Unconventional Activation of IRE1 Enhances TH17 Responses and Promotes Airway Neutrophilia

Heightened unfolded protein responses (UPRs) are associated with the risk for asthma, including severe asthma. Treatment-refractory severe asthma manifests a neutrophilic phenotype with TH17 responses. However, how UPRs participate in the deregulation of TH17 cells leading to neutrophilic asthma remains elusive. This study found that the UPR sensor IRE1 is induced in the murine lung with fungal asthma and is highly expressed in TH17 cells relative to naïve CD4+ T cells. Cytokine (e.g. IL-23) signals induce the IRE1-XBP1s axis in a JAK2-dependent manner. This noncanonical activation of the IRE1-XBP1s pathway promotes UPRs and cytokine secretion by both human and mouse TH17 cells. Ern1 (encoding IRE1)-deficiency decreases the expression of ER stress factors and impairs the differentiation and cytokine secretion of TH17 cells. Genetic ablation of Ern1 leads to alleviated TH17 responses and airway neutrophilia in a fungal airway inflammation model. Consistently, IL-23 activates the JAK2-IRE1-XBP1s pathway in vivo and enhances TH17 responses and neutrophilic infiltration into the airway. Taken together, our data indicate that IRE1, noncanonically activated by cytokine signals, promotes neutrophilic airway inflammation through the UPR-mediated secretory function of TH17 cells. The findings provide a novel insight into the fundamental understanding of IRE1 in TH17-biased TH2-low asthma.

Specific Inhibition of Orai1-mediated Calcium Signalling Resolves Inflammation and Clears Bacteria in an Acute Respiratory Distress Syndrome Model

Rationale: Acute respiratory distress syndrome (ARDS) has an unacceptably high mortality rate (35%) and is without effective therapy. Orai1 is a Ca2+ channel involved in store-operated Ca2+ entry (SOCE), a process that exquisitely regulates inflammation. Orai1 is considered a druggable target, but no Orai1-specific inhibitors exist to date. Objectives: To evaluate whether ELD607, a first-in-class Orai1 antagonist, can treat ARDS caused by bacterial pneumonia in preclinical models. Methods: ELD607 pharmacology was evaluated in HEK293T cells and freshly isolated immune cells from patients with ARDS. A murine acute lung injury model caused by bacterial pneumonia was then used: mice were infected with Pseudomonas aeruginosa, Staphylococcus aureus, methicillin-resistant S. aureus, or multidrug-resistant P. aeruginosa and then treated with ELD607 intranasally. Measurements and Main Results: ELD607 specifically inhibited SOCE in HEK293T cells with a half-maximal inhibitory concentration of 9 nM. ELD607 was stable in ARDS airway secretions and inhibited SOCE in ARDS immune cells. In vivo, inhaled ELD607 significantly reduced neutrophilia and improved survival. Surprisingly, Orai1 inhibition by ELD607 caused a significant reduction in lung bacteria, including methicillin-resistant S. aureus. ELD607 worked as an immunomodulator that reduced cytokine levels, reduced neutrophilia, and promoted macrophage-mediated resolution of inflammation and clearance of bacteria. Indeed, when alveolar macrophages were depleted with inhaled clodronate, ELD607 was no longer able to resolve inflammation or clear bacteria. Conclusions: These data indicate that specific Orai1 inhibition by ELD607 may be a novel approach to reduce multiorgan inflammation and treat antibiotic-resistant bacteria.

A Unique Case of Adult-Onset Still's Disease Not Responsive to Steroid Treatment

A 53-year-old patient was admitted to the emergency department, presenting with fever, generalized weakness, and various myalgias and arthralgias lasting over seven days. Based upon the patient's worsening symptoms, elevated white blood cell count with neutrophilia and overall presentation, she was initially treated for an infectious cause and prescribed various antibiotics and antipyretic medications. As the patient's condition continued to worsen throughout the initial days of her intake, she was tested for a variety of infections, including coronavirus disease 2019 (COVID-19), Streptococcus, and influenza, and was administered a viral respiratory panel, all of which resulted negative. Upon the development of an evanescent rash on hospital day 9, as well as other symptoms including sore throat, arthritis, and an elevated fever present for over a week, a rheumatology consult now expressed concern for a possible case of Adult-Onset Still's Disease (AOSD). In line with the current treatment used for AOSD and the absence of all other infectious causes, the patient discontinued antibiotic treatment and was started on 125 milligrams of intravenous methylprednisolone every six hours. The patient showed minor improvements in symptoms over the next 24 hours but soon became refractory to treatment, resulting from multiorgan damage, and expired on hospital day 13.

Neutrophilia with damage to the blood-brain barrier and neurovascular unit following acute lung injury

Background

Links between acute lung injury (ALI), infectious disease, and neurological outcomes have been frequently discussed over the past few years, especially due to the COVID-19 pandemic. Yet, much of the cross-communication between organs, particularly the lung and the brain, has been understudied. Here, we have focused on the role of neutrophils in driving changes to the brain endothelium with ensuing microglial activation and neuronal loss in a model of ALI.

Methods

We have applied a three-dose paradigm of 10μg/40μl intranasal lipopolysaccharide (LPS) to induce neutrophilia accompanied by proteinaceous exudate in bronchoalveolar lavage fluid (BALF) in adult C57BL/6 mice. Brain endothelial markers, microglial activation, and neuronal cytoarchitecture were evaluated 24hr after the last intranasal dose of LPS or saline. C57BL/6-Ly6g(tm2621(Cre-tdTomato)Arte (Catchup mice) were used to measure neutrophil and blood-brain barrier permeability following LPS exposure with intravital 2-photon imaging.

Results

Three doses of intranasal LPS induced robust neutrophilia accompanied by proteinaceous exudate in BALF. ALI triggered central nervous system pathology as highlighted by robust activation of the cerebrovascular endothelium (VCAM1, CD31), accumulation of plasma protein (fibrinogen), microglial activation (IBA1, CD68), and decreased expression of proteins associated with postsynaptic terminals (PSD-95) in the hippocampal stratum lacunosum moleculare, a relay station between the entorhinal cortex and CA1 of the hippocampus. 2-photon imaging of Catchup mice revealed neutrophil homing to the cerebral endothelium in the blood-brain barrier and neutrophil extravasation from cerebral vasculature 24hr after the last intranasal treatment.

Conclusions

Overall, these data demonstrate ensuing brain pathology resulting from ALI, highlighting a key role for neutrophils in driving brain endothelial changes and subsequent neuroinflammation. This paradigm may have a considerable translational impact on understanding how infectious disease with ALI can lead to neurodegeneration, particularly in the elderly.

Neutrophilia with damage to the blood-brain barrier and neurovascular unit following acute lung injury

Background

Links between acute lung injury (ALI), infectious disease, and neurological outcomes have been frequently discussed over the past few years, especially due to the COVID-19 pandemic. Yet, much of the cross-communication between organs, particularly the lung and the brain, has been understudied. Here, we have focused on the role of neutrophils in driving changes to the brain endothelium with ensuing microglial activation and neuronal loss in a model of ALI.

Methods

We have applied a three-dose paradigm of 10μg/40μl intranasal lipopolysaccharide (LPS) to induce neutrophilia accompanied by proteinaceous exudate in bronchoalveolar lavage fluid (BALF) in adult C57BL/6 mice. Brain endothelial markers, microglial activation, and neuronal cytoarchitecture were evaluated 24hr after the last intranasal dose of LPS or saline. C57BL/6-Ly6g(tm2621(Cre-tdTomato)Arte (Catchup mice) were used to measure neutrophil and blood-brain barrier permeability following LPS exposure with intravital 2-photon imaging.

Results

Three doses of intranasal LPS induced robust neutrophilia accompanied by proteinaceous exudate in BALF. ALI triggered central nervous system pathology as highlighted by robust activation of the cerebrovascular endothelium (VCAM1, CD31), accumulation of plasma protein (fibrinogen), microglial activation (IBA1, CD68), and decreased expression of proteins associated with postsynaptic terminals (PSD-95) in the hippocampal stratum lacunosum moleculare, a relay station between the entorhinal cortex and CA1 of the hippocampus. 2-photon imaging of Catchup mice revealed neutrophil homing to the cerebral endothelium in the blood-brain barrier and neutrophil extravasation from cerebral vasculature 24hr after the last intranasal treatment.

Conclusions

Overall, these data demonstrate ensuing brain pathology resulting from ALI, highlighting a key role for neutrophils in driving brain endothelial changes and subsequent neuroinflammation. This paradigm may have a considerable translational impact on understanding how infectious disease with ALI can lead to neurodegeneration, particularly in the elderly.

