Methylprednisolone pulse-enhanced neutrophil extracellular trap formation in mice with imiquimod-induced lupus-like disease, resulting in ischaemia of the femoral head cartilage

Association study of hypoxia inducible factor 1α ( HIF1α) with osteonecrosis of femoral head in a Korean population

Association of Neutrophil Extracellular Traps with the Development of Idiopathic Osteonecrosis of the Femoral Head

Aseptic osteonecrosis of the femoral head (ONFH) is a debilitating orthopedic disorder that predominantly affects young adults and has a multifactorial etiology. In mining-intensive regions such as Katanga (Democratic Republic of the Congo), chronic exposure to trace metal elements (TMEs) has raised concerns about potential environmental contributors to bone disease. This study aimed to investigate the association between bone TME accumulation and the occurrence of idiopathic ONFH in an environmentally exposed population. A case-control study was conducted between 2017 and 2025 at Medpark Clinic, Lubumbashi. Femoral head specimens were collected from 56 patients undergoing total hip arthroplasty, including 36 cases of idiopathic ONFH and 20 controls with primary osteoarthritis. Bone concentrations of eleven TMEs (Pb, Co, Cd, Cr, Zn, Cu, As, Mn, Mg, Ni, Al) were quantified using inductively coupled plasma-optical emission spectrometry (ICP-OES). Exposure was defined as a Z-score > 2 compared with a local reference population. Bivariate and multivariate logistic regression analyses were performed to assess associations. Patients with ONFH were significantly younger than controls (mean age: 49.5 vs. 62.9 years; p = 0.004). Bone concentrations of lead and cobalt were markedly higher in ONFH cases. In multivariate analysis, elevated bone lead levels (adjusted OR = 23.75; 95% CI: 2.30-181.57) and age ≤ 50 years were independently associated with ONFH. No significant associations were found for other TMEs. This study provides the first direct evidence that chronic bone accumulation of lead and cobalt is strongly associated with idiopathic ONFH in a mining-exposed African population. These findings highlight the urgent need for environmental monitoring, targeted public health interventions, and early clinical surveillance in high-risk regions.

Idiopathic osteonecrosis of the femoral head (ONFH) can be correctly diagnosed in accordance with the established criteria. However, some general orthopedic physicians have misdiagnosed patients as having ONFH. The goal of this study was to clarify the radiologic and clinical features of misdiagnosed patients. This study included 50 patients who were referred to the authors' hospital by general physicians with a diagnosis of ONFH. The correct diagnosis was made based on the Japanese Investigation Committee diagnostic criteria for ONFH. Demographic data were compared between patients with and without ONFH. Of the 50 patients, 24 were diagnosed with other diseases: 10 with osteoarthritis, 7 with transient osteoporosis of the femoral head, 4 with rapidly destructive coxopathy, and 3 with subchondral insufficiency fracture. Seventeen patients who did not have ONFH had magnetic resonance imaging findings that showed a bone marrow edema pattern at the femoral head. The mean age of 62.9 years among patients without ONFH was significantly higher than that of 45.2 years among patients with ONFH. There were 18 female patients in the non-ONFH group and 5 female patients in the ONFH group. Bilateral disease was found in 1 patient in the non-ONFH group and 17 patients in the ONFH group. No patients in the non-ONFH group had a history of systemic steroid administration compared with 11 patients in the ONFH group. Clinical features associated with the non-ONFH group were female sex, older age, unilateral disease, and no history of systemic steroid administration. For patients with these features, the diagnosis of ONFH should be made carefully. [Orthopedics. 2017; 40(1):e117-e123.].

