Methylprednisolone-induced neutrophil leukocytosis--down-modulation of neutrophil L-selectin and Mac-1 expression and induction of granulocyte-colony stimulating factor

Complement C3 vs C5 inhibition in severe COVID-19: Early clinical findings reveal differential biological efficacy

Growing clinical evidence has implicated complement as a pivotal driver of COVID-19 immunopathology. Deregulated complement activation may fuel cytokine-driven hyper-inflammation, thrombotic microangiopathy and NET-driven immunothrombosis, thereby leading to multi-organ failure. Complement therapeutics have gained traction as candidate drugs for countering the detrimental consequences of SARS-CoV-2 infection. Whether blockade of terminal complement effectors (C5, C5a, or C5aR1) may elicit similar outcomes to upstream intervention at the level of C3 remains debated. Here we compare the efficacy of the C5-targeting monoclonal antibody eculizumab with that of the compstatin-based C3-targeted drug candidate AMY-101 in small independent cohorts of severe COVID-19 patients. Our exploratory study indicates that therapeutic complement inhibition abrogates COVID-19 hyper-inflammation. Both C3 and C5 inhibitors elicit a robust anti-inflammatory response, reflected by a steep decline in C-reactive protein and IL-6 levels, marked lung function improvement, and resolution of SARS-CoV-2-associated acute respiratory distress syndrome (ARDS). C3 inhibition afforded broader therapeutic control in COVID-19 patients by attenuating both C3a and sC5b-9 generation and preventing FB consumption. This broader inhibitory profile was associated with a more robust decline of neutrophil counts, attenuated neutrophil extracellular trap (NET) release, faster serum LDH decline, and more prominent lymphocyte recovery. These early clinical results offer important insights into the differential mechanistic basis and underlying biology of C3 and C5 inhibition in COVID-19 and point to a broader pathogenic involvement of C3-mediated pathways in thromboinflammation. They also support the evaluation of these complement-targeting agents as COVID-19 therapeutics in large prospective trials.

Leukocyte Dynamics Reveal a Persistent Myeloid Dominance in Giant Cell Arteritis and Polymyalgia Rheumatica

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are inflammatory diseases requiring long-term glucocorticoid treatment. Limited data on dynamics in leukocyte counts before, during and after treatment are available. Leukocyte counts were measured, as cellular markers of inflammation, at fixed time points in our prospectively studied cohort of pre-treatment glucocorticoid-naive GCA (N = 42) and PMR (N = 31) patients. Values were compared with age-matched healthy controls (HCs; N = 51) and infection controls (N = 16). We report that before start of treatment monocyte and neutrophil counts were higher in GCA and PMR patients than in HCs, while NK- and B-cell counts were lower. C-reactive protein (CRP) levels correlated positively with monocyte counts in GCA, and negatively with B-cell and NK-cell counts in PMR. During glucocorticoid treatment, myeloid subsets remained elevated whereas lymphoid subsets tended to fluctuate. Interestingly, erythrocyte sedimentation rate (ESR) outperformed CRP as marker for relapses in GCA. We defined stable treatment-free remission groups in both GCA and PMR. GCA patients in treatment-free remission still demonstrated elevated monocytes, neutrophils, ESR, and platelets. PMR patients in treatment-free remission had normalized levels of inflammation markers, but did have elevated monocytes, lowered CD8+ T-cell counts and lowered NK-cell counts. Finally, we showed that low hemoglobin level was predictive for long-term GC treatment in PMR. Overall, leukocyte composition shifts toward the myeloid lineage in GCA and PMR. This myeloid profile, likely induced by effects of inflammation on hematopoietic stem cell differentiation, persisted during glucocorticoid treatment. Surprisingly, the myeloid profile was retained in treatment-free remission, which may reflect ongoing subclinical inflammation.

The neutrophil-to-lymphocyte ratio is associated with multiple sclerosis

Background

Subtypes of white blood cell counts are known biomarkers of systemic inflammation and a high neutrophil-to-lymphocyte ratio (NLR) has been associated with several autoimmune diseases. Few studies have investigated the NLR in multiple sclerosis (MS).

