Elevation of serum soluble E-selectin and VCAM-1 in severe asthma

OBJECTIVE: To investigate the significance of circulating adhesion molecules associated with leucocyte-endothelial cell interactions in asthma, serum levels of soluble E (sE)-selectin, soluble P (sP)-selectin, soluble L (sL)-selectin, and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured in mild, moderate and severe asthma. METHOD: Serum levels of sE-selectin, sP-selectin, sL-selectin, and sVCAM-1 were measured in 32 women with asthma and 30 healthy donors using an enzyme-linked immunosorbent assay method. Twenty patients were suffering from severe asthma, and 12 from mild/moderate asthma. RESULTS: Serum sE-selectin and sVCAM-1 levels from patients with asthma were significantly higher than those observed in healthy donors (p < 0.01). The levels of sP-selectin were the same as those of controls. The level of sE-selectin exhibited an important increase in the severe asthmatic patients compared with mild/moderate asthma (p < 0.01). The sVCAM-1 level was increased in severe asthma when compared with healthy controls. There was no correlation between the levels of soluble selectins and the age of the patients. A significant correlation was found between sE-selectin and sVCAM-1 levels. CONCLUSION: These data indicate that circulating soluble forms of the selectins may have different kinetics during the clinical course of asthma, suggesting that they may reflect different inflammatory pathways in severe asthma. Both sVCAM-1 and sE-selectin may be useful immunological markers for monitoring disease activity in asthma.     

创伤后多脏器功能衰竭患者白细胞流变性 和细胞粘附分子水平的变化

目的：探讨创伤后多器官功能衰竭（MOF）患者白细胞流变性和细胞粘附分子（CAMs）水平的变化。方法：采用DXC-300A型核孔膜红细胞变形能力测定仪、JYJ-Ⅲ型体外血栓血小板粘附两用仪、酶联免疫吸附法（ELISA）,分别检测了36例创伤后MOF患者、31例创伤患者和35例健康人外周血液白细胞变形能力（LD）、白细胞粘附功能（LAF）、白细胞CD18表达、血浆可溶性细胞间粘附分子-1（sICAM-1）和可溶性血管细胞间粘附分子-1（sVCAM—1）的变化。结果：MOF患者白细胞滤过指数（LFI）、白细胞粘附率（LAR）、白细胞CD180表达、sICAM—1,sVCAM—1均明显增高,与对照组和创伤组比较差异有极显著性（F=68．45-116．20,q=12．161—21、374,P〈0．001）,MOF组死亡者各指标变化较存活者更明显（t=6．920—11．665,P〈0,001）。MOF患者LFI和LAR与sICAM—1,sVCAM—1和白细胞CD18表达呈正相关（r=0．691～0．844,P〈0．001）,LFI与LAR呈正相关（r=0．771,P〈0．001）。结论：白细胞流变性和CAMs水平异常参与了MOF的发生,且与病情严重程度有密切关系。     

Altered p38 mitogen-activated protein kinase expression in different leukocytes with increment of immunosuppressive mediators in patients with severe acute respiratory syndrome

Severe acute respiratory syndrome (SARS) has spread to a global pandemic, especially in Asia. The transmission route of SARS has been clarified, but the immunopathogenesis of SARS is unclear. In an age-matched case-control design, we studied immune parameters in 15 SARS patients who were previously healthy. Plasma was harvested for detection of virus load, cytokines, and nitrite/nitrate levels, and blood leukocytes were subjected to flow cytometric analysis of intracellular mitogen-activated protein kinases (MAPKs) in different leukocytes. Patients with SARS had significantly higher IL-8 levels (p = 0.016) in early stage, and higher IL-2 levels (p = 0.039) in late stage than normal controls. Blood TNF-alpha, IL-6, and IL-10, and nitrite/nitrate levels were not significantly elevated. In contrast, TGF-beta and PGE(2) levels were significantly elevated in SARS patients. Five of the 15 SARS patients had detectable coronaviruses in blood, but patients with detectable and undetectable viremia had no different profiles of immune mediators. Flow cytometric analysis of MAPKs activation by phospho-p38 and phospho-p44/42 (extracellular signal-regulated kinase) expression showed that augmented p38 activation (p = 0.044) of CD14 monocytes associated with suppressed p38 activation (p = 0.033) of CD8 lymphocytes was found in SARS patients. These results suggest that regulation of TGF-beta and PGE(2) production and MAPKs activation in different leukocytes may be considered while developing therapeutics for the SARS treatment.     

