Bilateral basal ganglia involvement in a patient with Griscelli syndrome

We report a 6-year-old Iranian boy with silvery-gray hair, eyelashes and the eyebrows who was admitted because of seizures and subsequent stupor. He had previous history of acute hemiparesis at 1 year of age and hepatitis-like syndrome 3 months ago. Microscopic examination of the patient's hair shaft revealed different sized clumps of melanin seen in the center of the shafts. Bone marrow aspiration revealed erythroid hyperplasia and erythrophagocytic cells. Bilateral frontal cortical and subcortical high signal lesions, dirty white matter, high signal areas in the upper pons and in both caudates and lentiform nuclei in T2 WI were the brain MRI findings of the patient. He died in the accelerated phase of Griscelli Syndrome (GS) type 2. To our knowledge we report the first case of GS from Iran.

Oncologic emergencies: diagnosis and treatment

Patients with malignancies are subject to developing a unique set of complications that require emergent evaluation and treatment. With the increasing incidence of cancer in the general population and improved survival, these emergencies will be more frequently encountered. Physicians must be able to recognize these conditions and institute appropriate therapy after a focused initial evaluation. The approach to definitive therapy is commonly multidisciplinary, involving surgeons, radiation oncologists, medical oncologists, and other medical specialists. Prompt interventions can be lifesaving and may spare patients considerable morbidity and pain. In this review, we discuss the diagnosis of and initial therapy for common emergencies in hematology and oncology.

Why Does Acute Hyperglycemia Worsen the Outcome of Transient Focal Cerebral Ischemia?

Background and Purpose— Hyperglycemia adversely affects the outcome of stroke. Global ischemia data support that the harmful effect of hyperglycemia is mediated by glucose-induced elevated plasma glucocorticoids. Here we sought to evaluate the negative effects of hyperglycemia on transient focal ischemia in the rat, and to test whether these could be prevented by inhibition of either corticosteroid production or neutrophil infiltration.

Methods— Sprague-Dawley rats (n=217) were used. Ischemia was induced by 1 hour middle cerebral artery occlusion (n=196). Acute hyperglycemia was induced by IP injection of dextrose 30 minutes before ischemia. Neutrophil infiltration was blocked by neutropenia with vinblastine. Corticosterone synthesis was inhibited by chemical adrenalectomy with metyrapone. We measured MRI lesion and tissue infarct volumes, evaluated the neurological function, brain myeloperoxidase and matrix metalloproteinase-9 activities, and protein O-glycosylation.

Results— Hyperglycemia significantly enhanced MRI diffusion-weighted imaging alterations, increased cortical, but not subcortical, infarct volume, worsened neurological score, and enhanced brain myeloperoxidase and matrix metalloproteinase-9 activities. Metyrapone did not prevent hyperglycemic brain damage despite successful reduction of plasma corticosterone. Yet, metyrapone tended to reduce cortical infarction and apparent diffusion coefficient lesion volume, indicating some negative contribution of corticosterone. Blocking neutrophil infiltration was also ineffective to prevent the harmful effect of hyperglycemia. A new finding was that O-linked glycosylation of cerebral proteins was increased under hyperglycemia.

Conclusions— In transient middle cerebral artery occlusion, the hyperglycemia-exacerbated brain damage cannot be fully explained by the negative effects of plasma corticosteroids or neutrophil infiltration. The contribution of other intrinsic effects of high glucose, such as brain protein O-glycosylation, deserves further investigation.

Pathogenesis of neutropenia in large granular lymphocyte leukemia and Felty syndrome

T-cell large granular lymphocyte leukemia (TLGL) is an atypical chronic lymphoproliferative disorder derived from cytotoxic T-cells (CTL). Unlike most forms of leukemia, the pattern of bone marrow infiltration in TLGL may be subtle and the cytopenias are often lineage specific, with neutropenia dominating. Both granulocytic survival and proliferation defects are observed and are mediated by humoral and cell-mediated mechanisms respectively. Splenic production of immune complexes induces a neutrophil survival defect, where as Fas expression by leukemic CTL results in a marrow based proliferation defect. These humoral and cell-mediated pathways induce granulocytic apoptosis through independent intracellular mechanisms which are not mutually exclusive and may be observed concurrently in individual patients with either TLGL or FS. A variety of therapeutic interventions have been utilized in the management of TLGL and Felty syndrome, including methotrexate, cyclosporine A, cyclophosphamide, glucocorticoids, myeloid colony stimulating factors and splenectomy. Their efficacy and mechanisms of action are reviewed.