Objective

To examine the association between NLR, MS and disability measured by the MS severity score (MSSS).

Methods

Patients were included from the Danish Multiple Sclerosis Biobank. Information on patient NLR was obtained just before their first treatment and clinical information was provided by the Danish Multiple Sclerosis Treatment Register. Information on NLR from controls was collected from the Danish Blood Donor Study. Patients and controls were 1:2 propensity score matched by baseline confounders.

Results

Propensity score matching left 740 of 743 MS patients and 1420 of 4691 controls for further analyses. Odds-ratio (OR) was 3.64 (95% confidence interval 2.87–4.60, p < 0.001) for MS disease per unit increase of logarithmically transformed NLR (ln-NLR), corresponding to an OR of 2.68 for each doubling of NLR. Mean NLR was 2.12 for patients and 1.72 for controls (p < 0.001). Ln-NLR correlated weakly with patient MSSS (R² = 0.019, p = 0.008).

Conclusion

Patients with early MS had increased levels of NLR compared to healthy controls and NLR was weakly correlated with MSSS.

Systemic Inflammatory and Th17 Immune Activation among Patients Treated for Lumbar Radiculopathy Exceeds that of Patients Treated for Persistent Postoperative Neuropathic Pain

BACKGROUND

The pathophysiology of lumbar radiculopathy includes both mechanical compression and biochemical irritation of apposed neural elements. Inflammatory and immune cytokines have been implicated, induced by systemic exposure of immune-privileged intervertebral disc tissue. Surgical intervention provides improved symptoms and quality of life, but persistent postoperative neuropathic pain (PPNP) afflicts a significant fraction of patients.

OBJECTIVE

To compare the inflammatory and immune phenotypes among patients undergoing structural surgery for lumbar radiculopathy and spinal cord stimulation for neuropathic pain.

METHODS

Consecutive patients undergoing surgical intervention for lumbar radiculopathy or neuropathic pain were studied. Demographic data included age, gender, and VAS and neuropathic pain scores. Serum was evaluated for cytokine levels (IL-6, Il-17, TNF-α) and cellular content [white blood cell (WBC)/differential, lymphocyte subtypes]. The primary analysis differentiated molecular and cellular profiles between radiculopathy and neuropathic pain patients. Subgroup analysis within the surgical radiculopathy population compared those patients achieving relief of symptoms and those with PPNP.

RESULTS

Heightened IL-6, Il-17, and TNF-α levels were observed for the lumbar radiculopathy group compared with the neuropathic pain group. This was complemented by higher WBC count and a greater fraction of Th17 lymphocytes among radiculopathy patients. In the lumbar discectomy subgroup, pain relief was seen among patients with preoperatively elevated IL-17 levels. Those patients with PPNP refractory to surgical discectomy exhibited normal cytokine levels.

CONCLUSION

Differences in Th17 immune activation are seen among radiculopathy and neuropathic pain patients. These cellular and molecular profiles may be translated into biomarkers to improve patient selection for structural spine surgery.

Postoperative leukocyte changes in facial fracture patients: a randomized prospective study with short-term dexamethasone

PURPOSE

We investigated leukocyte changes in facial fracture patients undergoing surgery. Of specific interest was the effect of perioperative dexamethasone on leukocyte changes.

METHODS

Facial fracture patients were randomized to receive perioperatively a total dose of 30 mg of dexamethasone, whereas patients in the control group received no glucocorticoid. All patients received antibiotics until postoperative days 7-10. Leukocyte count was measured on postoperative days 1 and 2. Clinical infections were observed during the follow-up.

RESULTS

A total of 110 adult patients were included in the study. Postoperative leukocytosis was found in 91.2% of patients receiving dexamethasone and in 67.9% of controls. Dexamethasone was associated strongly with leukocyte rise (p < 0.001) on both postoperative days. Transoral surgery and younger age (≤40 years) showed significant associations with leukocytosis on the first postoperative day (p = 0.002). In regression analyses, dexamethasone associated with leukocytosis most significantly (p < 0.001). No association was found with infections.