The Effect of Iron Treatment on Adhesion Molecules in Patients with Iron Deficiency Anemia

The present study was aimed to determine the effect of iron supplementation on levels of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in patients with iron deficiency anemia (IDA). In this study, 26 female patients diagnosed with iron deficiency were treated approximately 3 months of oral iron supplementation (99 ± 10 days; ferrous glycine sulfate; 100 mg/day of elemental iron). Levels of sICAM-1 and sVCAM-1 were assessed prior to treatment and after approximately 3 months of treatment and compared with 26 healthy female subjects. A significant increase in sVCAM levels was found in the patients with iron deficiency at the end of the treatment relative to pretreatment levels compared to controls, whereas no significant differences were determined in sICAM levels. In the posttreatment period, no significant change was observed in sICAM levels compared to the pretreatment levels, whereas sVCAM levels decreased. However, after the treatment period, the sVCAM, hemoglobin, mean corpuscular volume (MCV), and serum ferritin levels did not return to the normal range compared to the controls. Pretreatment sVCAM-1 levels were inversely correlated with levels of hemoglobin, hemotocrit, MCV, serum iron, and ferritin. After treatment, the sVCAM-1 levels were negatively correlated with ferritin levels. Levels of sVCAM were significantly higher in patients with IDA than controls. After the treatment period, the sVCAM levels were not completely normalized in patients with IDA compared to controls, regardless of the presence of inadequate levels of hemoglobin, MCV, and serum ferritin. Thus, iron supplementation not only ameliorates anemia, but may also reduce the inflammation markers in cases with IDA.     

Persistent Inflammation and Endothelial Activation in HIV-1 Infected Patients after 12 Years of Antiretroviral Therapy

Objective

The study investigated markers of inflammation and endothelial activation in HIV infected patients after 12 years of successful combination antiretroviral treatment (cART).

Methods

Inflammation and endothelial activation were assessed by measuring levels of immunoglobulins, β2-microglobulin, interleukin (IL) 8, tumor necrosis factor α (TNFα), vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1), sE-Selectin, and sP-Selectin.

Results

HIV infected patients had higher levels of β2-microglobulin, IL-8, TNFα, and sICAM-1 than uninfected controls, and HIV infected patients lacked correlation between platelet counts and sP-Selectin levels found in uninfected controls.

Conclusion

Discrete signs of systemic and vascular inflammation persist even after very long term cART.     

Plasma profiles of circulating granulocyte-macrophage colony-stimulating factor and soluble cellular adhesion molecules in acute myocardial infarction. Contribution to post-infarction left ventricular dysfunction

No in vivo data exist about the relationship of circulating granulocyte-macrophage colony stimulating factor (GM-CSF) and soluble adhesion molecules ICAM-1 and VCAM-1 (sICAM-1 and sVCAM-1) to the severity of acute myocardial infarction (AMI) and the pathophysiological events of post-infarction left ventricular dysfunction. We investigated the kinetics of these inflammatory mediators in the plasma of patients with AMI, and correlated the findings with the clinical severity of the disease during the first week of hospitalization as well as the degree of left ventricular dysfunction one month after the AMI. Plasma levels of inflammatory markers were determined in 41 AMI patients (all received thrombolytic treatment) by ELISA assays, serially during the first week of hospitalization and one month after hospital admission. Patients (n = 20) with uncomplicated AMI (Killip class I) were classified as group A, patients (n = 21) with AMI complicated by heart failure manifestations (Killip classes II and III) were classified as group B, while 20 age- and sex-matched volunteers were used as healthy controls. A sustained increase in GM-CSF, sICAM-1 and sVCAM-1 plasma concentrations was observed only in group B during the first week of the study. Patients from group B exhibited significantly higher levels of GM-CSF (P < 0.01), sICAM-1 (P < 0.05) and sVCAM-1 (P < 0.01) than patients from group A and the healthy controls (P < 0.001). In group B patients, significant correlations were observed between the peak of GM-CSF levels and the peak of serum creatine kinase-MB (r = 0.42; P < 0.05), white blood cell counts (r = 0.67; P < 0.001) and LVEF (r =- 0.51; P < 0.01). At one month follow-up, patients (n = 17) with severe post-infarction left ventricular dysfunction (LVEF 35%). Significant correlations were observed between GM-CSF levels and left ventricular end-diastolic volume index (r = 0.55; P < 0.001) or left ventricular end-systolic volume index (r = 0.49; P = 0.001). We have found a significant elevation of plasma GM-CSF and soluble adhesion molecules during the course of AMI, with the highest values in patients with AMI complicated by heart failure manifestations and severe left ventricular dysfunction. These monocyte-related inflammatory mediators may actively contribute to the pathophysiology of the disease and post-infarction cardiac dysfunction.     