ZAKα/P38 kinase signaling pathway regulates hematopoiesis by activating the NLRP1 inflammasome

Chronic inflammatory diseases are associated with hematopoietic lineage bias, including neutrophilia and anemia. We have recently identified that the canonical inflammasome mediates the cleavage of the master erythroid transcription factor GATA1 in hematopoietic stem and progenitor cells (HSPCs). We report here that genetic inhibition of Nlrp1 resulted in reduced number of neutrophils and increased erythrocyte counts in zebrafish larvae. We also found that the NLRP1 inflammasome in human cells was inhibited by LRRFIP1 and FLII, independently of DPP9, and both inhibitors regulated hematopoiesis. Mechanistically, erythroid differentiation resulted in ribosomal stress-induced activation of the ZAKα/P38 kinase axis which, in turn, phosphorylated and promoted the assembly of NLRP1 in both zebrafish and human. Finally, inhibition of Zaka with the FDA/EMA-approved drug Nilotinib alleviated neutrophilia in a zebrafish model of neutrophilic inflammation and promoted erythroid differentiation and GATA1 accumulation in K562 cells. In conclusion, our results reveal that the NLRP1 inflammasome regulates hematopoiesis and pave the way to develop novel therapeutic strategies for the treatment of hematopoietic alterations associated with chronic inflammatory and rare diseases.

A review of pulmonary neutrophilia and insights into the key role of neutrophils in particle-induced pathogenesis in the lung from animal studies of lunar dusts and other poorly soluble dust particles

The mechanisms of particle-induced pathogenesis in the lung remain poorly understood. Neutrophilic inflammation and oxidative stress in the lung are hallmarks of toxicity. Some investigators have postulated that oxidative stress from particle surface reactive oxygen species (psROS) on the dust produces the toxicopathology in the lungs of dust-exposed animals. This postulate was tested concurrently with the studies to elucidate the toxicity of lunar dust (LD), which is believed to contain psROS due to high-speed micrometeoroid bombardment that fractured and pulverized lunar surface regolith. Results from studies of rats intratracheally instilled (ITI) with three LDs (prepared from an Apollo-14 lunar regolith), which differed 14-fold in levels of psROS, and two toxicity reference dusts (TiO2 and quartz) indicated that psROS had no significant contribution to the dusts' toxicity in the lung. Reported here are results of further investigations by the LD toxicity study team on the toxicological role of oxidants in alveolar neutrophils that were harvested from rats in the 5-dust ITI study and from rats that were exposed to airborne LD for 4 weeks. The oxidants per neutrophils and all neutrophils increased with dose, exposure time and dust's cytotoxicity. The results suggest that alveolar neutrophils play a critical role in particle-induced injury and toxicity in the lung of dust-exposed animals. Based on these results, we propose an adverse outcome pathway (AOP) for particle-associated lung disease that centers on the crucial role of alveolar neutrophil-derived oxidant species. A critical review of the toxicology literature on particle exposure and lung disease further supports a neutrophil-centric mechanism in the pathogenesis of lung disease and may explain previously reported animal species differences in responses to poorly soluble particles. Key findings from the toxicology literature indicate that (1) after exposures to the same dust at the same amount, rats have more alveolar neutrophils than hamsters; hamsters clear more particles from their lungs, consequently contributing to fewer neutrophils and less severe lung lesions; (2) rats exposed to nano-sized TiO2 have more neutrophils and more severe lesions in their lungs than rats exposed to the same mass-concentration of micron-sized TiO2; nano-sized dust has a greater number of particles and a larger total particle-cell contact surface area than the same mass of micron-sized dust, which triggers more alveolar epithelial cells (AECs) to synthesize and release more cytokines that recruit a greater number of neutrophils leading to more severe lesions. Thus, we postulate that, during chronic dust exposure, particle-inflicted AECs persistently release cytokines, which recruit neutrophils and activate them to produce oxidants resulting in a prolonged continuous source of endogenous oxidative stress that leads to lung toxicity. This neutrophil-driven lung pathogenesis explains why dust exposure induces more severe lesions in rats than hamsters; why, on a mass-dose basis, nano-sized dusts are more toxic than the micron-sized dusts; why lung lesions progress with time; and why dose-response curves of particle toxicity exhibit a hockey stick like shape with a threshold. The neutrophil centric AOP for particle-induced lung disease has implications for risk assessment of human exposures to dust particles and environmental particulate matter.

Clinical Utility of Bronchoalveolar Lavage Neutrophilia and Biomarkers for Evaluating Severity of Chronic Fibrosing Interstitial Lung Diseases

Introduction It is hypothesized that bronchoalveolar lavage (BAL) neutrophilia, Krebs von den Lungen-6 (KL-6), and C-reactive protein (CRP) predict the severity of chronic fibrosing interstitial lung diseases (CF-ILDs). Methods This cross-sectional study enrolled 30 CF-ILD patients. Using Pearson's correlation analysis, BAL neutrophils, KL-6, and CRP were correlated with forced vital capacity (FVC), diffusing lung capacity for carbon monoxide (DLCO), six-minute walk distance (6MWD), partial pressure of oxygen (PaO2), computed tomography fibrosis score (CTFS), and pulmonary artery systolic pressure (PASP). Using the receiver operator characteristic (ROC) curve, BAL KL-6 and CRP were evaluated against FVC% and DLCO% in isolation and combination with BAL neutrophilia for predicting the severity of CF-ILDs. Results BAL neutrophilia significantly correlated only with FVC% (r = -0.38, P = 0.04) and DLCO% (r = -0.43, P = 0.03). BAL KL-6 showed a good correlation with FVC% (r = -0.44, P < 0.05) and DLCO% (r = -0.50, P = 0.02), while BAL CRP poorly correlated with all parameters (r = 0.0-0.2). Subset analysis of BAL CRP in patients with CTFS ≤ 15 showed a better association with FVC% (r = -0.28, P = 0.05) and DLCO% (r = -0.36, P = 0.04). BAL KL-6 cut-off ≥ 72.32 U/ml and BAL CRP ≥ 14.55 mg/L predicted severe disease with area under the curve (AUC) values of 0.77 and 0.71, respectively. The combination of BAL neutrophilia, KL-6, and CRP predicted severity with an AUC value of 0.89. Conclusion The combination of BAL neutrophilia, KL-6, and CRP facilitates the severity stratification of CF-ILDs complementing existing severity parameters.

Probable paraneoplastic leukocytosis in a dog with a gastrointestinal stromal tumor

A 9-year-old female spayed Boston Terrier presented for diagnostic investigation of lethargy, poor appetite, weight loss, and a marked leukocytosis. Significant muscle wasting and a palpable abdominal mass were present on physical examination. Abdominal imaging revealed the mass to be of small intestinal origin; consequently, an intestinal resection and anastomosis were performed without complication. The histopathologic diagnosis was a gastrointestinal stromal tumor, verified by immunohistochemical positivity to CD117 (KIT). Two weeks after discharge, the leukocytosis had resolved. Though the exact molecular mediator of the severe leukocytosis was undetermined, resolution following tumor removal suggests a paraneoplastic cause. To the authors' knowledge, this is the first reported case of probable paraneoplastic leukocytosis secondary to a gastrointestinal stromal tumor in the dog. Gastrointestinal tract imaging should be performed when this uncommon hematologic abnormality is present.

Platelet, Neutrophil and Lymphocyte Quantitative Abnormalities in Patients with Heart Failure: A Retrospective Study

Background

Heart failure pathophysiology and its clinical symptoms are characterized by inflammation. Elevated levels of leukocyte subpopulations are a well-known indicator of inflammation and play a predictive role in determining the prognosis of patients with cardiovascular diseases. Besides, platelets are essential mediators of inflammation, especially when they interact with leukocytes. Platelet synthesis, activation, and function are all impacted by heart failure. Thus, the study was aimed at determining the magnitude of platelet, neutrophil, and lymphocyte abnormalities in patients with heart failure.

Methods

A retrospective cross-sectional study was conducted from June to July 2022 at the University of Gondar comprehensive specialized hospital. A total of 245 medical records of heart failure patients were included. Data regarding socio-demographic, clinical, and some hematological and biochemical parameters were collected from medical records. Data was entered into Epi-Data 4.6.0.2 and then exported to Stata 11.0 statistical software for analysis. A binary logistic regression analysis with its odds ratio was calculated to identify factors associated with the outcome variables. P-value <0.05 was considered statistically significant.

Results

The most frequent leukocyte abnormality among adults with heart failure was neutrophilia, which was detected in 17.55% (95% CI: 13.26-22.87). Besides, lymphocytosis was observed in 10.20% (95% CI: 6.97-14.70) of patients. The magnitude of thrombocytopenia and thrombocytosis among patients with heart failure was 12.24% (95% CI: 8.67-17.01%) and 2.86% (95% CI: 1.36-5.90%), respectively. Only being female was significantly associated with neutrophilia in patients with heart failure (AOR = 2.33; 95% CI: 1.05-5.16). However, none of the variables were significantly associated with platelet and lymphocyte abnormalities.

Conclusion

Neutrophilia, lymphocytosis, and thrombocytopenia are the common leukocyte and platelet abnormalities in heart failure patients. Therefore, early detection and management of the underlying causes of those abnormalities may be important to improve patients' outcomes and prevent further complications.

