Decreased peripheral blood memory B cells are associated with the presence of interstitial lung disease in rheumatoid arthritis: a case-control study

Peripheral Blood Single-Cell Sequencing Uncovers Common and Specific Immune Aberrations in Fibrotic Lung Diseases

Rationale and Objectives

The extent and commonality of peripheral blood immune aberrations in fibrotic interstitial lung diseases are not well characterized. In this study, we aimed to identify common and distinct immune aberrations in patients with idiopathic pulmonary fibrosis (IPF) and fibrotic hypersensitivity pneumonitis (FHP) using cutting-edge single-cell profiling technologies.

Methods

Single-cell RNA sequencing was performed on patients and healthy controls' peripheral blood and bronchoalveolar lavage samples using 10X Genomics 5' gene expression and V(D)J profiling. Cell type composition, transcriptional profiles, cellular trajectories and signaling, and T and B cell receptor repertoires were studied. The standard Seurat R pipeline was followed for cell type composition and differential gene expression analyses. Transcription factor activity was imputed using the DoRothEA-VIPER algorithm. Pseudotime analyses were conducted using Monocle3, while RNA velocity analyses were performed with Velocyto, scVelo, and CellRank. Cell-cell connectomics were assessed using the Connectome R package. V(D)J analyses were conducted using CellRanger and Immcantation frameworks. Across all analyses, disease group differences were assessed using the Wilcoxon rank-sum test.

Measurements and Main Results

327,990 cells from 83 samples were profiled. Overall, changes in monocytes were common to IPF and FHP, whereas lymphocytes exhibited disease-specific aberrations. Both diseases displayed enrichment of CCL3 hi /CCL4 hi CD14+ monocytes (p<2.2e-16) and S100A hi CD14+ monocytes (p<2.2e-16) versus controls. Trajectory and RNA velocity analysis suggested that pro-fibrotic macrophages observed in BAL originated from peripheral blood monocytes. Lymphocytes exhibited disease-specific aberrations, with CD8+ GZMK hi T cells and activated B cells primarily enriched in FHP patients. V(D)J analyses revealed unique T and B cell receptor complementarity-determining region 3 (CDR3) amino acid compositions (p<0.05) in FHP and significant IgA enrichment in IPF (p<5.2e-7).

Conclusions

We identified common and disease-specific immune mechanisms in IPF and FHP; S100A hi monocytes and SPP1 hi macrophages are common to IPF and FHP, whereas GMZK hi T lymphocytes and T and B cell receptor repertoires were unique in FHP. Our findings open novel strategies for the diagnosis and treatment of IPF and FHP.

Memory B-cells are enriched in the blood of patients with acute Buruli ulcer disease: a prospective observational study

BACKGROUND

Buruli ulcer disease (BUD) caused by Mycobacterium (M.) ulcerans is characterized by necrotic skin lesions. As for other mycobacterial infections, e.g., tuberculosis, the immune response is important for host protection. B-cells may play a role in antimycobacterial immunity but studies characterizing the B-cell repertoire and memory generation in BUD and during the course of treatment are scarce.

METHODS

We investigated the adaptive immune cell repertoire in children with BUD and healthy matched controls by flow cytometry. Analyses prior to treatment, also in a study group of patients with tuberculosis, as well as three time points during BUD treatment (i.e., week 8, 16, and 32) were performed. In addition, BUD disease severity as well as treatment response were analysed for association with B-cell repertoire differences.

RESULTS

Children with BUD had comparable total B- and T-cell proportions but differed largely in B-cell subsets. Memory B-cell (B _mem) proportions were higher in children with BUD whereas regulatory B-cell (B _reg) proportions were lower as compared to healthy controls and tuberculosis patients. Lower naïve (B _naïve) and higher transitional B-cell (B _trans) proportions characterized children with BUD in comparison with tuberculosis patients. Under treatment, B _mem proportions decreased significantly whereas proportions of B _reg and B _naive increased concomitantly in children with BUD. Also, we found significant correlation between lesion size and B _mem as well as B _reg. However, we did not detect associations between treatment efficacy and B-cell proportions.

CONCLUSIONS

These results suggest a role of B-cell subsets in the immune response against M. ulcerans. Furthermore, changes in B-cell subset proportions may be used as markers for treatment monitoring in BUD.

