Differential expression of the interleukin 5 receptor alpha isoforms in blood and tissue eosinophils of nasal polyp patients

BACKGROUND

Given the key role of interleukin-5 (IL-5) in eosinophil function, we investigated the regulated expression of the membrane-anchored (TM-IL-5Ralpha) isoform, or a secreted (SOL IL-5Ralpha) isoform, on both protein and transcript level in vitro and in vivo.

METHODS

A real-time PCR, FACS and ELISA were established to determine IL-5Ralpha isoform expression in peripheral blood and nasal tissue from control subjects and nasal polyp (NP) patients with or without asthma. Human peripheral blood eosinophils were incubated with IL-5 and were analyzed for SOL-IL-5Ralpha and TM-IL-5Ralpha mRNA and protein levels in comparison with CD-69 expression.

RESULTS

SOL-IL-5Ralpha and TM-IL-5Ralpha mRNA and protein expression was significantly increased in NP vs controls. In polyp tissue, SOL-IL-5Ralpha expression correlated to disease severity and eosinophils counts, whereas TM-IL-5Ralpha levels were inversely correlated to eosinophils counts and SOL-IL-5Ralpha expression. FACS analysis revealed increased CD-69 and decreased TM-IL-5Ralpha expression in NP tissue eosinophils vs blood eosinophils. Incubation of blood eosinophils with IL-5 caused up-regulation of CD-69 and down-regulation of TM-IL-5Ralpha after 2 and 24 h.

CONCLUSION

The expression of SOL-IL-5Ralpha and TM-IL-5Ralpha differs according to the eosinophil activation state and localization in the body (blood vs tissue) and may therefore be involved in the fine-tuning of the eosinophil homeostasis. Exposure of eosinophils to IL-5 reduces their responsiveness to IL-5 by regulated expression of the IL-5Ralpha isoforms. Since, TM-IL-5Ralpha is down-regulated and SOL-IL-5Ralpha (antagonistic) is upregulated in NP tissue, our findings are important to understand the clinical trials with anti-IL-5 in humans.

Regulation of the interleukin-5 receptor alpha-subunit on peripheral blood eosinophils from healthy subjects

The aim was to study in vitro regulation of the IL-5 receptor alpha (IL-5R alpha) on purified peripheral blood eosinophils from healthy subjects. The IL-5R alpha was down-regulated, in a dose-dependent manner, by recombinant IL-5 and GM-CSF, with IL-5 being most potent. This down-regulation was not induced by autocrine release of GM-CSF or IL-5, respectively. Incubation of eosinophils with cell-free peritoneal dialysis fluid (PF) collected from a patient with peritoneal fluid eosinophilia (PFE), induced up-regulation of the proportion of CD69 positive eosinophils, in parallel with down-regulation of the proportion of IL-5R alpha positive eosinophils. Experiments with neutralizing antibodies against IL-5 and GM-CSF, revealed that IL-5 was the principal cytokine responsible for the down-regulation of the IL-5R alpha. When eosinophils were incubated with PF collected from the same patient in remission or with PF collected from a newly started patient or a patient with bacterial peritonitis, less down-regulation of the IL-5R alpha was observed. In conclusion our data indicate that IL-5, as opposed to its proposed action on eosinophil progenitors, down-regulates the IL-5R alpha chain on mature eosinophils. We therefore suggest that an IL-5 driven inflammation generates an eosinophil tissue phenotype that is characterized by a low IL-5R alpha expression. These aspects of IL-5 action on IL-5R alpha expression could gain new insights into the mechanisms of specific immuno-modulatory therapies, such as anti-IL-5.

Down-regulated IL-5 receptor expression on peripheral blood eosinophils from budesonide-treated children with asthma

BACKGROUND

The expression and function of cytokine receptors on peripheral blood eosinophils (PBE) from healthy and asthmatic children are poorly characterized.

METHODS

The PBE count and expression of IL-5 receptor (R) and GM-CSFR positive PBE was analyzed in nonsteroid-treated asthmatic children (n = 13), budesonide-treated asthmatic children (n = 24) and healthy children (n = 16) by flow cytometry. Alterations in intracellular EG2-epitope expression were used to measure the in vitro responsiveness of PBE to recombinant IL-5 and GM-CSF.

