Association of stem cell factor gene expression with severity and atopic state in patients with bronchial asthma

Pulmonary immune profiling reveals common inflammatory endotypes of childhood wheeze and suppurative lung disease

Suppurative lung disease and wheezing are common respiratory diseases of childhood, however, due to poor understanding of underlying pathobiology, there are limited treatment options and disease recurrence is common. We aimed to profile the pulmonary and systemic immune response in children with wheeze and chronic suppurative lung disease for identification of endotypes that can inform improved clinical management. We used clinical microbiology data, highly multiplexed flow cytometry and immunoassays to compare pulmonary [bronchoalveolar lavage (BAL)] and systemic immunity in children with lung disease and controls. Unsupervised analytical approaches were applied to BAL immune data to explore biological endotypes. We identified two endotypes that were analogous in both frequency and immune signature across both respiratory diseases. The hyper-inflammatory endotype had a 12-fold increase in neutrophil infiltration and upregulation of 14 soluble signatures associated with type 2 inflammation and cell recruitment to tissue. The non-inflammatory endotype was not significantly different from controls. We showed these endotypes are measurable in a clinical setting and can be defined by measuring only three immune factors in BAL. We identified hyper-inflammatory and non-inflammatory endotypes common across pediatric wheeze and chronic suppurative lung disease that, if validated in future studies, have the potential to inform clinical management.

Stem cell factor inhibition reduces Th2 inflammation and cellular infiltration in a mouse model of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a T helper (Th)2-mediated inflammatory disorder characterized endoscopically by eosinophilic infiltration leading to fibrosis of the esophagus. Stem cell factor (SCF), a multifunctional cytokine, is upregulated in several allergic diseases, including in patients with EoE. Mast cells and eosinophils express c-kit, the cell surface receptor for SCF, and have been found to play an important role in EoE. Therefore, we investigated whether blocking SCF represents a potential therapeutic approach for EoE. Esophageal inflammation was induced in mice using peanut allergen. In mice with experimental EoE, we found that SCF was upregulated in the esophageal tissue. In EoE mice injected with a polyclonal antibody specific for SCF, we observed a decrease in both mast cells and eosinophils by histological and flow cytometric analysis. Furthermore, Th2 cytokines in the esophagus were decreased in anti-SCF treated mice, as were levels of Th2 cytokines from lung-draining and esophageal lymph nodes. Serum levels of peanut-specific immunoglobulin E were reduced following treatment with anti-SCF. In Kitlf/f-Col1-Cre-ERT mice, which have SCF deleted primarily in myofibroblasts that develop in EoE, we observed similar results as the anti-SCF treated animals for inflammatory cell accumulation, cytokines, and histopathology. These results indicate that therapeutic treatments targeting SCF can reduce allergic inflammation in EoE.

Asymptomatic Survivors of Childhood Acute Lymphoblastic Leukemia Demonstrate a Biological Profile of Inflamm-Aging Early in Life

Childhood acute lymphoblastic leukemia (ALL) survivors are at higher risk of developing many late effects later in life. They experience multiple health problems that have significant public health implications, such as frailty, premature onset of lifestyle diseases, and second tumors. There is some evidence that chronic inflammation causes accelerated aging in childhood cancer survivors; however, the available data are very limited. The aim of the study was to evaluate the broad panel of cytokines among asymptomatic ALL survivors after anticancer treatment. The study included 56 subjects with a mean age of 16.11 ± 3.98 years. The commercially available Bio-Plex Pro Human Cytokine Screening 48-Plex Panel Assay and Bio-Plex TGF-β Assay were used for simultaneous determination of 48 cytokines and 3 isoforms of TGF-β. Among 51 tested cytokines, the levels of 33 were statistically significantly higher in ALL survivors than in the control group (p < 0.05). Increased levels of pro-inflammatory cytokines, including the IL-1 family (IL-1 β, IL-1Ra; p < 0.0001), IL-6 (p < 0.001), IL-17 (p < 0.001), IL-18 (p < 0.05), TNFα (p < 0.01), IFNα2 (p < 0.05), and IFNγ (p < 0.01), were found elevated in the entire study group, compared with the controls. Subjects treated previously according to the high-risk protocol had higher IL-18 levels than low- and intermediate-risk groups (p < 0.05). Elevated levels of IL-1ra, IL-6, IL-12 (p70), IL-17, LIF, M-CSF, CSF, and VEGF were found in ALL survivors treated before the age of 5, compared with subjects treated over 5 years of age (p < 0.05). Moreover, individuals who received radiotherapy presented elevated levels of both IL-18 (p < 0.05) and MIG (p < 0.05). In conclusion, we found that young asymptomatic survivors after ALL treatment demonstrated a biological profile of complex low-grade chronic inflammation.