CONCLUSIONS

Dexamethasone use was the most significant predictor of leukocyte rise. As a drug response, perioperative dexamethasone caused sixfold postoperative leukocytosis. High-dose dexamethasone-induced leukocytosis may confuse the clinical decision-making especially in assessment of early infections.

Adjunct steroids in the treatment of peritonsillar abscess: A systematic review

OBJECTIVES

This study systematically reviews the existing literature on the efficacy of adjuvant corticosteroids in improving clinical outcomes after peritonsillar abscess (PTA) drainage.

STUDY DESIGN

Systematic review.

METHODS

We performed a literature search of MEDLINE, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Scopus, Embase, and ClinicalTrials.gov from inception to June 2016. Inclusion criteria included randomized controlled trials (RCTs) evaluating adjuvant corticosteroids after PTA drainage. Data were systematically collected on study design, patient demographics, and clinical characteristics. Two independent investigators reviewed all manuscripts and summarized the data.

RESULTS

Three RCTs comprising 153 patients were included. The results were not pooled due to heterogeneity in the method in which outcomes were measured and reported. The trials also varied on the type of steroid (dexamethasone, methylprednisolone) administered and method of drainage (incision, aspiration). All three RCTs reported statistically significant improvement in body temperature from adjuvant steroid administration compared to placebo. Pain scores, mouth opening, time to painless oral intake, and duration of hospitalization were significantly improved in only one or two of the three RCTs between the steroid and control group. No adverse side effects from steroid administration were reported.

CONCLUSIONS

Steroids as an adjunct therapy to the treatment of PTA may result in faster recovery. However, further investigation with larger RCTs and standardized outcomes are warranted.

LEVEL OF EVIDENCE

1a. Laryngoscope, 128:72-77, 2018.

Granulocyte colony-stimulating factor blockade enables dexamethasone to inhibit lipopolysaccharide-induced murine lung neutrophils

Glucocorticoids promote neutrophilic inflammation, the mechanisms of which are poorly characterized. Using a lipopolysaccharide (LPS)-induced acute murine lung injury model, we determined the role of granulocyte colony-stimulating factor (G-CSF) in mouse lung neutrophil numbers in the absence and presence of dexamethasone, a potent glucocorticoid. G-CSF was blocked using a neutralizing antibody. Airway neutrophil numbers, cytokine levels, and lung injury parameters were measured. Glucocorticoid treatment maintained LPS-induced airway G-CSF while suppressing TNF and IL-6. The addition of anti-G-CSF antibodies enabled dexamethasone to decrease airway G-CSF, neutrophils, and lung injury scores. In LPS-challenged murine lungs, structural cells and infiltrating leukocytes produced G-CSF. In vitro using BEAS 2B bronchial epithelial cells, A549 lung epithelial cells, human monocyte-derived macrophages, and human neutrophils, we found that dexamethasone and proinflammatory cytokines synergistically induced G-CSF. Blocking G-CSF production in BEAS 2B cells using shRNAs diminished the ability of BEAS 2B cells to protect neutrophils from undergoing spontaneous apoptosis. These data support that G-CSF plays a role in upregulation of airway neutrophil numbers by dexamethasone in the LPS-induced acute lung injury model.

Inhaled corticosteroids increase blood neutrophil count by decreasing the expression of neutrophil adhesion molecules Mac-1 and L-selectin

OBJECTIVE

The objective was to investigate the effect of commonly used inhaled corticosteroids on white blood cell count (WBC) and to examine the mechanisms involved.

METHODS

This randomized comparative study comprised 60 healthy adults. We measured the effects of budesonide (by face mask inhalation or aerosol inhaler), fluticasone (by inhaler), and saline inhalation (control) on WBC and the differential leukocyte count, especially the absolute neutrophil count (ANC). To elucidate the mechanisms involved, we measured the expression of the adhesion neutrophil ligands Mac-1 (CD11b) and L-selectin (CD62L), and granulocyte colony-stimulating factor serum levels.