Preventive effect of neutropenia on carbon tetrachloride-induced hepatotoxicity in rats

The preventive effect of neutropenia on carbon tetrachloride (CCl4)-induced hepatotoxicity was examined in rats. In rats treated once with CCl4 (1 ml kg(-1), i.p.), the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), indices of liver cell damage, and the hepatic activity of myeloperoxidase (MPO), an index of tissue neutrophil infiltration, increased at 6 h after the intoxication and further increased at 24 h. The liver of CCl4 -treated rats showed an increase in the concentration of thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation, and decreases in superoxide dismutase (SOD) activity and reduced glutathione (GSH) concentration at 6 h after the intoxication followed by a further increase in TBARS concentration and further decreases in SOD activity and GSH concentration at 24 h with increased xanthine oxidase (XO) activity at 24 h. Neutropenic treatment with anti-rat neutrophil antiserum (2 ml kg(-1), i.p.) at 0.5 h after CCl4 intoxication attenuated the increases in serum ALT and AST activities and hepatic MPO activity and TBARS concentration and the decreases in hepatic SOD activity and GSH concentration found at 6 and 24 h after CCl4 intoxication and the increase in hepatic XO activity found at 24 h after the intoxication. This neutropenia reduced the necrotic and degenerative changes with inflammatory cell infiltration in the liver cell of CCl4 -treated rats. These results indicate that neutropenia prevents CCl4 -induced hepatotoxicity in rats by attenuating the disruption of hepatic reactive oxygen species metabolism mediated by neutrophils accumulating in the liver tissue.

Mechanisms of Disordered Granulopoiesis in Congenital Neutropenia

Neutrophils are critical components of the innate immune response, and persistent neutropenia is associated with a marked susceptibility to infection. There are a number of inherited clinical syndromes in which neutropenia is a prominent feature. A study of these rare disorders has provided insight into the mechanisms regulating normal neutrophil homeostasis. Tremendous progress has been made at defining the genetic basis of these disorders. Herein, progress in understanding the genetic basis and molecular mechanisms of these disorders is discussed. We have focused our discussion on inherited disorders in which neutropenia is the sole or major hematopoietic defect.

Clinical experience with three combination regimens for the treatment of high-risk febrile neutropenia

INTRODUCTION

The objective of this study was to compare the safety and efficacy of ceftazidime (2 g every 8 h), piperacillin/tazobactam (4 g/500 mg every 6 h), and meropenem (1 g every 8 h), when combined with amikacin (15 mg/kg once daily), in the empirical treatment of high-risk febrile neutropenic episodes in patients with haematological malignancy.

MATERIALS AND METHODS

A prospective, comparative study designed in the haematology unit of a university hospital in Turkey.

RESULTS

A total of 89 febrile episodes in 60 neutropenic patients were treated; 29 febrile episodes in 23 patients with ceftazidime plus amikacin (group 1), 30 episodes in 25 patients with piperacillin/tazobactam plus amikacin (group 2), and 30 episodes in 25 patients with meropenem plus amikacin (group 3). The 3 groups were comparable in terms of age, sex, underlying malignancy, pretherapy neutrophil counts, duration of neutropenia and types of infections. Neutropenia, since the start of fever, persisted for > or =10 days in all of the episodes in the 3 study groups. Nearly all of the episodes were seen in patients with acute leukaemia. In 25.8% (23/89) of the febrile neutropenia episodes, an aetiologic organism was isolated, with gram-negative bacteria being the most commonly isolated. The success without modification rates were 34.5%, 30% and 36.7% for groups 1, 2 and 3, respectively (P >0.05). After modification with a different class of antimicrobial therapy, the response rates increased to 65.5%, 63.3% and 70% for groups 1, 2 and 3, respectively (P >0.05). The mean duration of treatment and the time to defervescence were also comparable in all groups. In all arms, side effects were minimal.

CONCLUSIONS

It is concluded that the 3 regimens were equally effective and safe in the empirical treatment of high-risk febrile neutropenic episodes.