Drug-Induced Mast Cell Eradication: A Novel Approach to Treat Mast Cell Activation Disorders?

Mast cell activation is a key event in allergic reactions, other inflammatory states, and mast cell activation syndromes. Mast cell-stabilizing agents, mediator-targeting drugs and drugs interfering with mediator effects are often prescribed in these patients. However, the clinical efficacy of these drugs varies, depending on the numbers of involved mast cells and the underlying pathology. One straightforward approach would be to eradicate the primary target cell. However, to date, no mast cell-eradicating treatment approach has been developed for patients suffering from mast cell activation disorders. Nevertheless, recent data suggest that long-term treatment with agents that effectively inhibit KIT-function results in the virtual eradication of tissue mast cells and a sustained decrease in serum tryptase levels. In many of these patients, mast cell depletion is associated with a substantial improvement in mediator-induced symptoms. In patients with an underlying KIT D816V+ mastocytosis, such mast cell eradication requires an effective inhibitor of KIT D816V, such as avapritinib. However, the use of KIT inhibitors must be balanced against potential side effects. We here discuss mast cell-eradicating strategies in various disease models, the feasibility of this approach, available clinical data, and future prospects for the use of KIT-targeting drugs in mast cell activation disorders.

The association of stem cell factor and soluble c-Kit (s-cKit) receptor serum concentrations with the severity and risk prediction of autism spectrum disorders

S tem cell factor (SCF) and its receptor (c-kit) signaling play important role in normal brain physiology including neurogenesis, synapse formation and spatial learning function of the hippocampal region of the brain. Autism spectrum disorder (ASD) is believed to result from abnormal development of neuronal networks and synaptic function. The aim of this study was to evaluate the SCF and its soluble receptor (s-ckit) serum concentrations in ASD. We also studied the serum SCF and s-ckit concentration with the severity of ASD (Levels 1-3; Mild, Moderate and severe, respectively). Ninety five patients with ASD (Mild; n=33, Moderate; n=32 and severe; n=30) and 82 normal controls age matched were included in this study. The serum concentration of SCF and s-ckit were measured by enzyme-linked immunosorbent assay (ELISA). The SCF serum concentration in control subjects was 3.45±1.06 ng/ml and in ASD was 3.41±0.92 ng/ml (P=0.88). The serum levels of s-ckit in control and ASD groups were 56.82±13.22 ng/ml and 67.11±12.00, respectively (P=001). We have also studied serum SCF and s-ckit concentrations with the severity of ASD. The serum concentration of SCF in mild, moderate and severe ASD groups was 3.45±0.93, 3.4±0.87 and 3.43±0.98 ng/ml, respectively (P>0.05) and for s-ckit was 48.77±9.28, 61.66±12.18 and 93.11±14.81ng/ml, respectively (P<0.05). The result of this study suggests that serum s-cKit concentrations may provide a reliable and practical indicator of ASD and positively correlated with disease severity. It is also concluded that s-cKit might be involved in the pathophysiology of ASD.