Hematopathology of SARS-CoV-2 infection and COVID-19 disease

Coronavirus disease 2019 is caused by severe acute respiratory syndrome coronavirus 2 and is associated with pronounced hematopathologic findings. Peripheral blood features are heterogeneous and very often include neutrophilia, lymphopenia, myeloid left shift, abnormally segmented neutrophils, atypical lymphocytes/plasmacytoid lymphocytes, and atypical monocytes. Bone marrow biopsies and aspirates are often notable for histiocytosis and hemophagocytosis, whereas secondary lymphoid organs may exhibit lymphocyte depletion, pronounced plasmacytoid infiltrates, and hemophagocytosis. These changes are reflective of profound innate and adaptive immune dysregulation, and ongoing research efforts continue to identify clinically applicable biomarkers of disease severity and outcome.

Assessment of cerebrospinal fluid analysis and short-term survival outcomes in South American camelids: A retrospective study of 54 cases (2005-2021)

BACKGROUND

Cerebrospinal fluid (CSF) is commonly analyzed in South American camelids with suspected neurologic disease because of ease of collection and characteristic findings associated with certain diseases.

OBJECTIVES

To assess CSF findings associated with short-term survival or non-survival in South American camelids in which neurologic disease was a differential diagnosis based on history and physical examination.

ANIMALS

Twenty-one llamas and 33 alpacas that underwent CSF analysis at the University of Missouri Veterinary Health Center.

METHODS

Retrospective study. Medical records of camelids that underwent CSF analysis between January 2005 and September 2021 were studied. Short-term survival was defined as survival to discharge from the Veterinary Health Center. A Fisher's exact test was used to compare species, CSF results, and survival.

RESULTS

Odds of survival were 3.9 times higher in camelids with a total nucleated cell count (TNCC) <3 cells/μL (P = .04). No significant association was found between survival and total protein concentration (TPC; P = .15) or percentage of eosinophils (P = 1.0). No significant correlation was found between species and increased TNCC (P = .63), TPC (P = .55), or percentage of eosinophils (P = .30). Among camelids diagnosed with Paralephostrongylus tenuis infestation, odds of survival were 4.95 times higher in alpacas (P = .05).

CONCLUSIONS

Cerebrospinal fluid TNCC ≥3 cells/μL is associated with decreased odds of short-term survival in South American camelids.

Prolonged neutrophilia is associated with worse outcomes after Esophagectomy

Neutrophilia is a potential biomarker for postoperative complications and oncologic outcomes. There is a paucity of data regarding neutrophilia in patients with esophageal adenocarcinoma. Our Institutional Database was queried for esophageal adenocarcinoma patients who underwent esophagectomy from 2006 to 2019. Complete blood counts (CBC), demographic characteristics, perioperative and oncologic outcomes were evaluated. Two groups were created based on the presence of prolonged neutrophilia (PN, >7,000 absolute neutrophils 90 days after surgery). Univariate, multivariable, and survival analysis were performed (P-value < 0.05). We identified 686 patients with complete CBC data: 565 in the no prolonged neutrophilia (NPN) and 121 in the PN groups (17.6%). The mean age was 54 versus 48 years in the NPN and PN groups (P = 0.01). There was no difference in height, weight, gender, race, tumor size, histology, pTNM, PS, ASA, salvage procedure, neoadjuvant treatment and comorbidities. On multivariable analysis, the PN group had increased transfusions (19.8% vs. 11.9%; P = 0.02), aspiration (13.2% vs. 2.5%; P = 0.002), pulmonary embolus (3.3% vs. 0.4%; P = 0.02), cardiac arrest (5% vs. 0.4%; P = 0.02) and hematologic complications (23.1% vs. 12.6%; P = 0.01). After controlling for any postoperative complication, PN had increased distant recurrence (24% vs. 12.7%; hazard ration [HR]: 2.3, 95% confidence interval [CI] 1.42-3.9; P = 0.001) and decreased OS (33.8% vs. 49.7%, HR: 1.83, 95% CI: 1.19-2.81; P = 0.006); median follow up 77 months (46-109). PN was predictive of distant recurrence and decreased overall survival. Further work investigating these neutrophil populations represents a potential area for biomarker research, immunomodulation, and may guide postoperative surveillance strategies.

CHARACTERIZATION OF PATIENTS IN THE POST-ACUTE PHASE OF COVID-19 WHO PRESENTED THEMSELVES TO AN EMERGENCY DEPARTMENT

BACKGROUND

Patients that recovered from COVID-19 may remain with symptoms which can persist for an uncertain period of time.

AIM

The purpose of this study was to investigate the reasons why patients who passed the acute phase of COVID-19 presented themselves to the Emergency Department.

PATIENTS AND METHODS

We selected 87 patients admitted to the Emergency Department of the Bucharest University Emergency Hospital between 01.01.2021-31.05.2021. Patients had pulmonary fibrosis (11.49%), pleural effusion (16.09%) or a history of hypertension (73.56%), type 2 diabetes (42.53%), stroke (24.14%), malignant diseases (10.34%).

RESULTS

Association between neutrophil levels and acute stroke and between fibrinogen levels and alveolar condensation were identified. The percentage of deaths was significantly higher in the subgroup of subjects that had maxim 11 days of hospitalization (p=0.004); we observed a trend of association between the age of more than 51 years old and admission in the Emergency Unit at less than a month after the SARS Cov2 infection, the positive result at the RT-PCR test or a lung damage of over 30% (p<0.05).

CONCLUSION

A significant percentage of patients that were admitted to the Emergency Unit post COVID-19 had chronic pathologies and their characteristics were associated with neutrophilia, high fibrinogen levels or length of hospitalization.

Natterin-Induced Neutrophilia Is Dependent on cGAS/STING Activation via Type I IFN Signaling Pathway

Natterin is a potent pro-inflammatory fish molecule, inducing local and systemic IL-1β/IL-1R1-dependent neutrophilia mediated by non-canonical NLRP6 and NLRC4 inflammasome activation in mice, independent of NLRP3. In this work, we investigated whether Natterin activates mitochondrial damage, resulting in self-DNA leaks into the cytosol, and whether the DNA sensor cGAS and STING pathway participate in triggering the innate immune response. Employing a peritonitis mouse model, we found that the deficiency of the tlr2/tlr4, myd88 and trif results in decreased neutrophil influx to peritoneal cavities of mice, indicative that in addition to MyD88, TRIF contributes to neutrophilia triggered by TLR4 engagement by Natterin. Next, we demonstrated that gpcr91 deficiency in mice abolished the neutrophil recruitment after Natterin injection, but mice pre-treated with 2-deoxy-d-glucose that blocks glycolysis presented similar infiltration than WT Natterin-injected mice. In addition, we observed that, compared with the WT Natterin-injected mice, DPI and cyclosporin A treated mice had a lower number of neutrophils in the peritoneal exudate. The levels of dsDNA in the supernatant of the peritoneal exudate and processed IL-33 in the supernatant of the peritoneal exudate or cytoplasmic supernatant of the peritoneal cell lysate of WT Natterin-injected mice were several folds higher than those of the control mice. The recruitment of neutrophils to peritoneal cavity 2 h post-Natterin injection was intensely impaired in ifnar KO mice and partially in il-28r KO mice, but not in ifnγr KO mice. Finally, using cgas KO, sting KO, or irf3 KO mice we found that recruitment of neutrophils to peritoneal cavities was virtually abolished in response to Natterin. These findings reveal cytosolic DNA sensors as critical regulators for Natterin-induced neutrophilia.

Impact of Sex on Circulating Leukocytes Composition in COPD Patients

Purpose

Chronic obstructive pulmonary disease is characterized by chronic inflammatory response both at the lung site and at the systemic level. Abnormalities in circulating leukocytes have been reported to occur in COPD patients and have been often shown to correlate with the decline in lung function. COPD affects men and women at a virtually comparable rate, even though distinct sex specific symptoms, progression and therapeutic implications have been described. Nonetheless, these sex-associated differences have not been analyzed in terms of circulating leukocytes. To assess the impact of sex on the changes of circulating immune cells in COPD patients.

Patients and Methods

Blood samples were collected from 50 COPD patients (31 males, 19 females) and 63 age and sex-matched controls (35 males, 28 females) enrolled in this pilot study. Complete blood cell count and multi-parametric flow cytometry analysis were performed to characterize the leukocyte populations and subsets.

Results

Male COPD patients are distinguished from controls by a significant increase in white blood cell counts, neutrophil total and differential counts, and neutrophil-to-lymphocyte ratio. Conversely, a generalized leukocyte decrease discriminated female COPD patients from the related controls. The impact of sex is further remarked by a decrease in adaptive immune cell subpopulations in males as opposed to a consistent increase of innate immune cell types in females correlating with disease severity.

Conclusion

These data indicate that the definition of specific changes of circulating leukocytes to be used as reliable biomarkers of the disease severity cannot be accomplished irrespectively of sex.