Role of alveolar macrophage and migrating neutrophils in hemorrhage-induced priming for ALI subsequent to septic challenge

Acute lung injury (ALI) is identified with the targeting/sequestration of polymorphonuclear leukocytes (PMN) to the lung. Instrumental to PMN targeting are chemokines [e.g., macrophage inflammatory protein-2 (MIP-2), keratinocyte-derived chemokine (KC), etc.] produced by macrophage, PMN, and other resident pulmonary cells. However, the relative contribution of resident pulmonary macrophages as opposed to PMN in inducing ALI is poorly understood. We therefore hypothesize that depletion of peripheral blood PMN and/or the oblation of a macrophage-mediated PMN chemokine signal (via macrophage deficiency) will reduce the inflammation and ALI observed in mice following hemorrhage (Hem) and subsequent sepsis (CLP) in our murine model of ALI. To examine this we pretreated mice with either 500 μg anti-mouse Gr1 antibody/animal (to deplete PMN) or subjected mice deficient in mature macrophage (B6C3Fe-a/a-CsF1op) to Hem (90 min at 35 ± 5 mmHg) followed by resuscitation. Twenty-four hours post-Hem, mice were subjected to CLP and killed 24 h later, and lung tissue samples were collected. Our data showed that in the absence of either peripheral blood PMN or mature tissue macrophages there was a suppression of IL-6, KC, and MIP-2 levels in lung tissue from Hem/CLP mice as well as a reduction in PMN influx to the lung and lung injury (bronchoalveolar lavage fluid protein). In contrast, lung tissue IL-10 and TNF-α levels were suppressed in the macrophage-deficient Hem/CLP mice compared with PMN-depleted Hem/CLP mice. Together, these data suggest that both the PMN and the macrophage are required to induce inflammation seen here, however, macrophage not PMN regulate the release of IL-10, independent of local changes in TNF.

Pharmacological neutropenia prevents endothelial dysfunction but not smooth muscle functions impairment induced by middle cerebral artery occlusion

1. The polymorphonuclear neutrophils (PMN) activation and mobilization observed in acute cerebral infarction contribute to the brain tissue damage, but PMN could also be involved in postischemic functional injury of ischemied blood vessel. 2. This study was undertaken to investigate whether pharmacological neutropenia could modify the postischemic endothelial dysfunction in comparison to smooth muscle whose impairment is likely more related to reperfusion and oxidative stress. 3. A cerebral ischemia-reperfusion by endoluminal occlusion of right middle cerebral artery (MCA) was performed 4 days after intravenous administration of vinblastine or 12 h after RP-3 anti-rat neutrophils monoclonal antibody (mAb RP-3) injection into the peritoneal cavity, on male Wistar rats with 1-h ischemia then followed by 24-h reperfusion period. Brain infarct volume was measured by histomorphometric analysis and vascular endothelial and smooth muscle reactivity of MCA was analysed using Halpern myograph. 4. Neutropenia induced a neuroprotective effect as demonstrated by a significant decrease of brain infarct size. In parallel to neuroprotection, neutropenia prevented postischemic impairment of endothelium-dependent relaxing response to acetylcholine. In contrast, smooth muscle functional alterations were not prevented by neutropenia. Ischemia-reperfusion-induced myogenic tone impairment remained unchanged in vinblastine and mAb RP-3-treated rats. Postischemic Kir2.x-dependent relaxation impairment was not prevented in neutropenic conditions. The fully relaxation of smooth muscle response to sodium nitroprusside was similar in all groups. 5. Our results evidenced the dissociate prevention of pharmacologically induced neutropenia on postischemic vascular endothelial and smooth muscle impairment. The selective endothelial protection by neutropenia is parallel to a neuroprotective effect suggesting a possible relationship between the two phenomena.

Imipenem/cilastatin versus piperacillin/tazobactam plus amikacin for empirical therapy in febrile neutropenic patients: results of the COSTINE study

BACKGROUND

Combinations of beta-lactams plus aminoglycosides have become standard therapy for suspected infections in patients with profound neutropenia. However, it is not clear whether such combinations are advantageous over therapy with a broad-spectrum antibiotic.

