twenty-one of the leukaemia cases showed one cytopenia, fourteen had two cytopenias and twenty-one cases had pancytopenia. Anaemia was the most common cytopenia seen in isolation (17/21). No dogs had neutropenia without anaemia and/or thrombocytopenia. Total white blood cell counts were not different between the groups. The atypical cell counts within the peripheral blood were significantly higher in ALL than AML; both in isolation and as a percentage of the total white blood cell count (P = 0.03). This study strengthens the hypothesis that acute leukaemias give rise to more profound cytopenias, affecting more cell lines, than chronic leukaemias.

Translational imaging: imaging of apoptosis

Since its original description in 1972, apoptosis or programmed cell death has been recognized as the major pathway by which the body precisely regulates the number and type of its cells as part of normal embryogenesis, development, and homeostasis. Later it was found that apoptosis was also involved in the pathogenesis of a number of human diseases, cell immunity, and the action of cytotoxotic drugs and radiation therapy in cancer treatment. As such, the imaging of apoptosis with noninvasive techniques such as with radiotracers, including annexin V and lipid proton magnetic resonance spectroscopy, may have a wide range of clinical utility in both the diagnosis and monitoring therapy of a wide range of human disorders. In this chapter we review the basic biochemical and morphologic features of apoptosis and the methods developed thus far to image this complex process in humans.

Failure of neutrophil chemotactic function in breast cancer patients treated with chemotherapy

Neutrophil migration is a key host event against infection. Chemotherapy may alter neutrophil function and favor increased risk of infection. Herein, we investigated the effect of chemotherapy on the migration capacity of circulating neutrophils obtained from breast cancer patients and mechanisms involved in this event. Breast cancer women (n=23) at disease stage I-III and healthy control women (n=25) were prospectively enrolled. No differences in the in vitro migratory responses towards the chemotactic stimuli N-formyl- L-methionyl- L-leucyl- L-phenylalanine (fMLP), leukotriene B(4) (LTB(4)) and interleukin (IL)-8 were observed in purified neutrophils from controls and patients, in a microchemotaxis chamber assay. However, the migration capacity evaluated upon chemotherapy (5-fluoruracil, adriamycin and cyclophosphamide, 21-day intervals between cycles, total leukocyte count >/=2,000/mm(3)), on the day immediately before the beginning of the sixth cycle, showed that patient neutrophils (n=14) failed to migrate in response to fMLP compared to response observed upon diagnosis. Considering patients (n=8) with documented bacterial infection between cycles, the number of migrated neutrophils (mean+/-SD) compared to response at diagnosis was markedly reduced upon chemotherapy to either fMLP (30.1+/-8.26 vs. 2.81+/-1.28) or LTB(4) (15.72+/-4.8 vs. 2.8+/-1.64) stimuli respectively. Treatment of control neutrophils with sera of chemotherapy-treated patients with infective episodes, to test for the presence of circulating immunosuppressive factors, significantly reduced the migratory capacity of healthy neutrophils to fMLP, LTB(4) and IL-8, in a dose-dependent way. But no significant differences were found in the serum levels of nitric oxide (NO) metabolites, tumor necrosis factor (TNF)-alpha, IL-6, IL-8 and IL-10 collected at the same time as the collection of blood for neutrophil migration experiments. In conclusion, breast cancer patients showed suppressed neutrophil migratory response upon chemotherapy, accompanied by bacterial infection episodes. Circulating factors are involved, at least partially, in the inhibitory mechanism on neutrophil migration.

