Non-immune chronic idiopathic neutropenia of adult: an overview

There is strong evidence that non-immune chronic idiopathic neutropenia of adult is a cytokine-mediated syndrome characterized by (a) neutropenia of varying degree associated with a low number of lineage-specific CD34+ cells and increased production of inhibitors of hematopoiesis, including transforming growth factor-beta1 and tumor necrosis factor-alpha; (b) lymphopenia due to selective loss of primed/memory T-cells and NK cells; (c) increased splenic volume on ultrasonography in 48.1% of patients; (d) osteopenia and/or osteoporosis in 60.0% of patients; (e) anemia, mostly of the type of anemia of chronic disease, in 15.6% of patients; (f) features of chronic antigenic stimulation, including increased proportion of bone marrow plasma cells, increased serum levels of IgG1 and/or IgA, increased frequency of monoclonal gammopathy of undetermined significance, increased frequency of antinuclear antibodies with specific reactivity, and increased serum levels of circulating immune complexes; and (g) increased concentrations of a variety of macrophage-derived pro-inflammatory cytokines and chemokines capable of affecting bone metabolism, bone marrow function, and leukocyte trafficking. All these findings are suggestive of the existence of an unrecognized low-grade chronic inflammatory process which may be involved in the pathogenesis of the disorder. Neutropenia in these patients is probably the result of a combination of at least three factors, reduced neutrophil production in bone marrow, enhanced neutrophil extravasation, and increased sequestration and/or extravasation of neutrophils into the spleen.

Megakaryocyte emperipolesis in a child with chronic neutropenia: an unusual coexistence

The term emperipolesis defines the temporary presence of one cell within another's cytoplasm. In clinical use, megakaryocyte emperipolesis is the penetration of hematopoietic cells into the cytoplasm of megakaryocytes. The pathophysiological significance of megakaryocyte emperipolesis is uncertain. It has been described in association with neoplastic disorders, and in a few instances in idiopathic thrombocytopenic purpura, iron deficiency anemia, bleeding, and during the administration of recombinant human granulocyte colony-stimulating factor. However, megakaryocyte emperipolesis in a patient with chronic neutropenia has not been reported. In the current report, emperipolesis of hematopoietic cells within megakaryocytes in a boy with chronic neutropenia is described and the possible mechanisms are discussed.

Kinetics of neutrophil production in normal and neutropenic animals during the response to filgrastim (r-metHu G-CSF) or filgrastim SD/01 (PEG-r-metHu G-CSF)

Filgrastim G-CSF has a short, biologically active half-life, and its effective use depends on repeated inoculations. A major aim, therefore, has been to develop a once-per-chemotherapy cycle formulation. To this end, a polyethylene glycolylated form of Filgrastim, known as SD/01, has been developed. In this study, we compared the cellular kinetics of granulocyte production in mice stimulated with SD/01 and granulocyte colony-stimulating factor (G-CSF). Mice were injected with a single dose of SD/01 (1 mg/kg) or G-CSF (125 microg/kg) twice per day for 4 days. Mice rendered leukopenic with a single injection of cyclophosphamide (200 mg/kg) and temozolomide (90 mg/kg) were similarly treated at their 3-day neutrophil nadir. Tritiated thymidine was injected for autoradiographic labeling studies. Bone marrow labeling indices and the release of labeled neutrophils and monocytes into the peripheral blood were assessed. Granulocytopoiesis was stimulated similarly by both SD/01 and G-CSF in both normal and neutropenic animals, with counts rising to >20 x 10(9) polymorphonuclear neutrophils/l in both cases. Bone marrow thymidine labeling indices were increased, indicating a greater proportion of cells in DNA synthesis and an elevated proliferative activity. Compared with the normally slow release of neutrophils into the peripheral blood, labeled neutrophils (and monocytes) were rapidly released, increasing to peak levels at approximately 24 h. The peripheral half-life of neutrophils was not significantly different from normal, and the mitotic amplification factors for increase in granulocytopoiesis, accounted for by 3-3.9 extra cell divisions, were comparable for both factors. We conclude that neutrophil kinetics are stimulated in the same way and to the same extent by both SD/01 and G-CSF.

