An aberrant immune-epithelial progenitor niche drives viral lung sequelae.

The long-term physiological consequences of respiratory viral infections, particularly in the aftermath of the COVID-19 pandemic-termed post-acute sequelae of SARS-CoV-2 (PASC)-are rapidly evolving into a major public health concern1-3. While the cellular and molecular aetiologies of these sequelae are poorly defined, increasing evidence implicates abnormal immune responses3-6 and/or impaired organ recovery7-9 after infection. However, the precise mechanisms that link these processes in the context of PASC remain unclear. Here, with insights from three cohorts of patients with respiratory PASC, we established a mouse model of post-viral lung disease and identified an aberrant immune-epithelial progenitor niche unique to fibroproliferation in respiratory PASC. Using spatial transcriptomics and imaging, we found a central role for lung-resident CD8+ T cell-macrophage interactions in impairing alveolar regeneration and driving fibrotic sequelae after acute viral pneumonia. Specifically, IFNγ and TNF derived from CD8+ T cells stimulated local macrophages to chronically release IL-1ß, resulting in the long-term maintenance of dysplastic epithelial progenitors and lung fibrosis. Notably, therapeutic neutralization of IFNγ + TNF or IL-1ß markedly improved alveolar regeneration and pulmonary function. In contrast to other approaches, which require early intervention10, we highlight therapeutic strategies to rescue fibrotic disease after the resolution of acute disease, addressing a current unmet need in the clinical management of PASC and post-viral disease.

Predicting the conversion from clinically isolated syndrome to multiple sclerosis: An explainable machine learning approach.

INTRODUCTION: Predicting the conversion of clinically isolated syndrome (CIS) to clinically definite multiple sclerosis (CDMS) is critical to personalizing treatment planning and benefits for patients. The aim of this study is to develop an explainable machine learning (ML) model for predicting this conversion based on demographic, clinical, and imaging data. METHOD: The ML model, Extreme Gradient Boosting (XGBoost), was employed on the public dataset of 273 Mexican mestizo CIS patients with 10-year follow-up. The data was divided into a training set for cross-validation and feature selection, and a holdout test set for final testing. Feature importance was determined using the SHapley Additive Explanations library (SHAP). Then, two experiments were conducted to optimize the model's performance by selectively adding variables and selecting the most contributive variables for the final model. RESULTS: Nine variables including age, gender, schooling, motor symptoms, infratentorial and periventricular lesion at imaging, oligoclonal band in cerebrospinal fluid, lesion and symptoms types were significant. The model achieved an accuracy of 83.6 %, AUC of 91.8 %, sensitivity of 83.9 %, and specificity of 83.4 % in cross-validation. In the final testing, the model achieved an accuracy of 78.3 %, AUC of 85.8 %, sensitivity of 75 %, and specificity of 81.1 %. Finally, a web-based demo of the model was created for testing purposes. CONCLUSION: The model, focusing on feature selection and interpretability, effectively stratifies risk for treatment decisions and disability prevention in MS patients. It provides a numerical risk estimate for CDMS conversion, enhancing transparency in clinical decision-making and aiding in patient care.

Evaluating the application of argon laser on pterygium surgery: Report of 30 patients.

BACKGROUND: The recurrence rate plays a key role in using various treatments of pterygium. This study assessed the effectiveness of argon laser therapy before the excision of pterygium on the recurrence rate. MATERIALS AND METHODS: The eyes (n = 60) of patients (n = 30) were divided into two groups based on the treatment. All eyes had undergone pterygium excision with the bare sclera technique. Three weeks before surgery, an argon laser was applied to 30 eyes. Patients have been followed up for 1 year, and the progression of pterygium has been evaluated at days 1, 7, 14, and 30, and then, every 2 months until month 6 and then every 3 months until month 12. Recurrence was defined as more than 1 mm growth of pterygium from the limbus. RESULTS: In the group with adjuvant argon laser therapy, the mean size of pterygium was 3.7 ± 0.47 mm before surgery and 2.3 ± 0.98 after 12 months (P = 0.001). These were 3.8 ± 0.43 mm and 2.4 ± 1 mm in the other group (P = 0.001). The recurrence of the pterygium was 76% (23/30) in the group treated with an argon laser and 90% (27/30) in another group (P = 0.16). There was no correlation between pterygium sizes before surgery and the pterygium recurrence rate in both eyes (P = 0.272 [right] and 0.916 [left]). CONCLUSION: Argon laser therapy on pterygium before surgery cannot decrease its recurrence rate, but its application gives a good vision and clarifies the surgery's target area.