RESULTS

The PBE count was increased (P < 0.05) in both asthmatic groups, independent of treatment, as compared to healthy children. The IL-5R expression on PBE, as well as the in vitro responsiveness of PBE to recombinant IL-5, was reduced (P < 0.05), in budesonide-treated asthmatic children compared to nonsteroid-treated asthmatic children and healthy children. The proportion of GM-CSFR positive PBE and in vitro responsiveness of PBE to recombinant GM-CSF were not different between the groups. In vitro treatment with budesonide did not down-regulate the proportion of IL-5R positive PBE.

CONCLUSIONS

Budesonide-treatment of asthmatic children induces a selectively reduced IL-5R expression on PBE, concomitant with a reduced in vitro responsiveness of PBE to IL-5. We suggest that this budesonide-related down-regulation of the IL-5R might be a mechanism by which steroid treatment inhibits the action of IL-5 on eosinophil accumulation and activation in vivo.

Eosinophil markers in blood, serum, and urine for monitoring the clinical course in childhood asthma: impact of budesonide treatment and withdrawal

BACKGROUND

Markers of airway inflammation are needed for prediction of asthma deterioration and evaluation of disease severity. Few studies have focused on the dynamics of airway inflammation as reflected by the activity of the eosinophils and their proteins after withdrawal of inhaled corticosteroids.

OBJECTIVE

Our goal was to investigate the effect of withdrawal of inhaled budesonide on eosinophil count in blood and eosinophil proteins in serum and urine and to relate the levels of these markers to the risk of symptoms of asthma, increased bronchial hyperresponsiveness, and deterioration of lung function.

METHODS

Thirty-three children were randomly selected to continue or discontinue use of inhaled budesonide in a double-blind, placebo-controlled study. They were followed up for 4 months with regular analysis of blood, serum, and urine samples; lung function; and methacholine challenges. Eosinophil activity markers were analyzed. Age-matched healthy children provided reference data for all parameters measured.

RESULTS

The eosinophil number in blood and eosinophil protein levels in serum (serum eosinophil cationic protein [ECP] and serum eosinophil peroxidase [EPO]) increased significantly in the withdrawal group, and the difference between the groups was significant (P =.02 for all). Twenty-nine percent of the children in the withdrawal group remained symptom free. This subgroup had eosinophil counts at baseline below 350/microL, a serum ECP level below 15 microg/L, and a serum EPO level below 25 microg/L, each of which was related to a low risk of exacerbation (relative risk = 0.37, 0.48, and 0.37 respectively; P <.05 for all). All eosinophil markers were lower in the healthy children than in the symptom-free children with asthma.

CONCLUSION

Our data indicate that eosinophil count and/or ECP and EPO levels can be used to estimate the short-term risk of deterioration and the need for corticosteroid treatment in cases of mild and moderate allergic asthma.

Phenotypic alterations of recruited eosinophils in peritoneal fluid eosinophilia

OBJECTIVE

To characterize eosinophils and soluble factors in effluent from continuous ambulatory peritoneal dialysis (CAPD) patients and connect these findings to related conditions with eosinophilic accumulation.

PATIENTS

Three newly started CAPD patients, two with peritoneal fluid eosinophilia (PFE) and one with bacteria-induced peritonitis. One patient with PFE was followed up for 10 visits during a 7-month period.

METHODS

Leukocytes were analyzed in dialysate and peripheral blood from the patients, by flow cytometry, and soluble mediators by ELISA or CAP technique.

RESULTS

We found an increased number of neutrophils in the effluent from the patient with bacteria-induced peritonitis; accumulation of eosinophils in combination with negative cultures was noted in the patients with PFE. Increased levels of interleukin (IL)-5 and eosinophil cationic protein, but equal levels of eotaxin, were found in effluent from the PFE patients compared to the patient with neutrophilia. Peritoneal fluid eosinophils were activated by means of EG2, CD11b, CD9, and CD69 expression. Compared to blood eosinophils, the cytokine receptors for IL-5 and granulocyte-macrophage colony-stimulating factor, but not IL-3, were down regulated.

CONCLUSION

The finding of activated eosinophils in combination with IL-5 and eotaxin in PFE indicates existing similarities between PFE and conditions found during recruitment of eosinophils in allergic inflammatory responses.