Assessment of Procalcitonin as a Diagnostic Marker of Underlying Infection in Patients with Febrile Neutropenia

The novel inflammatory marker procalcitonin (PCT) was assessed as an index of infection in patients with febrile neutropenia. Blood samples were obtained from 115 patients with febrile neutropenia for determination of PCT levels before onset of fever and daily until the resolution of fever. The median PCT level on the first day of fever was 8.23 ng/mL in patients with bacteremia, compared with 0.86 ng/mL in patients with localized bacterial infections (P=.017). The median PCT level on the first day of fever was 2.62 ng/mL in patients with severe sepsis, compared with 0.57 ng/mL in patients with clinically localized infections (P<.001). A dramatic decrease in PCT levels was documented after resolution of the infection; PCT levels were elevated when the infection worsened. Pronounced PCT levels were also found in patients with fever of unknown origin who were responding to antimicrobial chemotherapy, compared with those not responding to treatment with antibiotics. PCT levels were particularly elevated in patients with bacteremia and severe sepsis. These findings provide new insight into the application of PCT in clinical trials as a diagnostic tool of the severity of an infection in patients with febrile neutropenia and of the need to change antimicrobial regimen.

The molecular basis of type 1 glycogen storage diseases

Glycogen storage disease type 1 (GSD-1), also known as von Gierke disease, is a group of autosomal recessive metabolic disorders caused by deficiencies in the activity of the glucose-6-phosphatase (G6Pase) system that consists of at least two membrane proteins, glucose-6-phosphate transporter (G6PT) and G6Pase. G6PT translocates glucose-6-phosphate (G6P) from cytoplasm to the lumen of the endoplasmic reticulum (ER) and G6Pase catalyzes the hydrolysis of G6P to produce glucose and phosphate. Therefore, G6PT and G6Pase work in concert to maintain glucose homeostasis. Deficiencies in G6Pase and G6PT cause GSD-1a and GSD-1b, respectively. Both manifest functional G6Pase deficiency characterized by growth retardation, hypoglycemia, hepatomegaly, kidney enlargement, hyperlipidemia, hyperuricemia, and lactic acidemia. GSD-1b patients also suffer from chronic neutropenia and functional deficiencies of neutrophils and monocytes, resulting in recurrent bacterial infections as well as ulceration of the oral and intestinal mucosa. The G6Pase gene maps to chromosome 17q21 and encodes a 36-kDa glycoprotein that is anchored to the ER by 9 transmembrane helices with its active site facing the lumen. Animal models of GSD-1a have been developed and are being exploited to delineate the disease more precisely and to develop new therapies. The G6PT gene maps to chromosome 11q23 and encodes a 37-kDa protein that is anchored to the ER by 10 transmembrane helices. A functional assay for the recombinant G6PT protein has been established, which showed that G6PT functions as a G6P transporter in the absence of G6Pase. However, microsomal G6P uptake activity was markedly enhanced in the simultaneous presence of G6PT and G6Pase. The cloning of the G6PT gene now permits animal models of GSD-1b to be generated. These recent developments are increasing our understanding of the GSD-l disorders and the G6Pase system, knowledge that will facilitate the development of novel therapeutic approaches for these disorders.

The combined administration of daniplestim and Mpl ligand augments the hematopoietic reconstitution observed with single cytokine administration in a nonhuman primate model of myelosuppression