Osteonecrosis of the femoral head (ONFH) is a multifactorial disease and is associated with genetic predisposition, and exposure to certain risk factors. In particular, idiopathic ONFH in twins and the clustering of cases in families have indicated that genetic factors are involved. However, the majority of cases of ONFH are sporadic and various studies have demonstrated that differences in the study design and/or the ethnic groups analyzed leads to different results. The present study performed one of the first genome-wide association studies to identify genetic loci that may increase the risk of idiopathic ONFH. In total, 217 patients with idiopathic ONFH and 217 control samples, without ONFH, were genotyped using Axiom™ chips. Following quality control, 509,886 single-nucleotide polymorphisms (SNPs) were included in the association analysis to identify genetic variants that may influence susceptibility to idiopathic ONFH. The lowest P-value identified by the current study was for an association with rs220324 (P=3.57×10-7), an SNP that is located near to the uromodulin-like 1 gene region on chromosome 21q22.3, although none of the SNPs reached the traditional genome-wide significance level of 5×10–8. However, the DnaJ heat shock protein family (Hsp40) member C6 (DNAJC6) locus, a region between 65.37 and 65.67 Mb located on chromosome 1p31.3, harbored a cluster of SNPs that were associated with idiopathic ONFH at a significance level of P<1×10–5. Four variants, rs10493374, rs12032616, rs17127529 and rs6679032, with marginal associations were located in and around the DNAJC6 locus and were in strong linkage disequilibrium with each other. In conclusion, the current study did not identify any SNPs that were associated with idiopathic ONFH at a genome-wide significance level, however, the results suggest that future studies should investigate the effects of SNPs in the DNAJC6 gene on the idiopathic ONFH risk.

BackgroundThis study examined whether use of a specific questionnaire sheet for nontraumatic osteonecrosis of the femoral head (ONFH) could affect the subclassification of ONFH compared with a conventional medical interview.Material/MethodsStudy participants consisted of 400 patients with ONFH who visited our hospital between February 2011 and March 2015. Data on history of systemic steroid therapy and habitual alcohol intake were obtained during a conventional medical interview at the first visit and were re-evaluated using a specific questionnaire sheet at another visit. Patients were subclassified into 4 groups: steroid-associated, alcohol-associated, steroid/alcohol-associated, or idiopathic ONFH.ResultsUse of the specific questionnaire sheet resulted in a 4.0% increase in the proportion of patients with a history of systemic steroid therapy, from 57.3% (n=229) to 61.3% (n=245), and a 14.3% increase for history of habitual alcohol intake, from 35.0% (n=140) to 49.3% (n=197). The proportion of patients with steroid/alcohol-associated ONFH increased from 2.5% (n=10) to 17.8% (n=71), while the proportion in the other 3 groups decreased: steroid-associated ONFH from 54.8% (n=219) to 43.5% (n=174); alcohol-associated ONFH from 32.5% (n=130) to 31.5% (n=126); and idiopathic ONFH from 10.2% (n=41) to 7.2% (n=29). Ninety-six patients (24.0%) were classified into a different subgroup based on the specific questionnaire sheet.ConclusionsThe use of a specific questionnaire sheet can change the distribution of ONFH subclassifications compared with use of a conventional medical history interview. Use of a specific questionnaire sheet can allow for more detailed self-reporting regarding potential causative factors for nontraumatic ONFH, especially habitual alcohol intake.

Ischemic stroke prompts a strong inflammatory response which is associated with exacerbated stroke outcomes. However, classic anti-inflammatory strategies have been unsuccessful in stroke patients implying other unknown mechanisms contribute to injurious inflammation in stroke. Increasing evidence suggests immunothrombosis, a process involving coagulation, neutrophil and platelet activation, and neutrophil extracellular trap (NET) formation, is an important contributor to cardiovascular diseases. However, mechanistic regulators of immunothrombosis and their role in ischemic stroke remain unclear. We examined markers of immunothrombosis in ischemic stroke patients and matched healthy donors. Stroke patients had significantly increased levels of D-Dimers, platelet factor 4, neutrophil calprotectin, citrullinated histone H3 (H3cit) and MPO-DNA complexes, markers of NET formation. In particular, H3cit and MPO-DNA complexes positively correlated with long-term stroke outcomes. Mechanistically, we observed increased plasma and platelet HMGB1 in stroke patients, which significantly correlated with plasma NETs, indicating a role for platelet HMGB1 in NET formation. To directly examine the role of platelet HMGB1, we employed a transient ischemic stroke mouse model. Depleting platelets significantly reduced plasma HMGB1 levels, inhibited NET formation and improved stroke outcomes. Correspondingly, administrating a HMGB1 inhibitor reduced NET formation and improved stroke outcomes, implying a causative role for platelet HMGB1 in mediating NET formation after stroke. As NETs appeared detrimental in ischemic stroke, we investigated the therapeutic potential of an endogenous NET inhibitory factor (NIF), recently discovered in neonates. Mice pretreated with NIF had reduced brain injury, improved neurological and motor function and enhanced survival after stroke. Importantly, NIF specifically blocked NET formation after stroke without affecting brain neutrophil recruitment. Critically, NIF still improved stroke outcomes when administered after stroke onset. These results support a pathological role for NETs in stroke brain injury and indicate the use of NIF as a therapeutic strategy to target immunothrombosis in stroke.