Regulation of human polymorphonuclear leukocytes functions by the neuropeptide pituitary adenylate cyclase-activating polypeptide after activation of MAPKs

Anti-inflammatory activities of pituitary adenylate cyclase-activating protein (PACAP) are mediated in part through specific effects on lymphocytes and macrophages. This study shows that in human polymorphonuclear neutrophils (PMNs), PACAP acts as a proinflammatory molecule. In PMNs, vaso-intestinal peptide/PACAP receptor 1 (VPAC-1) was the only receptor found to be expressed by RT-PCR. Using VPAC-1 Ab, we found that VPAC-1 mRNA was translated into proteins. In PMNs, PACAP increases cAMP, inositol triphosphate metabolites, and calcium. It activates two of the three members of the MAPK superfamily, the ERK and the stress-activated MAPK p38. U73122, an inhibitor of phospholipase C (PLC), inhibits PACAP-induced ERK activation, whereas p38 MAPK phosphorylation was unaffected. Using specific pharmalogical inhibitors of ERK (PD098059) and p38 MAPK (SB203580), we found that PACAP-mediated calcium increase was ERK and PLC dependent and p38 independent. PACAP primes fMLP-associated calcium increase; it also primes fMLP activation of the respiratory burst as well as elastase release, these last two processes being ERK and PLC dependent and p38 MAPK independent. PACAP also increases membrane expression of CD11b and release of lactoferrin and metallo proteinase-9 (MMP-9). These effects were PLC dependent (CD 11b, lactoferrin, MMP-9), ERK dependent (CD 11b, lactoferrin, MMP-9), and p38 dependent (CD11b, lactoferrin). We conclude that PACAP is a direct PMN activator as well as an effective PMN priming agent that requires PLC, ERK, and p38 MAPK activities.

Fluorouracil induces apoptosis and surface molecule modulation of peripheral blood leukocytes

Little is known about the direct effect of chemotherapy on normal peripheral blood leukocytes (PBL) or its contribution to leukopenia. We examined 5'-fluorouracil's (5FU) effect on PBL apoptosis and adhesion molecules' expression in a single-drug solid-tumor model. Possible apoptosis mediators were examined. The study included 32 colorectal cancer patients; apoptosis was determined by annexin-V binding and light-scatter morphology before and after drug infusion. CD18, CD11a, CD11b, and CD63 membranal levels were assayed by flow cytometry. Apoptosis was increased post-5FU administration in neutrophils (PMN), monocytes and lymphocytes (P < 0.05). Levels of Fas receptor and activated caspase 3 did not vary indicating that the process was not mediated by caspase 3 in the timeframe studied. Reduced CD63 on monocytes and decreased CD18 expression on PMN and non-apoptotic monocytes were observed (P < or = 0.05). CD11a,b expression did not vary. Decreased CD18 and CD63 levels were demonstrated in apoptotic and non-apoptotic PBL implying a more direct association with the drug itself.

Molecular imaging: The latest generation of contrast agents and tissue characterization techniques

Molecular Imaging technologies will have a profound impact on both basic research and clinical imaging in the near future. As the field covers many different specialties and scientific disciplines it is not possible to review all in a single article. In the current article we will turn our attention to those modalities that are either currently in use or in development for the medical imaging clinic.

Bone marrow stroma damage induced by chemotherapy for acute lymphoblastic leukemia in children

Several studies have suggested a role of bone marrow stroma injury in long-term chemotherapy-induced hematopoietic failure. To evaluate whether bone marrow microenvironment is altered by chemotherapy for acute lymphoblastic leukemia (ALL) and to determine its contribution to postchemotherapy anemia, we investigated the ability of stroma from children receiving maintenance chemotherapy for ALL to support hematopoiesis. Long-term bone marrow cultures (LTBMC) were established with bone marrow cells either from ALL children under therapy (n = 24) or from control subjects (n = 19). Nonadherent cells and colony forming units-granulocytic monocytic (CFU-GM) output in LTBMC did not differ between patients and controls. In contrast, burst forming unit-erythroid (BFU-E) numbers were lower in patient LTBMC (p = 0.013). Co-cultures of normal CD34+ cells and preformed patient or control stromas showed significantly reduced hematopoietic supportive capabilities of patient stromas: both CFU-GM and BFU-E were reduced (p = 0.002 and 0.046, respectively). In addition, supernatants (SN) of patients' LTBMC inhibited normal BFU-E growth compared with SN of normal LTBMC. Transforming growth factor (TGF)-beta1 levels were increased in patient cultures (p = 0.0039) and inversely correlated with BFU-E produced in LTBMC (r = -0.36, p = 0.04). Neutralization of TGF-beta1 significantly increased the BFU-E output of patient LTBMC (p = 0.0078). In contrast, macrophage inflammatory peptide (MIP)-1alpha levels were lower in SN of patients compared with controls (p = 0.015). Thus, chemotherapy for ALL induces functional deregulation within bone marrow stromal cells with an increase in the growth-inhibiting factor TGF-beta1, together with a decrease in MIP-1alpha, which might contribute to hematopoietic toxicity.