This study evaluated the ability of daniplestim, a high affinity interleukin 3 receptor agonist, to enhance the hematopoietic response of Mpl ligand (Mpl-L) administration in nonhuman primates following severe, radiation-induced myelosuppression. Rhesus monkeys were total body x-irradiated (TBI) to 600 cGy, midline tissue dose. Beginning on day 1 post-TBI, animals were s.c. administered daniplestim (100 microg/kg bid; n = 4), Mpl-L (10 microg/kg qd; n = 3), daniplestim (100 microg/kg bid) plus Mpl-L (10 microg/kg qd) (n = 4) or 0.1% autologous serum (AS) (n = 11) for 18 days. CBCs were monitored for 60 d after TBI. The duration of thrombocytopenia (platelet count; PLT <20,000/microl) was significantly decreased by the administration of daniplestim (6.5 d, p = .01), Mpl-L (3.0 d, p = .003) and the coadministered daniplestim/Mpl-L (1.3 d, p = .001) compared to controls (10.4 d). As monotherapy Mpl-L but not daniplestim significantly improved the PLT nadir (21,000/microl, p = .023 and 5,000/microl, p = .266, respectively) compared to the control (3,000/microl). The combined administration of daniplestim and Mpl-L significantly improved the PLT nadir (28,000/microl, p = .007) compared to both the control cohort (3,000/microl) and the daniplestim only cohort (5,000/microl, p = .043). Recovery of PLT to preirradiation values occurred earlier in the daniplestim only (d 21) or the daniplestim/Mpl-L cohorts (d 18) than in the Mpl-L only or control cohorts (d 28, d 29, respectively). The administration of daniplestim or Mpl-L alone neither shortened the duration of neutropenia (ANC<500/microl) compared to the controls (15.8 d, 16.0 d versus 16.2 d, respectively), nor improved the recovery time of neutrophils to baseline values (d 22, d 25, and d 23, respectively). The ANC nadir was significantly improved by daniplestim alone but not Mpl-L administration (76/microl, p = .001 and 50/microl, p = .093, respectively) compared to the controls (8/microl). Coadministration of daniplestim and Mpl-L significantly improved the ANC nadir (196/microl, p = .001) compared to either the AS- or the monotherapy-treated cohorts. Also the duration of neutropenia observed in the AS-controls (16.2 d) was significantly reduced in the daniplestim/Mpl-L cohort (10.8 d, p = .002). The combined administration of daniplestim and Mpl-L significantly improved hematopoietic recovery and further enhanced the stimulatory effect of cytokine monotherapy, as well as reducing clinical support requirements after radiation-induced bone marrow myelosuppression.

Community-acquired Acinetobacter radioresistens bacteremia in an HIV-positive patient

We describe the first case of community-acquired bacteremia caused by Acinetobacter radioresistens; the patient was a 32-year-old HIV-positive neutropenic woman. Ambiguous Gram staining and poor biochemical reactivity of blood culture isolates misguided early diagnosis and therapy. Bacterial identification was based on 16S rDNA sequence analysis. A. radioresistens can be considered as a cause of opportunistic infection in immunodeficient patients.

Serum and plasma parameters in clinical evaluation of neutropenic fever

Clinicians are searching for a marker which may add to exclusion or diagnosis of relevant infection underlying neutropenic fever. The rise of such a parameter should ideally precede the date of significant microbiologic findings or justify additional intensive search for a focus of infection even in patients without pyrexia. However, the literature concerning the significance of CRP, proinflammatory cytokines and soluble adhesion molecules in the clinical evaluation of neutropenic fever is surprisingly small. In the case of procalcitonin, available data look very preliminary. Furthermore, in case of CRP, it appears that the widespread view that its determination may add substantially to the clinical evaluation of neutropenic fever is not well founded by most clinical trials listed here. Most of the studies available demonstrate several limitations such as poor design and small size of the study population. Additionally, studies were heterogeneous with respect to patients recruited (children and adults, patients with leukemia and patients with solid tumors) and compared different categories of febrile episodes. None of the investigators analyzed cost-effectiveness or impact of serial measurements of these parameters on patients' outcome. To our knowledge no single multicenter trial has been published addressing this issue. Although the group of proinflammatory cytokines and known acute-phase reactants will surely grow, more data on relevance of the available parameters in the diagnosis of neutropenic fever are needed.

Noninvasive continuous positive airway pressure in neutropenic patients with acute respiratory failure requiring intensive care unit admission

OBJECTIVE

To evaluate the tolerance and the efficacy of noninvasive continuous positive airway pressure (CPAP) in severe acute respiratory failure occurring in intensive care unit (ICU) neutropenic patients with hematologic malignancies, and to establish predictive variables of efficacy of this method.