There have been few studies investigating the cumulative effect of individual factors related to bone metabolism on the systemic balance between bone formation and resorption in patients with osteonecrosis of the femoral head (ONFH). We investigated bone mineral density (BMD) of lumbar spine and bone turnover markers that reflect systemic bone metabolism. Two-hundred twenty patients with ONFH were matched to 220 healthy subjects according to age, gender, and body mass index. ONFH patients were divided into steroid-induced (18%), alcoholic (21%), and idiopathic ONFH (61%) and subgroup analysis was performed to exclude the effect of steroid and malnutrition on bone metabolism. We compared lumbar spine bone mineral density (BMD) between groups and measured serum bone-specific alkaline phosphatase (BALP) and urinary deoxypyridinoline/creatinine (Dpd/Cr) ratio. Logistic regression analysis revealed low spine BMD was significantly associated with each subgroup of ONFH when compared with that of the control group (odds ratio of 2.27, 4.24, and 1.86 in alcoholic, steroid, and idiopathic ONFH, respectively). The mean value of serum BALP (27.02U/L) was within the normal reference range while average urine Dpd/Cr ratio (6.24nM/mM) increased in ONFH group when compared with respective reference range. Spine BMD decreased and urinary Dpd/Cr ratio increased in patients with non-traumatic ONFH. Further studies will be necessary to identify whether non-traumatic ONFH is merely a regional disease confined to the femoral head or may affect systemic bone metabolism.

Heme-Induced Neutrophil Extracellular Traps (NETs) Formation Contributes To Sickle Cell Disease Pathogenesis

A Novel Assay of Neutrophil Extracellular Traps (NETs) Formation Independently Predicts DIC and Identifies the Rationale for Anti-IL-8 Therapies

PurposeNitric oxide (NO) synthesised by endothelial NO synthase (eNOS) is a potent regulator of internal haemodynamics. A polymorphism in intron 4 of the eNOS is associated with different vascular disorders. We investigated the potential involvement of this polymorphism in idiopathic and secondary osteonecrosis of the femoral head (ONFH) in Polish patients.MethodsWe performed a study involving 68 patients with ONFH (45 idiopathic and 23 secondary) and 100 healthy controls. All subjects were genotyped for the eNOS4 polymorphism by the polymerase chain reaction followed by agarose gel electrophoresis.ResultsThe analysis revealed that the frequencies of eNOS4 genotypes were significantly different in ONFH patients (both idiopathic and secondary) than in controls. The frequencies of the 4a allele were significantly higher in the total group of patients versus controls [22.79 vs 9 %, p = 0.00039, odds ratio (OR) 2.98]. In subgroup analysis the 4a allele increased significantly in both idiopathic (20 vs 9 %, p = 0.0074, OR = 2.52) and secondary (28.26 vs 9 %, p = 0.00047, OR = 3.98) ONFH patients compared to control subjects. The frequency of the 4a/b genotype in the total group of patients (36.76 vs 16 %, p = 0.0011, OR = 3.24) as well as patients with idiopathic (35.56 vs 16 %, p = 0.0069, OR = 2.96) and secondary (39.13 vs 16 %, p = 0.0073, OR = 3.89) ONFH was higher than in the control group.ConclusionsThere was a significantly higher frequency of eNOS 4a allele carriers among the total group of patients as well as in idiopathic and secondary ONFH. This suggests that the eNOS gene polymorphism may be associated with increased risk of ONFH.

