Neutrophils Research Articles

The oncolytic bacteria-mediated delivery system of CCDC25 nucleic acid drug inhibits neutrophil extracellular traps induced tumor metastasis

BackgroundNeutrophil extracellular traps (NETs), antibacterial weapons of neutrophils (NEs), have been found to play a crucial role in cancer metastasis in recent years. More and more cancer research is focusing on anti-NETs. However, almost all anti-NETs treatments have limitations such as large side effects and limited efficacy. Therefore, exploring new anti-NETs therapeutic strategies is a long-term goal.ResultsThe transmembrane protein coiled-coil domain containing 25 (CCDC25) on tumor cell membranes can bind NETs-DNA with high specificity and affinity, enabling tumor cells to sense NETs and thus promote distant metastasis. We transformed shCCDC25 into VNP20009 (VNP), an oncolytic bacterium, to generate VNP-shCCDC25 and performed preclinical evaluation of the inhibitory effect of shCCDC25 on cancer metastasis in B16F10 lung metastasis and 4T1 orthotopic lung metastasis models. VNP-shCCDC25 effectively blocked the downstream prometastatic signaling pathway of CCDC25 at tumor sites and reduced the formation of NETs while recruiting more neutrophils and macrophages to the tumor core, ultimately leading to excellent metastasis inhibition in the two lung metastasis models.ConclusionThis study is a pioneer in focusing on the effect of anti-NET treatment on CCDC25. shCCDC25 is effectively delivered to tumor sites via the help of oncolytic bacteria and has broad application in the inhibition of cancer metastasis via anti-NETs.Graphical

Crosstalk between keratinocytes and neutrophils shapes skin immunity against S. aureus infection.

Staphylococcus aureus (S. aureus) infection of the skin leads to a rapid initial innate immune response with keratinocytes in the epidermis as the initial sensors. Polymorphonuclear neutrophils (PMNs) are the first innate immune cells to infiltrate infection sites where they provide an effective first-line of defense. Previous work of our group showed that in inflamed skin a crosstalk between PMNs and keratinocytes results in enhanced S. aureus skin colonization. In this work, we used an in vitro co-culture model to studied the crosstalk between primary human keratinocytes (PHKs) and PMNs in a sterile environment and upon S. aureus infection. We investigated the influence of PHKs on PMN activation by analyzing PMN lifespan, expression of degranulation markers and induction of proinflammatory cytokines. Furthermore, we analyzed the influence of PMNs on the inflammatory response of PHKs. Finally, we investigated the influence of the skin microbiome on PMN-mediated skin inflammation. We show that co-culture of PMNs with PHKs induces activation and degranulation of PMNs and significantly enhances their lifespan compared to PMN cultivation alone by an IL-8 mediated mechanism and, furthermore, primes PMNs for enhanced activity after S. aureus infection. The prolonged incubation with PMNs also induces inflammatory responses in PHKs which are further exacerbated in the presence of S. aureus and induces further PMN recruitment thus fueling skin inflammation. Interestingly, infection of PHKs with the skin commensal S. epidermidis reduces the inflammatory effects of PMNs in the skin and exhibits an anti-inflammatory effect. Our data indicate that skin infiltrating PMNs and PHKs influence each other in such a way to enhance skin inflammation and that commensal bacteria are able to reduce the inflammatory effect.

A nomogram of preoperative indicators predicting lymph vascular space invasion in cervical cancer.

To develop predictive nomograms of lymph vascular space invasion (LVSI) in patients with early-stage cervical cancer. We identified 403 patients with cervical cancer from the Affiliated Hospital of Jiangnan University from January 2015 to December 2019. Patients were divided into the training set (n = 242) and the validation set (n = 161), with patients in the training set subdivided into LVSI (+) and LVSI (-) groups according to postoperative pathology. Preoperative hematologic indexes were compared between the two subgroups. Univariate and multivariate logistic regression analyses were used to analyze the independent risk factors for LVSI, from which a nomogram was constructed using the R package. LVSI (+) was present in 94 out of 242 patients in the training set, accompanied by a significant increase in the preoperative squamous cell carcinoma antigen (SCC), white blood cells (WBC), neutrophil (NE), platelet (PLT), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic inflammation index (SII), and tumor size (P < 0.05). Univariate analysis showed that SCC, WBC, NE, NLR, PLR, SII, and tumor size were correlated with LVSI (P < 0.05), and multivariate analysis showed that tumor size, SCC, WBC, and NLR were independent risk factors for LVSI (P < 0.05). A nomogram was correspondingly established with good performance in predicting LVSI [training: ROC-AUC = 0.845 (95% CI: 0.731-0.843) and external validation: ROC-AUC = 0.704 (95% CI: 0.683-0.835)] and high accuracy (training: C-index = 0.787; external validation: C-index = 0.759). The nomogram based on preoperative tumor size, SCC, WBC, and NLR had excellent accuracy and discriminative capability to assess the risk of LVSI in early-stage cervical cancer patients.