DESIGN

Prospective study over a 5-yr period.

SETTING

Hematologic and medical intensive care unit of a teaching hospital.

METHODS

Among 129 neutropenic patients admitted to the ICU, 64 patients presented with febrile acute hypoxemic normocapnic respiratory failure (PaO2/FIO2 ratio <200) and were enrolled. In addition to standard therapy, patients received CPAP with a facial mask. The initial settings of the CPAP were 6 cm H2O positive end-expiratory pressure and FIO2 0.8 (80%). Physiologic measurements were performed at the end of 45 mins of ventilation with first adjustments. CPAP was used with a sequential mode (45 mins/3 hrs). CPAP was efficient if intubation was avoided.

RESULTS

The setting of CPAP, after adjustments, was as follows: positive end-expiratory pressure 7 +/- 1 cm H2O and FIO2 0.7 +/- 0.1 (70% +/- 10%). For the 64 patients, CPAP was administered for a total of 6 +/- 2 hrs during the first 24 hrs. The mean duration of CPAP was 7 +/- 3 days. A reduction in respiratory rate to less than 25 breaths/min was achieved in 53% of patients. PaO2/FIO2 ratio increased from 128 +/- 32 to 218 +/- 28. CPAP was successful in avoiding endotracheal intubation in 16/64 patients. A total of 16 responders and four nonresponders survived. Hepatic failure was a criterion indicating the failure of CPAP: 1/16 vs. 26/48 (p = .001). In multivariate analysis, two variables were predictive of failure of CPAP: Simplified Acute Physiology Score II (58 +/- 14 vs. 41 +/- 11) and a hepatic failure at the entry into the study.

CONCLUSION

CPAP was efficient in 25% of cases. All the responders survived. This noninvasive method was used as a way to avoid mechanical ventilation, which is well correlated with a poor prognosis in neutropenic ICU patients. Further controlled studies are needed to confirm the efficacy of noninvasive CPAP and to evaluate the most appropriate selection of immunocompromised patients.

Endothelial selectin blockade attenuates lung permeability of experimental acid aspiration

BACKGROUND

A central role for the polymorphonuclear leukocyte (PMN) in experimental acid aspiration has been demonstrated by the observation that PMN depletion reduced pulmonary vascular permeability. This study investigates the role of recombinant soluble P-selectin glycoprotein ligand-immunoglobulin fusion protein (rPSGL-Ig), a P- and E-selectin antagonist in moderating acid aspiration lung injury.

METHODS

Tracheostomy tubes were placed in male C57BL/6 mice and 0.1 N HCl was instilled into the trachea at 2 mL/kg after intravenous injection of (125)I-albumin. After 4 hours the lung vascular permeability index (PI) and PMN accumulation in the bronchoalveolar lavage fluid were assessed.

RESULTS

PI in neutropenic mice was 63% reduced compared with the untreated group and similar to the PI of mice treated with 1 mg/kg rPSGL-Ig before acid aspiration. PMN count of 19 +/- 5 in the bronchoalveolar lavage fluid in rPSGL-Ig treated mice was significantly less than the untreated group PMN count of 586 +/- 72. The respective PI in mice treated with rPSGL-Ig (1/2) hour and 1 hour after acid aspiration was 45% and 39% reduced compared with the untreated group.

CONCLUSIONS

Endothelial selectin blockade is as effective as PMN depletion in moderating acid aspiration induced lung permeability. Delayed antiselectin therapy can decrease lung injury.

Neutropenia, neutrophil dysfunction, and inflammatory bowel disease in glycogen storage disease type Ib: results of the European Study on Glycogen Storage Disease type I

OBJECTIVE

To investigate the incidence, the severity, and the course of neutropenia, neutrophil dysfunction, and inflammatory bowel disease (IBD) in glycogen storage disease (GSD) type Ib.

METHOD

As part of a collaborative European Study on GSD type I, a retrospective registry was established in 12 European countries that included all patients with GSD-I who were known at the centers and were born from 1960 to 1995. Of a total of 288 patients with GSD-I, 57 who had GSD-Ib form the basis of this study.