Neutropenia, neutrophilia, and neutrophil-lymphocyte ratio as prognostic markers in patients with metastatic castration-resistant prostate cancer

Background and purpose

Chemotherapy-induced neutropenia and neutrophil-to-lymphocyte ratio (NLR) are potentially useful prognostic markers in patients with metastatic castration-resistant prostate cancer (mCRPC). This post hoc analysis investigated whether these markers can be utilized for dose considerations and evaluated the prognostic impact of leukocyte subtypes.

Patients and methods

PROSELICA assessed the non-inferiority of cabazitaxel 20 mg/m² (C20; n = 598) versus 25 mg/m² (C25; n = 602) for overall survival (OS) in patients with mCRPC previously treated with docetaxel. The association of grade ⩾ 3 neutropenia, NLR, baseline neutrophilia and lymphopenia with OS, progression-free survival (PFS), and prostate-specific antigen response rate (PSArr) was investigated by an unplanned uni- and multivariate analyses.

Results

PROSELICA confirmed the negative prognostic value of increased baseline NLR [⩾3, hazard ratio (HR) 1.40; p < 0.0001], but did not identify a subgroup of patients benefiting more from C20 or C25. In this post hoc analysis, patients who developed grade ⩾3 neutropenia (n = 673) had a significantly improved OS [∆OS = 2.7 months, HR = 0.78 (95% CI 0.68-0.89)] with the greatest advantage observed in patients with baseline neutrophilia [n = 85; 5.3 months, 0.60 (0.42-0.84)]. After adjustment for the Halabi criteria, neutropenia grade ⩾ 3 was the only biomarker that remained significantly associated with OS [ (HR 0.86 (0.75-0.98)], PFS [HR 0.78 (0.68-0.88)], and PSArr [odds ratio (OR) 1.82 (1.37-2.41)] while neutrophilia showed the strongest association with OS [1.53 (1.29-1.81)].

Conclusions

Grade ⩾ 3 neutropenia was the only leukocyte-based biomarker associated with all key outcome parameters in mCRPC patients receiving cabazitaxel and might be able to overcome the negative prognostic effect of baseline neutrophilia.

NCT number

NCT01308580.

Glycan Activation of Clec4b Induces Reactive Oxygen Species Protecting against Neutrophilia and Arthritis

Animal models for complex diseases are needed to position and analyze the function of interacting genes. Previous positional cloning identified Ncf1 and Clec4b to be major regulators of arthritis models in rats. Here, we investigate epistasis between Ncf1 and Clec4b, two major regulators of arthritis in rats. We find that Clec4b and Ncf1 exert an additive effect on arthritis given by their joint ability to regulate neutrophils. Both genes are highly expressed in neutrophils, together regulating neutrophil availability and their capacity to generate reactive oxygen species. Using a glycan array, we identify key ligands of Clec4b and demonstrate that Clec4b-specific stimulation triggers neutrophils into oxidative burst. Our observations highlight Clec4b as an important regulator of neutrophils and demonstrate how epistatic interactions affect the susceptibility to, and severity of, autoimmune arthritis.

Peripheral white blood cell responses as emerging biomarkers for patient stratification and prognosis in acute spinal cord injury

PURPOSE OF REVIEW

To date, prognostication of patients after acute traumatic spinal cord injury (SCI) mostly relies on the neurological assessment of residual function attributed to lesion characteristics. With emerging treatment candidates awaiting to be tested in early clinical trials, there is a need for wholistic high-yield prognostic biomarkers that integrate both neurogenic and nonneurogenic SCI pathophysiology as well as premorbid patient characteristics.

RECENT FINDINGS

It is becoming clearer that effective prognostication after acute SCI would benefit from integrating an assessment of pathophysiological changes on a systemic level, and with that, extend from a lesion-centric approach. Immunological markers mirror tissue injury as well as host immune function and are easily accessible through routine blood sampling. New studies have highlighted the value of circulating white blood cells, neutrophils and lymphocytes in particular, as prognostic systemic indicators of SCI severity and outcomes.

SUMMARY

We survey recent advances in methods and approaches that may allow for a more refined diagnosis and better prognostication after acute SCI, discuss how these may help deepen our understanding of SCI pathophysiology, and be of use in clinical trials.

Metastatic BRAF V600E-Mutated Adenocarcinoma of the Lung Presenting as Extreme Neutrophilia and Eosinophilia

Hematologic paraneoplastic syndromes with extreme neutrophilia and eosinophilia are very rarely associated with adenocarcinoma of the lung. We describe a case of a 57-year-old female who presented with neutrophil- and eosinophil-predominant hyperleukocytosis and hypoxic respiratory insufficiency. Bone marrow biopsy confirmed metastatic adenocarcinoma, similar to the biopsy-proven adenocarcinoma of the lung. She was administered one dose of cytotoxic chemotherapy with carboplatin and pemetrexed and started on leukoreductive therapy with hydroxyurea. Molecular testing revealed a BRAF V600E mutation and she was started on dabrafenib and trametinib with significant clinical improvement. This is the first reported case of metastatic BRAF V600E mutated non-small cell lung cancer presenting with extreme neutrophilia and eosinophilia treated with a combination BRAF and mitogen-activated extracellular kinase (MEK) inhibitor.

Pretreatment neutrophil-to-lymphocyte ratio as an important prognostic marker in stage III locally advanced non-small cell lung cancer: confirmatory results from the PROCLAIM phase III clinical trial

Background

Neutrophil-to-lymphocyte ratio (NLR) is an important pretreatment marker of systemic inflammation and tumor aggressiveness. Increased levels of this ratio have been associated with reduced survival in several observational studies of lung cancer. However, supporting analyses from large clinical trial data are lacking.

Methods

To validate the prognostic role of NLR, the current study evaluated data from a randomized phase III study (PROCLAIM; clinicaltrial.gov ID: NCT00686959) of patients with stage IIIA/B, unresectable, non-squamous, non-small cell lung cancer (NSCLC), originally comparing combination pemetrexed-cisplatin chemoradiotherapy with etoposide-cisplatin chemoradiotherapy. Adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for survival were estimated using a Cox proportional hazards model. Models were adjusted for age, race, sex, stage, treatment, and body mass index (BMI). Patients were followed for a median of 24 months.

Results

Increased NLR levels at baseline were associated with reduced overall (P_Trend <0.0001) and progression-free survival (P_Trend <0.005). A similar but decreasing linear trend was not observed for lymphocytes count alone.

Conclusions

These findings provide substantiating evidence that NLR, which is routinely available from standard blood testing of patients diagnosed with NSCLC, is an important inflammation-based prognostic marker for survival among patients with locally advanced disease undergoing chemoradiation. Future research will benefit by assessing the prognostic potential of NLR in the context of genetic mutations and molecular markers.

Glucagon-like peptide-1 receptor agonist inhibits aeroallergen-induced activation of ILC2 and neutrophilic airway inflammation in obese mice

BACKGROUND

Obesity is a risk factor for the development of asthma. However, pharmacologic therapeutic strategies that specifically target obese asthmatics have not been identified. We hypothesize that glucagon-like peptide-1 receptor agonist (GLP-1RA) treatment inhibits aeroallergen-induced early innate airway inflammation in a mouse model of asthma in the setting of obesity.

METHODS

SWR (lean) and TALLYHO (obese) mice were challenged intranasally with Alternaria alternata extract (Alt-Ext) or PBS for 4 consecutive days concurrent with GLP-1RA or vehicle treatment.

RESULTS

TALLYHO mice had greater Alt-Ext-induced airway neutrophilia and lung protein expression of IL-5, IL-13, CCL11, CXCL1, and CXCL5, in addition to ICAM-1 expression on lung epithelial cells compared with SWR mice, and all endpoints were reduced by GLP-1RA treatment. Alt-Ext significantly increased BALF IL-33 in both TALLYHO and SWR mice compared to PBS challenge, but there was no difference in the BALF IL-33 levels between these two strains. However, TALLYHO, but not SWR, mice had significantly higher airway TSLP in BALF following Alt-Ext challenge compared to PBS, and BALF TSLP was significantly greater in TALLYHO mice compared to SWR mice following airway Alt-Ext challenge. GLP-1RA treatment significantly decreased the Alt-Ext-induced TSLP and IL-33 release in TALLYHO mice. While TSLP or ST2 inhibition with a neutralizing antibody decreased airway eosinophils, they did not reduce airway neutrophils in TALLYHO mice.

CONCLUSIONS

These results suggest that GLP-1RA treatment may be a novel pharmacologic therapeutic strategy for obese persons with asthma by inhibiting aeroallergen-induced neutrophilia, a feature not seen with either TSLP or ST2 inhibition.

Congenital disorders of glycosylation with defective fucosylation

Fucosylation is essential for intercellular and intracellular recognition, cell-cell interaction, fertilization, and inflammatory processes. Only five types of congenital disorders of glycosylation (CDG) related to an impaired fucosylation have been described to date: FUT8-CDG, FCSK-CDG, POFUT1-CDG SLC35C1-CDG, and the only recently described GFUS-CDG. This review summarizes the clinical findings of all hitherto known 25 patients affected with those defects with regard to their pathophysiology and genotype. In addition, we describe five new patients with novel variants in the SLC35C1 gene. Furthermore, we discuss the efficacy of fucose therapy approaches within the different defects.