OBJECTIVE

To assess the clinical effectiveness and the cost-effectiveness ratio of empirical therapy of febrile neutropenia with imipenem/cilastatin (I/C) versus piperacillin/tazobactam plus amikacin (P/T+A).

RESEARCH DESIGN AND METHODS

Prospective, multicenter observational study with 2 matched parallel cohorts treated with I/C (500 mg/6 h iv) or P/T+A (P/T: 4 g/6 h iv; A: 20 mg/kg/day iv).

MAIN OUTCOME MEASURES

Therapeutic success was defined as the resolution of fever following > or = 7 days of unchanged antibiotic treatment. An economic comparison was conducted focusing on the daily treatment costs, and the management of its toxicity.

RESULTS

There were 343 eligible patients (180 I/C, 163 P/T+A), of whom 290 were evaluable for the primary clinical effectiveness analysis. Follow-up information beyond 7 days of study inclusion was only available for 52% of all evaluable patients. Treatment success was observed in 42% of I/C patients compared with 31% of P/T+A patients (95% CI: -0.01, 21.4). The incidence of drug-related adverse experiences was 13% for I/C and 6% for P/T+A, with no differences in moderate or severe adverse experiences nor in those causing discontinuation of antibiotic therapy. Treatment costs were 189.55 euros (95% CI: 127.46-251.46) lower per episode of febrile neutropenia for patients treated with I/C.

CONCLUSIONS

The clinical effectiveness of I/C was similar to that of P/T+A. In both treatment groups toxicity was low and did not limit antibiotic therapy. Resource consumption was lower with I/C.

Effects of filgrastim on granulopoietic cells of mice pretreated with methotrexate

We have evaluated the effect of filgrastim on proliferation and differentiation activity of granulopoietic cells in mice pretreated with methotrexate. Filgrastim was injected daily, from day 8 to 28 after cytotoxic agent administration. The granulopoiesis changes were measured by assessment of GM-CFU cells content, marrow and spleen granuloid cells pool as well as circulating neutrophils. In MTX pretreated mice, bone marrow GM-CFU oscillating values were higher than normal values, but these changes were not followed by high proliferative activity in granuloid precursor cell compartment. After MTX treatment, filgrastim administration was unable to stimulate marrow granulopoiesis as observed in normal mice. In the spleen, MTX led to dramatic changes in the proliferative activity of GM-CFU cells, but did not result in spleen granuloid cell changes. However, filgrastim treatment induced a spleen granuloid amplification, similar to the changes observed in circulating neutrophils values. We suggest that these findings can be explained by inhibition of differentiation of marrow GM-CFU cells into the more mature granulopoietic cells and/or by an inhibited proliferative activity of marrow granuloid cells. They can be also explained in terms of an unfavorable marrow microenvironment for granulopoiesis, contrary to a supportive spleen microenvironment.

Granulocyte colony-stimulating factor and leukemogenesis

The granulocyte colony-stimulating factor (G-CSF) plays an important role in normal granulopoiesis. Its functions are mediated by specific receptors on the surface of responsive cells and, upon ligand binding, several cytoplasmic tyrosine kinases are activated. The cytoplasmic region proximal to the membrane of the G-CSF receptor (G-CSF-R) transduces proliferative and survival signals, whereas the distal carboxy-terminal region transduces maturation signals and suppresses the receptor's proliferative signals. Mutations in the G-CSF-R gene resulting in truncation of the carboxy-terminal region have been detected in a subset of patients with severe congenital neutropenia who developed acute myelogenous leukemia (AML). In addition, the AML1-ETO fusion protein, expressed in leukemic cells harboring the t(8;21), disrupt the physiological function of transcription factors such as C/EBPalpha and C/EBPepsilon, which in turn deregulate G-CSF-R expression. The resulting high levels of G-CSF-R and G-CSF-dependent cell proliferation may be associated with pathogenesis of AML with t(8;21). Moreover, in vitro and in vivo studies demonstrated that G-CSF may act as a co-stimulus augmenting the response of PML-RARalpha acute promyelocytic leukemia cells to all-trans-retinoic acid treatment. Finally, in the PLZF-RARalpha acute promyelocytic leukemia transgenic model, G-CSF deficiency suppressed leukemia development. Altogether, these data suggest that the G-CSF signaling pathway may play a role in leukemogenesis.