RESULTS

Neutropenia (defined as an absolute neutrophil count <1 x 10(9)/L) was found in 54 patients. In 64% of the patients neutropenia was documented before the age of 1 year, but in 18% of the patients neutropenia was first noted between the ages of 6 and 9 years. Neutropenia was persistent in 5 patients and intermittent without any clear cyclical course in 45. Neutrophil function was investigated in 18 patients with neutropenia and was abnormal in all. Perioral infections were reported in 37 patients, perianal infections in 27 patients, and protracted diarrhea in 23 patients. Findings on colonoscopy and radiologic studies in 10 of 20 patients suspected to have IBD were abnormal in all. All patients with IBD, perioral infections, and perianal infections had neutropenia.

CONCLUSIONS

Intermittent severe neutropenia is frequently found in patients with GSD-Ib. The study also indicates that IBD in GSD-Ib is underdiagnosed; up to 77% of the patients studied had evidence of IBD, all of whom had neutropenia. IBD was not detected in those with normal neutrophil counts. These findings support the notion that neutropenia and/or neutrophil dysfunction in GSD-Ib and IBD are causally related.

[Severe congenital neutropenia: trends in diagnosis and therapy]

Severe congenital neutropenia (CN; Kostmann syndrome) is a hematologic disorder characterized by a maturation arrest of myelopoiesis at the promyelocyte/myelocyte stage of development. This arrest results in severe neutropenia with absolute neutrophil counts (ANC) less than 0.2 x 10(9)/l associated with severe systemic bacterial infections from early infancy. Data on over 300 patients with CN collected by the Severe Chronic Neutropenia International Registry (SCNIR) since 1994 indicate that > 90% of these patients respond to recombinant human granulocyte-colony stimulating factor (rHuG-CSF) treatment with an ANC > 1.0 x 10(9)/l. In these patients rHuG-CSF is required daily as subcutaneous injection with individual doses ranging between 0.27 and 120 mcg/kg/day to maintain ANC above 1.0 x 10(9)/l. Adverse events documented in this group of patients include splenomegaly, thrombocytopenia, osteoporosis and malignant transformation into MDS/leukemia. If and how rHuG-CSF treatment impacts on these adverse events remains unclear since there are no historical controls for comparison. For those patients who are refractory to rHuG-CSF treatment and continue to have severe and often life-threatening bacterial infections, hematopoietic stem cell transplantation (HSCT) is still the only currently available treatment.

Nutritional issues in patients with severe neutropenia

OBJECTIVES

To provide information on the assessment and management of the nutritional needs of patients with severe neutropenia.

DATA SOURCES

Textbook chapters, research articles, and review articles.

CONCLUSIONS

Malnutrition is a common result of high-dose chemotherapy treatment. Clinical outcomes are directly related to careful assessment, early intervention, and ongoing evaluation and monitoring in the severely neutropenic population.

IMPLICATIONS FOR NURSING PRACTICE

Early assessment, management, and psychological support are essential in meeting the needs of this patient population.

Fever and sepsis during neutropenia are associated with expansion of extracellular and loss of intracellular water

BACKGROUND AND AIMS

Shifts from intracellular to extracellular water are features of a catabolic reaction to sepsis. Bedside assessment of fluid shifts was carried out in neutropenic patients at high risk of systemic infection.

METHODS

Multifrequency bioelectrical impedance analysis was performed in 41 patients with leukemia or high-malignant lymphoma and chemotherapy-induced neutropenia.

RESULTS

Hydration was stable during afebrile periods except for transient intra- and extracellular dehydration after chemotherapy. The risk of over-hydration and dehydration increased 3-fold during fever. Over-hydration was more severe when occurring during fever. Extracellular water was highly variable and tended to increase, and intracellular water was slowly depleted. During sepsis, these alterations were enhanced. Changes in hydration status did not predict subsequent progression to sepsis because it developed more slowly than other symptoms of infection.