Trained Innate Immunity in Animal Models of Cardiovascular Diseases.

Acquisition of immunological memory is an important evolutionary strategy that evolved to protect the host from repetitive challenges from infectious agents. It was believed for a long time that memory formation exclusively occurs in the adaptive part of the immune system with the formation of highly specific memory T cells and B cells. In the past 10-15 years, it has become clear that innate immune cells, such as monocytes, natural killer cells, or neutrophil granulocytes, also have the ability to generate some kind of memory. After the exposure of innate immune cells to certain stimuli, these cells develop an enhanced secondary response with increased cytokine secretion even after an encounter with an unrelated stimulus. This phenomenon has been termed trained innate immunity (TI) and is associated with epigenetic modifications (histone methylation, acetylation) and metabolic alterations (elevated glycolysis, lactate production). TI has been observed in tissue-resident or circulating immune cells but also in bone marrow progenitors. Risk-factors for cardiovascular diseases (CVDs) which are associated with low-grade inflammation, such as hyperglycemia, obesity, or high salt, can also induce TI with a profound impact on the development and progression of CVDs. In this review, we briefly describe basic mechanisms of TI and summarize animal studies which specifically focus on TI in the context of CVDs.

A study of clinical and serological correlation of early myocardial injury in elderly patients infected with the Omicron variant.

Myocardial injury in elderly Omicron variant patients is a leading cause of severe disease and death. This study focuses on elucidating the clinical characteristics and potential risk factors associated with myocardial injury in elderly patients infected with the Omicron variant. Myocardial injury was defined based on elevated cardiac troponin concentrations exceeding the 99th percentile upper reference limit. Among 772 elderly Omicron-infected patients, categorized into myocardial injury (n = 263) and non-myocardial injury (n = 509) groups. The stratified log-rank statistic was used to compare the probability of patients developing intensive care. Receiver operating characteristic curves were used to determine the best cut-off values of clinical and laboratory data for predicting myocardial injury. Univariate and multivariate logistic regression was adopted to analyze the risk factors for myocardial injury. The occurrence of myocardial injury in Omicron variant-infected geriatric patients was up to 34.07% and these patients may have a higher rate of requiring intensive care (P < 0.05). By comparing myocardial injury patients with non-myocardial injury patients, notable differences were observed in age, pre-existing medical conditions (e.g., hypertension, coronary heart disease, cerebrovascular disease, arrhythmia, chronic kidney disease, and heart failure), and various laboratory biomarkers, including cycle threshold-ORF1ab gene (Ct-ORF1ab), cycle threshold-N gene (Ct-N), white blood cell count, neutrophil (NEUT) count, NEUT%, lymphocyte (LYM) count, LYM%, and D-dimer, interleukin-6, procalcitonin, C-reactive protein, serum amyloid A, total protein, lactate dehydrogenase, aspartate aminotransferase, glomerular filtration rate, blood urea nitrogen, and serum creatinine (sCr) levels (P < 0.05). Furthermore, in the multivariable logistic regression, we identified potential risk factors for myocardial injury in Omicron variant-infected elderly patients, including advanced age, pre-existing coronary artery disease, interleukin-6 > 22.69 pg/ml, procalcitonin > 0.0435 ng/ml, D-dimer > 0.615 mg/L, and sCr > 81.30 μmol/L. This study revealed the clinical characteristics and potential risk factors associated with myocardial injury that enable early diagnosis of myocardial injury in Omicron variant-infected elderly patients, providing important reference indicators for early diagnosis and timely clinical intervention.

Neutrophils in HNSCC Can Be Associated with Both a Worse or Favorable Prognosis.