Management of infections in critically ill neutropenic cancer patients

Because of improving antineoplastic treatment options with increasing cure rates, prolonging survival, and improving quality of life, the reluctance to admit patients with malignant disease to an intensive care unit is not justified; thus, the number of patients with malignancies treated in intensive care units rises. The use of more aggressive anticancer regimens leads to an increase of attendant infections, which are the most frequent and often life-threatening complications in cancer patients. A multidisciplinary practical approach to evaluation and treatment is needed to optimize treatment results and to meet the various diagnostic and therapeutic challenges in this subset of patients on an intensive care unit.

Enhanced recovery from thrombocytopenia and neutropenia in mice constitutively expressing a placental hematopoietic cytokine

Expression of the placental hormone, prolactin-like protein E (PLP-E), a potent cytokine that acts on multiple myeloid lineages, is normally restricted to pregnancy and certain hematopoietic disease states. We hypothesized that the restricted pattern of PLP-E expression is necessary to avoid hyperstimulation of myelopoiesis. To test this idea, we have produced PLP-E transgenic mice and analyzed their steady-state blood cell levels. We find that blood cell levels remain in the normal range, and thus the constitutive expression of a cytokine of pregnancy fails to overcome the tight control of hematopoietic set points for blood cell levels. In contrast, an effect of constitutive PLP-E expression is detected during the recovery from low blood platelet levels (acute thrombocytopenia) and from low granulocyte levels (acute neutropenia) but not from anemia. Mice producing high circulating concentrations of PLP-E recover more rapidly from both thrombocytopenia and neutropenia, as seen both by an earlier increase of progenitor numbers in the bone marrow and the earlier return to normal circulating blood cell levels.

Optimum management of pediatric patients with fever and neutropenia

Fever with neutropenia is a common clinical problem in patients receiving cancer treatment. Prevention and optimum management of infectious complications is critical to the overall success of cancer therapy. This article provides an overview of the current status of this evolving subject. While the basic principles of rapid institution of broad spectrum antibiotics, early intervention with empiric antifungal therapy and continuation of antimicrobials during period of risk are unlikely to change, there is increasing interest in titrating this aggressive approach based on the projected risk of the development of a serious invasive infection. Oral antibiotic therapy and outpatient management are currently being studied in pediatric oncology patients, but even when successful these alternatives to the traditional "in hospital, parenteral antibiotic therapy" approach are unlikely to be applicable in all patient populations and clinical settings. While there is no replacement for clinical acumen and careful monitoring, judicious use of diagnostic resources such as blood cultures and imaging studies is a key component of optimum care. Selection of empiric antibiotics based on ongoing monitoring of antimicrobial susceptibility patterns is emphasized.

A mathematical model of haemopoiesis as exemplified by CD34 cell mobilization into the peripheral blood

A mathematical model for the kinetics of haemopoietic cells, including CD34+cells, is proposed. This minimal model reflects the known kinetics of haemopoietic progenitor cells, including peripheral blood CD34+ cells, white blood cells and platelets, in the presence of granulocyte colony-stimulating factor. Reproducing known perturbations within this system, subjected to granulocyte colony-stimulating factor treatment and apheresis of peripheral blood progenitor cells (CD34+ cells) in healthy individuals allows validation of the model. Predictions are made with this model for reducing the length of time with neutropenia after high-dose chemotherapy. Results based on this model indicate that myelosuppressive treatment together with infusion of CD34+ peripheral blood progenitor cells favours a faster recovery of the haemopoietic system than with granulocyte colony-stimulating factor alone. Additionally, it predicts that infusion of white blood cells and platelets can relieve the symptoms of neutropenia and thrombocytopenia, respectively, without drastically hindering the haemopoietic recovery period after high dose chemotherapy.

Congenital neutropenia

The term "congenital neutropenia" signifies neutropenia that is present at birth. It includes a wide variety of disorders, some transient and others life long. Some varieties of congenital neutropenia are mild, with blood neutrophil concentrations below normal but not low enough to constitute a significant host defense deficiency. Other varieties of congenital neutropenia are characterized by low blood neutrophil concentrations and a predisposition to repeated infections.