CONCLUSIONS

Extracellular over-hydration and intracellular dehydration are observed in febrile infection in neutropenia, similar to severe sepsis. If the technical limits of bioelectrical impedance are taken into account, this method may be useful for non-invasive monitoring of these features of metabolic stress.

Neutropenic enterocolitis in children with acute lymphoblastic leukemia

Neutropenic enterocolitis is an acute, life-threatening inflammation of the small and large bowel, often seen in children with malignancies during periods of prolonged or severe neutropenia. During the period 1990-1995, 180 children were treated at the authors' center for acute lymphoblastic leukemia using a standard chemotherapy protocol. Among them, 11 children (6.1%) aged 4 to 12 years, were diagnosed clinically to have neutropenic enterocolitis. Eight had severe neutropenia (absolute neutrophil count < 10(8)/L and 5 had prolonged neutropenia (> 7 days duration). The symptoms included diffuse abdominal pain (10 children), oral mucositis (7), hematochezia (7), diarrhea (6), hematemesis (5), and right lower quadrant tenderness (4). Three children had radiological evidence of free intraperitoneal gas and an additional 3 children were found on surgical exploration to have cecal perforation. Laparotomy was performed on 8 children (73%), 4 of whom survived. Among the 3 children managed conservatively, 1 died awaiting surgical exploration, while the other 2 did well. The overall survival was 55%. The authors recommend an approach to management that respects the heterogeneity of the disease.

Prophylaxis and treatment of chemo- and radiotherapy-induced oral mucositis - are there new strategies?

Oral mucositis is a major dose-limiting toxic effect of intensive cancer chemotherapy. Oral complications may lead to dose reduction or delay in further cancer treatment. Mucositis can be caused directly by cytotoxic effects and indirectly by sustained neutropenia after cytostatic therapy. An impaired mucosal barrier predisposes to life-threatening septic complications during aplasia. The prevalence of an oral focus in febrile neutropenia has been reported in up to 30% of cases and also reduces quality of life. The basic strategies aim at pain relief and prevention of bacterial and fungal infectious complications. However, no effective causal prophylaxis or treatment of oral mucositis is widely accepted. The introduction of cytokines, eg granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) for oral mucositis may be particularly effective and offer a new and hopeful approach. At present, the optimal growth factor, best schedule, effective dosage and best mode of application is not known.

Plasma granulocyte colony-stimulating factor concentrations in neutropenic, parvoviral enteritis-infected puppies

We evaluated the temporal relationship between neutrophil numbers and plasma granulocyte colony-stimulating factor (G-CSF) concentrations in dogs infected with canine parvovirus, a common infectious cause of neutropenia. G-CSF is produced in response to neutropenia, infection, or inflammation, and results in the production and release of neutrophils from the bone marrow. Adequate numbers of functional neutrophils are necessary for protection from infection, and the timely production of G-CSF is a crucial response to certain diseases. The relationship between peripheral neutrophil numbers and plasma G-CSF concentrations during the course of an infectious disease characterized by neutropenia has not been described previously in dogs. Eight mixed-breed puppies were given an oronasal challenge with canine parvovirus, and peripheral neutrophil numbers as well as plasma G-CSF concentrations were measured daily. G-CSF was not detectable in plasma of any dog before the onset of neutropenia, but G-CSF became detectable just after the onset of neutropenia in the 7 dogs that developed clinical illness. Neutropenia persisted or worsened for at least 2 days after plasma G-CSF became detectable in all 7 dogs. Neutrophil nadir, the highest plasma G-CSF concentrations, and the most severe clinical illness occurred concurrently in most dogs. Although 1 dog died while still neutropenic, plasma G-CSF concentrations declined before resolution of neutropenia in the other 6 dogs, and were again below the limits of detection in 5 of the 6 dogs at the time of resolution.

Additive effects of infection and neutropenia on the induction of granulocytopoietic activity in vivo

BACKGROUND

Granulocyte-colony stimulating factor (G-CSF) is a potent stimulator of granulocytopoiesis and granulocyte function. It has been used in the treatment of children with neutropenic infection; in this context, it was expected to shorten aplasia and limit the severity of infection. Clinical trials, however, have demonstrated conflicting results as to whether these aims can be met. Recently, the use of other, less lineage specific growth factors, such as interleukin (IL)-11 and stem cell factor (SCF), has also been discussed. The dynamics of growth factors and growth factor-regulating proteins during neutropenic infection, particularly in youngsters, are not well understood.