RESULTS

Six hours after a single-dose inhalation of budesonide, mean increases of 23.4% in WBC (95% confidence interval [CI], 11.3-35.4) and 30.1% in ANC (95% CI, 7.2-53.0) were noted. The percentage of neutrophils increased from 54.6% to 58.1% (P< .001). Inhaled fluticasone increased WBC and ANC by 12.6% (95% CI, 1.5-23.7) and 22.7% (95% CI, 6.2-39.2), respectively (P< .01 for both). The absolute lymphocyte and eosinophil counts did not change significantly from baseline. The expression of Mac-1 and L-selectin decreased by 51.0% (P< .01) and 30.9% (P= .02), respectively, following face mask inhalation of budesonide and by 39.8% (P= .01) and 17.4% (P= .17), respectively, following inhalation of fluticasone. No significant changes in granulocyte colony-stimulating factor levels were noted.

CONCLUSIONS

Glucocorticoid inhalation increases WBC by increasing ANC. Reduced neutrophil adhesion to the endothelial surface, mediated by decreased adhesion molecule expression on neutrophils, is a plausible mechanism. Physicians should be aware of the effect of inhaled corticosteroids on WBC, as it may influence clinical decisions, especially in the emergency department.

Subclinical hypothyroidism: Comparison of adhesion molecule levels before and after levothyroxine therapy

OBJECTIVE

Adhesion molecules are involved in inflammation, atherosclerosis and malignancy. This study measured levels of adhesion molecules before and after levothyroxine therapy in patients with subclinical hypothyroidism (SHO).

METHODS

Levels of soluble (s) intracellular adhesion molecule (ICAM)-1, s vascular cell adhesion molecule (sVCAM) VCAM-1 and sE-selectin were analysed in patients diagnosed with SHO, prior to administration of 50 µg/day levothyroxine orally for 3 months. Subsequently, levels of sICAM-1, sVCAM-1 and sE-selectin were reanalysed then compared with the pretreatment levels.

RESULTS

In 30 patients with SHO, levels of sICAM-1 were found to be significantly higher than those in healthy controls, (P = 0.001). Post-treatment sICAM-1 levels were significantly lower than pretreatment levels (P = 0.001). No significant differences were found in sVCAM-1 or sE-selectin levels between healthy controls and patients with SHO before treatment, or between patients with SHO pre- and post-treatment.

CONCLUSIONS

Patients with SHO had significantly higher levels of sICAM-1 compared with controls. Levels became normal after treatment with levothyroxine. These findings emphasize the need for levothyroxine therapy in cases of SHO to normalize sICAM-1 levels. Such treatment helps to prevent the future development of atherosclerosis or cancer.

Comparison of the approaches to non-febrile neutropenia developing in children with acute lymphoblastic leukemia

The objectives of this study was to investigate of the influences of high-dose (20 mg/kg/day) methyl prednisolone (HDMP) and granulocyte colony stimulating factor (G-CSF) in shortening the duration of chemotherapy-induced neutropenia encountered in children with ALL receiving maintenance therapy. Sixty-four non-febrile neutropenic attacks developed in 29 patients with ALL receiving St Jude XIII maintenance protocol were evaluated retrospectively. The patients were clinically followed up without drugs for shortening the duration of neutropenia in 21 (32.8%) attacs, while HDMP and G-CSF were administered in 26 (40.6%) and 17 (26.6%) attacks, respectively. After the detection of neutropenia, restoration of neutrophil counts at 2nd or 4th days to the levels that allow resuming the chemotherapy were considered as success. While second day and overall success rates in patients administered HDMP and G-CSF were significantly higher than the patients who were observed clinically. Both second day and overall neutrophil counts were significantly higher in patients administered G-CSF than the other groups. Methyl prednisolone and G-CSF treatments were well-tolerated by the patients. The cost-per neutropenic attack was significantly higher in G-CSF group than of the HDMP group. Especially in patients experiencing frequent neutropenic attacks and hence interruptions of the therapy, one of the myelopoiesis induction therapies can be used to shorten the duration of neutropenia. For this indication short-course HDMP therapy can be considered as an alternative to G-CSF in this patients due to its relatively low cost, amenability to outpatient administration, and well-tolerability by children.