Increased levels of IL-5 positive peripheral blood eosinophils and lymphocytes in mild asthmatics after allergen inhalation provocation

BACKGROUND

In allergic inflammation eosinophils and TH2-like lymphocytes are supposed to be the major effector cells and considered to contribute as cellular source of the key cytokine interleukin (IL)-5.

OBJECTIVE

The purpose of this study was to enable detection of IL-5 containing leucocytes and to investigate whether the number of these cells in the blood circulation differed between healthy and asthmatics before and after allergen provocation.

METHODS

The distribution of intracellular IL-5 in human peripheral blood eosinophils (PBE) and lymphocytes (PBL) has been investigated using fixation and cell membrane permeabilization with octyl-glucopyranoside, the FOG-method, and flow cytometry. The intracellular staining was performed on leucocytes without any prior purification and in vitro stimulation. The specificity of IL-5 binding to intracellular compartment of both PBE and PBL was confirmed by complete inhibition with human recombinant IL-5.

RESULTS

Preformed intracellular IL-5 was detected in the main population of PBE (> 70%) in both healthy individuals and asymptomatic patients. Moreover, preformed intracellular IL-5 was also detected in 4.8% and 2.4% of PBL from healthy individuals and asymptomatic patients, respectively. There was a correlation between the absolute number of PBE and IL-5 positive PBE. In patients with pollen-related asthma, the number of IL-5 positive PBE and PBL increased significantly 24 h after an allergen inhalation provocation (P < 0.05). In the healthy control group no differences regarding IL-5 positive PBE and PBL were obtained pre- and post-allergen challenge.

CONCLUSIONS

In patients with mild allergic asthma, but not in healthy individuals, allergen provocation induces an increased absolute number of IL-5 positive PBE and PBL. The reason for the relatively high number of IL-5 positive PBL is unclear, but a plausible explanation might be that other lymphocyte subsets besides CD4+ TH2 can produce IL-5. However, enumeration of IL-5 positive leucocytes may be used as an activity marker and also be a useful tool in monitoring the inflammation in asthma.

Evaluation of leg perfusion during exercise using technetium 99m sestamibi. A new test for peripheral vascular disease

Thirty patients with occlusive peripheral vascular disease underwent clinical examination, segmental blood pressure determinations, intra-arterial digital subtraction angiography, and treadmill stress testing with injection of technetium 99m sestamibi at peak exercise. Radionuclide images of the thighs, calves, and feet showed clear delineation of major muscle groups. Diminished radiotracer distribution was closely correlated with the presence of occlusive vascular disease on angiography and with the presence of claudication and reduced segmental blood pressure. A quantitative scheme based on pixel intensity was developed to compare areas of regional perfusion.

Motivational syndromes associated with natural killer cell activity

This article reports three studies that taken together support two hypotheses: (a) that the stressed power motivation syndrome is associated with relatively low natural killer cell activity (NKCA) and (b) that the unstressed affiliation motivation syndrome is associated with higher NKCA. In Study 1, college students who were relatively high in stressed power motivation had significantly lower NKCA than did their peers. In addition, students high in unstressed affiliation motivation had significantly greater NKCA than did those showing less evidence of this syndrome. Study 2 replicated these findings on a sample of middle-class men. In Study 3, which tested the hypotheses among adult patients from a Health Maintenance Organization, results were in the same direction but less significant. Meta-analyses clearly indicate that the combined evidence from the three studies reliably supports both hypotheses.

Osmium-191/iridium-191m generator based on silica gel impregnated with tridodecylmethylammonium chloride

A new separation system for an 191Os/191mIr generator is described. The system is composed of two columns in a series: a main column, packed with silica gel impregnated with tridodecylmethylammonium chloride (loaded with high activity 191Os as an osmyl chloride); and a scavenger column, packed with activated charcoal. Iridium-191m is eluted from the generator by pH 1 saline. For clinical use the eluate is buffered by succinate solution before injection. This new system is characterized by high performance (approximately 25% 191mIr recovery with 5 X 10(-4)% 191Os breakthrough) and long shelf-life (3 wk). The buffered eluate is sterile, pyrogen-free, and nontoxic, and contains no 192Ir. It is suitable for first-pass radionuclide angiocardiography with a very low radiation dose to the patient.

