The Regulation of Neutrophil Migration in Patients with Sepsis: The Complexity of the Molecular Mechanisms and Their Modulation in Sepsis and the Heterogeneity of Sepsis Patients.

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Common causes include gram-negative and gram-positive bacteria as well as fungi. Neutrophils are among the first cells to arrive at an infection site where they function as important effector cells of the innate immune system and as regulators of the host immune response. The regulation of neutrophil migration is therefore important both for the infection-directed host response and for the development of organ dysfunctions in sepsis. Downregulation of CXCR4/CXCL12 stimulates neutrophil migration from the bone marrow. This is followed by transmigration/extravasation across the endothelial cell barrier at the infection site; this process is directed by adhesion molecules and various chemotactic gradients created by chemotactic cytokines, lipid mediators, bacterial peptides, and peptides from damaged cells. These mechanisms of neutrophil migration are modulated by sepsis, leading to reduced neutrophil migration and even reversed migration that contributes to distant organ failure. The sepsis-induced modulation seems to differ between neutrophil subsets. Furthermore, sepsis patients should be regarded as heterogeneous because neutrophil migration will possibly be further modulated by the infecting microorganisms, antimicrobial treatment, patient age/frailty/sex, other diseases (e.g., hematological malignancies and stem cell transplantation), and the metabolic status. The present review describes molecular mechanisms involved in the regulation of neutrophil migration; how these mechanisms are altered during sepsis; and how bacteria/fungi, antimicrobial treatment, and aging/frailty/comorbidity influence the regulation of neutrophil migration.

Weight gain during treatment course of allogenic hematopoietic stem cell transplantation in patients with hematological malignancies affects treatment outcome.

BACKGROUND AIMS: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective treatment for patients with hematological malignancies; however, allo-HSCT does not come without the cost of treatment-related morbidity and mortality. Early detection of risk factors could be helpful in identifying patients who could benefit from early interventions. Many patients gain weight during the allo-HSCT treatment, although little is known about the impact of weight gain. METHODS: Weight gain in 146 consecutively enrolled adult patients undergoing allo-HSCT was explored. RESULTS: In total, 141 patients (97%) gained weight along the course of allo-HSCT. Median weight increase was 4.8 kg (range 0.0-16.1 kg), with median increase in body weight 6.5% (range 0.0%-30.8%). Maximum weight increase was observed at day +7 (range day -8, +44). Weight gain was associated with increased incidence of acute graft-versus-host disease. Patients with weight gain >10% had a significantly greater 5-year mortality compared with those with lower weight gain (P = 0.031, rank sum test). CONCLUSIONS: Weight gain is a simple variable with the ability to provide prognostic information for patients undergoing allo-HSCT.

Endocan in Acute Leukemia: Current Knowledge and Future Perspectives.

Endocan is a soluble dermatan sulfate proteoglycan expressed by endothelial cells and detected in serum/plasma. Its expression is increased in tumors/tumor vessels in several human malignancies, and high expression (high serum/plasma levels or tumor levels) has an adverse prognostic impact in several malignancies. The p14 endocan degradation product can also be detected in serum/plasma, but previous clinical studies as well as previously unpublished results presented in this review suggest that endocan and p14 endocan fragment levels reflect different biological characteristics, and the endocan levels seem to reflect the disease heterogeneity in acute leukemia better than the p14 fragment levels. Furthermore, decreased systemic endocan levels in previously immunocompetent sepsis patients are associated with later severe respiratory complications, but it is not known whether this is true also for immunocompromised acute leukemia patients. Finally, endocan is associated with increased early nonrelapse mortality in (acute leukemia) patients receiving allogeneic stem cell transplantation, and this adverse prognostic impact seems to be independent of the adverse impact of excessive fluid overload. Systemic endocan levels may also become important to predict cytokine release syndrome after immunotherapy/haploidentical transplantation, and in the long-term follow-up of acute leukemia survivors with regard to cardiovascular risk. Therapeutic targeting of endocan is now possible, and the possible role of endocan in acute leukemia should be further investigated to clarify whether the therapeutic strategy should also be considered.

