Evaluation of serum interleukin-6 (IL-6), IL-13, and IL-17 levels and computed tomography finding in interstitial lung disease associated with connective tissue disease patients

Immunotherapy for Pulmonary Arterial Hypertension: From the Pathogenesis to Clinical Management

Pulmonary hypertension (PH) is a progressive cardiovascular disease, which may lead to severe cardiopulmonary dysfunction. As one of the main PH disease groups, pulmonary artery hypertension (PAH) is characterized by pulmonary vascular remodeling and right ventricular dysfunction. Increased pulmonary artery resistance consequently causes right heart failure, which is the major reason for morbidity and mortality in this disease. Although various treatment strategies have been available, the poor clinical prognosis of patients with PAH reminds us that further studies of the pathological mechanism of PAH are still needed. Inflammation has been elucidated as relevant to the initiation and progression of PAH, and plays a crucial and functional role in vascular remodeling. Many immune cells and cytokines have been demonstrated to be involved in the pulmonary vascular lesions in PAH patients, with the activation of downstream signaling pathways related to inflammation. Consistently, this influence has been found to correlate with the progression and clinical outcome of PAH, indicating that immunity and inflammation may have significant potential in PAH therapy. Therefore, we reviewed the pathogenesis of inflammation and immunity in PAH development, focusing on the potential targets and clinical application of anti-inflammatory and immunosuppressive therapy.

Expression and diagnostic value of interleukin-22 in rheumatoid arthritis-associated interstitial lung disease

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is characterized by a high incidence and mortality rate, highlighting the need for biomarkers to detect ILD early in RA patients. Previous studies have shown the protective effects of Interleukin-22 (IL-22) in pulmonary fibrosis using mouse models. This study aims to assess IL-22 expression in RA-ILD to validate foundational experiments and explore its diagnostic value. The study included 66 newly diagnosed RA patients (33 with ILD, 33 without ILD) and 14 healthy controls (HC). ELISA was utilized to measure IL-22 levels and perform intergroup comparisons. The correlation between IL-22 levels and the severity of RA-ILD was examined. Logistic regression analysis was employed to screen potential predictive factors for RA-ILD risk and establish a predictive nomogram. The diagnostic value of IL-22 in RA-ILD was assessed using ROC. Subsequently, the data were subjected to 30-fold cross-validation. IL-22 levels in the RA-ILD group were lower than in the RA-No-ILD group and were inversely correlated with the severity of RA-ILD. Logistic regression analysis identified IL-22, age, smoking history, anti-mutated citrullinated vimentin antibody (MCV-Ab), and mean corpuscular hemoglobin concentration (MCHC) as independent factors for distinguishing between the groups. The diagnostic value of IL-22 in RA-ILD was moderate (AUC = 0.75) and improved when combined with age, smoking history, MCV-Ab and MCHC (AUC = 0.97). After 30-fold cross-validation, the average AUC was 0.886. IL-22 expression is dysregulated in the pathogenesis of RA-ILD. This study highlights the potential of IL-22, along with other factors, as a valuable biomarker for assessing RA-ILD occurrence and progression.

Association between choroidal thickness and interstitial lung disease in patients with rheumatoid arthritis: A cross-sectional study

Objectives

This study aimed to evaluate choroidal thickness (CT) in patients with rheumatoid arthritis (RA) and healthy controls and to determine its relationship with RA-associated interstitial lung disease (RA-ILD).

Patients and methods

A total of 63 patients with RA and 36 age- and sex-matched healthy controls were recruited in the cross-sectional study. Serological findings, Disease Activity Score-28, disease duration, and medical treatment of patients were recorded. Patients with RA were subdivided into two groups: patients with RA-ILD (Group 1) and patients with RA but without ILD (RA-noILD; Group 2). CTs were measured using enhanced depth imaging optical coherence tomography. CT was measured at five points: the subfoveal region, 750 μm nasal and temporal to the fovea, 1500 μm nasal and temporal to the fovea. Patients with RA-ILD were evaluated with delta high-resolution computed tomography (ΔHRCT) and pulmonary function test to determine the severity of interstitial lung disease.

Results

Four of 63 RA patients were excluded due to comorbidities. Thus, 59 RA patients, 20 in the RA-ILD group and 39 in the RA-noILD group, were included in the analyses. The RA groups were similar in terms of clinical characteristics and laboratory findings. There were statistically significant differences between Group 1, Group 2 and healthy controls (Group 3) compared to all CT values (p<0.05). The mean CT measured at 750 μm and 1500 μm nasal to the fovea was lowest in the RA-ILD group, followed by the RA-noILD and healthy groups (p<0.05). CT measurements did not correlate with the pulmonary function test and ΔHRCT.

Conclusion

RA-ILD patients had a thinner CT measured at nasal points. However, there was no association between CT measurements and the severity of ILD.