Evaluation of ventricular function with first-pass iridium-191m radionuclide angiocardiography

Iridium-191m would appear to be a highly useful agent for first-pass radionuclide angiocardiography (FPNA), with its very short half-life (4.96 sec), dual photopeaks (65 and 129 keV), and high injectable activity levels (greater than 100 mc). In order to compare 191mIr FPNA to current methods used to define cardiac function, 20 patients referred for cardiac catheterization were studied. Count rate data, right ventricular (RV), and left ventricular ejection fraction (LVEF), LV and diastolic volume (EDV), and end diastolic long axis (AXIS) were evaluated. Count rate data using 191mIr FPNA was consistently better than similar data obtained by 99mTc FPNA. There were acceptable correlations between 191mIr and 99mTc FPNA RVEF (r = 0.848), 191mIr FPNA and contrast angiography LVEF (r = 0.944), LVEDV (r = 0.917), and LV AXIS (r = 0.866). The data thus suggests that 191mIr FPNA has great potential in the evaluation of cardiac function.

Short- and long-term dobutamine treatment in chronic ischemic heart failure

This study was undertaken in order to characterize the short-term (1 hour) and long-term (72 hours) effect of dobutamine on hemodynamic and regional ejection fraction parameters measured by radionuclear angiography in patients with chronic congestive heart failure due to coronary artery disease. Baseline hemodynamic and radionuclear parameters were measured and then intravenous dobutamine (8.5 mu/kg/min) was administered. The above parameters were determined again after 1 hour and 72 hours of continuous dobutamine administration. Sixty minutes (short-term) after dobutamine administration heart rate and cardiac index increased significantly (p less than 0.001 for both) and peripheral resistance decreased concomitantly (p less than 0.005). Global left ventricular ejection fraction (LVEF) as measured by multigated equilibrium nuclear angiography (MUGA) increased from 21.8 +/- 10.6% to 25 +/- 13.5 (p less than 0.02). Count-based mean regional ejection fraction in the septal, inferoapical, posterolateral (45 degrees left anterior oblique view) and inferior apical and anterolateral (30 degree right anterior oblique gated first pass) regions increased also. At 72 hours (long-term) after continuous dobutamine infusion, heart rate and cardiac index were still significantly higher and peripheral resistance lower than in the control study. However, global and count-based regional ejection fraction decreased to control values in the right anterior oblique view (first-pass analysis) and the left anterior oblique view (MUGA). Global LVEF measured in the right anterior oblique view by first-pass technique was significantly higher than control in the long-term study (23 +/- 9.7 vs. 27.8 +/- 2.4; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Predominant right ventricular infarction. Clinical and electrocardiographic features

Based on two-dimensional echocardiographic wall motion abnormalities, 82 patients with acute inferior wall myocardial infarction were divided into 3 groups: group 1. predominant right ventricular infarction-20 patients; group 2. combined right and left ventricular infarction-33 patients; and group 3. predominant left ventricular infarction-29 patients. There were no significant statistical differences between the three groups regarding age, sex, Killip class on admission and jugular venous engorgement. Group 2 patients had higher peak creatine kinase levels and a lower rate of life threatening ventricular arrhythmia than the other groups. On M-mode echo, patients in group 1 had higher RV/LV ratios and lower left ventricular systolic and diastolic dimensions than group 3 patients. On 2-D echo and radionuclear studies, group 1 patients had more right ventricular wall motion abnormalities and minimal left ventricular wall motion disturbances. The left ventricular ejection fraction was higher and the right ventricular ejection fraction lower in group 1 patients than in those groups 2 and 3. The electrocardiogram showed small Q and relatively tall R waves in II, III, AVF in group 1 patients, and deep Q with loss of R waves in patients with combined or exclusive left ventricular infarction (groups 2 and 3). We conclude that predominant right ventricular infarction, which occurs in 24% of inferior wall infarction patients cannot be characterized clinically; however, an electrocardiographic pattern was found to detect this form of infarction with a sensitivity of 80% and a specificity of 70%. Combined left and right ventricular infarction and exclusive left ventricular infarction could be detected electrocardiographically with a sensitivity of 70% and a specificity of only 30%.