Neutrophil function in inflammation and inflammatory diseases

In inflammatory conditions such as RA, the neutrophil has tended to be dismissed as a short-lived, terminally differentiated, irrelevant bystander cell. However, this is clearly not the case. A better understanding of the complex heterogeneous pathways and processes that constitute RA, in parallel with a more sophisticated knowledge of neutrophil biology has identified many potential roles for these cells in the persistence of inflammation and progression of joint damage, which should not be underestimated. Not only are neutrophils found in high numbers within the rheumatoid joint, both in synovial tissue and in joint fluid, they have a huge potential to directly inflict damage to tissue, bone and cartilage via the secretion of proteases and toxic oxygen metabolites, as well as driving inflammation through antigen presentation and secretion of cytokines, chemokines, prostaglandins and leucotrienes. Drugs already used to treat RA down-regulate many neutrophil functions, including migration to the joint, degranulation and production of inflammatory mediators, and these cells should be considered as important targets for the development of new therapies in the future.

Population pharmacokinetic and pharmacodynamic analysis for time courses of docetaxel-induced neutropenia in Japanese cancer patients

The present study describes a population pharmacokinetic and pharmacodynamic (PK/PD) analysis based on data obtained from cancer patients treated with docetaxel at the National Cancer Center Hospital East in Japan. Docetaxel was infused intravenously over 1 h every 3 weeks, and time courses of absolute neutrophil counts (ANC) for a total of 395 observations (62 patients) were analyzed using a semimechanistic-physiological PK/PD model in the NONMEM program. The prominent feature of our PK/PD model is that it has the capability to predict a temporary increase in ANC. Among 10 patient factors, alpha(1)-acid glycoprotein was selected as a significant covariate for drug effect as the increase in alpha(1)-acid glycoprotein was negatively correlated with the drug effect. Goodness-of-fit plots indicated that the model fitted well with the observed data, and the bootstrap method guaranteed robustness of the model. In conclusion, we developed a novel population PK/PD model that can adequately analyze ANC profiles after docetaxel administration in oncology practice, where temporary but consistent increases in ANC were observed.

Effect of hematopoietic growth factors on severity of experimental autoimmune encephalomyelitis

We have investigated the influence of different hematopoietic growth factors, including granulocyte colony-stimulating factor (G-CSF), stem cell factor (SCF), Flt-3 ligand (Flt-3L) and thrombopoietin (TPO), on the course of relapsing experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis. Disease course and central nervous system histology were evaluated in all groups. When given after immunization but before either disease onset or during remission, Flt-3L, SCF and G-CSF exacerbated disease severity whereas TPO had no effect compared to non-cytokine-treated controls. When compared to controls, TPO did not exacerbate disease. We conclude that autoimmune disease severity may be affected by hematopoietic growth factors currently being employed in hematopoietic stem cell transplantation of patients with autoimmune disease. The mechanism of their effects remains unknown: it may be related to both T helper (Th) 1/Th2 skewing and/or homing of inflammatory cells to the disease-affected organ.

Blood neutrophil activation markers in severe asthma: lack of inhibition by prednisolone therapy

Background

Neutrophils are increased in the airways and in induced sputum of severe asthma patients. We determined the expression of activation markers from circulating neutrophils in severe asthma, and their supressibility by corticosteroids.

Methods

We compared blood neutrophils from mild, moderate-to-severe and severe steroid-dependent asthma, and non-asthmatics (n = 10 each). We examined the effect of adding or increasing oral prednisolone (30 mg/day;1 week).

Results

Flow cytometric expression of CD35 and CD11b, but not of CD62L or CD18, was increased in severe asthma. F-met-leu-phe increased CD11b, CD35 and CD18 and decreased CD62L expression in all groups, with a greater CD35 increase in severe asthma. In severe steroid-dependent asthma, an increase in prednisolone dose had no effect on neutrophil markers particularly CD62L, but reduced CD11b and CD62L on eosinophils. Phorbol myristate acetate-stimulated oxidative burst and IL-8 release by IL-1β, lipopolysaccharide and GM-CSF in whole blood from mild but not severe asthmatics were inhibited after prednisolone. There were no differences in myeloperoxidase or neutrophil elastase release from purified neutrophils.