Serum IgA augments adhesiveness of cultured lung microvascular endothelial cells and suppresses angiogenesis

Immunoglobulin A (IgA) is important in local immunity and is also abundant in the blood. This study aimed to evaluate the effects of serum IgA on cultured lung microvascular endothelial cells (HMVEC-Ls), which are involved in the pathogenesis of inflammatory lung diseases. Serum IgA induced adhesion molecules and inflammatory cytokine production from HMVEC-Ls, and enhanced adhesion of peripheral blood mononuclear cells to HMVEC-Ls. In contrast, migration, proliferation, and tube formation of HMVEC-Ls were significantly suppressed by serum IgA. Experiments with siRNAs and western blotting revealed that two known IgA receptors, β1,4-galactosyltransferase 1 (b4GALT1) and asialoglycoprotein receptor 1 (ASGR1), and mitogen-activated protein kinase and nuclear factor-kappa B pathways were partly involved in serum IgA-induced cytokine production by HMVEC-Ls. Collectively, serum IgA enhanced cytokine production and adhesiveness of HMVEC-L, with b4GALT1 and ASGR1 partially being involved, and suppressed angiogenesis. Thus, serum IgA may be targeted to treat inflammatory lung diseases.

Immunotherapy-related pneumonitis and the synergic impact of thoracic radiation and preexisting interstitial lung disease

PURPOSE OF REVIEW

Immune checkpoint inhibitors (ICIs) are the frontline of therapy for most cancers. Although ICIs are sometimes considered to be less harmful than systemic chemotherapies, ICIs may cause immune-related adverse events, which are cases of off-target inflammation in healthy tissues. Pneumonitis, an immune-related adverse event, is the leading cause of therapy-related mortality with ICIs. The aim of this review is to discuss how preexisting interstitial lung disease (ILD) and thoracic radiation increase the risk for ICI-pneumonitis. We discuss potential mechanisms of lung injury and how pneumonitis may impact cancer treatments.

RECENT FINDINGS

Preexisting ILD and thoracic radiation are major risk factors for ICI-pneumonitis. The mechanisms of injury are still not fully understood but may involve the same inflammatory and profibrotic cytokines as those seen in sporadic ILD. Thoracic radiation increases the risk for ICI-pneumonitis and may synergize with preexisting ILD to worsen toxicity.

SUMMARY

Preexisting ILD and thoracic radiation may increase the risk for the future development of ICI-pneumonitis. However, while these should not preclude potentially life-saving immunotherapy, in some cases, an alternative treatment strategy may be advisable. A multidisciplinary approach is required involving oncologists, pulmonologists, and radiation oncologists to guide in the selection of cancer treatment and in the diagnosis and treatment of pneumonitis.

Interleukin-6 cytokine: An overview of the immune regulation, immune dysregulation, and therapeutic approach

Several studies have shown that interleukin 6 (IL-6) is a multifunctional cytokine with both pro-inflammatory and anti-inflammatory activity, depending on the immune response context. Macrophages are among several cells that secrete IL-6, which they express upon activation by antigens, subsequently inducing fever and production of acute-phase proteins from the liver. Moreover, IL-6 induces the final maturation of B cells into memory B cells and plasma cells as well as an adaptive role for short-term energy allocation. Activation of IL-6 receptors results in the intracellular activation of the JAK/STAT pathway with resultant production of inflammatory cytokines. Several mechanisms-controlled IL-6 expression, but aberrant production was shown to be crucial in the pathogenesis of many diseases, which include autoimmune and chronic inflammatory diseases. IL-6 in combination with transforming growth factor β (TGF-β) induced differentiation of naïve T cells to Th17 cells, which is the cornerstone in autoimmune diseases. Recently, IL-6 secretion was shown to form the backbone of hypercytokinemia seen in the Coronavirus disease 2019 (COVID-19)-associated hyperinflammation and multiorgan failure. There are two classes of approved IL-6 inhibitors: anti-IL-6 receptor monoclonal antibodies (e.g., tocilizumab) and anti-IL-6 monoclonal antibodies (i.e., siltuximab). These drugs have been evaluated in patients with rheumatoid arthritis, juvenile idiopathic arthritis, cytokine release syndrome, and COVID-19 who have systemic inflammation. JAK/STAT pathway blockers were also successfully used in dampening IL-6 signal transduction. A better understanding of different mechanisms that modulate IL-6 expression will provide the much-needed solution with excellent safety and efficacy profiles for the treatment of autoimmune and inflammatory diseases in which IL-6 derives their pathogenesis.

Contributions of Immune Cells and Stromal Cells to the Pathogenesis of Systemic Sclerosis: Recent Insights

Systemic sclerosis (SSc) is a multisystem rheumatic disease characterized by vascular dysfunction, autoimmune abnormalities, and progressive organ fibrosis. A series of studies in SSc patients and fibrotic models suggest that immune cells, fibroblasts, and endothelial cells participate in inflammation and aberrant tissue repair. Furthermore, the growing number of studies on single-cell RNA sequencing (scRNA-seq) technology in SSc elaborate on the transcriptomics and heterogeneities of these cell subsets significantly. In this review, we summarize the current knowledge regarding immune cells and stromal cells in SSc patients and discuss their potential roles in SSc pathogenesis, focusing on recent advances in the new subtypes by scRNA-seq.