Leukocytosis Associated with Clozapine Treatment: A Case Series and Systematic Review of the Literature

BACKGROUND AND OBJECTIVES

Clozapine is the only antipsychotic approved for treatment-resistant schizophrenia. Despite its superior efficacy profile as compared with other antipsychotics, clozapine remains underutilized. Clozapine monitoring systems clearly describe the proposed management of clozapine-induced neutropenia; however, no specific mention is made of how to interpret neutrophilic leukocytosis, despite that being a relatively frequent finding. Prescribers unfamiliar with this molecule may misjudge its clinical significance, potentially leading to untimely treatment interruption. Here, we systematically review the literature on the risk of neutrophilic leukocytosis during clozapine treatment, and describe eight additional cases among our patient cohort.

MATERIALS AND METHODS

We performed a systematic review of the literature on PubMed and Embase using the PRISMA 2020 guidelines, and selected all original reports describing either (1) the prevalence of neutrophilic leukocytosis during clozapine treatment, or (2) the clinical significance of neutrophilic leukocytosis. We described eight additional cases of neutrophilic leukocytosis during clozapine treatment while attending an outpatient psychiatric clinic.

RESULTS

Our research ultimately yielded the selection of 13 articles included in this systematic review. The case series highlighted the presence of stable and clinically unremarkable neutrophilia during a follow-up ranging from one to ten years.

CONCLUSIONS

Existing evidence indicates that leukocytosis associated with clozapine treatment can be considered as an asymptomatic and benign condition, suggesting that no change in clozapine treatment is needed upon its detection.

Involvement of G-CSF, IL-6, and cortisol in transient neutrophilia after marathon races

OBJECTIVES

The aim of this study was to clarify the mechanisms of the transient increase in neutrophils after running standard marathon races by measurement of cytokines involved in the production and survival of neutrophils, and cortisol.

METHODS

Fourteen male runners who participated in the Hokkaido Marathon, which is the sole marathon race held in summer in Japan, and finished the standard marathon were analyzed sequentially from the start until a maximum of 8 days after the finish.

RESULTS

Neutrophilia was observed in all runners just after they reached the goal (mean neutrophils: 13 226/μL). IL-6, G-CSF, and cortisol, but not GM-CSF, increased at the same time. Time-course studies with complete blood counts, biochemical markers, cytokines, and cortisol showed transient increases in neutrophils, monocytes, myoglobin, high-sensitivity C-reactive protein (hsCRP), G-CSF, IL-6, and cortisol. The increase in hsCRP was delayed 6 hours from the first increase in neutrophils. Correlations were observed between the neutrophil count and G-CSF, IL-6, and cortisol (G-CSF; r = .667, IL-6; r = .667, cortisol; r = .623).

CONCLUSION

These results suggest that G-CSF is directly involved, and IL-6 is involved via cortisol in the transient neutrophilia that occurs after marathon races.

Neutrophilia, lymphopenia and myeloid dysfunction: a living review of the quantitative changes to innate and adaptive immune cells which define COVID-19 pathology

Destabilization of balanced immune cell numbers and frequencies is a common feature of viral infections. This occurs due to, and further enhances, viral immune evasion and survival. Since the discovery of the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), which manifests in coronavirus disease 2019 (COVID-19), a great number of studies have described the association between this virus and pathologically increased or decreased immune cell counts. In this review, we consider the absolute and relative changes to innate and adaptive immune cell numbers, in COVID-19. In severe disease particularly, neutrophils are increased, which can lead to inflammation and tissue damage. Dysregulation of other granulocytes, basophils and eosinophils represents an unusual COVID-19 phenomenon. Contrastingly, the impact on the different types of monocytes leans more strongly to an altered phenotype, e.g. HLA-DR expression, rather than numerical changes. However, it is the adaptive immune response that bears the most profound impact of SARS-CoV-2 infection. T cell lymphopenia correlates with increased risk of intensive care unit admission and death; therefore, this parameter is particularly important for clinical decision-making. Mild and severe diseases differ in the rate of immune cell counts returning to normal levels post disease. Tracking the recovery trajectories of various immune cell counts may also have implications for long-term COVID-19 monitoring. This review represents a snapshot of our current knowledge, showing that much has been achieved in a short period of time. Alterations in counts of distinct immune cells represent an accessible metric to inform patient care decisions or predict disease outcomes.

Scavenger Receptor BI Attenuates IL-17A-Dependent Neutrophilic Inflammation in Asthma

Asthma is a common respiratory disease currently affecting more than 300 million worldwide and is characterized by airway inflammation, hyperreactivity, and remodeling. It is a heterogeneous disease consisting of corticosteroid-sensitive T-helper cell type 2-driven eosinophilic and corticosteroid-resistant, T-helper cell type 17-driven neutrophilic phenotypes. One pathway recently described to regulate asthma pathogenesis is cholesterol trafficking. Scavenger receptors, in particular SR-BI (scavenger receptor class B type I), are known to direct cellular cholesterol uptake and efflux. We recently defined SR-BI functions in pulmonary host defense; however, the function of SR-BI in asthma pathogenesis is unknown. To elucidate the role of SR-BI in allergic asthma, SR-BI-sufficient (SR-BI+/+) and SR-BI-deficient (SR-BI-/-) mice were sensitized (Days 0 and 7) and then challenged (Days 14, 15, and 16) with a house dust mite (HDM) preparation administered through oropharyngeal aspiration. Airway inflammation and cytokine production were quantified on Day 17. When compared with SR-BI+/+ mice, the HDM-challenged SR-BI-/- mice had increased neutrophils and pulmonary IL-17A production in BAL fluid. This augmented IL-17A production in SR-BI-/- mice originated from a non-T-cell source that included neutrophils and alveolar macrophages. Given that SR-BI regulates adrenal steroid hormone production, we tested whether the changes in SR-BI-/- mice were glucocorticoid dependent. Indeed, SR-BI-/- mice were adrenally insufficient during the HDM challenge, and corticosterone replacement decreased pulmonary neutrophilia and IL-17A production in SR-BI-/- mice. Taken together, these data indicate that SR-BI dampens pulmonary neutrophilic inflammation and IL-17A production in allergic asthma at least in part by maintaining adrenal function.

A Case of Chronic Neutrophilic Leukemia Incidentally Detected by 18F-FDG PET/CT

Chronic neutrophilic leukemia (CNL) is a rare, potentially aggressive, myeloproliferative neoplasm. To the best of our knowledge, there are no previous reports dealing with ¹⁸F-FDG PET findings in CNL. We describe a case of CNL in a 69-year-old male, imaged with ¹⁸F-FDG PET/CT at diagnosis and during treatment.

Commensal Microbiome Expands Tγδ17 Cells in the Lung and Promotes Particulate Matter-Induced Acute Neutrophilia

Particulate matter (PM) induces neutrophilic inflammation and deteriorates the prognosis of diseases such as cardiovascular diseases, cancers, and infections, including COVID-19. Here, we addressed the role of γδ T cells and intestinal microbiome in PM-induced acute neutrophilia. γδ T cells are a heterogeneous population composed of Tγδ1, Tγδ2, Tγδ17, and naïve γδ T cells (TγδN) and commensal bacteria promote local expansion of Tγδ17 cells, particularly in the lung and gut without affecting their Vγ repertoire. Tγδ17 cells are more tissue resident than Tγδ1 cells, while TγδN cells are circulating cells. IL-1R expression in Tγδ17 cells is highest in the lung and they outnumber all the other type 17 cells such as Th17, ILC3, NKT17, and MAIT17 cells. Upon PM exposure, IL-1β-secreting neutrophils and IL-17-producing Tγδ17 cells attract each other around the airways. Accordingly, PM-induced neutrophilia was significantly relieved in γδ T- or IL-17-deficient and germ-free mice. Collectively, these findings show that the commensal microbiome promotes PM-induced neutrophilia in the lung via Tγδ17 cells.