Mutations in the ELA2 gene correlate with more severe expression of neutropenia: a study of 81 patients from the French Neutropenia Register

Heterozygous mutations of the gene encoding neutrophil elastase (ELA2) have been associated with cyclic neutropenia (CN) and severe congenital neutropenia (SCN). To date, 30 different mutations have been reported, but no correlation has been found with the degree of neutropenia. To address this issue, we analyzed the clinical, hematologic, and molecular characteristics of 81 unrelated patients with SCN (n = 54) or CN (n = 27). We identified mutations in 31 patients, two thirds of whom had sporadic forms. Familial cases were consistent with dominant inheritance. Seventeen novel mutations were identified, showing that the mutational spectrum encompasses not only the region encoding the mature enzyme but also the prodomains and promoter region. Genotype-phenotype analysis strongly suggested that ELA2 mutations correlate with more severe expression of neutropenia, specifically in patients diagnosed with SCN. This study underlines the importance of ELA2 molecular screening to identify patients who may be at particular risk of severe bacterial infections and/or acute myeloid leukemia/myelodysplasia. By phenotypic analysis of affected relatives and carriers of the same ELA2 mutations, we showed that the expression of neutropenia in CN and SCN may be either homogeneous or variable according to the type of mutations, suggesting different pathogenetic mechanisms.

Effects of vinblastine on healing in microvascular anastomosis

Reconstructive microsurgical procedures are getting more common in cancer patients. Adjuvant therapies, such as chemotherapy, radiotherapy, and immune therapy, are usually combined with surgical approaches to improve outcomes. This study was designed to investigate the effects of preoperative chemotherapy on healing in microvascular anastomosis. As a commonly preferred drug for neoadjuvant cancer treatment, vinblastine was used on rats in our study. Ninety-three Sprague-Dawley rats were used and randomly allocated into two groups as 72 experimental and 21 control rats. Vinblastine 2 mg/kg was administered as a single dose intraperitoneally on day 0 in the experimental group. Leukocytes and erythrocytes were counted on days 0, 1, 3, 5, 7, 10, and 15 in 6 rats of the experimental and 6 rats of the control group. We found that the neutropenia period ended on approximately day 7. After applying the medication, the experimental group (n = 72) was divided into three main groups (n = 24). We performed end-to-end femoral artery anastomosis on days 7 or 14 or 21, respectively, in each group. Each main group was divided into three subgroups (n = 8), and then we tested patency and took biopsies on days 7 or 14 or 21, respectively, in each subgroup. Histopathologic evaluation was carried out. The comparison of patency tests and pathologic examination indicated that there was no statistically significant difference between the two groups.

The chemotaxis defect of Shwachman-Diamond Syndrome leukocytes

Shwachman-Diamond Syndrome (SDS) is a rare autosomal recessive, multisystem disorder presenting in childhood with intermittent neutropenia and pancreatic insufficiency. It is characterized by recurrent infections independent of neutropenia, suggesting a functional neutrophil defect. While mutations at a single gene locus (SBDS) appear to be responsible for SDS in a majority of patients, the function of that gene and a specific defect in SDS neutrophil behavior have not been elucidated. Therefore, employing 2D and 3D computer-assisted motion analysis systems, we have analyzed the basic motile behavior and chemotactic responsiveness of individual polymorphonuclear leukocytes (PMNs) of 14 clinically diagnosed SDS patients. It is demonstrated that the basic motile behavior of SDS PMNs is normal in the absence of chemoattractant, that SDS PMNs respond normally to increasing and decreasing temporal gradients of the chemoattractant fMLP, and that SDS PMNs exhibit a normal chemokinetic response to a spatial gradient of fMLP. fMLP receptors were also distributed uniformly through the plasma membrane of SDS PMNs as in control PMNs. SDS PMNs, however, were incapable of orienting in and chemotaxing up a spatial gradient of fMLP. This unique defect in orientation was manifested by the PMNs of every SDS patient tested. The PMNs of an SDS patient who had received an allogenic hematopoietic stem cell transplant, as well as PMNs from a cystic fibrosis patient, oriented normally. These results suggest that the defect in SDS PMNs is in a specific pathway emanating from the fMLP receptor that is involved exclusively in regulating orientation in response to a spatial gradient of fMLP. This pathway must function in parallel with additional pathways, intact in SDS patients, that emanate from the fMLP receptor and regulate responses to temporal rather than spatial changes in receptor occupancy.