Carbapenem-Resistant Enterobacteriaceae-Implications for Treating Acute Leukemias, a Subgroup of Hematological Malignancies.

Acute leukemias (AL) are a group of aggressive malignant diseases associated with a high degree of morbidity and mortality. Patients with AL are highly susceptible to infectious diseases due to the disease itself, factors attributed to treatment, and specific individual risk factors. Enterobacteriaceae presence (e.g., Klebsiella pneumonia and Escherichia coli) is a frequent cause of bloodstream infections in AL patients. Carbapenem-resistant Enterobacteriaceae (CRE) is an emerging health problem worldwide; however, the incidence of CRE varies greatly between different regions. Carbapenem resistance in Enterobacteriaceae is caused by different mechanisms, and CRE may display various resistance profiles. Bacterial co-expression of genes conferring resistance to both broad-spectrum ß-lactam antibiotics (including carbapenems) and other classes of antibiotics may give rise to multidrug-resistant organisms (MDROs). The spread of CRE represents a major treatment challenge for clinicians due to lack of randomized clinical trials (RCTs), a limited number of antibiotics available, and the side-effects associated with them. Most research concerning CRE infections in AL patients are limited to case reports and retrospective reviews. Current research recommends treatment with older antibiotics, such as polymyxins, fosfomycin, older aminoglycosides, and in some cases carbapenems. To prevent the spread of resistant microbes, it is of pivotal interest to implement antibiotic stewardship to reduce broad-spectrum antibiotic treatment, but without giving too narrow a treatment to neutropenic infected patients.

Critical upper airway obstruction as the first symptom of acute myeloid leukemia - an anesthesiologic reminder.

Acute upper airway obstruction can be fatal. Early recognition of airway distress followed by diagnostic laryngoscopy and prompt intervention to secure airway control is crucial. We here present a 62-year old male patient who presented with cough and increasing respiratory distress for three weeks. Within the next 24 h, he developed symptoms of critical upper airway obstruction, endotracheal intubation was not possible, and an acute surgical tracheotomy was performed to retain patent airways. A computer tomography scan revealed severe laryngopharyngeal soft tissue thickening and upper airway obstruction caused by leukemic infiltration. He was diagnosed with acute leukemia and responded to induction chemotherapy. This case report points out the importance of establishing the diagnosis of critical upper airway obstruction in patients presenting with respiratory symptoms, and highlights the emergency management of airway obstruction due to malignant infiltration of leukemic blasts. laryngotracheal trauma, bleeding, tonsillar hypertrophy, paralysis of the vocal cords or folds, allergic reactions, and acute infections affecting the upper respiratory tract.1 We present a 62-year old male patient with cough and increasing respiratory distress for the last three weeks. Within 24 h in hospital, he developed symptoms of critical upper airway obstruction. Endotracheal intubation with the patient awakes and selfbreathing using a fiber optic scope was not possible, thus an acute surgical tracheotomy was performed to retain patent airways. Acute myeloid leukemia (AML) with leukemic infiltrations of the upper airways was found to be the underlying cause.

Febrile Neutropenia in Acute Leukemia. Epidemiology, Etiology, Pathophysiology and Treatment.

Acute leukemias are a group of aggressive malignant diseases associated with a high degree of morbidity and mortality. An important cause of both the latter is infectious complications. Patients with acute leukemia are highly susceptible to infectious diseases due to factors related to the disease itself, factors attributed to treatment, and specific individual risk factors in each patient. Patients with chemotherapy-induced neutropenia are at particularly high risk, and microbiological agents include viral, bacterial, and fungal agents. The etiology is often unknown in infectious complications, although adequate patient evaluation and sampling have diagnostic, prognostic and treatment-related consequences. Bacterial infections include a wide range of potential microbes, both Gram-negative and Gram-positive species, while fungal infections include both mold and yeast. A recurring problem is increasing resistance to antimicrobial agents, and in particular, this applies to extended-spectrum beta-lactamase resistance (ESBL), Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE) and even carbapenemase-producing Enterobacteriaceae (CPE). International guidelines for the treatment of sepsis in leukemia patients include the use of broad-spectrum Pseudomonas-acting antibiotics. However, one should implant the knowledge of local microbiological epidemiology and resistance conditions in treatment decisions. In this review, we discuss infectious diseases in acute leukemia with a major focus on febrile neutropenia and sepsis, and we problematize the diagnostic, prognostic, and therapeutic aspects of infectious complications in this patient group. Meticulously and thorough clinical and radiological examination combined with adequate microbiology samples are cornerstones of the examination. Diagnostic and prognostic evaluation includes patient review according to the multinational association for supportive care in cancer (MASCC) and sequential organ failure assessment (SOFA) scoring system. Antimicrobial treatments for important etiological agents are presented. The main challenge for reducing the spread of resistant microbes is to avoid unnecessary antibiotic treatment, but without giving to narrow treatment to the febrile neutropenic patient that reduce the prognosis.