Leptin Receptor q223r Polymorphism Influences Clostridioides difficile Infection-Induced Neutrophil CXCR2 Expression in an Interleukin-1β Dependent Manner

Neutrophils are key first-responders in the innate immune response to C. difficile infection (CDI) and play a central role in disease pathogenesis. Studies have clearly shown that tissue neutrophil numbers need to be tightly regulated for optimal CDI outcomes: while excessive colonic neutrophilia is associated with severe CDI, neutrophil depletion also results in worse outcomes. However, the biological mechanisms that control CDI-induced neutrophilia remain poorly defined. C-X-C chemokine receptor 2 (CXCR2) is a chemotactic receptor that is critical in neutrophil mobilization from bone marrow to blood and tissue sites. We have previously reported that a single nucleotide polymorphism (SNP) in leptin receptor (LEPR), present in up to 50% of people, influenced CDI-induced neutrophil CXCR2 expression and tissue neutrophilia. Homozygosity for mutant LEPR (i.e. RR genotype) was associated with higher CXCR2 expression and more tissue neutrophils. Here, we investigated the biological mechanisms that regulate neutrophil CXCR2 expression after CDI, and the influence of host genetics on this process. Our data reveal that: a) CXCR2 plays a key role in CDI-induced neutrophil extravasation from blood to colonic tissue; b) plasma from C. difficile-infected mice upregulated CXCR2 on bone marrow neutrophils; c) plasma from C. difficile-infected RR mice induced a higher magnitude of CXCR2 upregulation and had more IL-1β; and d) IL-1β neutralization reduced CXCR2 expression on bone marrow and blood neutrophils and their subsequent accrual to colonic tissue. In sum, our data indicate that IL-1β is a key molecular mediator that communicates between gastro-intestinal tract (i.e. site of CDI) and bone marrow (i.e. primary neutrophil reservoir) and regulates the intensity of CDI-induced tissue neutrophilia by modulating CXCR2 expression. Further, our studies highlight the importance of host genetics in affecting these innate immune responses and provide novel insights into the mechanisms by which a common SNP influences CDI-induced neutrophilia.

Venous Thromboembolism in Sickle Cell Disease is Associated with Neutrophilia

Venous thromboembolism (VTE) in individuals with sickle cell disease is common and portends a poor prognosis. The role of leukocyte count and its subsets on risk of VTE in sickle cell disease are not known. We conducted a retrospective case-control study and analyzed for leukocyte count at the time of VTE and 3 months prior. Leukocyte and neutrophil counts were elevated at the time of VTE (p = 0.003 and p = 0.0006, respectively) and 3 months prior (p = 0.001 and p = 0.0096, respectively) when compared to controls. Baseline leukocytosis and neutrophilia may be associated with subsequent risk for thrombosis in sickle cell disease.

The hematologic inflammatory index is a new prognostic marker in patients resected for gastric cancer

Background

The role of the systemic inflammatory response in cancer has been shown in many studies. The present study aims to investigate the prognostic significance of a new hematologic index obtained by the combination of platelet, neutrophil, and lymphocyte counts in patients undergoing curative gastrectomy for gastric cancer.

Methods

We retrospectively analyzed 95 consecutive patients who underwent curative gastrectomy for gastric cancer between January 2013 and December 2018. Receiver operating characteristics curve analysis was used to determine the optimal cutoff values for hematologic inflammatory index (HII). The optimal cutoff value for HII was 2.69. Baseline parameters categorized into two groups were compared with the Chi-square test. Variables were evaluated by the univariate analysis were further assessed by the multivariate analysis using Cox's proportional-hazards regression model.

Results

According to HII, 44 patients (46.3%) had values lower than 2.69 and 51 patients (53.7%) had values higher than 2.69. HII was significantly correlated with depth of tumor invasion (P = 0.009), tumor histologic type (P = 0.048), and need for adjuvant therapy (P = 0.04). Median disease-free survival (DFS) (P = 0.003, hazard ratio (HR), 0.423; 95% confidence interval [CI], 0.234-0.762) and median overall survival (OS) (P = 0.002, HR, 0.385; 95% CI, 0.207-0.716) were found to be significantly shorter in the patient group where HII was higher than 2.69 compared to the patient group whose HII was lower than 2.69. When the multivariate analysis was performed, both DFS (P = 0.025, HR, 0.484; 95% CI, 0.257-0.912) and OS (P = 0.04, HR, 0.497; 95% CI, 0.255-0.970) were found to be independent prognostic factors.

Conclusions

In this retrospective study, HII is independently associated with both DFS and OS in gastric cancer. HII is an inexpensive, powerful, and easily accessible prognostic marker.

Anticoagulant protein S in COVID-19: low activity, and associated with outcome

Introduction. COVID-19 disease was associated with both thrombo-embolic events and in-situ thrombi formation in small vessels. Antiphospholipidic antibodies were found in some studies.Aim. Assessment of protein S activity in patients with COVID-19 as a cause of this prothrombotic state, and of the association of protein S activity with worse outcome.Methods. All patients admitted for COVID-19 disease in a university hospital between 15^th of May and 15^th of July 2020 were prospectively enrolled into this cohort study. Patients treated with antivitamin K anticoagulants and with liver disease were excluded. All patients had protein S activity determined at admission. The main outcome was survival, while secondary outcomes were clinical severity and lung damage.Results. 91 patients were included, of which 21 (23.3%) died. Protein S activity was decreased in 65% of the patients. Death was associated with lower activity of protein S (median 42% vs. 58%, p < 0.001), and the association remained after adjustment for age, inflammation markers and ALAT. There was a dose-response relationship between protein S activity and clinical severity (Kendall_tau coefficient = -0.320, p < 0.001; Jonckheere-Terpstra for trend: p < 0.001) or pulmonary damage on CT scan (Kendall_tau coefficient = -0.290, p < 0.001; Jonckheere-Terpstra for trend: p < 0.001). High neutrophil count was also independently associated with death (p = 0.002).Conclusion. Protein S activity was lower in COVID-19 patients, and its level was associated with survival and disease severity, suggesting that it may have a role in the thrombotic manifestations of the disease.

Zebrafish Models to Study Inflammasome-Mediated Regulation of Hematopoiesis

Hematopoiesis is a complex process through which immature bone marrow precursor cells mature into all types of blood cells. Although the association of hematopoietic lineage bias (including anemia and neutrophilia) with chronic inflammatory diseases has long been appreciated, the causes involved are obscure. Recently, cytosolic multiprotein inflammasome complexes were shown to activate inflammatory and immune responses, and directly regulate hematopoiesis in zebrafish models; this was deemed to occur via cleavage and inactivation of the master erythroid transcription factor GATA1. Herein summarized are the zebrafish models that are currently available to study this unappreciated role of inflammasome-mediated regulation of hematopoiesis. Novel putative therapeutic strategies, for the treatment of hematopoietic alterations associated with chronic inflammatory diseases in humans, are also proposed.

Using the Systemic Immune-Inflammation Index (SII) as a Mid-Treatment Marker for Survival among Patients with Stage-III Locally Advanced Non-Small Cell Lung Cancer (NSCLC)

The Systemic Immune-Inflammation Index (SII) is an important marker of immune function, defined as the product of neutrophil-to-lymphocyte ratio (NLR) and platelet count (P). Higher baseline SII levels have been associated with improved survival in various types of cancers, including lung cancer. Data were obtained from PROCLAIM, a randomized phase III trial comparing two different chemotherapy regimens pemetrexed + cisplatin (PEM) vs. etoposide + cisplatin (ETO), in combination with radiotherapy (RT) for the treatment of stage III non-squamous non-small cell lung cancer (NSCLC). We aimed to determine if SII measured at the mid-treatment window for RT (weeks 3-4) is a significant predictor of survival, and if the effect of PEM vs. ETO differs by quartile (Q) level of SII. Hazard-ratios (HR) for survival were estimated using a proportional hazards model, accounting for the underlying correlated structure of the data. A total of 548 patients were included in our analysis. The median age at baseline was 59 years. Patients were followed for a median of 24 months. Adjusting for age, body mass index, sex, race, and chemotherapy regimen, SII was a significant mid-treatment predictor of both overall (adjusted HR (aHR) = 1.6, p < 0.0001; OS) and progression-free (aHR = 1.3, p = 0.0072; PFS) survival. Among patients with mid-RT SII values above the median (6.8), those receiving PEM (vs. ETO) had superior OS (p = 0.0002) and PFS (p = 0.0002). Our secondary analysis suggests that SII is an informative mid-treatment marker of OS and PFS in locally advanced non-squamous NSCLC.

Educational Case: Hematologic and Immunologic Response to Allergic Rhinitis With Other Causes of Leukocytosis

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Excessive Neutrophils and Neutrophil Extracellular Traps in COVID-19

Background: Cases of excessive neutrophil counts in the blood in severe coronavirus disease (COVID-19) patients have drawn significant attention. Neutrophil infiltration was also noted on the pathological findings from autopsies. It is urgent to clarify the pathogenesis of neutrophils leading to severe pneumonia in COVID-19. Methods: A retrospective analysis was performed on 55 COVID-19 patients classified as mild (n = 22), moderate (n = 25), and severe (n = 8) according to the Guidelines released by the National Health Commission of China. Trends relating leukocyte counts and lungs examined by chest CT scan were quantified by Bayesian inference. Transcriptional signatures of host immune cells of four COVID19 patients were analyzed by RNA sequencing of lung specimens and BALF. Results: Neutrophilia occurred in 6 of 8 severe patients at 7-19 days after symptom onset, coinciding with lesion progression. Increasing neutrophil counts paralleled lesion CT values (slope: 0.8 and 0.3-1.2), reflecting neutrophilia-induced lung injury in severe patients. Transcriptome analysis revealed that neutrophil activation was correlated with 17 neutrophil extracellular trap (NET)-associated genes in COVID-19 patients, which was related to innate immunity and interacted with T/NK/B cells, as supported by a protein-protein interaction network analysis. Conclusion: Excessive neutrophils and associated NETs could explain the pathogenesis of lung injury in COVID-19 pneumonia.