Lung Function in African American Children with Asthma Is Associated with Novel Regulatory Variants of the KIT Ligand KITLG/SCF and Gene-By-Air-Pollution Interaction

Baseline lung function, quantified as forced expiratory volume in the first second of exhalation (FEV1), is a standard diagnostic criterion used by clinicians to identify and classify lung diseases. Using whole-genome sequencing data from the National Heart, Lung, and Blood Institute Trans-Omics for Precision Medicine project, we identified a novel genetic association with FEV1 on chromosome 12 in 867 African American children with asthma (P = 1.26 × 10-8, β = 0.302). Conditional analysis within 1 Mb of the tag signal (rs73429450) yielded one major and two other weaker independent signals within this peak. We explored statistical and functional evidence for all variants in linkage disequilibrium with the three independent signals and yielded nine variants as the most likely candidates responsible for the association with FEV1 Hi-C data and expression QTL analysis demonstrated that these variants physically interacted with KITLG (KIT ligand, also known as SCF), and their minor alleles were associated with increased expression of the KITLG gene in nasal epithelial cells. Gene-by-air-pollution interaction analysis found that the candidate variant rs58475486 interacted with past-year ambient sulfur dioxide exposure (P = 0.003, β = 0.32). This study identified a novel protective genetic association with FEV1, possibly mediated through KITLG, in African American children with asthma. This is the first study that has identified a genetic association between lung function and KITLG, which has established a role in orchestrating allergic inflammation in asthma.

Serum level of stem cell factor and its soluble receptor in aspirin-exacerbated respiratory disease

Aim: Stem cell factor (SCF) may be associated with inflammatory processes leading to aspirin-induced asthma. This study evaluated the relationship between serum level of SCF and its soluble receptor with aspirin-induced asthma. Methods & materials: Twenty-five patients and 25 healthy controls were enrolled in this study. The concentration of SCF and mast/stem cell growth factor receptor (C-kit) was determined in serum samples. Spirometry and rhinometry were performed to determine the severity of the disease. p < 0.05 were considered significant. Results: The serum levels of SCF and C-kit receptor were significantly higher in the case group. The serum SCF and C-kit level had a significant positive correlation with the severity of asthma, disease duration and nasal obstruction. Conclusion: Our findings suggest that SCF and C-kit receptors have a direct effect on the severity of aspirin-induced asthma.

Prognostic and Clinic-Pathological Significances of SCF and COX-2 Expression in Inflammatory and Malignant Prostatic Lesions

The initiation of prostatic malignancy has been linked to chronic inflammation. Stem cell factor (SCF) is an inflammatory cytokine that is specific to the c-KIT receptor which is type III receptor tyrosine kinase (RTK). Cyclooxygenases (COXs) are the main enzymes which are responsible for prostaglandins production from arachidonic acid. COX2 is an enzyme which is produced under different pathological conditions. The aim of our study; is to investigate the clinicopathological and the prognostic significance of SCF and COX-2 expression in prostatic adenocarcinoma (PC), chronic prostatitis and nodular prostatic hyperplasia (NPH) in a trial to clarify the role of inflammation as a risk factor for prostatic carcinogenesis and cancer progression. SCF and COX-2 tissue protein expression were evaluated in 50 cases of PC, 20 cases of chronic prostatitis and 10 cases of NPH using immunohistochemistry, patients were followed up for 5 years. The relationship between their levels of expressions, clinicopathological, and prognostic criteria were studied. SCF expression in PC was positively correlated with advanced patient age (p = <0.001), high level of PSA (p = 0.010), higher Gleason score (p = 0.011). COX-2 expression in PC was positively correlated with advanced patient age (p = <0.001), high level of PSA (p = 0.016), advanced D'Amico risk group (p = 0.038). High levels of expression of both SCF& COX-2 are associated with higher incidence of tumor relapse, worse disease overall survival and free survival (p < 0.001). SCF and COX-2 are associated with PC progression and associated with poor prognosis in PC patients.