A somnolent woman in her fifties with acute circulatory failure. / En somnolent kvinne i 50-årene med akutt sirkulasjonssvikt.

BACKGROUND: A woman in her fifties was admitted to hospital with decreased awareness and circulatory failure. She had been treated with left atrial cryoablation a few weeks before admission and had been cardioverted a few days after the procedure because of relapse of atrial fibrillation. CASE PRESENTATION: On admission, the patient had systolic blood pressure of 80 mm Hg and an ECG with broad QRS-complexes at 380 ms. We suspected intoxication and she was intubated to administer activated charcoal after gastric lavage. She was cardiovascularly unstable and in need of intravenous infusion of noradrenaline and adrenaline. Further investigations at her home suggested that she had poisoned herself with 4-5 g flecainide, 0.3 g oxazepam and 0.5 g meclizine. After administration of 500 mmol sodium bicarbonate and 5 mmol calcium chloride, the QRS complexes narrowed temporarily. On day 2, due to sustained bradycardia and hypotension despite receiving adrenergic medications, a temporary pacemaker was implanted, leading to improved heart rate and blood pressure. She experienced several complications including hypertensive pulmonary oedema, atrial fibrillation, extensively prolonged QT interval because of polypharmacy and Takotsubo cardiomyopathy. She was discharged from the hospital in good health on day 17. At a follow-up visit at the outpatient clinic 12 weeks later, cardiac function had normalised. The QT interval was now normal; however, there were persistent T-wave inversions in leads I, aVL and V4-6. INTERPRETATION: Flecainide blocks sodium channels in cardiomyocytes. Intoxication with flecainide is rare, with mortality rates of about 10 %. Sodium bicarbonate in larger doses has been reported to stabilise patients with flecainide intoxication due to modification of the binding of flecainide to sodium receptors in cardiomyocytes, and due to alkalisation which makes flecainide detach from sodium receptors. Our patient had a temporary effect with narrowing of QRS complexes after receiving sodium bicarbonate. She also showed a beneficial effect from implantation of a temporary pacemaker, although earlier case reports have described problems with high thresholds and capture failure.

Infective endocarditis in Western Norway: a 20-year retrospective survey.

BACKGROUND: To investigate epidemiological trends of infective endocarditis (IE) in western Norway a retrospective study was performed. METHODS: Characteristics of 706 IE admissions from 1996 to 2005 and 2006 to 2015 were analysed and compared using the Chi-square test for categorical variables and the t-test for age. Survival was analysed by multiple Cox regression and reported by the hazard ratio (HR). RESULTS: Mean annual incidence rates increased from 4.6 to 7.4 per 100,000 inhabitants (rate ratio: 1.97, 95% confidence interval: 1.52-2.56, p < .001). Non-viridans streptococci, enterococci and Staphylococcus aureus (S. aureus), were all independently associated with increased mortality. The frequency of IE caused by enterococci increased from 3.7 to 13.0% (p < .001). The proportion of intravenous drug users (IVDU) increased from 16.5 to 23.5% (p = .015) and had increasing aortic valve involvement (p = .023). Prosthetic valve endocarditis (PVE) constituted 30% of IE cases in both decades with biological PVE increasing from 9.4 to 22.1% (p < .001) and mechanical PVE decreasing from 18.7 to 8.9% (p < .001). In the last decade, valve replacement surgery was performed in 37.6% of the patients, of which 85.5% received a bioprosthesis. CONCLUSIONS: The incidence of IE increased significantly. Non-viridans streptococci, enterococci and S. aureus were all significantly associated with increased mortality. The increased number of enterococcal IE and the increased number of IVDUs with left-sided IE constituted new challenges. Biological implants were preferred in a majority of patients requiring surgery.