The prognostic significance of tumor-infiltrating neutrophils in head and neck squamous cell carcinoma (HNSCC) is poorly understood. It is unclear how the presence of neutrophils affects prognosis due to their polarization into cytotoxic N1 or immunosuppressive N2. Therefore, we determined the number of CD66b+ neutrophil granulocytes separately in the stromal and epithelial compartments in cancer tissues from 397 patients with HNSCC. Tumor samples from six historical patient groups were processed into tissue microarrays and stained immunohistochemically. In total, 21.9% were HPV positive (p16+). Neutrophil counts were much lower in the stromal compartment (372 ± 812) than in the epithelial cancer compartment (1040 ± 1477) (p < 0.001), with large differences between groups. In three groups with high neutrophil infiltration, high rates were associated with a favorable prognosis, whereas in two groups, high rates were a negative prognostic factor. In p16- oropharyngeal and hypopharyngeal cancer high infiltration was associated with a favorable prognosis. Cancers with an exclusion of neutrophils in the epithelial compartment were associated with improved prognosis. In oropharyngeal and hypopharyngeal HPV-negative cancer high neutrophil infiltration rates were clearly associated with prolonged survival. Neutrophil granulocytes in HNSCC may contribute to a favorable or unfavorable prognosis.

Macrophage subpopulations in pediatric patients with lupus nephritis and other inflammatory diseases affecting the kidney

BackgroundMacrophages play an important role in the pathogenesis of lupus nephritis (LN), but less is known about macrophage subtypes in pediatric LN. Here we compared renal inflammation in LN with other inflammatory pediatric kidney diseases and assessed whether inflammation correlates with clinical parameters.MethodsUsing immunofluorescence microscopy, we analyzed renal biopsies from 20 pediatric patients with lupus nephritis (ISN/RPS classes II–V) and pediatric controls with other inflammatory kidney diseases for infiltration with M1-like (CD68 + /CD206 − , CD68 + /CD163 −), M2a-like (CD206 + /CD68 +), and M2c-like macrophages (CD163 + /CD68 +) as well as CD3 + T-cells, CD20 + B-cells, and MPO + neutrophilic granulocytes. In addition, the correlation of macrophage infiltration with clinical parameters at the time of renal biopsy, e.g., eGFR and serum urea, was investigated. Macrophage subpopulations were compared with data from a former study of adult LN patients.ResultsThe frequency of different macrophage subtypes in biopsies of pediatric LN was dependent on ISN/RPS class and showed the most pronounced M1-like macrophage infiltration in patients with LN class IV, whereas M2c-like macrophages were most abundant in class III and IV. Interestingly, on average, only half as many macrophages were found in renal biopsies of pediatric LN compared to adult patients with LN. The distribution of frequencies of macrophage subpopulations, however, was different for CD68 + CD206 + (M2a-like) but comparable for CD68 + CD163 − (M1-like) CD68 + CD163 + (M2c-like) cells in pediatric and adult patients. Compared to other inflammatory kidney diseases in children, fewer macrophages and other inflammatory cells were found in kidney biopsies of LN. Depending on the disease, the frequency of individual immune cell types varied, but we were unable to confirm disease-specific inflammatory signatures in our study due to the small number of pediatric cases. Worsened renal function, measured as elevated serum urea and decreased eGFR, correlated particularly strongly with the number of CD68 + /CD163 − M1-like macrophages and CD20 + B cells in pediatric inflammatory kidney disease.ConclusionAlthough M1-like macrophages play a greater role in pediatric LN patients than in adult LN patients, M2-like macrophages appear to be key players and are more abundant in other pediatric inflammatory kidney diseases compared to LN.

A typical presentation of a laryngeal foreign body in an infant

Background: A 1-year-old boy presented with a one-day history of fever and cough, potentially linked to an episode of aspiration during homemade rice feeding. Following the incident, he refused to feed, displaying irritability. The detection of neutrophil leucocytosis and dehydration prompted IV antibiotics and fluid. Persistent symptoms led to a lateral neck x-ray, revealing a radiopaque material near the epiglottis. Fibre optic laryngoscopy identified a metallic wire lodged in the right arytenoid cartilage and posterior pharyngeal wall, possibly a fragment from a rice polishing machine. Extraction under general anaesthesia resulted in minimal mucosal injury, and the child quickly recovered postoperatively.Conclusion: This report serves as a reminder to consider foreign body ingestion in the differential diagnosis, particularly in cases with subtle or unrelated symptoms in the paediatric age group. The multidisciplinary approach emphasises prompt intervention to prevent life-threatening complications in paediatric patients. Furthermore, employing awake fibre-optic laryngoscopy in the context of a suspected respiratory tract infection to confirm the presence of a foreign body is considered a clinically safer approach than immediately resorting to examination under anaesthesia.