Potential of resveratrol in the treatment of interstitial lung disease

Interstitial lung disease (ILD) is a heterogeneous group of diseases characterized by lung injury caused by lung fibroblast proliferation, interstitial inflammation, and fibrosis. Different cell signal transduction pathways are activated in response to various proinflammatory or fibrotic cytokines, such as IL-6, and these cytokines are increased in different ILDs. The overexpressed cytokines and growth factors in ILD can activate TGF-β/Smad2/3/4, NF-κB, and JAK/STAT signal transduction pathways, promote the activation of immune cells, increase the release of pro-inflammatory and pro-fibrotic factors, differentiate fibroblasts into myofibroblasts, and promote the occurrence and development of ILD. This finding suggests the importance of signal transduction pathways in patients with ILD. Recent evidence suggests that resveratrol (RSV) attenuates excessive inflammation and pulmonary fibrosis by inhibiting the TGF-β/Smad2/3/4, NF-κB, and JAK/STAT signal transduction pathways and overactivation of immune cells. In this review, advances in lung protection and the underlying mechanisms of RSV are summarized, and the potential efficacy of RSV as a promising treatment option for ILD is highlighted.

Relationship between the Degree of Illness in Elderly Patients with Rheumatoid Arthritis and Parameters of Musculoskeletal Ultrasound and Oswestry Dysfunction Index and Clinical Value Analysis

Objective

The aim of the study is to explore the relationship between the degree of illness in elderly patients with rheumatoid arthritis (RA) and parameters of musculoskeletal ultrasound (MSUS) and Oswestry Dysfunction Index (ODI) and its clinical value.

Methods

The clinical data of 100 elderly patients with RA admitted to our hospital from May 2016 to May 2022 were retrospectively analyzed. The patients were divided into four groups, including the remission group (DAS28 ≤ 2.6, n = 25), low activity group (2.6 ≤ DAS28 ≤ 3.2, n = 25), middle activity group (3.2 ≤ DAS28 ≤ 5.1, n = 25), and high activity group (DAS > 5.1, n = 25) according to the disease activity score-28 (DAS28). All patients underwent ultrasonic detection to compare the relationship between the degree of illness in elderly patients with RA and parameters of MSUS and ODI.

Results

The total semiquantitative score of MSUS and ODI score in the remission group were obviously lower than those in the other three groups (P < 0.001). The degree of illness in elderly patients with RA was positively correlated with parameters of MSUS (r = 0.886, P < 0.001). The degree of illness in elderly patients with RA was positively correlated with ODI (r = 0.907, P < 0.001).

Conclusion

The degree of illness in elderly patients with RA is closely related to parameters of MSUS and ODI, and the parameters of MSUS have a higher evaluation value for the degree of illness in elderly patients with RA, which are correlated with ODI.

Peripheral Blood Lymphocyte Phenotype Differentiates Secondary Antibody Deficiency in Rheumatic Disease from Primary Antibody Deficiency

The phenotype of primary immunodeficiency disorders (PID), and especially common variable immunodeficiency (CVID), may be dominated by symptoms of autoimmune disorders. Furthermore, autoimmunity may be the first manifestation of PID, frequently preceding infections and the diagnosis of hypogammaglobulinemia, which occurs later on. In this case, distinguishing PID from hypogammaglobulinemia secondary to anti-inflammatory treatment of autoimmunity may become challenging. The aim of this study was to evaluate the diagnostic accuracy of peripheral blood lymphocyte phenotyping in resolving the diagnostic dilemma between primary and secondary hypogammaglobulinemia. Comparison of B and T cell subsets from patients with PID and patients with rheumatic disease, who developed hypogammaglobulinemia as a consequence of anti-inflammatory regimes, revealed significant differences in proportion of naïve B cells, class-switched memory B cells and CD21^low B cells among B cells as well as in CD4⁺ memory T cells and CD4⁺ T follicular cells among CD4⁺ T cells. Identified differences in B cell and T cell subsets, and especially in the proportion of class-switched memory B cells and CD4⁺ T follicular cells, display a considerable diagnostic efficacy in distinguishing PID from secondary hypogammaglobulinemia due to anti-inflammatory regimens for rheumatic disease.