Non-curative surgery for aortoenteric fistula.

Graft infection with secondary aortic fistula is a rare complication following implantation of aortic prostheses, frequently occurring after emergency procedures and reoperations. The condition is associated with considerable morbidity and mortality. Curative treatment consists of explantation of the infected graft followed by fistula revision and implantation of a new graft in combination with antimicrobial therapy. Non-curative treatment with aortic stentgraft and long-term substitution treatment with antibiotics may be an option in cases where graft explantation is deemed too risky. We present an elderly patient with aortoenteric fistula following surgery for ruptured abdominal aortic aneurysm. Implantation of an aortic stentgraft and fistula revision was performed but the original aortic prosthesis was not explanted. The aortoenteric fistula recurred twice, but the patient has survived more than 12 years following non-curative surgery with good quality of life.

Cardiac surgery for infective endocarditis in patients with intravenous drug use.

OBJECTIVES: Intravenous drug users have a high risk of infective endocarditis and reduced survival. Cardiac surgery may be recommended for these patients, but redo surgery is controversial. This study describes the characteristics and outcomes of intravenous drug users accepted for surgery during a 12-year period. METHODS: This retrospective study included 29 injecting drug users treated with valve surgery for endocarditis between January 2001 and December 2013 at a tertiary academic centre. Survival was assessed by Kaplan-Meier analysis. RESULTS: The median patient age was 36 (24-63) years and 27 patients (93%) were male. Staphylococcus aureus (52%) and Enterococcus faecalis (17%) were the most common microorganisms. Common illicit drugs were opioids (69%), amphetamines (52%) and benzodiazepines (24%). Mixed abuse was reported in 66% of patients. Seven patients (24%) had prior intracardial implants or native valve pathology. Twenty-five patients (86%) were positive for hepatitis C virus antibody, but none carried the human immunodeficiency virus. Twelve (41%) were homeless and 15 (52%) had poor dental hygiene. Three patients (10%) received medication-assisted rehabilitation before surgery. The main indications for surgery were regurgitation and secondary heart failure (86%), embolization (41%) and uncontrolled infection (24%). Aortic valve replacement was performed in 24 patients (83%), either as part of univalvular or multiple valve surgery. Seven patients (24%) had multivalvular endocarditis. All but 3 patients received biological valve prostheses. The 30-day mortality was 7% after first time surgery. During follow-up, 15 patients (52%) presented with reinfection: 10 (35%) were offered a second and 2 (7%) a third operation. Thirty-day mortality was 10% after redo surgery. Thirteen patients (45%) died within a median of 22 (0-84) months. Continued intravenous drug use was reported in 70 and 44% of patients after the first and second operation, respectively. CONCLUSIONS: Cardiac surgery for infective endocarditis has acceptable early postoperative results among intravenous drug users. The 2- and 5-year survival were 79 and 59%, respectively. The number of reinfections was high within 2 years, as continued drug use seems to be a major challenge for this group.

Circulating T cells in patients with untreated acute myelogenous leukemia are heterogeneous and can be activated through the CD3/TCR complex.