Conclusion

Because blood neutrophils in severe asthma are activated and are not inhibited by oral corticosteroids, they may be important in the pathogenesis of severe asthma.

Changes in the leukocyte distribution and surface expression of adhesion molecules induced by hypothalamic stimulation in the cat

Emotions and the neuroendocrine system are known to affect leukocyte distribution. However, there have so far been few reports on the relationship between hypothalamically induced emotional behavior and the endocrine-immune response. We previously reported changes in the leukocyte distribution and adhesion molecules induced by anteromedial hypothalamus stimulation (AH stimulation), which elicits restlessness behaviors in the cat. In this study, we examined ventromedial hypothalamus stimulation (VMH stimulation), which elicits threat behaviors. In addition, the endocrine responses after VMH stimulation were evaluated. VMH stimulation as well as AH stimulation induced elevations of plasma cortisol and epinephrine levels and granulocytosis and lymphopenia. In contrast, VMH stimulation induced only an elevation of plasma norepinephrine and elicited an opposite pattern of CD62L expression on the leukocyte subpopulations. The different endocrine-immunological reactions between VMH stimulation and AH stimulation were thus associated with different types of behavioral responses.

Induced sputum cell profiles in lung transplant recipients with or without chronic rejection: correlation with lung function

BACKGROUND

Sputum induction is a non-invasive procedure for measuring inflammatory processes of the lower respiratory tract. The aim of this study was to establish sputum cell counts and differentials in patients after lung transplantation (LTx), with or without chronic transplant rejection.

METHODS

Sputum induction was performed in 41 LTx patients (25 single LTx (sLTx), 16 double LTx (dLTx) and 15 healthy non-smoking volunteers. Sputum was processed according to standard protocols. Total cell count was calculated as mean (SE) cells x 10(6)/ml sputum and cell differential (%) was evaluated after staining. Cellular profiles were correlated with lung function.

RESULTS

Total sputum cell counts were increased in sLTx (9 (1.9) cells x 10(6)/ml, p=0.01) and dLTx patients (7.2 (1.5) x 10(6)/ml, p=0.01) compared with healthy controls (2.6 (0.6) x 10(6)/ml). There was also a marked sputum neutrophilia in both patient groups (59 (6)% and 62 (6)%, respectively, p<0.001 v controls). Moreover, in both sLTx and dLTx patients with chronic transplant rejection there was an increased number of sputum neutrophils compared with patients with normal graft function (p<0.05 both comparisons), and neutrophils were inversely correlated with lung function (forced expiratory volume in one second (FEV(1)) % predicted): sLTx, r=-0.61, p=0.001; dLTx, r=-0.75, p=0.001, respectively). Sputum lymphocytes and eosinophils were similar in both groups. No relevant side effects occurred during sputum induction.

CONCLUSIONS

Sputum induction is a safe and non-invasive tool for monitoring lower respiratory tract inflammation in LTx patients. Both sLTx and dLTx patients with chronic rejection had increased sputum neutrophils compared with patients with normal transplant function. These data support findings of other authors highlighting a possible role for neutrophils in the pathogenesis of chronic transplant rejection.

Induced sputum cell profiles in lung transplant recipients with or without chronic rejection: correlation with lung function

BACKGROUND

Sputum induction is a non-invasive procedure for measuring inflammatory processes of the lower respiratory tract. The aim of this study was to establish sputum cell counts and differentials in patients after lung transplantation (LTx), with or without chronic transplant rejection.

METHODS

Sputum induction was performed in 41 LTx patients (25 single LTx (sLTx), 16 double LTx (dLTx) and 15 healthy non-smoking volunteers. Sputum was processed according to standard protocols. Total cell count was calculated as mean (SE) cells × 106/ml sputum and cell differential (%) was evaluated after staining. Cellular profiles were correlated with lung function.