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 <0.5×10⁹/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.     

Soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1) Is Elevated in Bronchoalveolar Lavage Fluid of Patients with Acute Respiratory Distress Syndrome

Introduction

Pulmonary vascular endothelial activation has been implicated in acute respiratory distress syndrome (ARDS), yet little is known about the presence and role of endothelial activation markers in the alveolar space in ARDS. We hypothesized that endothelial activation biomarkers would be differentially expressed in bronchoalveolar lavage fluid from patients with ARDS compared with healthy volunteers, and that biomarker concentrations would be associated with ARDS severity.

Methods

We performed a cross-sectional analysis of data from 26 intubated patients with ARDS undergoing evaluation for clinically suspected ventilator-associated pneumonia and five healthy volunteers. Patients underwent bronchoalveolar lavage a median of five days after intubation. Healthy volunteers also underwent bronchoalveolar lavage. Endothelial activation biomarkers (soluble vascular cell adhesion molecule-1 [sVCAM-1], soluble endothelial selectin [sESEL], angiopoietin-1 [Ang-1] and angiopoietin-2 [Ang-2]) were measured in bronchoalveolar lavage fluid. Clinically suspected ventilator-associated pneumonia was confirmed with microbiologic culture data.

Results

Patients with ARDS had significantly higher median sVCAM-1 concentrations in the bronchoalveolar lavage fluid compared with healthy volunteers (985 vs 119 pg/mL, p = 0.03). Additionally, there was a trend toward greater bronchoalveolar lavage fluid sVCAM-1 concentrations among patients with moderate/severe compared to mild ARDS (1395 vs 209 pg/mL, p = 0.06). We did not detect significant differences in bronchoalveolar lavage fluid levels of sESEL, Ang-1 or Ang-2 between patients with ARDS and healthy volunteers. Median bronchoalveolar lavage fluid biomarker levels did not differ between patients with and without microbiologically-confirmed ventilator-associated pneumonia.

Conclusions

sVCAM-1 concentrations were significantly higher in the bronchoalveolar lavage fluid of patients with ARDS compared to healthy controls, and tended to be higher in moderate/severe ARDS compared to mild ARDS. Our findings add to the growing evidence supporting the concept that endothelial activation plays an important mechanistic role in the pathogenesis of ARDS. Further studies are necessary to characterize the role and/or clinical significance of sVCAM-1 and other endothelial activation markers present in the alveolar space in ARDS.     

Inflammatory cells and apoptosis in respiratory and limb muscles of patients with COPD

Discrepancies exist regarding the involvement of cellular inflammation and apoptosis in the muscle dysfunction of chronic obstructive pulmonary disease (COPD) patients with preserved body composition. We explored whether levels of inflammatory cells and apoptosis were increased in both respiratory and limb muscles of COPD patients without nutritional abnormalities. In the vastus lateralis, external intercostals, and diaphragms of severe and moderate COPD patients with normal body composition, and in healthy subjects, intramuscular leukocytes and macrophage levels were determined (immunohistochemistry). Muscle structure was also evaluated. In the diaphragm and vastus lateralis of severe and moderate COPD patients and controls, apoptotic nuclei were explored using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay, electron microscopy, and caspase-3 expression. In COPD patients compared with controls, diaphragm and intercostal levels of inflammatory cells were extremely low and not significantly different. However, in the vastus lateralis of the severe patients, inflammatory cell counts, although also very low, were significantly greater. In those patients, TUNEL-positive nuclei levels were also significantly greater in diaphragms and vastus lateralis. A significant inverse relationship was found between quadriceps TUNEL-positive nuclei levels and muscle force. Ultrastructural apoptotic nuclei revealed no differences in respiratory or limb muscles between COPD patients and controls. Muscle caspase-3 expression did not differ between patients and controls. In severe COPD patients with preserved body composition, while increased apoptotic nuclei seems to be a contributor to their muscle dysfunction, cellular inflammation does not. The increased numbers of TUNEL-positive nuclei in their muscles suggest that they may also be exposed to a continuous repair/remodeling process.     