Congenital and Acquired Neutropenia

Our understanding of the pathogenesis of congenital and acquired neutropenia is rapidly evolving. New ground-breaking observations have identified the genes responsible for many of the congenital neutropenia syndromes and are also providing new insights into normal neutrophil commitment and differentiation. Acquired neutropenia remains a poorly understood syndrome, although new insights into its pathogenesis are also emerging, especially with regard to subsets of immune neutropenia.

In Section I, Dr. Marshall Horwitz reviews the current understanding of the genetic basis, molecular pathology, and approaches to treatment of congenital neutropenia and cyclic hematopoiesis. Mutations in the ELA2 gene, which encodes for neutrophil elastase, cause cyclic hematopoiesis. ELA2 mutations are also the most common cause of congenital neutropenia, where their presence may equate with a more severe clinical course and higher frequency of leukemic progression. Emerging evidence indicates interrelatedness with Hermansky Pudlak syndrome and other disorders of neutrophil and platelet granules.

In Section II, Dr. Nancy Berliner presents an overview of the clinical approach to the evaluation and treatment of acquired neutropenia. This includes a review of the pathogenesis of primary and secondary immune neutropenia, drug-induced neutropenia, and non-immune chronic idiopathic neutropenia of adults. Studies used to evaluate patients for potential immune neutropenia are reviewed. Management issues, especially the use of granulocyte colony-stimulating factor (G-CSF), are discussed.

In Section III, Dr. Thomas Loughran, Jr., reviews the pathogenesis and clinical manifestations of large granular lymphocyte (LGL) leukemia. Possible mechanisms of neutropenia are discussed. In particular, discussion focuses on the relationship between LGL leukemia, rheumatoid disease, and Felty’s syndrome, and the complex interplay of defects in neutrophil production, distribution, destruction, and apoptosis that underly the development of neutropenia in those syndromes.

[Langerhans cell histiocytosis in a child with congenital neutropenia]

Congenital neutropenia predisposes to the development of haematopoetic malignancies. We present a 3,5-year child, diagnosed with congenital neutropenia at the age of I month. The diagnosis was based on peripheral blood and bone marrow aspirate analyses, performed after the treatment of multiple axillar abscesses. Recurrent infections were treated with broad-spectrum antibiotics and leukocyte colony stimulating factors. At the age of 19 months during routine check-up the child presented with gingival hypertrophy, fragility and bleeding. The histopathological analysis of gingival biopsy was consisted with the diagnosis of Langerhans cell histiocytosis. The child was treated according to LCH protocol for therapeutic group C. After 12 months of such chemotherapy, the follow-up histopathological analysis of gingival biopsy revealed the presence of Langerhans cells, which was the indication for chemotherapy prolongation (6 additional VP courses). Chemotherapy was completed after 6 additional courses and the disease remission was confirmed by histopathological analysis of gingival biopsy. Congenital neutropenia predisposes to myeloproliferative disorders, particularly to childhood myeloblastic leukemia. Based on the presented case report we would like to emphasize the possibility of other hematological syndromes development.

Dimensions of Neutropenia in Adult Cancer Patients

Neutropenia is a common and dangerous toxicity of cancer therapy that profoundly affects patients' lives. Neutropenia is typically defined by the numerical value of the absolute neutrophil count. However, considering neutropenia exclusively as the numerical value of the absolute neutrophil count limits its conceptualizations to physiologically related aspects, minimizes its complexities, and neglects dimensions of human response and the patient experience. This article offers a dimensional analysis of neutropenia derived from 42 research and clinical articles. Schatzman's dimensional analysis methods were applied to the literature to identify aspects of this phenomenon lying beyond its numerical boundaries. Dimensions of neutropenia that emerged were sorted into categories of perspective, context, conditions, processes, and consequences. The presence of the same dimension in more than 1 category and the circuitous relationships among categories begin to explicate the complexity and gravity of neutropenia. Articulation of these dimensions is necessary to assemble the beginnings of a theoretical understanding of neutropenia, which is crucial for the development and application of knowledge to research and practice. Limitations evident in the literature illuminate the urgent need for research into the psychosocial as well as physiologic dimensions of neutropenia.