BackgroundIn this retrospective case investigation, we analysed the data of patients with osteonecrosis of the femoral head (ONFH) to reveal demographic and clinical diagnostic features of ONFH in three northeastern provinces of China and provide a reference for its prevention, diagnosis, and treatment.MethodsWe collected data from patients in Beijing Orthopaedic Hospital of Liaoning, focusing on the aetiology and diagnosis of ONFH. Medical records and self-designed questionnaires were used to collect information for statistical analysis, including age, aetiology, reason for glucocorticoid use, hospital level at first visit, and diagnosis.ResultsIn total, 906 patients with complete medical records were included in the analysis. The mean patient age was 47.65 ± 12.12 years. The peak age distribution was in the 40s for men and the 50s for women. Among the total cohort, 72 patients (7.95%; 40 men and 32 women) had traumatic ONFH, 198 (21.85%; 131 men and 67 women) had steroid-induced ONFH, 230 (25.39%; 121 men and 109 women) had idiopathic ONFH, and 406 (44.81%; 397 men and 9 women) had alcohol-induced ONFH. Six hundred and twenty patients were diagnosed with ONFH at the first visit, while 286 patients were misdiagnosed, with a diagnosis rate of 68.43%. The diagnosis rate at the first visit in tertiary hospitals was 76.14%. The diagnosis rate at the first visit in second-class hospitals was 52.07%.ONFH was most likely to be misdiagnosed as lumbar disc herniation.ConclusionsMost patients with ONFH in three northeastern provinces of China were middle-aged, male, and had alcohol-induced ONFH. The misdiagnosis rate of ONFH at the first visit was very high, especially for misdiagnosis of lumbar disc herniation, indicating that the diagnosis of ONFH requires further improvement.

Secretoglobin family 1A member 1 (SCGB 1A1) is a small protein mainly secreted by mucosal epithelial cells of the lungs and uterus. SCGB 1A1, also known as club (Clara) cell secretory protein, represents a major constituent of airway surface fluid. The protein has anti-inflammatory properties, and its concentration is reduced in equine recurrent airway obstruction (RAO) and human asthma. RAO is characterized by reversible airway obstruction, bronchoconstriction and neutrophilic inflammation. Direct effects of SCGB 1A1 on neutrophil functions are unknown. We have recently identified that the SCGB1A1 gene is triplicated in equids and gives rise to two distinct proteins. In this study we produced the endogenously expressed forms of SCGBs (SCGB 1A1 and 1A1A) as recombinant proteins, and analyzed their effects on reactive oxygen species production, phagocytosis, chemotaxis and neutrophil extracellular trap (NET) formation ex vivo. We further evaluated whether NETs are present in vivo in control and inflamed lungs. Our data show that SCGB 1A1A but not SCGB 1A1 increase neutrophil oxidative burst and phagocytosis; and that both proteins markedly reduce neutrophil chemotaxis. SCGB 1A1A reduced chemotaxis significantly more than SCGB 1A1. NET formation was significantly reduced in a time- and concentration-dependent manner by SCGB 1A1 and 1A1A. SCGB mRNA in bronchial biopsies, and protein concentration in bronchoalveolar lavage fluid, was lower in horses with RAO. NETs were present in bronchoalveolar lavage fluid from horses with exacerbated RAO, but not in fluid from horses with RAO in remission or in challenged healthy horses. These findings indicate that SCGB 1A1 and 1A1A have overlapping and diverging functions. Considering disparities in the relative abundance of SCGB 1A1 and 1A1A in airway secretions of animals with RAO suggests that these functional differences may contribute to the pathogenesis of RAO and other neutrophilic inflammatory lung diseases.

BackgroundRenal involvement in ANCA-associated vasculitis (AAV) and systemic lupus erythematosus (SLE) manifests as autoimmune-mediated glomerulonephritis (AIGN). In AAV, crescentic lesions and a pauci-immune immunofluorescence is typically seen while in SLE...

Thrombosis in Myeloproliferative Neoplasms Is Linked to Increased Neutrophil Extracellular Trap (NET) Formation