Persistence of lung inflammation and lung cytokines with high-resolution CT abnormalities during recovery from SARS

Background

During the acute phase of severe acute respiratory syndrome (SARS), mononuclear cells infiltration, alveolar cell desquamation and hyaline membrane formation have been described, together with dysregulation of plasma cytokine levels. Persistent high-resolution computed tomography (HRCT) abnormalities occur in SARS patients up to 40 days after recovery.

Methods

To determine further the time course of recovery of lung inflammation, we investigated the HRCT and inflammatory profiles, and coronavirus persistence in bronchoalveolar lavage fluid (BALF) of 12 patients at recovery at 60 and 90 days.

Results

At 60 days, compared to normal controls, SARS patients had increased cellularity of BALF with increased alveolar macrophages (AM) and CD8 cells. HRCT scores were increased and correlated with T-cell numbers and their subpopulations, and inversely with CD4/CD8 ratio. TNF-α, IL-6, IL-8, RANTES and MCP-1 levels were increased. Viral particles in AM were detected by electron microscopy in 7 of 12 SARS patients with high HRCT score. On day 90, HRCT scores improved significantly in 10 of 12 patients, with normalization of BALF cell counts in 6 of 12 patients with repeat bronchoscopy. Pulse steroid therapy and prolonged fever were two independent factors associated with delayed resolution of pneumonitis, in this non-randomized, retrospective analysis.

Conclusion

Resolution of pneumonitis is delayed in some patients during SARS recovery and may be associated with delayed clearance of coronavirus, Complete resolution may occur by 90 days or later.     

Plasma macrophage colony-stimulating factor levels during cardiopulmonary bypass with extracorporeal circulation

Leukocytosis and thrombocytopenia occur during cardiopulmonary bypass (CPB) with extracorporeal circulation (ECC). Elevated circulating concentrations of macrophage colony-stimulating factor (M-CSF) are reported during thrombocytopenia and leukopenia of different origins. We have assessed M-CSF concentrations in 40 patients undergoing CPB with ECC. Plasma M-CSF concentrations were stable during ECC and increased at the 6th (7.3 +/- 0.7 IU/mug protein) and 24th (8.6 +/- 0.8 IU/mug protein) postoperative hour compared with pre-ECC values (4.9 +/- 0.5 IU/mug protein). A deep thrombocytopenia was found during ECC and until the 24th postoperative hour. A drop of leukocyte counts was found during ECC followed by an increase after ECC weaning. While no correlation was found between M-CSF concentrations and the leukocyte counts, M-CSF values were positively correlated with platelet counts only before and during ECC. Thus, M-CSF is not implicated in the thrombocytopenia and the leukopenia generated during CPB with ECC. However the elevated levels of M-CSFa few hours after the end of ECC might play a role in the inflammatory process often observed after CPB.     

A meal rich in oleic acid beneficially modulates postprandial sICAM-1 and sVCAM-1 in normotensive and hypertensive hypertriglyceridemic subjects

This study investigated whether subjects with permanent activated endothelium have altered soluble forms of intercellular adhesion molecule 1 (sICAM-1) and vascular cell adhesion molecule 1 (sVCAM-1) postprandial response to a high-fat meal and whether this phenomenon is modulated by the nature of dietary fats. Twenty-eight hypertriglyceridemic (14 normotensives and 14 hypertensives) and 14 healthy male subjects were placed in a randomized and crossover design on diets enriched in refined olive oil (ROO) or high-palmitic sunflower oil (HPSO) for a 1-week lead-in period. Thereafter, subjects ate the corresponding fat-rich meal as a breakfast and underwent sampling hourly for 8 h. Plasma triglycerides (TG), sICAM-1 and sVCAM-1 were assayed. sICAM-1 and sVCAM-1 postprandial peak levels were significantly higher and occurred later in hypertriglyceridemic subjects (all P<.001) compared with healthy subjects. ROO meal resulted in smaller areas under the curve for sICAM-1 and sVCAM-1 in hypertriglyceridemic (normotensive and hypertensive) and healthy subjects compared to HPSO meal. Hypertension did not aggravate the postprandial response of TG, sICAM-1 and sVCAM-1. We conclude that the challenge of a meal with ROO appears to have a significant postprandial benefit on sICAM-1 and sVCAM-1 as surrogate markers of endothelial activation and vascular inflammation in healthy and more importantly in hypertriglyceridemic (normotensive and hypertensive) subjects.     