T lymphocyte defects may contribute to the immune insufficiency seen in acute myelogenous leukemia (AML). We therefore characterized the T cell system for untreated AML patients. T lymphocyte subsets were analyzed by flow cytometry for 45 AML patients. The in vitro interferon-gamma (IFNgamma) release in response to stimulation with anti-CD3 plus anti-CD28 in the presence of autologous AML cells was examined for 31 patients. The majority of circulating lymphocytes were CD3(+)T cells, and CD19(+)B cells usually constituted < 10% of the lymphocytes. Most T cells expressed the alphabeta T cell receptor (TCRalphabeta(+)), and only a minority of the cells was TCRgammadelta(+). Both CD4(+) and CD8(+)T cells were detected, the CD4:CD8 ratio showed a wide variation but was generally >1.0. The majority of CD4(+) and CD8(+)T cells were CD45RA(+) cells. The T cells could be stimulated to release IFNgamma in response to anti-CD3 plus anti-CD28 ligation even in the presence of excess autologous AML blasts, and for a subset of patients (6 of 27) these IFNgamma levels could be further increased by the novel protein kinase C (PKC) agonist PEP005. In conclusion, circulating T cells in patients with untreated AML are mainly CD4(+) or CD8(+) TCRalphabeta(+); both CD45RA(+) and CD45R0(+) can be detected, and these cells can be activated through the CD3/TCR complex even in the presence of excess AML cells. For a subset of patients T cell responsiveness can be further increased by targeting PKC and these data therefore suggest that T cell function is not inhibited in AML patients.

T cells remaining after intensive chemotherapy for acute myelogenous leukemia show a broad cytokine release profile including high levels of interferon-gamma that can be further increased by a novel protein kinase C agonist PEP005.

Cytokines are released during T cell activation, including the potentially anti-leukemic interferon-gamma (IFNgamma), but also the hematopoietic growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF) that enhance proliferation and inhibit apoptosis of acute myelogenous leukemia (AML) cells. In the present study we investigated the release of IFNgamma and GM-CSF by circulating T cells in AML patients with chemotherapy-induced cytopenia. T cells were activated with anti-CD3 plus anti-CD28 in a whole-blood assay in the presence of their natural cytokine network. We examined 63 samples derived from 16 AML patients during 28 chemotherapy cycles. Activated T cells showed a broad cytokine release profile, but IFNgamma and GM-CSF levels showed a significant correlation and were generally higher than the other cytokine levels. Higher IFNgamma and GM-CSF responses were associated with a low CD4:CD8 ratio, older patient age and no ongoing chemotherapy indicating potential utility of T cell activation regimes for the older AML patient. The cytokine levels could be further increased by the novel protein kinase C agonist PEP005, which also induced significant production of IL2 and TNFalpha which could contribute to anti-tumor effects in AML patients. We conclude that remaining T cells after intensive AML therapy show a broad cytokine release profile including high and significantly correlated levels of potentially anti-leukemic IFNgamma and the AML growth factor GM-CSF. The final outcome of an AML-initiated T cell cytokine response will thus depend on the functional characteristics of the AML cells, in particular the relative expression of IFNgamma and GM-CSF receptors which differs between AML patients.

Lipoteichoic acid derived from Enterococcus faecalis modulates the functional characteristics of both normal peripheral blood leukocytes and native human acute myelogenous leukemia blasts.

OBJECTIVES: Several case reports have described complete hematological remissions for patients with otherwise untreated acute myelogenous leukemia (AML) who receive hematopoietic growth factor therapy during complicating bacterial infections. This may be caused by indirect cytokine effects, but direct effects of infecting agents on the malignant cells are also possible because bacterial molecules can bind to specific receptors expressed by normal and malignant leukocytes. Lipoteichoic acid (LTA) is a cell wall component of gram-positive bacteria, and it can activate normal immunocompetent cells through binding to specific cell membrane receptors. METHODS: We investigated effects of LTA derived from Enterococcus faecalis on in vitro cultured (i) normal peripheral blood mononuclear cells (PBMC); (ii) remaining T cells derived from patients with hematologic malignancies and chemotherapy-induced leukopenia; and (iii) native human AML cells. RESULTS: Increased interleukin 1beta (IL1beta) and IL8 release by in vitro cultured normal PBMC was observed after stimulation with LTA at concentrations > or =5 microg/mL; these levels were lower than for lipopolysaccharide (LPS)-stimulated cells and LTA antagonized LPS-induced cytokine release by normal PBMC. In most cases LTA did not alter T-cell proliferation for patients with chemotherapy-induced leukopenia. The LTA effects on AML blasts were investigated for 62 consecutive patients. LTA altered either cytokine (granulocyte-macrophage colony-stimulating factor + stem cell factor + IL3)-dependent proliferation or the release of IL1beta/IL8 for 23 patients; the effects were divergent but increased proliferation/cytokine levels were most commonly observed. CONCLUSION: The LTA derived from E. faecalis can modulate the functional characteristics of normal leukocytes and native human AML blasts.