Echocardiographic evaluation of patients with systemic sarcoidosis

Echocardiographic evaluation of 42 patients with sarcoidosis disclosed 13 patients (group A) with abnormalities compatible with sarcoid heart involvement such as thickening or thinning of the septum (eight patients), pericardial effusion (four patients), and increased end-diastolic dimension of the left ventricle with decreased systolic function (three patients). The remaining 29 patients (group B) were diagnosed as having normal echocardiograms. The clinical data revealed no statistically significant difference between the groups regarding age, sex, chest x-ray stage, activity, and previous heart disease. Group A patients had older clinical onset of the disease (52 vs 83 months; p less than 0.05) and higher incidence of ECG abnormalities than group B patients. There were no statistically significant differences between the groups regarding two-dimensional echocardiographic internal dimensions of both ventricular chambers. The radionuclear right ventricular ejection fraction was low in both groups and the left ventricular ejection fraction was depressed in group A patients (p less than 0.01). As observed in pathologic studies, the septum is a target structure which can be characterized echocardiographically. Screening suspected sarcoid heart disease involvement is important to characterize patients with a relatively high risk of clinical cardiac abnormalities such as complete atrioventricular block, ventricular arrhythmias, congestive heart failure, and sudden death.

Right ventricular dysfunction in acute inferoposterior myocardial infarction. An echocardiographic and isotopic study

We analyzed right ventricular (RV) regional wall motion by two-dimensional echocardiographic (2D echo) and multigated acquisition radionuclear (MUGA) studies in 104 patients with acute inferoposterior myocardial infarction (AIPMI). Sixty-eight patients (65 percent) had 2D echo RV regional wall motion abnormalities (RV dysfunction(RVD) group) while 36 patients showed no 2-D echo RV regional wall motion abnormalities (no-RVD group). The RVD group had a higher incidence of jugular venous engorgement (p less than 0.05), Kusmaul's sign, (p less than 0.05) complete atrio-ventricular block (p less than 0.05), and in-hospital death (p less than 0.02). The RVD group had significantly higher 2-D echo RV end-systolic dimensions (p less than 0.005) and lower values of percentage of fractional shortening (%FS) (p less than 0.005) in the long and short axis of the RV four-chamber view than patients in the no-RVD group and a control group of 20 patients with normal hearts. There was no statistical significant difference in the 2-D echo RV end-diastolic dimensions among the three groups. Patients in the RVD group had a lower MUGA derived RV ejection fraction (EF) than patients in the no-RVD and control groups (26.5 +/- 13.2 vs. 46.3 +/- 7 and vs. 50.6 +/- 4, respectively; p less than 0.05). RVD was diagnosed by both 2-D echo and MUGA in 60 of 104 patients (57.7 percent) with a sensitivity for 2-D echo of 92 percent and 79 percent specificity (when compared to the MUGA study). The predictive value for a positive test was 88 percent and for a negative test 86 percent. The accuracy was 87.5 percent. Recognition of regional wall motion abnormalities by 2-D echo permits a prompt and accurate bedside identification of right ventricular dysfunction (RVD) within the first 72 hours of clinical onset. An enlarged RV 2D echo end-diastolic dimension was not a sensitive parameter for the diagnosis of this pathology, whereas an increased end-systolic RV diameter and decreased RV %FS were better indicators of RV dysfunction in patients with acute inferoposterior wall myocardial infarction.

Left and right ventricular function in inferior acute myocardial infarction and significance of advanced atrioventricular block

Of 139 consecutive patients with a first inferior acute myocardial infarction, 26 (19%) had advanced atrioventricular (AV) block and 113 (81%) did not. All were evaluated by 2-dimensional echocardiography (2-D echo) and radionuclide angiography. Patients with advanced AV block had lower radionuclide left ventricular (LV) ejection fraction (51 +/- 10 vs 58 +/- 11%, p less than 0.01), higher LV wall motion score on 2-D echo (5.6 +/- 2.6 vs 3.1 +/- 2.7, p less than 0.001), lower radionuclide right ventricular (RV) ejection fraction (32 +/- 15 vs 39 +/- 16%, p less than 0.001) and higher RV wall motion score on 2-D echo (3.4 +/- 1.7 vs 1.5 +/- 2, p less than 0.002) than did patients without AV block. The incidence rate of RV dysfunction was higher in patients with advanced AV block (78 vs 40%, p less than 0.02), and the mortality rate was also higher (although not significantly) in patients with advanced AV block (15 vs 6%). In conclusion, patients with inferior acute myocardial infarction and advanced AV block have larger infarct sizes (as seen on radionuclide angiography and 2-D echo) and lower RV and LV function than patients without AV block. This finding may explain the higher mortality rate observed in this group.