Predictors of Gastrointestinal Involvement in Children with IgA Vasculitis: Results from a Single-Center Cohort Observational Study.

Background and objective: IgA vasculitis (IgAV), a predominantly pediatric leukocytoclastic disease, has an unpredictable, though largely benign, evolution. The aim of this study was to retrospectively investigate any potential clinical or laboratory predictors of gastrointestinal involvement in a single-center cohort of children with IgAV. Patients and methods: A total of 195 children with a history of IgAV, regularly followed-up for an average period of 1 ± 2.6 years via outpatients clinics of the pediatric rheumatology unit in our University, were assessed, analyzing their clinical and laboratory variables in relationship with their disease evolution and outcome. Results: Univariate analysis showed that a higher neutrophil granulocyte count and lower lymphocyte count (expressed as a percentage of the total white blood cells) were significantly associated with the presence of gastrointestinal involvement at the first examination (65.2 ± 13% versus 58.8 ± 12%, p = 0.02, and 26.4 ± 11% versus 32.1 ± 11%, p = 0.02, respectively). A positive pharyngeal swab for Streptococcus pyogenes, a deficiency of 25-hydroxyvitamin D, a persistence of purpuric rash for more than 1 month, and purpuric lesions in the genital area were also associated with gastrointestinal involvement (p = 0.0001, p = 0.0001, p = 0.007 and p = 0.001, respectively). However, multiple logistic regressions with correction for the patients' sex and age showed that lower 25-hydroxyvitamin D levels, persistent rash, and genital lesions were independently and significantly associated with signs of gastrointestinal involvement. We then performed a secondary analysis (both univariate and multivariate) to investigate whether vitamin D deficiency was associated with other IgAV manifestations: we found that only 25-hydroxyvitamin D deficiency remained significantly associated with gastrointestinal involvement in IgAV. Conclusions: Patients with IgAV and vitamin D deficiency might be more prone to developing gastrointestinal manifestations of variable severity.

Risk of treatment-altering haematological toxicity and its dependence on bone marrow doses in peptide receptor radionuclide therapy

BackgroundPeptide receptor radionuclide therapy is effective in treating neuroendocrine tumours, but treatment may be limited by kidney and bone marrow toxicity. In this work, the absorbed dose burden to the bone marrow was estimated using image-based dosimetry and its potential use for predicting treatment-altering toxicity was studied. Peripheral blood samples taken before and after 229 treatments with 177Lu-DOTATATE in 59 patients were studied. In connection to the treatments, a total of 940 blood sample occasions provided data on white blood cell, neutrophil granulocyte, platelet, erythrocyte and haemoglobin concentrations. SPECT/CT image data were collected at two or three time points after each treatment. Absorbed doses to bone marrow were calculated from the activity concentration in a metastasis-free lumbar vertebra. The rate of delayed and aborted treatments was analysed based on medical records.ResultsThe average absorbed dose to the bone marrow was 0.42 Gy (median 0.33 Gy, SD 0.27 Gy) per treatment. Dose–response relationships between white blood cells, neutrophil granulocytes and haemoglobin concentrations were observed, most prominently at 31–45 days after each treatment. The correlations were stronger in patients with skeletal metastases. The rates of haematological toxicity-related delays and aborted treatments were 6% and 12%, respectively. None of the studied bone marrow dosimetric parameters could clearly predict treatment-related toxicity. However, patients with skeletal metastases had higher risk of treatment-altering toxicity (odds ratio = 6.0).ConclusionsTreatment-altering haematological toxicity in peptide receptor radionuclide therapy is relatively rare and appears difficult to fully predict from post-therapeutic image-based dosimetry. However, for patients with skeletal metastases, the haematological dose–response relationships are stronger. Future studies may focus on this patient group, to further investigate the usefulness of dosimetry in predicting decreases in blood values.

Mesenchymal Stromal/Stem Cells Know Best: The Remarkable Complexities of Its Interactions With Polymorphonuclear Neutrophils.