Neutrophilia and NETopathy as Key Pathologic Drivers of Progressive Lung Impairment in Patients With COVID-19

There is an urgent need for new therapeutic strategies to contain the spread of the novel coronavirus disease 2019 (COVID-19) and to curtail its most severe complications. Severely ill patients experience pathologic manifestations of acute respiratory distress syndrome (ARDS), and clinical reports demonstrate striking neutrophilia, elevated levels of multiple cytokines, and an exaggerated inflammatory response in fatal COVID-19. Mechanical respirator devices are the most widely applied therapy for ARDS in COVID-19, yet mechanical ventilation achieves strikingly poor survival. Many patients, who recover, experience impaired cognition or physical disability. In this review, we argue the need to develop therapies aimed at inhibiting neutrophil recruitment, activation, degranulation, and neutrophil extracellular trap (NET) release. Moreover, we suggest that currently available pharmacologic approaches should be tested as treatments for ARDS in COVID-19. In our view, targeting host-mediated immunopathology holds promise to alleviate progressive pathologic complications of ARDS and reduce morbidities and mortalities in severely ill patients with COVID-19.

A prospective study of hospitalized patients with leukemoid reaction; causes, prognosis and value of manual peripheral smear review

INTRODUCTION

Several diagnoses have been associated with leukemoid reaction (LR). In patients with LR the diagnostic and prognostic value of detailed manual blood smear counts (such as the percentage of band cells or grading of neutrophil toxic changes) has not been studied previously.

METHODS

We prospectively recorded all hospitalized adult (> 18 years old) patients with LR (≥ 30000/ul) of neutrophilic predominance, excluding patients with pre-existing leukocytosis due to hematological malignancies. We examined the diagnoses and prognosis (in-hospital mortality and post-discharge mortality up to a year after the end of the study) of these patients as well as the value of manual peripheral smear review.

RESULTS

We recorded a total of 93 patients with LR from January 2017 to December 2017. Infection was the most common diagnosis (70%), followed by malignancy (7.5%) and bleeding (6.5%). In-hospital mortality (45%) and post-discharge mortality (35% of those discharged) were very high. Among blood smear findings, only neutrophil vacuolation was significantly more common in patients with infections (34%), although it was also observed in many patients without any infection (13%). Blood smear findings were not associated with prognosis.

CONCLUSION

Detailed manual smear review is a labor-intensive procedure and it has limited diagnostic and prognostic value in unselected hospitalized patients with neutrophilic LR.

Immune Responses after Vascular Photodynamic Therapy with Redaporfin

Photodynamic therapy (PDT) relies on the administration of a photosensitizer (PS) that is activated, after a certain drug-to-light interval (DLI), by the irradiation of the target tumour with light of a specific wavelength absorbed by the PS. Typically, low light doses are insufficient to eradicate solid tumours and high fluence rates have been described as poorly immunogenic. However, previous work with mice bearing CT26 tumours demonstrated that vascular PDT with redaporfin, using a low light dose delivered at a high fluence rate, not only destroys the primary tumour but also reduces the formation of metastasis, thus suggesting anti-tumour immunity. This work characterizes immune responses triggered by redaporfin-PDT in mice bearing CT26 tumours. Our results demonstrate that vascular-PDT leads to a strong neutrophilia (2-24 h), systemic increase of IL-6 (24 h), increased percentage of CD4⁺ and CD8⁺ T cells producing IFN-γ or CD69⁺ (2-24 h) and increased CD4⁺/CD8⁺ T cell ratio (2-24 h). At the tumour bed, T cell tumour infiltration disappeared after PDT but reappeared with a much higher incidence one day later. In addition, it is shown that the therapeutic effect of redaporfin-PDT is highly dependent on neutrophils and CD8⁺ T cells but not on CD4⁺ T cells.

Immature granulocytes index as early marker of sepsis

INTRODUCTION

Sepsis induces the recruitment of immature neutrophils into the circulation. An immature granulocyte percentage (IG%) count greater than 3% has been shown to be an indicator for the risk of sepsis. The aim of this study was to evaluate the IG% as predictor of sepsis compared to blood culture results and sepsis diagnostic confirmation.

METHODS

The study included individuals (n = 301) of both sexes aged ≥18 years who underwent Hospital São Lucas examinations between January and November 2017. For all the patients, IG%, as well as blood culture results, were evaluated. All examinations were obtained from Clinical Laboratory database. Data were analyzed through the SPSS program version 18.0.

RESULTS

There was statistical association between blood culture and IG% results (P = 0.009) and between sepsis confirmation and IG% on Pearson chi-square test (P < 0.001). An IG% cutoff point of 2.0% was able to exclude sepsis based on clinical diagnosis with a specificity of 90.9% and a sensitivity of 38.5%. The cutoff value in ROC analyses of IG% based on blood culture results was 0.3% and 0.4% based on clinical diagnosis.

CONCLUSION

Our study demonstrated that IG% <2.0% are helpful on the exclusion of sepsis diagnosis with a very high specificity (90.9%). The IG% is a useful additional marker for sepsis diagnosis allowing the early initiation of therapy and better possibilities of recovery.

Eosinopenia is a predictive factor for the severity of acute ischemic stroke

Previous data have revealed an association between eosinopenia and mortality of acute ischemic stroke. However, the relationship of eosinopenia with infarct volume, infection rate, and poor outcome of acute ischemic stroke is still unknown. The retrospective study included 421 patients (273 males, 65%; mean age, 68.0 ± 13.0 years) with first acute ischemic stroke who were hospitalized in the Second Affiliated Hospital of Soochow University, China, from January 2017 to February 2018. Laboratory data, neuroimaging results, and modified Rankin Scale scores were collected. Patients were divided into four groups according to their eosinophil percentage level (< 0.4%, 0.4–1.1%, 1.1–2.3%, ≥ 2.3%). Spearman’s correlation analysis showed that the percentage of eosinophils was negatively correlated with infarct volume (r_s = −0.514, P < 0.001). Receiver operating characteristic analysis demonstrated that eosinopenia predicted a large infarct volume more accurately than neutrophilia; the area under curve was 0.906 and 0.876, respectively; a large infarct was considered as that with a diameter larger than 3 cm and involving more than two major arterial blood supply areas. Logistic regression analysis revealed that eosinophil percentage was an independent risk factor for acute ischemic stroke (P = 0.002). Moreover, eosinophil percentage was significantly associated with large infarct volume, high infection rate (pulmonary and urinary tract infections), and poor outcome (modified Rankin Scale score > 3) after adjusting for potential confounding factors (P-trend < 0.001). These findings suggest that eosinopenia has the potential to predict the severity of acute ischemic stroke. This study was approved by the Ethics Committee of the Second Affiliated Hospital of Soochow University, China (approval number: K10) on November 10, 2015.

Utility of cell population data (VCS parameters) as a rapid screening tool for Acute Myeloid Leukemia (AML) in resource-constrained laboratories

INTRODUCTION

Despite advances in diagnostic techniques, many cases of acute myeloid leukemia (AML) remain underdiagnosed in remote centers unequipped with these technologies. We hypothesized that the automated cellular indices with scatter plots and flags may aid in rapid and cost-effective screening of AML.

METHODS

Cell population data (CPD) parameters from 100 de novo AML samples were analyzed by Coulter LH 780 automated analyzer and were compared with 100 age-matched controls. Similar parameters were also compared with 100 and 50 reactive cases of neutrophilia and monocytosis, respectively. System-generated flags and scatter plot patterns were also analyzed.

RESULTS

Results were compared between AML cases and normal controls; AML FAB M2, M3, M4 vs reactive neutrophilia; AML FAB M4, M5 vs reactive monocytosis. Significant parameters were selected from all comparison groups. Using appropriate statistical tools, we calculated the cutoff values of these parameters and were able to screen out AML cases with 94% sensitivity and 95% specificity. Three statistical equations were generated using two of the most significant parameters which improved the sensitivity to 98% and specificity to 99%. Five hypothetical scatter plot patterns were devised and were classified according to FAB categories of AML. Most common pattern was selected in AML which was seen in 56% of the cases. Output was analyzed combining these patterns and flags with CPD parameters.

CONCLUSION

CPD either alone or in the form of statistical equations along with scatter plots and flags can provide rapid and economic tool in preliminary diagnosis of AML in cost-constrained settings.

Colony-stimulating Factor 3 Receptor Mutated Chronic Neutrophilic Leukemia: A Rare Case Report

Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative neoplasm, which is characterized by sustained peripheral leukocytosis with neutrophilia, hepatosplenomegaly, and hypercellularity of the bone marrow, with less than 5% myeloblasts along with normal neutrophil maturation and no dysplasia. In 2016, World Health Organization (WHO) included activating mutations in the gene for colony-stimulating factor 3 receptor (CSF3R) as one of the diagnostic criteria with CSF3RT618I being the most common mutation. We report a rare case of CNL (JAK2V617F negative, BCR-ABL1 negative, CSF3RT618I positive) in an elderly female who had an aggressive clinical course of the disease.