RESULTS

Total sputum cell counts were increased in sLTx (9 (1.9) cells × 106/ml, p=0.01) and dLTx patients (7.2 (1.5) × 106/ml, p=0.01) compared with healthy controls (2.6 (0.6) × 106/ml). There was also a marked sputum neutrophilia in both patient groups (59 (6)% and 62 (6)%, respectively, p<0.001v controls). Moreover, in both sLTx and dLTx patients with chronic transplant rejection there was an increased number of sputum neutrophils compared with patients with normal graft function (p<0.05 both comparisons), and neutrophils were inversely correlated with lung function (forced expiratory volume in one second (FEV1) % predicted): sLTx,r=–0.61, p=0.001; dLTx,r=–0.75, p=0.001, respectively). Sputum lymphocytes and eosinophils were similar in both groups. No relevant side effects occurred during sputum induction.

CONCLUSIONS

Sputum induction is a safe and non-invasive tool for monitoring lower respiratory tract inflammation in LTx patients. Both sLTx and dLTx patients with chronic rejection had increased sputum neutrophils compared with patients with normal transplant function. These data support findings of other authors highlighting a possible role for neutrophils in the pathogenesis of chronic transplant rejection.

Chemotactic properties of ICAM-1 and PECAM-1 on neutrophil granulocytes in ulcerative colitis: effects of prednisolone and mesalazine

BACKGROUND

ICAM-1 seems to exhibit effects other than passive leucocyte/endothelial interaction.

AIM

To investigate the attracting properties of selected adhesion molecules, assessing the influence of the two major anti-inflammatory drugs in ulcerative colitis, prednisolone and mesalazine.

METHODS

Circulating neutrophils (11 ulcerative colitis, 15 controls) were assessed in microchemotaxis chambers by the leading front technique, using physiologically relevant concentrations of ICAM-1 (0.005-5000 pM), PECAM-1 (0.001-1000 nM), and P-selectin (0.01-100 nM). Neutrophils pre-incubated with prednisolone (10(-8)-10(-4) M) or mesalazine (0.65-10. 4 nM) were assessed towards ICAM-1.

RESULTS

Migration of neutrophils towards ICAM-1 showed a bell-shaped curve with a maximum at 5 pM (migration: 37.7 microm; P<0.001), whereas PECAM-1 attracted neutrophils equally in the range of 0.1-10 nM (25.0 microm; P<0.001). P-selectin had no cell-attracting effect. No differences were detected between cells from ulcerative colitis patients and controls. Pre-treatment with prednisolone decreased the cell attracting effect of ICAM-1 in a dose-dependent manner to 72% of the basal migration (P<0.001). Conversely, prednisolone showed a pro-chemokinetic effect by increasing the spontaneous locomotion of neutrophils by 40% (P<0.001).

CONCLUSIONS

Specific chemotactic properties were observed for ICAM-1 and PECAM-1. Prednisolone exhibited a dual effect in inhibiting the ICAM-1-mediated migration and stimulating the general locomotion of neutrophils.

Multiple sclerosis flares associated with recombinant granulocyte colony-stimulating factor

Four of 10 patients who were enrolled on protocols of high-dose immunosuppression with peripheral blood stem cell rescue for MS experienced neurologic worsening while receiving recombinant human granulocyte colony-stimulating factor. There was improvement when methylprednisolone was given to three of the patients, but one patient died of respiratory failure. The mechanism of the neurologic worsening is uncertain.

Regulation of ICAM-3 and other adhesion molecule expressions on eosinophils in vitro. Effects of dexamethasone

BACKGROUND

ICAM-3 has been recently identified as the third leukocyte-function associated-1 (LFA-1) ligand. ICAM-3 is expressed in eosinophils, but its regulation has not been studied. The objective of this study was to investigate the differential expression of ICAM-3 and other adhesion molecules (AM) on the surface of eosinophils. We also evaluated the effects of dexamethasone on AM expression.

METHODS

Normodense eosinophils were isolated from peripheral blood and incubated with calcium ionophore A23187 (calcimycin) with and without dexamethasone. Expression of AM was assessed by flow cytometry and expressed as fluorescence mean intensity (FMI).