The effects of doxorubicin on apoptosis and adhesion molecules of normal peripheral blood leukocytes-an ex vivo study

This ex vivo study was designed to evaluate the effect of doxorubicin (Dox) on normal peripheral blood leukocytes (PBL) in terms of apoptosis and membranal expression levels of adhesion molecules. Blood was drawn immediately prior to and after Dox administration from 21 breast cancer patients, and incubated at room temperature for 24 h. Flow cytometry was employed in analysis of apoptosis with Annexin-V and protein membranal expression levels with monoclonal antibodies to CD49d, CD18, CD11a-c and CD63. Dox induced statistically significant apoptosis in all three major PBL subpopulations (p<0.01). Between 70 and 90% of samples underwent apoptosis in all PBL subgroups. No significant change was observed in the membranal level of CD63, CD49d and CD11a-c after chemotherapy in any PBL subpopulation. However, a significant reduction in the membranal level of CD18 was demonstrated in polymorphonuclear cells after Dox (p<0.005) both in apoptotic and non-apoptotic cells (p<0.05), suggesting a direct effect of Dox rather than an apoptosis-associated phenomenon. We observed the expected leukopenia 10 days after Dox administration with no correlation to apoptosis, suggesting that leukopenia by Dox is largely attributed to toxicity of blood progenitors.

Bactericidal activity response of blood neutrophils from critically ill patients to in vitro granulocyte colony-stimulating factor stimulation

OBJECTIVE

Neutrophil function impairment is common in nonneutropenic critically ill patients. Whether granulocyte colony-stimulating factor (G-CSF) may be useful for preventing nosocomial infection in these patients is debated. The response of blood neutrophils from critically ill patients to G-CSF was investigated in vitro.

DESIGN AND SETTING

Prospective study, laboratory investigation in two intensive care units.

PATIENTS

52 critically ill patients without immunosuppression.

MEASUREMENTS

Neutrophils obtained from 52 patients on the 5th day of their intensive care unit stay were incubated with and without G-CSF (1, 10, 100 ng/ml). Reactive oxygen species (ROS) release and bactericidal activity against Staphylococcus aureus and Pseudomonas aeruginosa were evaluated. Plasma cytokines (interleukin 10, tumor necrosis factor alpha, and G-CSF) were measured.

RESULTS

Median values (25th-75th percentiles) indicated no stimulatory effect of G-CSF on neutrophil bactericidal activity against either organism: S. aureus, 100% (95-109) of the unstimulated condition with 1 ng/ml G-CSF, and P. aeruginosa, 102% (98-109) with 1 ng/ml G-CSF. However, wide interindividual variability was found, ranging from marked inhibition to marked stimulation. Similar variability was found for ROS release. No correlations were found between ROS release and bactericidal activities against either bacterial strain. Inhibition of neutrophil bactericidal activity by G-CSF was associated with significantly higher plasma interleukin 10 concentrations. Plasma G-CSF levels were significantly higher in patients whose neutrophil bactericidal activity was unresponsive to G-CSF, suggesting G-CSF receptor downregulation.