Functional characterization of T lymphocytes derived from patients with acute myelogenous leukemia and chemotherapy-induced leukopenia.

T-cell-targeting immunotherapy is now considered in acute myelogenous leukemia (AML). Immunotherapy seems most effective for patients with a low AML cell burden, and a possible strategy is therefore to administer immunotherapy early after intensive chemotherapy when patients have a low leukemia cell burden and severe treatment-induced cytopenia. To further investigate this possible therapeutic approach we used a whole blood assay to characterize the proliferative responsiveness (3H-thymidine incorporation) of circulating T cells from AML patients with severe treatment-induced leukopenia, i.e., peripheral blood leukocyte counts < 0.5x10(9)/l. This assay will reflect both quantitative and qualitative differences. Responses were compared for 17 AML patients, 6 patients with acute lymphoblastic leukemia (ALL), and a group of 21 healthy controls. Most circulating leukocytes in the AML patients were T lymphocytes, whereas B lymphocytes and monocytes usually constituted < 10%. Anti-CD3-stimulated proliferation was significantly lower for AML patients compared with healthy controls. However, proliferation in response to anti-CD3 + anti-CD28 did not differ for AML patients and healthy controls, an observation suggesting that T cells from AML patients have an increased responsiveness in the presence of optimal costimulation that compensates for the quantitative T-cell defect. In contrast, the responses were significantly lower for ALL than for AML patients. We conclude that the remaining T-cell population in AML patients with severe chemotherapy-induced cytopenia show an increased proliferative responsiveness and may represent a therapeutic target when antileukemic immunotherapy is tried in combination with intensive chemotherapy.

Cellular immune responses in multiple myeloma patients with treatment-induced cytopenia early after high-dose chemotherapy and autologous peripheral blood stem cell transplantation.

Proliferative T cell responses were compared for two patient groups with severe treatment-induced leukopenia (white blood cell counts < 0.5 x 10(9)/l): (i). multiple myeloma patients receiving high-dose melphalan and autologous peripheral blood stem cell transplantation; (ii). patients receiving conventional intensive chemotherapy for acute leukemia or myelodysplasia. Although the majority of circulating leukocytes were CD2(+)TCRalphabeta(+) in both groups, the myeloma patients showed significantly lower T cell proliferation in responses to several activation signals (anti-CD3, anti-CD3 + IL2, anti-CD3 + anti-CD28, anti-CD3 + anti-CD28+IL2. Our results suggest that myeloma patients with post-transplant cytopenia have a more severe cellular immune defect than patients with other hematological malignancies and severe cytopenia due to conventional intensive chemotherapy.

[Brucellosis--a rare zoonosis]. / Brucellose--en sjelden zoonose.

BACKGROUND: Brucellosis is a rare infectious disease in Norway. MATERIAL AND METHODS: We present a patient admitted to the department of medicine at Haraldsplass Hospital, Bergen and give a review of the epidemiology, symptoms, diagnosis and treatment of Brucellosis. RESULTS AND INTERPRETATION: The clinical picture of Brucellosis is often non-specific, with swings in fever, general malaise and myalgia. Complications such as osteomyelitis, endocarditis and coagulase-negative staphylococcus (CNS) infection occur in rare cases. The diagnosis is established by detection of Brucella species in blood cultures or tissue aspirate. Brucella is often difficult to isolate, but the available serological tests are highly sensitive and specific. The infection is treated with long-term administration of a combination of two appropriate antibiotic drugs. Surgery may be necessary in case of serious complications. If adequately treated, Brucellosis has a good overall prognosis.

Functional evaluation of proliferative T cell responses in patients with severe T lymphopenia: characterization of optimal culture conditions and standardized activation signals for a simple whole blood assay.