Serum soluble Fas ligand (sFasL) in patients with primary squamous cell carcinoma of the esophagus

Esophageal carcinomas have been shown to express Fas ligand (FasL) and down-regulate Fas to escape from host immune surveillance. Circulating soluble FasL (sFasL) has been suggested to provide protection from Fas-mediated apoptosis. The aim of this study was to assess serum sFasL levels in esophageal cancer. The pretreatment levels of sFasL in the serum of 100 patients with esophageal squamous cell cancer and 41 healthy volunteers were determined by ELISA. Probability of survival was calculated according to the method of Kaplan-Meier. The prognostic influence of high and low level of sFasL was analyzed with the log-rank test. The mean serum level of sFasL in patients with esophageal cancer was significantly higher than that in healthy donors (1.567+/-1.786 vs 0.261+/-0.435, p<0.0001). The levels of serum sFasL were significantly higher in advanced stages (II vs IV p<0.034; III vs IV p<0.041; except II vs III p=0.281), patients with lymph node (N0 vs N1 p<0.0389) or distant (M0 vs. M1 p<0.0388) metastases and significantly lower in patients with well differentiated tumors (G1 vs G2 p<0.0272). The serum levels of soluble FasL were not related to gender, age, tumor size, T-stage, tobacco smoking and history of chronic alcohol intake. The survival difference between pretreatment high and low level of sFasL in surgery and chemio- and/or radiotherapy group was not statistically significant (p=0.525; p=0.840). Our results indicate that elevated serum sFasL levels might be associated with a disease progression in patients with esophageal squamous cell carcinoma.     

华支睾吸虫病患者血管内皮细胞黏附分子水平与肝功能的临床关系

目的探讨华支睾吸虫病患者可溶性血管内皮细胞黏附分子(sVCAM-1)的表达,以及与肝功能的临床关系。方法50例未经治疗的华支睾吸虫病患者,参照Child-Pugh肝功能分级法,分成A22例、B 14例、C 14例3组。采用双抗体夹心ELISA法,检测血清sVCAM-1水平;采用放射免疫分析方法检测血清白细胞介素-4(IL-4)含量;采用鲎三肽基质染色定量法检测血清细菌脂多糖(LPS)水平。对照组为健康献血员20例。结果(1)华支睾吸虫病患者血清sVCAM-1、LPS和IL-4的水平明显高于对照组;(2)经相关性检验,患者血清sVCAM-1、LPS含量与TBL、ALT均呈正相关,与ALB呈负相关;(3)参照Child-Pugh分级,肝功能受累越重,患者血清中sVCAM-1、LPS和IL-4含量依次递增。结论sVCAM-1及LPS参与介导了华支睾吸虫病肝损伤过程;IL-4对华支睾吸虫感染具有一定的保护作用。     

Interleukin-7 (IL-7): immune function, involvement in the pathogenesis of HIV infection and therapeutic potential

Interleukin 7 (IL-7), which is constitutively produced particularly by stromal cells from the bone marrow and thymus, plays a crucial role in T cell homeostasis. This cytokine is implicated in thymopoiesis since it sustains thymocyte proliferation and survival. It regulates peripheral naive T cell survival by modulating the expression of the anti-apoptotic molecule Bcl-2, and sustains peripheral T cell expansion in response to antigenic stimulation. Infection by the human immunodeficiency virus (HIV) leads to severe T lymphopenia and general immune dysfunction. Increased IL-7 plasma levels are generally observed in HIV-infected patients. The existence of an inverse correlation between IL-7 plasma levels and the CD4+ T cell count suggests that a direct feedback mechanism is working to restore peripheral T cell counts in lymphopenic patients. Here, IL-7 plasma levels are a good predictive marker of CD4+ T cell restoration during therapy. Combinations of antiretroviral treatments considerably slow disease progression. They drastically decrease the viral load and, in most patients, significantly increase peripheral CD4+ T cell counts. However, despite their usual ability to reduce viral replication, such treatments often fail to reverse lymphopenia and do not restore specific antiviral immune responses. IL-7, based therapy, combined with efficient antiretroviral treatment, may be beneficial to HIV-infected patients by promoting thymic output, sustaining naive T cell counts and increasing memory T cell activation.     