CONCLUSIONS

The effect of G-CSF on in vitro neutrophil bactericidal activity varied widely, depending on endogenous levels of G-CSF and was not predictable based on severity scores.

Exacerbation with granulocyte colony-stimulating factor of prior acute lung injury during neutropenia recovery in rats

OBJECTIVE

Neutropenia recovery may be associated with an increased risk of respiratory function deterioration. A history of pneumonia complicating neutropenia has been identified as the leading cause of adult respiratory distress syndrome during neutropenia recovery in patients receiving anticancer chemotherapy, suggesting that neutropenia recovery may worsen prior lung injury.

DESIGN

Controlled animal study.

SETTING

Research laboratory of an academic institution.

SUBJECTS

Male Sprague-Dawley rats.

INTERVENTIONS

We studied the effect of recovery from cyclophosphamide-induced neutropenia on endotoxin (lipopolysaccharide)- or hydrochloric acid-induced acute lung injury in rats. We also studied the effects of adding granulocyte colony-stimulating factor.

MEASUREMENTS AND MAIN RESULTS

Compared with noncyclophosphamide-treated rats, rats undergoing neutropenia recovery had a higher wet/dry lung weight ratio after hydrochloric acid-induced but not lipopolysaccharide-induced acute lung injury. Granulocyte colony-stimulating factor significantly increased both alveolar cell recruitment (bronchoalveolar lavage fluid counts) and pulmonary edema (wet/dry lung ratio) in both acute lung injury models during neutropenia recovery. Furthermore, in an experiment in hydrochloric acid-instilled rats, exacerbation by granulocyte colony-stimulating factor of hydrochloric acid-induced acute lung injury was inhibited by lidocaine, which prevents adhesion of neutrophils to endothelial cells. Tumor necrosis factor-alpha and interleukin-1 beta concentrations in supernatants of lipopolysaccharide-stimulated alveolar macrophages from rats undergoing neutropenia recovery with granulocyte colony-stimulating factor treatment were significantly increased compared with rats undergoing neutropenia recovery without granulocyte colony-stimulating factor.

CONCLUSION

Neutropenia recovery can worsen acute lung injury, and this effect is exacerbated by granulocyte colony-stimulating factor.

Neutrophil defense in patients undergoing bone marrow transplantation: bactericidal/permeability-increasing protein (BPI) and defensins in graft-derived neutrophils

BACKGROUND

Even after neutrophil counts return to near normal levels, patients undergoing myeloablative chemotherapy and bone marrow transplantation (BMT) are at risk for invasive bacterial infections, raising the possibility that their neutrophil function might be impaired. To assess potential qualitative defects in neutrophil function in patients undergoing BMT, we measured neutrophil content of the antimicrobial (poly)peptides BPI and defensins.

METHODS

Neutrophil extracts were analyzed for content of BPI by Western blotting and ELISA and for defensin peptides by acid-urea polyacrylamide gel electrophoresis (PAGE). Antibacterial activity of neutrophil extracts was measured against Escherichia coli K1/r, a clinical isolate sensitive to synergistic killing by BPI and defensins.

RESULTS

Neutrophil extract BPI content on post-BMT days +20, +30, and +100 (169+/-35, 232+/-57, and 160+/-55 ng per 106 neutrophils, respectively) was similar to the neutrophil BPI content of normal controls (163+/-35 ng per 106 neutrophils). Neutrophil defensin content also did not vary during this time-span. Activity of neutrophil extracts against E. coli K1/r did not differ between BMT patients and controls.

CONCLUSION

At post-BMT days +20 to +100, neutrophils derived from engrafted marrow contain normal quantities of BPI and defensins. Any deficiencies of neutrophil function during this phase are not due to inadequate expression of these antimicrobial (poly)peptides but could reflect abnormalities in other aspects of neutrophil function.

Defective functional activity and accelerated apoptosis in neutrophils from children with cancer are differentially corrected by granulocyte and granulocyte-macrophage colony stimulating factors in vitro

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.