Dressler's syndrome after right ventricular infarction

Undiagnosed myocardial infarction of the right ventricle presented as Dressler's syndrome. Radioisotopic diagnostic procedures including first-pass and multigated acquisition nuclear angiography ( MUGA ) and thallium-201 perfusion studies enabled a retroactive diagnosis of myocardial infarction, showed it to be in the right ventricle, and clarified the aetiology of the unexplained fever and pleuropericarditis.

Comparative analysis of physiologic responses to three different maximal graded exercise test protocols in healthy women

The purpose of this study was to compare the three most commonly used maximal graded exercise test (GXT) protocols in healthy women. Submaximal and maximal metabolic and hemodynamic responses were determined from two treadmill protocols, Bruce and Balke, and a bicycle protocol, in 49 women. Maximum oxygen uptake (VO2 max) was significantly different among protocols (Bruce=40.3, Balke=38.4, and Bike=36.6 ml/kg . min -1). Maximum heart rate (HR max) was significantly lower during Bike (178 beats/min) than during Bruce (182) and Balke (183) protocols. No differences in rate of increase in HR or systolic blood pressure (BP) per increase in multiples of the rest metabolic (METs) were found between Bruce and Balke protocols. The rate of recovery of HR and systolic BP was not different among tests. Comparisons of active and sedentary groups showed differences in VO2 max and submaximal HR and recovery HR at common minutes; however, the rate of increase in HR and systolic BP during exercise and the rate of decrease during recovery were not significantly different. Prediction of VO2 max with Bruce and Balke protocols from treadmill time was r=0.91 (SEE +/- 2.7 ml/kg . min -1) and r=0.94 (SEE 2.2 ml/kg . min -1), respectively. These data suggest a difference between men and women in increased HR and systolic BP per METs increase in exertion.

Fifty years of training and competition in the marathon: Wally Hayward, age 70--a physiological profile

A 70-year-old South African long-distance runner, holder of his age group's marathon record and former Olympic marathon runner, was studied to determine the effects of 52 years of regular training on functional capacity and health. Maximal treadmill exercise testing revealed no ischaemic ECG abnormalities and an excellent functional capacity (58,6 ml/kg/min). Submaximal testing showed that the subject ran at approximately 86% of maximum aerobic capacity when completing the marathon in his record time. The subject was very lean (13,6% fat) for his age. Muscles contained 82% slow-twitch fibres. Pulmonary function and blood chemical values were within normal limits. Although total cholesterol was somewhat high (247 mg/dl), high-density lipoprotein cholesterol was elevated (53 mg/dl). Twenty-four-hour Holter monitoring revealed no significant ventricular ectopic activity although frequent premature atrial contractions were noted. M-mode echocardiography revealed a normal heart with moderately hypertrophied left ventricular wall thickness. Radionuclide cine angiography showed a normal ejection fraction at rest (69%), followed by a slight drop at maximal exercise (62%). Left ventricular regional wall motion was considered normal at both rest and exercise. He had no significant orthopaedic abnormalities but showed normal flexibility and well-balanced muscular strength. Thickened heel pads were also noted. These results appear to indicate a beneficial effect of habitual physical activity upon the retention of functional capacity with ageing.

Right atrial myxoma: unusual clinical presentation and atypical glandular histology

A 57-year-old black female presented with a 1-month of right-sided congestive heart failure and clinical evidence of pulmonic and tricuspid valvular stenosis and insufficiency. The echocardiographic examination and ventriculography demonstrated a large right atrial tumor interfering with the function of both right-sided valves. The patient underwent successful surgical resection of the tumor. Histologically, the tumor had cellular areas typical of myxoma, as well as glandular areas, a feature which has been described very rarely in this lesion. Electron microscopy of the glandular zones, which has never been reported previously, shown cells having essential homology with the usual myxoma elements. The atypical histopathology of this lesion supports the theory that atrial myxomas are true neoplasms, and are not derived from unusually organized mural thrombi.