Mechanisms of platelet and leukocyte recruitment in experimental colitis

Both leukocytes and platelets accumulate in the colonic microvasculature during experimental colitis, leading to microvascular dysfunction and tissue injury. The objective of this study was to determine whether the recruitment of leukocytes and platelets in inflamed colonic venules are codependent processes. The rolling and adherence of leukocytes and platelets in colonic venules of mice with dextran sodium sulfate (DSS)-induced colitis were monitored by intravital videomicroscopy. DSS elicited an increased recruitment of both rolling and adherent leukocytes and platelets. DSS-colitic mice rendered thrombocytopenic with anti-platelet serum exhibited profound reductions in leukocyte adhesion. Neutropenia, induced with anti-neutrophil serum, significantly reduced the adhesion of leukocytes and the accumulation of platelet-leukocyte aggregates while greatly enhancing the number of platelets that roll and adhere directly to venular endothelial cells. The enhanced platelet adhesion associated with neutropenia was mediated by platelet P-selectin interactions with endothelial cell P-selectin glycoprotein ligand (PSGL-1). DSS colitis was also associated with an increased expression of PSGL-1 in the colonic vasculature. These findings indicate that the recruitment of leukocytes and platelets in inflamed colonic venules are co-dependent processes.     

Haematological manifestations in patients with severe acute respiratory syndrome: retrospective analysis

Objectives To evaluate the haematological findings of patients with severe acute respiratory syndrome (SARS).Design Analysis of the demographic, clinical, and laboratory characteristics of patients with SARS.Setting Prince of Wales Hospital, Hong Kong.Subjects All patients with a diagnosis of SARS between 11 March and 29 March 2003 who had no pre-existing haematological disorders.Main outcome measures Clinical end points included the need for intensive care and death. Univariate and multivariate analyses were performed to examine factors associated with adverse outcome.Results 64 male and 93 female patients were included in this study. The most common findings included lymphopenia in 153 (98%) of the 157 patients, neutrophilia in 129 (82%), thrombocytopenia in 87 patients (55%), followed by thrombocytosis in 77 (49%), and isolated prolonged activated partial thromboplastin time in 96 patients (63%). The haemoglobin count dropped by more than 20 g/l from baseline in 95 (61%) patients. Four patients (2.5%) developed disseminated intravascular coagulation. Lymphopenia was shown in haemato-lymphoid organs at postmortem examination. Multivariate analysis showed that advanced age and a high concentration of lactate dehydrogenase at presentation were independent predictors of an adverse outcome. Subsets of peripheral blood lymphocytes were analysed in 31 patients. The counts of CD4 positive and CD8 positive T cells fell early in the course of illness. Low counts of CD4 and CD8 cells at presentation were associated with adverse outcomes.Conclusions Abnormal haematological variables were common among patients with SARS. Lymphopenia and the depletion of T lymphocyte subsets may be associated with disease activity.     

Macrophages of patients with X-linked thrombocytopenia display an attenuated Wiskott-Aldrich syndrome phenotype

The immunodeficiency disorder Wiskott-Aldrich syndrome and its milder form X-linked thrombo-cytopenia are caused by mutations in the WASp gene. Wiskott-Aldrich syndrome is characterized by a plethora of clinical symptoms which are due to functional defects of haematopoietic cells, including the inability of macrophages to form actin-rich adhesion structures called podosomes. In contrast, X-linked thrombocytopenia patients show reduced platelet size and counts but no cytoskeletal white blood cell defects have been detected so far. Here we use immunofluorescence technique to evaluate podosome formation in macrophages from X-linked thrombocyto-penia and Wiskott-Aldrich syndrome patients and from healthy donors. We find that X-linked thrombocytopenia macrophages, cells previously thought to be unaffected in this disorder, are compromised in the formation of podosomes. Western blot analysis shows that this phenotype is not due to lower levels of WASp expression. Interestingly, the bacterial chemoattractant formyl-methionyl-leucyl-phenylalanine can rescue podosome formation in X-linked thrombocytopenia cells. Our findings indicate that: 1. The spectrum of WASp-dependent disorders contains defects more subtle than originally recognized and 2. in X-linked thrombocytopenia, some of these defects may not be evident under conditions of bacterial stimulation. Further evaluation of this and other, as yet unrecognized, cellular defects may provide a more complete picture of the continuum of Wiskott-Aldrich syndrome and X-linked thrombocytopenia defects.