Proximal immune-epithelial progenitor interactions drive chronic tissue sequelae post COVID-19.

The long-term physiological consequences of SARS-CoV-2, termed Post-Acute Sequelae of COVID-19 (PASC), are rapidly evolving into a major public health concern. The underlying cellular and molecular etiology remain poorly defined but growing evidence links PASC to abnormal immune responses and/or poor organ recovery post-infection. Yet, the precise mechanisms driving non-resolving inflammation and impaired tissue repair in the context of PASC remain unclear. With insights from three independent clinical cohorts of PASC patients with abnormal lung function and/or viral infection-mediated pulmonary fibrosis, we established a clinically relevant mouse model of post-viral lung sequelae to investigate the pathophysiology of respiratory PASC. By employing a combination of spatial transcriptomics and imaging, we identified dysregulated proximal interactions between immune cells and epithelial progenitors unique to the fibroproliferation in respiratory PASC but not acute COVID-19 or idiopathic pulmonary fibrosis (IPF). Specifically, we found a central role for lung-resident CD8+ T cell-macrophage interactions in maintaining Krt8hi transitional and ectopic Krt5+ basal cell progenitors, thus impairing alveolar regeneration and driving fibrotic sequelae after acute viral pneumonia. Mechanistically, CD8+ T cell derived IFN-γ and TNF stimulated lung macrophages to chronically release IL-1ß, resulting in the abnormal accumulation of dysplastic epithelial progenitors and fibrosis. Notably, therapeutic neutralization of IFN-γ and TNF, or IL-1ß after the resolution of acute infection resulted in markedly improved alveolar regeneration and restoration of pulmonary function. Together, our findings implicate a dysregulated immune-epithelial progenitor niche in driving respiratory PASC. Moreover, in contrast to other approaches requiring early intervention, we highlight therapeutic strategies to rescue fibrotic disease in the aftermath of respiratory viral infections, addressing the current unmet need in the clinical management of PASC and post-viral disease.

Proximal immune-epithelial progenitor interactions drive chronic tissue sequelae post COVID-19.

The long-term physiological consequences of SARS-CoV-2, termed Post-Acute Sequelae of COVID-19 (PASC), are rapidly evolving into a major public health concern. The underlying cellular and molecular etiology remain poorly defined but growing evidence links PASC to abnormal immune responses and/or poor organ recovery post-infection. Yet, the precise mechanisms driving non-resolving inflammation and impaired tissue repair in the context of PASC remain unclear. With insights from three independent clinical cohorts of PASC patients with abnormal lung function and/or viral infection-mediated pulmonary fibrosis, we established a clinically relevant mouse model of post-viral lung sequelae to investigate the pathophysiology of respiratory PASC. By employing a combination of spatial transcriptomics and imaging, we identified dysregulated proximal interactions between immune cells and epithelial progenitors unique to the fibroproliferation in respiratory PASC but not acute COVID-19 or idiopathic pulmonary fibrosis (IPF). Specifically, we found a central role for lung-resident CD8+ T cell-macrophage interactions in maintaining Krt8hi transitional and ectopic Krt5+ basal cell progenitors, thus impairing alveolar regeneration and driving fibrotic sequelae after acute viral pneumonia. Mechanistically, CD8+ T cell derived IFN-γ and TNF stimulated lung macrophages to chronically release IL-1ß, resulting in the abnormal accumulation of dysplastic epithelial progenitors and fibrosis. Notably, therapeutic neutralization of IFN-γ and TNF, or IL-1ß after the resolution of acute infection resulted in markedly improved alveolar regeneration and restoration of pulmonary function. Together, our findings implicate a dysregulated immune-epithelial progenitor niche in driving respiratory PASC. Moreover, in contrast to other approaches requiring early intervention, we highlight therapeutic strategies to rescue fibrotic disease in the aftermath of respiratory viral infections, addressing the current unmet need in the clinical management of PASC and post-viral disease.