In this methodological study, we describe an assay for analysis of proliferative T cell responses in patients with severe leukopenia. Severe treatment-induced cytopenia is observed in patients with malignant disorders who receive conventional intensive chemotherapy or autologous stem cell transplantation. The quantitative T cell defect can then be characterized by flow cytometric analysis of membrane molecule expression, whereas the functional status of the remaining T cell population is more difficult to evaluate. In the present study, we describe a standardized whole blood assay that requires small sample volumes and can be used for repeated analysis even in severely ill patients. The assay is based on the following strategy: (i) blood samples are diluted with the serum-free medium X-vivo 10, (ii) T cells are activated either with monoclonal immunoglobulin E (IgE) anti-CD3 or anti-CD3 plus anti-CD28; (iii) T cell proliferation is assayed by [(3)H]thymidine incorporation after 4 days of in vitro culture. These proliferative responses are not affected by the plasma levels of interleukin-2 (IL-2), sIL-2-R alpha, IL-7 and IL-15, and the kinetics of the response are not altered by the presence of exogenous cytokines. Detectable proliferation is observed for most patients with treatment-induced cytopenia. We conclude that the assay can be used for functional characterization of remaining T lymphocytes in patients with severe T lymphopenia.

The angioregulatory phenotype of native human acute myelogenous leukemia cells: influence of karyotype, Flt3 abnormalities and differentiation status.

INTRODUCTION: The cytogenetic abnormalities and the response to induction therapy have been regarded as the most important prognostic parameters in acute myelogenous leukemia (AML) patients. Recent studies have demonstrated that internal tandem duplications and specific D-835 point mutations of the Flt3 gene, as well as the angioregulatory phenotype represent additional adverse prognostic factors. The aim of the study was to investigate possible associations between genetic abnormalities, differentiation status and angioregulatory phenotype in native human AML blasts. METHOD: Native AML blasts derived from consecutive patients were cultured in vitro and concentrations of angioregulatory molecules determined in the supernatants. RESULTS: Most patients released at least two different angioregulatory mediators. Pro-angiogenic interleukin 8 (IL8) was released at relatively high levels for most patients, many of these patients showed additional release of pro-angiogenic vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF). High release of anti-angiogenic IL12 was associated with high release of pro-angiogenic IL8 and VEGF. Furthermore, patients with D-835 mutations showed increased IL12 release, whereas patients with normal karyotype had decreased HGF release. Myelomonocytic differentiation was associated with IL18 release and CD34 expression with low IL12 release. CONCLUSION: Our results suggest that native human AML blasts have a pro-angiogenic phenotype. Although the investigated genetic abnormalities are associated with variation in the in vitro release of angioregulators, these differences are relatively small and do not quantitatively involve the most important IL8 release. It therefore seems unlikely that this phenotypic variation can explain the prognostic impact of the genetic abnormalities.

Interleukin-7 (IL-7) in patients receiving intensive chemotherapy for acute myelogenous leukemia: studies of systemic IL-7 Levels and IL-7 responsiveness of circulating T lymphocytes.

Early immune reconstitution after intensive chemotherapy for acute myelogenous leukemia (AML) occurs after 2-4 weeks of cytopenia, but T cell reconstitute is usually completed after several months. Interleukin-7 (IL-7) is a T cell growth factor involved in the late immune reconstitution, but its function during the early period of cytopenia has not been investigated. In the present study, we found that patients with untreated AML had decreased IL-7 serum levels, and induction chemotherapy had divergent effects on these levels. In contrast, patients in complete remission (CR) had intermediate levels immediately before consolidation therapy, and these levels decreased significantly when the patients developed therapy-induced cytopenia. Systemic IL-7 levels showed only minor increases during febrile neutropenia. Furthermore, IL-7 enhanced in vitro proliferative responses of polyclonal T cells derived from cytopenic patients, and the majority of circulating clonogenic CD4(+) and CD8(+) T cells from cytopenic patients could respond to both IL-2 and IL-7. To conclude, patients with untreated AML and severe chemotherapy-induced leukopenia (1) differ from other patients with CD4(+) T lymphopenia in that they show decreased IL-7 serum levels, and (2) the detection of circulating IL7-responsive T cells indicates that variations in systemic IL-7 levels are functionally important and contribute to an additional qualitative T cell defect in these severely T lymphopenic patients.