The Frequency and Prognostic Value of Neutrophilia in Chronic Lymphocytic Leukemia

BACKGROUND/AIM

In chronic lymphocytic leukemia (CLL) the absolute neutrophil count (ANC) has generally been reported to be within normal limits and leukocytosis is due to absolute lymphocytosis. However, other cell types such as neutrophils and monocytes may also exceed the normal range in this disorder. The aim of this retrospective study was to evaluate the frequency and prognostic value of neutrophilia defined as an ANC>7×10⁹/l and monocytosis- an absolute monocyte count (AMC)>1×10⁹/l in 113 patients with chronic lymphocytic leukemia (CLL).

MATERIALS AND METHODS

We analyzed clinical and laboratory data from the records of patients with CLL followed in the Hematology unit of a tertiary hospital in Israel. Patients were categorized according to their ANC and AMC before treatment and their data compared.

RESULTS

In 24 (21%) patients, neutrophilia was present at diagnosis while 40 (35%) had monocytosis. We identified that 9% of cases had neutrophilia with normal AMC. This subgroup of patients had a better prognosis with lower mortality rate, longer time-to-treatment interval and a higher rate of complete or partial response to treatment compared to patients without neutrophilia or monocytosis.

CONCLUSION

The presence of neutrophilia without monocytosis before treatment appears to be associated with a more favorable prognosis in CLL. These observations still need to be confirmed and validated in a larger cohort of patients.

Susceptibility to Tuberculosis Is Associated With PI3K-Dependent Increased Mobilization of Neutrophils

Neutrophilia is a condition commonly observed in patients with late-stage tuberculosis, but evidence suggests that increased neutrophil influx begins early after infection in susceptible hosts and functions to promote a nutrient-replete niche that promotes Mycobacterium tuberculosis survival and persistence. As the disease progresses, an increase in the number of neutrophil-like cells is observed, all of which exhibit characteristics associated with (i) phenotypic and biochemical features of immaturity, (ii) the inability to activate T-cells, (iii) hyper-inflammation, and (iv) prolonged survival. Transcriptomics reveal a common set of molecules associated with the PI3–Kinase pathway that are dysregulated in patients with active tuberculosis. Closer inspection of their individual biological roles reveal their ability to modulate the IL-17/G–CSF axis, induce leukocyte receptor activation, and regulate apoptosis and motility. This review draws attention to neutrophil hyper-reactivity as a driving force for both the establishment and progression of tuberculosis disease in susceptible individuals.

The platelets-neutrophils to lymphocytes ratio: a new prognostic marker in metastatic colorectal cancer

Background

The cancer micro-environment is recognized as having an increasing importance in cancer progression. Immune cells originating from the peripheral blood are important elements of this environment. Thrombocytosis, neutrophilia and lymphocytopenia have been found to be negative prognostic indicators in many cancers. This study aims to evaluate the potential of the use of a novel hematological marker, the platelet-neutrophil to lymphocyte ratio (PNLR) as a practical, reliable, and inexpensive prognostic tool in metastatic colorectal adenocarcinomas.

Methods

Charts from 305 patients with colorectal cancer were retrospectively reviewed. Of these, 152 had metastatic disease with complete follow-up data on progression and survival. Data were extracted and stratified by a PNLR cut-off point of 2,000. Baseline parameters of the two groups were evaluated and compared with the χ² test. Univariate and multivariate Cox proportional-hazards regression analyses were performed on variables of interest.

Results

A total of 102 (67.1%) patients had a PNLR of less than 2,000 while the index for 50 (32.9%) patients was 2,000 or higher. Patients with a PNLR above 2,000 had a shorter median progression-free survival (PFS) [6.5 vs. 13.3 months; hazard ratio (HR), 2.05; 95% CI, 1.32-3.19, P=0.001] than in patients with a PNLR below the threshold. Similar results were observed for median overall survival (OS) (9.6 vs. 21.8 months; HR, 2.33; 95% CI, 1.44-3.79, P=0.001). PNLR had a higher predictive HR than Eastern Cooperative Oncology Group (ECOG) performance status (PS).

Conclusions

In this retrospective analysis of metastatic colorectal cancer patients, PNLR had prognostic value for both OS and PFS. While other variables held significance for poorer prognosis, PNLR had the highest HR and the highest significance in multivariate analysis for both PFS and OS. Thus, it represents a powerful and objective prognostic tool in the evaluation of metastatic colorectal cancer patients that is readily available and does not require any additional expenses.

Association of neutrophil morphology with bacterial isolates in equine tracheal wash samples

BACKGROUND

Tracheal wash sample neutrophilia is common in lower airway inflammation of various causes; however, relevance of cytomorphological features to culture of bacterial pathogens has not been established.

OBJECTIVES

To investigate whether the presence of nondegenerate or degenerate neutrophils in tracheal washes is associated with culture of bacteria and, if so, whether this is influenced by age or temporal factors.

STUDY DESIGN

Cross-sectional study.

METHODS

Tracheal wash samples submitted to Rossdales LLP from 1/1/2013 to 31/7/2015 were evaluated using set criteria. Neutrophilia and degenerate neutrophilia (graded ≥2/4 on Rossdales cytological scale [0-4]) were analysed in relation to bacterial isolates considered potentially pathogenic in respiratory disease. Statistical analyses included multivariable logistic regression to identify associations between two separate outcomes: 1) the presence of neutrophilia compared with no neutrophilia and 2) the presence of degenerate neutrophilia compared with nondegenerate neutrophilia and four independent variables.

RESULTS

Sufficient data for inclusion in the multivariable model for nondegenerate neutrophilia were available from 1100 horses. Culture of potentially pathogenic bacteria was associated with increased odds of degenerate neutrophilia compared with samples with negative culture (OR 4.5, 95% CI 3.1, 6.4, P-value<0.001). Horses over 9 years old had lower odds of having degenerate neutrophilia than those aged 1-3 years (OR 0.6, 95% CI 0.4, 0.9, P-value<0.02). In the spring/summer, horses had reduced odds of a degenerate neutrophilia compared with winter (OR 0.4, 95% CI 0.3, 0.7, P-value <0.001).

MAIN LIMITATIONS

The study relied on routine laboratory submissions, with no control over sample collection or submitted clinical history.

CONCLUSIONS

Cytological evaluation of tracheal washes should include cytomorphological features of the neutrophil response. The presence of degenerate neutrophils, especially in young horses, indicates added value of culture and sensitivity for antimicrobial therapeutics. The absence of degenerate changes, in combination with clinical factors, can help support diagnosis of a nonseptic cause of airway neutrophilia.

Eosinophilic Myocarditis With Hypersegmented Granulocytes and Neutrophilia Without Eosinophilia: A Case Mimicking Neutrophilic Myocarditis

We report a case of a 78-year-old woman with neutrophilia without eosinophilia who was pathologically diagnosed with eosinophilic myocarditis by myocardial biopsy. The biopsy specimen showed infiltrating granulocytes with hypersegmentation, mimicking neutrophils; however, they were confirmed to be eosinophils by Giemsa staining.

Neutrophilia in locally advanced cervical cancer: A novel biomarker for image-guided adaptive brachytherapy?

Objective

To study the prognostic value of leucocyte disorders in a prospective cohort of cervical cancer patients receiving definitive chemoradiation plus image—guided adaptive brachytherapy (IGABT).

Results

113 patients were identified. All patients received a pelvic irradiation concomitant with chemotherapy, extended to the para-aortic area in 13 patients with IVB disease. Neutrophilia and leukocytosis were significant univariate prognostic factors for poorer local failure-free survival (p = 0.000 and p = 0.002, respectively), associated with tumor size, high-risk clinical target volume (HR-CTV) and anemia. No effect was shown for distant metastases but leukocytosis and neutrophila were both poor prognostic factors for in-field relapses (p = 0.003 and p < 0.001). In multivariate analysis, HR-CTV volume (p = 0.026) and neutrophils count > 7,500/μl (p = 0.018) were independent factors for poorer survival without local failure, with hazard ratio (HR) of 3.1.

Materials and methods

We examined patients treated in our Institution between April 2009 and July 2015 by concurrent chemoradiation (45 Gy in 25 fractions +/− lymph node boosts) followed by a magnetic resonance imaging (MRI)-guided adaptive pulse-dose rate brachytherapy (15 Gy to the intermediate-risk clinical target volume). The prognostic value of pretreatment leucocyte disorders was examined. Leukocytosis and neutrophilia were defined as a leukocyte count or a neutrophils count exceeding 10,000 and 7,500/μl, respectively.

Conclusions

Neutrophilia is a significant prognostic factor for local relapse in locally advanced cervical cancer treated with MRI-based IGABT. This biomarker could help identifying patients with higher risk of local relapse and requiring dose escalation.