Polymorphonuclear neutrophils (PMNs), the predominant immune cell type in humans, have long been known as first-line effector cells against bacterial infections mainly through phagocytosis and production of reactive oxygen species (ROS). However, recent research has unveiled novel and pivotal roles of these abundant but short-lived granulocytes in health and disease. Human mesenchymal stromal/stem cells (MSCs), renowned for their regenerative properties and modulation of T lymphocytes from effector to regulatory phenotypes, exhibit complex and context-dependent interactions with PMNs. Regardless of species or source, MSCs strongly abrogate PMN apoptosis, a critical determinant of PMN function, except if PMNs are highly stimulated. MSCs also have the capacity to fine-tune PMN activation, particularly in terms of CD11b expression and phagocytosis. Moreover, MSCs can modulate numerous other PMN functions, spanning migration, ROS production, and neutrophil extracellular trap (NET) formation/NETosis, but directionality is remarkably dependent on the underlying context: in normal nondiseased conditions, MSCs enhance PMN migration and ROS production, whereas in inflammatory conditions, MSCs reduce both these functions and NETosis. Furthermore, the state of the MSCs themselves, whether isolated from diseased or healthy donors, and the specific secreted products and molecules, can impact interactions with PMNs; while healthy MSCs prevent PMN infiltration and NETosis, MSCs isolated from patients with cancer promote these functions. This comprehensive analysis highlights the intricate interplay between PMNs and MSCs and its profound relevance in healthy and pathological conditions, shedding light on how to best strategize the use of MSCs in the expanding list of diseases with PMN involvement.

HylS’, a fragment of truncated hyaluronidase of Streptococcus suis, contributes to immune evasion by interaction with host complement factor C3b

ABSTRACT Pathogenic bacteria have evolved many strategies to evade surveillance and attack by complements. Streptococcus suis is an important zoonotic pathogen that infects humans and pigs. Hyaluronidase (HylA) has been reported to be a potential virulence factor of S. suis. However, in this study, it was discovered that the genomic region encoding HylA of the virulent S. suis strain SC19 and other ST1 strains was truncated into four fragments when aligned with a strain containing intact HylA and possessing hyaluronidase activity. As a result, SC19 had no hyaluronidase activity, but one truncated HylA fragment, designated as HylS,’ directly interacted with complement C3b, as confirmed by western ligand blotting, pull-down, and ELISA assays. The deposition of C3b and membrane attack complex (MAC) formation on the surface of a HylS’-deleted mutant (ΔhylS’) was significantly increased compared to wild-type SC19. In human sera and whole blood, ΔhylS’ survival was significantly reduced compared to that in SC19. The resistance of ΔhylS’ to macrophages and human polymorphonuclear neutrophil PMNs also decreased. In a mouse infection model, ΔhylS’ showed reduced lethality and lower bacterial load in the organs compared to that of SC19. We conclude that the truncated hyaluronidase HylS’ fragment contributes to complement evasion and the pathogenesis of S. suis.

Bacterial Meningitis in Buffaloes in Brazil

Meningitis is the inflammation of the membranes surrounding the central nervous system and is poorly described in water buffaloes. Five cases of meningitis in adults buffaloes of the Murrah and Mediterranean breads were studied. All buffaloes came from a farm located in the municipality of Castanhal, Pará, Brazil at different times. Clinical examination showed neurological clinical signs, such as apathy, reluctance to move, spastic paresis especially of the pelvic limbs, hypermetria, difficulty getting up, pressing of the head into obstacles and convulsion. In three buffaloes, a large part of the horn had been lost, exposing the corresponding frontal sinus, through which a bloody to purulent exudate flowed. The hemogram revealed neutrophilic leukocytosis. At necropsy, adherence of the dura mater to the periosteum and a purulent to fibrinopurulent exudate were observed in the sulci of the cerebral cortex and on the pia mater over almost the entire surface of the brain and throughout the spinal cord. The cerebrospinal fluid had a cloudy aspect with fibrin filaments. The histopathology of buffaloes confirmed the diagnosis of bacterial fibrinopurulent meningitis. Buffaloes are susceptible to bacterial inflammation of the meninges due to fractures of the base of the horn and mostly present with neurological manifestations.