Comparative Evaluation of Tacrolimus Versus Interferon Alpha-2b Eye Drops in the Treatment of Vernal Keratoconjunctivitis: A Randomized, Double-Masked Study.

PURPOSE: Vernal keratoconjunctivitis (VKC) is a bilateral, chronic, external ocular inflammatory disorder that mainly affects patients in their first or second decade. This study was designed to compare tacrolimus and interferon alpha-2b (IFN alpha-2b) eye drops in the treatment of VKC. METHODS: In this randomized, double-masked clinical trial, 40 consecutive patients with VKC were sent to a referral eye hospital in a tropical region southeast of Iran. Patients were randomly assigned to receive either 0.005% tacrolimus or IFN alpha-2b (1,000,000 units/cc). Chi-square and t tests were used for comparison of outcomes between both groups. RESULTS: Mean ± SD age was 11.1 ± 5.2 years. Thirty-one patients (77.5%) were male. The mean duration of disease was 3.4 ± 2.9 years. In this study, the signs and symptoms were significantly reduced in patients after treatment in both groups (P = 0.0001). In the tacrolimus group, all patients responded to treatment whereas only one subject in the IFN group failed to respond (P = 0.99). Side effects in both groups were mild and tolerable. CONCLUSIONS: This study indicated that both 0.005% tacrolimus and IFN alpha-2b are effective and appear to be safe in treatment of recalcitrant VKC.

A novel approach to investigation of the pathogenesis of pterygium based on assessment of promoter hyper-methylation and expression profile of CTLA4 gene: A credible report of CTLA4 gene expression in human eye tissue.

BACKGROUND: Pterygium is the human eye lesion whose prevalence in the general population is estimated about 2%. The disease, in extreme phase, can lead to visual disturbance and eventually causes complete loss of vision due to the lesion growth over the papillary axis. Pterygium invasive tissue is a tumor-like tissue that is initially identified and then is attacked by cytotoxic T cells. Cytotoxic T lymphocyte associated antigen 4 (CTLA4), as a modulator molecule of the adaptive immune system, plays a critical role in maintaining peripheral T cell tolerance by diminishing its responsiveness and increasing its activation threshold. The aim of this study is to investigate the association between some epigenetic changes of the CTLA4 gene, such as promoter methylation and gene expression, and pathogenesis of pterygia. MATERIALS AND METHODS: Genomic DNA was extracted from 75 formalin-fixed, paraffin-embedded tissues of pterygia and 70 specimens of normal conjunctiva from eyes without pterygium as the control group, collected from Sistan and Baluchestan population. CTLA4 gene promoter methylation was carried out by methylation-specific PCR technique. The gene expression analysis was done on extracted total RNA from 20 healthy and 23 pterygium tissue samples using Real-Time PCR technique. RESULTS: Promoter methylation changes of CTLA4 gene were not statistically different in patients with pterygium in comparison with healthy controls (OR=1.614; 95% CI=0.57-4.75; P value=0.37). However, gene expression level of CTLA4 was remarkably different in patients and healthy controls (Mean±SD: 1.343±0.133 and 2.027±0.219, respectively; P value=0.009). CONCLUSION: This is a credible evidence of CTLA4 gene expression in human eye tissue. This first hand attempt of investigating the association of epigenetic changes of the CTLA4 gene and pathogenesis of pterygia, indicated a significant intensification of the gene expression of CTLA4 in patients with pterygia. We suggest that increasing CTLA4 gene expression can be a trigger which promotes pterygium enlargement. However, further studies on more populations with larger sample sizes need to be done to verify this hypothesis in the future.