METHODS

Serial blood samples from children and adolescents with infection during chemotherapy-induced neutropenia were assayed for C-reactive protein, white blood cell count, IL-11, SCF, G-CSF, IL-10, IL-4, IL-lalpha, and IL-1beta.

RESULTS

Although no correlation could be demonstrated between endogenous IL-11 or SCF levels, infection, and leukocyte counts, endogenous G-CSF levels were increased during both aplasia and infection. However, only the additive effects of infection and neutropenia led to maximally stimulated endogenous G-CSF levels.

CONCLUSIONS

The elevated G-CSF levels in a majority of patients during severe neutropenic infection may explain why a therapeutic benefit of G-CSF treatment cannot be demonstrated in all cases. There remains, however, a subgroup of patients in whom infection and cytopenia do not yield a good G-CSF response. This latter group should be identified, because they might derive some benefit from adjuvant growth factor therapy. The authors predict that the efficacy of G-CSF in the treatment of patients with neutropenic fever might depend on each individual's ability to initiate the necessary cytokine production.

Neutrophils do not mediate blood-brain barrier permeability early after controlled cortical impact in rats

Controlled cortical impact (CCI) produces blood-brain barrier (BBB) permeability and an acute inflammatory response in injured brain, associated with upregulation of cell adhesion molecules and accumulation of neutrophils. Nevertheless, the role of acute inflammation in the pathogenesis of BBB permeability after traumatic brain injury (TBI) is undefined. The purpose of this study was to examine the time course of acute inflammation and BBB permeability after CCI in rats and to determine the effect of neutrophil depletion on BBB permeability early after CCI. In the first protocol, four groups of rats (n = 4-7/group) were subjected to CCI. Expression of endothelial (E)-selectin on cerebrovascular endothelium, accumulation of neutrophils, and BBB permeability were measured in brain at 1, 4, 8, and 24 hours after injury by immunohistochemistry or spectrophotometric quantification of Evans blue. E-selectin upregulation and neutrophil accumulation in injured brain occurred at later times than maximal BBB permeability. In a second protocol, rats made neutropenic with a murine monoclonal IgM antibody (RP-3) specific for rat neutrophils were subjected to CCI, given Evans blue at 3.5 hours, and sacrificed at 4 hours after injury. Neutrophil depletion did not affect BBB permeability at 4 hours after CCI. We conclude that events other than those mediated by neutrophils initiate BBB permeability early after CCI.

Hematopoietic dynamics in grey collies

Using Lomb periodogram analysis we have quantified variations in the peripheral neutrophil and platelet counts of the cyclical neutropenia animal model-the grey collie. We found that the amplitudes of the oscillations in these two cell lineages vary concomitantly. Further, the power spectrum and the shape of the oscillations in the absolute neutrophil counts vary together with the amplitude of the oscillations. As the amplitude of the oscillations increases, the height of the second subharmonic increases, giving rise to a distorted oscillation with two peaks per cycle. The particular dynamics of the absolute neutrophil counts can be reproduced by a combination of a delayed peripheral feedback, representing the peripheral control of granulopoiesis through granulocyte colony stimulating factor, together with a sinusoidal input representing an oscillatory input from the pluripotential stem cells to the granulocytic lineage. The same pluripotential stem cell input is probably responsible for the sinusoidal oscillations observed in the other cell lineages.