The mechanism of Xuebijing injection in preventing and treating lung injury induced by cardiopulmonary bypass by regulating the apoptosis of alveolar polymorphonuclear neutrophil

To investigate the protective effect of Xuebijing injection on acute lung injury (ALI) associated with cardiopulmonary bypass (CPB) by regulating the apoptosis of polymorphonuclear neutrophils (PMN). Thirty male Sprague-Dawley (SD) rats were randomly divided into sham operation group (Sham group), CPB model group (CPB group) and Xuebijing pretreatment group (XBJ group) according to the random number table method, with 10 rats in each group. Rats in the CPB group and XBJ group undergoing CPB procedures for 60 minutes. Rats in the Sham group did not undergo CPB. Rats in the XBJ group received intraperitoneal injection of 4 mL/kg Xuebijing injection 2 hours before CPB. Rats in the Sham group and CPB group were injected with an equal amount of normal saline. 4 hours after CPB, arterial blood was collected for blood gas analysis to calculate respiratory index (RI), and lung tissue of rats was collected for determination of lung index (LI) and pulmonary water containing rate. PMN in bronchoalveolar lavage fluid (BALF) were collected and the activity of caspase-3 was detected. The apoptosis rate was detected by flow cytometry. The expressions of microRNA-142-3p (miR-142-3p) and FoxO1 mRNA were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). The protein expression of FoxO1 was detected by Western blotting. In addition, HL-60 cells were divided into control oligonucleotide transfection group, miR-142-3p mimics transfection group, and miR-142-3p inhibitor transfection group. After 48 hours of transfection, the activity of miR-142-3p binding to FoxO1 was detected using dual luciferase reporter genes. Compared with Sham group, RI, LI and pulmonary water containing rate were significantly increased in CPB group. The caspase-3 activity and apoptosis rate of PMN obtained from BALF were significantly decreased, the expression of miR-142-3p was decreased, and the expression of FoxO1 protein was increased. However, compared with CPB group, RI, LI and pulmonary water containing rate were significantly decreased in XBJ group [RI: 0.281±0.066 vs. 0.379±0.071, LI: 4.50±0.26 vs. 5.71±0.42, pulmonary water containing rate: (80.31±32.50)% vs. (84.59±3.41)%, all P < 0.01]. The caspase-3 activity and apoptosis rate of PMN obtained from BALF were significantly increased [caspase-3 activity: 0.350±0.021 vs. 0.210±0.014, apoptosis rate: (15.490±1.382)% vs. (8.700±0.701)%, both P < 0.01], the expression of miR-142-3p was significantly up-regulated (2-ΔΔCt: 2.61±0.17 vs. 0.62±0.05, P < 0.01), and the protein expression of FoxO1 was decreased [FoxO1/GAPDH (relative expression level): 0.81±0.04 vs. 1.22±0.06, P < 0.01]. However, there was no statistically significant difference in FoxO1 mRNA expression among the three groups. The bioinformatics analysis results showed that miR-142-3p can bind to the FoxO1 3'untranslated region (3'UTR). In HL-60 cells, compared with control oligonucleotide transfection group, the transfection of miR-142-3p mimics could reduce the expression of FoxO1 protein [FoxO1/GAPDH (relative expression level): 0.48±0.06 vs. 1.00±0.05, P < 0.01], however, the transfection of miR-142-3p inhibitor increased the expression of FoxO1 protein [FoxO1/GAPDH (relative expression level): 1.37±0.21 vs. 1.00±0.05, P < 0.05]. But, transfection with miR-142-3p mimics or inhibitor had no effect on FoxO1 mRNA expression. The luciferase reporter gene showed that miR-142-3p could bind to the FoxO1 3'UTR to inhibit FoxO1 expression. Xuebijing injection may promote the apoptosis of pulmonary alveolar PMN through the miR-142-3p/FoxO1 axis, and play a role in the prevention and treatment of CPB-induced ALI.

Synovial Calprotectin is Superior to Synovial Leukocyte Count in Excluding Chronic Periprosthetic Joint Infections, a Retrospective Cohort Study

BackgroundSynovial calprotectin is a promising biomarker for diagnosing chronic periprosthetic joint infections (PJIs), but its diagnostic value has not been directly compared to synovial leukocyte count and polymorphonuclear neutrophils. This study aimed to: (1) evaluate and compare the diagnostic accuracy between these markers in patients undergoing revision arthroplasty for chronic PJI or aseptic reasons; and (2) determine the best rule-out and rule-in test for PJI. MethodsSynovial fluid samples from patients undergoing revision arthroplasty in hip and knee joints were collected and analyzed. Patients diagnosed with an acute PJI, patients treated with antibiotics 2 weeks prior to revision surgery, and/or patients who had active inflammatory joint disease were excluded. Periprosthetic joint infections were diagnosed based on the presence of a sinus tract and/or positive intraoperative cultures according to the European Bone and Joint Infection Society microbiological criteria. ResultsA total of 137 patients were included, of whom 19 (14%) were diagnosed with a PJI. Overall, synovial calprotectin had the highest diagnostic accuracy of all studied markers (area under the curve 96%). Synovial calprotectin, with a cutoff of 50 mg/L, had the highest negative predictive value of 100%. However, PMNs (> 80%) combined with a leukocyte count (> 3,000 cells/μL) showed the highest positive predictive value of an infection (positive predictive value17). ConclusionsSynovial calprotectin is the most accurate biomarker for ruling out a chronic PJI, while the combination of synovial leukocyte count and PMN is most reliable for ruling in a chronic PJI.