RESULTS

Peripheral blood eosinophils constitutively expressed low levels of ICAM-1 and ICAM-2 (<10 FMI), moderate levels (10-50 FMI) of CD29 and L-selectin, and high levels (>50 FMI) of ICAM-3, LFA-1, and Mac-1. Calcium ionophore (1 microM) significantly increased Mac-1 and ICAM-1 expression at 6 and 24 h. L-selectin expression decreased at 6 and 24 h, but ICAM-2, ICAM-3, LFA-1, and CD29 expression did not show any significant change after calcium ionophore stimulation. Dexamethasone decreased ICAM-3 and increased L-selectin basal expression, and it caused a dose-related inhibition of calcium ionophore-induced ICAM-1 expression.

CONCLUSIONS

These findings suggest that some AM, such as ICAM-1, Mac-1, and L-selectin, may be involved in adhesion during eosinophil activation and that glucocorticoids may prevent airway inflammation by regulating the expression of AM in eosinophils. The role of ICAM-3, a leukocyte AM highly expressed in resting eosinophils, remains to be clarified.

CD80 (B7-1) and CD86 (B7-2) expression in multiple sclerosis patients: clinical subtype specific variation in peripheral monocytes and B cells and lack of modulation by high dose methylprednisolone

Autoimmune activation of T cells by central nervous system (CNS)-derived antigens is hypothesised to underlie neural damage in multiple sclerosis (MS) patients. The role of coreceptor mediated signalling is currently under investigation in order to further elucidate the immunopathogenic mechanisms implicated and to determine possible targets for immune modulation. We have investigated whether differential coreceptor (B7-1/CD80; B7-2/CD86; CD28) expression on circulating lymphocytes and monocytes is (i) a feature of distinctive clinical subtypes of MS (relapsing-remitting in remission/stable-RRMS; relapsing-remitting in relapse/relapsing-RRMS; primary progressive/PPMS), (ii) related to disease activity, and (iii) altered by high dose corticocosteroid treatment. CD80(+) B cells were significantly reduced (P<0.05) in PPMS (4.0+/-0.8%) compared with normal subjects (CON) (9.1+/-1.1%), stable-RRMS (6.7+/-0.7%) and relapsing-RRMS (7.8+/-0.9%) patients. Comparatively fewer monocytes from relapsing-RRMS patients expressed CD86 (relapsing-RRMS 50+/-4.9% vs. stable-RRMS 75.1+/-3.4%, PPMS 77. 7+/-3.2%, CON 72.1+/-3.6%/P<0.05). Otherwise expression of coreceptors did not vary significantly between the groups. A 3-day course of methylprednisolone therapy did not alter coreceptor expression, but did suppress monocyte and B cell HLA-DR expression. There is evidence for differential coreceptor expression on circulating B cells and monocytes in MS disease subtypes. The biological significance of these findings is discussed in relation to alternative theories regarding coreceptor functioning.

Purification and N-terminal amino acid sequence of sheep neutrophil cathepsin G and elastase

Sheep cathepsin G (CG) and neutrophil elastase (NE) were isolated from a crude leukocyte membrane preparation by elastin-Sepharose 4B and CM-Sepharose 4B chromatography, followed by native preparative PAGE. The N-termini of CG and NE were sequenced to 24 and 20 residues, showing 96 and 85% identity with human CG and NE, respectively. During SDS-PAGE, sheep CG and NE migrated parallel to human CG and NE and have apparent molecular masses of 28 and 26 kDa, respectively. Following incubation of sheep CG and NE with human alpha(1)-antichymotrypsin and alpha(1)-proteinase inhibitor, complexes with apparent molecular masses of 89 and 81 kDa respectively were observed by SDS-PAGE. Polyclonal antibodies to human CG and NE cross-reacted with purified sheep CG and NE, respectively. These results indicate that sheep neutrophils contain CG and elastase that are analogous to human CG and NE in terms of molecular mass, reactivity with endogenous inhibitors, immunocross-reactivity, and N-terminal sequence.