X-linked cardioskeletal myopathy and neutropenia (Barth syndrome) (MIM 302060)

X-linked cardioskeletal myopathy, neutropenia and abnormal mitochondria (MIM 302060) (synonyms: Barth syndrome, 3-methylglutaconic acid-uria type II, endocardial fibroelastosis type 2) has been reported in patients and families from Europe, North America and Australia. Previous studies characterized the main components of the disease: dilated cardiomyopathy, skeletal myopathy, neutropenia, 3-methylglutaconic aciduria and diminished statural growth. Respiratory chain impairments have been found in several studies, without pinpointing a single enzyme complex. 3-Methylglutaconic aciduria is shared with several other disorders that affect the respiratory chain. Previous studies excluded a block in the major pathway of leucine catabolism. We performed leucine loading, accompanied by fasting, in patients and observed a significant rise of 3-methylglutaconic acid and 3-methylglutaric acid. Taken together with the absence of an enzymatic block in the major leucine catabolic route, the possibility remains that the increased basal excretion of 3-methylglutaconic acid and other products of branched-chain amino acids is the result of overload of this pathway or--more likely--mitochondrial leakage. Linkage studies have localized the gene to the Xq28 region. The associated tafazzin gene (TAZ), has been fully characterized recently, and mutations located in conserved regions have been reported. Carrier detection and prenatal diagnosis have now become possible through mutation analysis. Sequence homology of the TAZ gene to a highly conserved superclass of acyltransferases (Neuwald's hypothesis) predicts a glycerophospholipid as the missing end product. This points to the (lipid) structure of the inner mitochondrial membrane as a promising new area of research.

Chronic idiopathic neutropenia of adults is associated with decreased bone mineral density and alterations in bone turnover biochemical markers

The aim of this study was to assess bone mineral density (BMD) and biochemical indices of bone metabolism in patients with chronic idiopathic neutropenia of adults (CINA) and define the relationships, if any, between these parameters and serum levels of interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha), two cytokines normally involved in bone metabolism. Femoral neck BMD, serum osteocalcin (OC), bone-specific alkaline phosphatase (BAP) and type I procollagen carboxy-terminal propeptide (PICP), as well as urine-free deoxypyridoline (Dpd) cross-links, N-telopeptide (NTx) and C-telopeptide (CTx) cross-links of type I of collagen were measured in 45 CINA patients and 36 normal subjects. Patients were arbitrarily classified in two groups, A and B, as having mild (neutrophils 1700-2500/microl) or 'pronounced' (neutrophils<1700/microl) neutropenia, respectively. BMD values were found significantly reduced in both groups of patients, compared to controls, and they strongly correlated with the number of circulating neutrophils. Serum OC and urinary NTx were significantly increased in patients of group B. Both serum OC and urinary NTx correlated inversely with the number of circulating neutrophils. Serum BAP and PICP and urine Dpd and CTx were within normal range. Serum IL-1beta and TNF-alpha were elevated in both groups of patients and correlated inversely with the number of circulating neutrophils and the values of BMD. In addition, TNF-alpha, but not IL-1beta, inversely correlated with OC and NTx. These findings indicate that CINA patients have biochemical evidence of increased bone turnover which leads to decreased BMD. The elevated serum IL-1beta and TNF-alpha concentrations, suggestive of an underlying chronic inflammatory process in these patients, may be part of a mechanism accelerating bone turnover which, if prolonged, causes lowering of BMD.

The use of granulocyte colony stimulating factor to promote wound healing in a neutropenic patient after head and neck surgery

BACKGROUND

Neutropenia and neutrophil dysfunction, in association with a variety of diseases, has been shown to play a role in poor wound healing. Wound breakdown with fistula formation in patients undergoing total laryngectomy results in significant morbidity and increased hospital stay. Although malnutrition, prior radiation, diabetes, and other diseases are recognized as factors predisposing patients with head and neck cancer to developing fistulas, neutrophil dysfunction should also be considered. Granulocyte colony stimulating factor (G-CSF) has been used successfully to treat neutropenia and neutrophil dysfunction.

METHODS

This study was conducted as a case report.

RESULTS

We present the first report of a neutropenic head and neck cancer patient with a persistent wound of 6 months' duration who showed dramatic improvement after treatment with G-CSF.

CONCLUSION

We conclude that G-CSF may represent a useful adjunct in patients with persistent wound healing problems and neutropenia despite adequate treatment by conventional means. Further clinical experience with G-CSF in patients with delayed healing is indicated.