Estimation of Phagocytic activity by normal human peripheral blood mononuclear cells on various oral isolates of Candida species – An in-vitro study

Polymorphonuclear neutrophils (PMN) and mononuclear phagocytes represent an important first line and effector function in control of Candida infections. The aim of the study is to determine the in-vitro phagocytic activity of human peripheral blood mononuclear cells against oral isolates of Candida species and its antifungal susceptibility. The study also evaluates the degree of respiratory burst activity of PBMCs. Phagocytic and lytic indices by PBMCs were determined for Candida spp. The respiratory burst activity was evaluated by nitroblue tetrazolium test. Antifungal disc diffusion susceptibility testing was performed. A total of 100 Candida were isolated belonging to the species C.albicans, C. tropicalis, C.krusei and C.auris. Phagocytic and lytic indices of C.albicans was significant when compared to standard strain of C.albicans. For C.tropicalis and C.krusei phagocytic index was significant while lytic index was not significant when compared to standard strain. The inter species comparison of both the indices was not significant for the clinical isolates of Candida. A significant reduction in phagocytic activity was observed for clinical isolates of Candida spp. but lytic activity was variable when compared to the standard strain of C.albicans.

Anaplasma phagocytophilum infection associated with strong inflammatory response in 3 cats.

Anaplasmosis is a vector-borne disease caused by Anaplasma (A.) spp. which currently is still rarely diagnosed in cats. This article describes 3 independent cases of anaplasmosis in cats from different regions of Germany presented to veterinarians in 2021. All cats showed unspecific clinical signs, such as fever, reduced general condition, and decreased appetite. One cat additionally had generalized limb pain, another showed reluctance to move as well as vomiting. On complete blood cell count, only 1 of 3 cats showed mild thrombocytopenia. A. phagocytophilum was detected in blood samples of all 3 cats by polymerase chain reaction. Additionally, in 2 cats (in which blood smears were evaluated) morulae could be detected within neutrophilic granulocytes. Initially, all 3 cats had highly elevated serum amyloid A (SAA) concentrations. Treatment with doxycycline caused a rapid improvement of clinical signs, followed by a decrease of SAA concentrations to normal levels as well as negative PCR results after a treatment duration of at least 28 days. In cats with fever, otherwise unspecific clinical signs with only mild or no hematological changes, elevated SAA concentrations, and previous exposure to ticks, attending veterinarians should consider anaplasmosis as differential diagnosis.

Soluble signal inhibitory receptor on leukocytes-1 reflects disease activity and assists diagnosis of patients with rheumatoid arthritis

BackgroundSIRL-1, an immunosuppressive receptor encoded by the VSTM1 gene, has recently been linked to rheumatoid arthritis (RA) due to its association with activated polymorphonuclear neutrophils (PMNs). Considering that the activated PMNs play a crucial role in the pathogenesis of rheumatoid arthritis (RA), we aimed to measure the levels of soluble SIRL-1, investigating whether they add value to RA in the clinical diagnosis. MethodsUtilizing an enzyme-linked immunosorbent assay, the concentration of sSIRL-1 was measured in serum samples from cohort 1 diagnosed with RA (n = 96), gout (n = 54), osteoarthritis (n = 47), healthy controls (n = 86) and synovial fluid samples from OA (n = 8) and RA (n = 8) patients, respectively. Additionally, an external validation in cohort 2 (n = 156) comprising various inflammatory diseases was employed. ResultsThe study revealed a distinctive upregulation of sSIRL-1 in the serum of RA compared to HC and other arthralgia diseases (p < 0.0001), which also displayed a significant elevation in synovial fluid from RA compared to OA (p < 0.05). Notably, sSIRL-1 levels exhibited a significant decrease in patients who achieved disease remission (p < 0.05). Furthermore, the diagnostic accuracy of RA was enhanced when sSIRL-1 was combined with anti-CCP and RF, yielding an impressive AUC value of 0.950. ConclusionThe expression pattern of sSIRL-1 in RA, coupled with its correlation with disease activity, underscores its potential clinical utility for both diagnosis and disease monitoring in RA patients. This study offers valuable insights into the evolving diagnostic landscape of RA.

Association of Hematological Parameters and Diabetic Neuropathy: A Retrospective Study.

Diabetic neuropathy (DN) is a common complication of type 2 diabetes (T2DM) and is characterized by persistent inflammation. Hematological parameters have emerged as a novel marker for detecting chronic inflammatory conditions, including diabetes. We aim to examine the association between HbA1c levels, which can indicate the presence of diabetic neuropathy, and hematological parameters to explore the possibility of using hematological parameters as a new indicator for DN in T2DM patients. This was a retrospective study of 768 (483 males and 284 females) medical records of adult T2DM patients with or without neuropathy who attending the outpatient neuromuscular clinic at King Abdul-Aziz University Hospital from January 2016 to December 2021. The results showed significant increases in HbA1c levels (p=0.000), lymphocyte levels (p=0.028), and the neutrophil-lymphocyte ratio (NLR) (p=0.011). In the T2DM group, HBA1C levels were found to be positively correlated with age (r=0.306, p=0.000), neutrophil (NEUT) (r=0. 287, p=0.000), platelet (PLT) (r=0. 148, p=0.039), and neutrophil-lymphocyte ratio (NLR) (r=0.306193, p=0.0007), and negatively correlated with gender (r=-0.306193, p=0.0007). In the T2DMN group, HBA1C levels showed a positive correlation with hemoglobin (HB) (r=0.084, p=0.045), PLT (r=0.087, p=0.037), and PLT/mean corpuscular hemoglobin (MCH) ratio (PLT/MCH ratio) (r=0.12, p=0.004), and a negative correlation with age (r=-0.204, p=0.000), gender (r=-0.086, p=0.041), weight (WT) (r=-0.113, p=0.007), Body Surface Area (BSA) (r=-0.09, p=0.031), mean corpuscular volume (MCV) (r=-0.292, p=0.000), and MCH (r=-0.186, p=0.000). Our study found a significant association between HbA1c, a biomarker for diabetic neuropathy, and various hematological parameters (HB, MCV, MCH, PLT, PLT/MCH ratio) in T2DMN patients. By effectively controlling and monitoring these variables, it may be feasible to prevent or delay the progression of peripheral neuropathy in diabetic patients. However, further research is needed to validate these findings.

Pulmonary superinfection diagnosed with bronchoalveolar lavage at intubation in COVID patients: A Swedish single-centre study.

Patients with severe coronavirus disease 2019 (COVID) pneumonia and acute respiratory distress syndrome (C-ARDS) on invasive mechanical ventilation (IMV) have been found to be prone to having other microbial findings than severe acute respiratory syndrome coronavirus 2 (SARS-2)-CoV-19 in the bronchoalveolar lavage (BAL) fluid at intubation causing a superinfection. These BAL results could guide empirical antibiotic treatment in complex clinical situations. However, there are limited data on the relationship between microbial findings in the initial BAL at intubation and later ventilator-associated pneumonia (VAP) diagnoses. To analyse the incidence of, and microorganisms responsible for, superinfections in C-ARDS patients at the time of first intubation through microbial findings in BAL fluid. To correlate these findings to markers of inflammation in plasma and later VAP development. Retrospective single-centre study. One COVID-19 intensive care unit (ICU) at a County Hospital in Sweden during the first year of the pandemic. All patients with C-ARDS who were intubated in the ICU. We analysed BAL fluid specimens from 112 patients at intubation, of whom 31 (28%) had superinfections. Blood levels of the C-reactive protein, procalcitonin, neutrophil granulocytes, and lymphocytes were indistinguishable between patients with and without a pulmonary superinfection. Ninety-eight (88%) of the patients were treated with IMV for more than 48 h and of these patients, 37% were diagnosed with VAP. The microorganisms identified in BAL at the time of intubation are normally found at the oral, pharyngeal, and airway sites. Only one patient had an indistinguishable bacterial strain responsible for both superinfection at intubation and in VAP. One fourth of the patients with C-ARDS had a pulmonary superinfection in the lungs that was caused by another microorganism identified at intubation. Routine serum inflammatory markers could not be used to identify this complication. Microorganisms located in BAL at intubation were rarely associated with later VAP development.