Serum KL-6 as predictive and prognostic marker of interstitial lung disease in childhood connective tissue diseases: a pilot study

A correlation study of serum tumor markers with systemic lupus erythematosus-associated interstitial lung disease

Background

Systemic lupus erythematosus-associated interstitial lung disease (SLE-ILD) is a pulmonary manifestation of SLE. Currently, serum biomarkers for early identification of SLE-ILD are lacking. Our study aimed to investigate the correlation and clinical significance of serum tumor markers (TMs) in patients with SLE-ILD.

Methods

We conducted a retrospective analysis of medical records from SLE patients between January 2017 and November 2023. We compared the differences in serum levels of TMs including carcinoembryonic antigen (CEA), carbohydrate antigens (CA125, CA15-3, and CA19-9), squamous cell carcinoma antigen (SCC), cytokeratin-19-fragment (CYFRA21-1), neuron-specific enolase (NSE) and ferritin (FER), between SLE-ILD and SLE patients.

Results

A total of 386 SLE patients were enrolled in this study, comprising 64 individuals with SLE-ILD. Compared with SLE group, SLE-ILD group exhibited higher serum levels of CEA, CA125, CA15-3, CA19-9, SCC, CYFRA21-1, and FER. Multivariate regression indicated that age (OR = 1.038, 95% CI = [1.004, 1.074]), CA15-3 (OR = 1.099, 95% CI = [1.039, 1.162]), and CA19-9 (OR = 1.032, 95% CI = [1.005, 1.059]) were associated factors for SLE-ILD (p < 0.05). Serum levels of CA15-3 demonstrated good diagnostic value with an area under the receiver operating characteristic curve (AUC) = 0.72; furthermore, combining age with serum levels of CA19-9 and CA15-3 presented enhanced diagnostic performance as reflected by an AUC = 0.80 (95% CI = [0.73, 0.86]). Serum levels of SCC and CYFRA21-1 moderately positively correlated with serum creatinine levels (r = 0.562 and 0.713, respectively).

Conclusion

Serum levels of CA125, CA15-3, and CA19-9 could act as associated markers for SLE-ILD. Serum SCC, CYFRA21-1 and FER levels may also be linked to kidney involvement in SLE-ILD.

Development of a multi-laboratory integrated predictive model for silicosis utilizing machine learning: a retrospective case-control study

Objective

Due to the high global prevalence of silicosis and the ongoing challenges in its diagnosis, this pilot study aims to screen biomarkers from routine blood parameters and develop a multi-biomarker model for its early detection.

Methods

A case-control study was conducted to screen biomarkers for the diagnosis of silicosis using LASSO regression, SVM and RF. A sample of 612 subjects (half cases and half controls) were randomly divided into training and test groups in a 2:1 ratio. Logistic regression analysis and receiver operating characteristic (ROC) curves were used to construct a multiple biomarker-based model for the diagnosis of silicosis, which was applied to both the training and the testing datasets.

Results

The training cohort revealed significant statistical differences (P < 0.05) in multiple hematologic parameters between silicosis patients and healthy individuals. Based on machine learning, eight silicosis biomarkers were screened and identified from routine blood cell, biochemical and coagulation parameters. D-dimer (DD), Albumin/Globulin (A/G), lactate dehydrogenase (LDH) and white blood cells (WBC) were selected for constructing the logistic regression model for silicosis diagnostics. This model had a satisfactory performance in the training cohort with an area under the ROC curve (AUC) of 0.982, a diagnostic sensitivity of 95.4%, and a specificity of 92.2%. In addition, the model had a prediction accuracy of 0.936 with an AUC of 0.979 in the independent test cohort. Moreover, the diagnostic accuracies of the logistic model in silicosis stages 1, 2, and 3 were 88.0, 95.4, and 94.3% with an AUC of 0.968, 0.983, and 0.990 for silicosis, respectively.

Conclusion

A diagnostic model based on DD, A/G, LDH and WBC is successfully proposed for silicosis diagnostics. It is cheap, sensitive, specific, and preliminarily offers a potential strategy for the large-scale screening of silicosis.

Clinical Evaluation of Acute Exacerbation of Interstitial Lung Disease in a Single Tertiary Center: Perspectives before and after the Coronavirus Disease 2019 Pandemic

Background/Objectives: Acute exacerbation (AE) of interstitial lung disease (ILD) is a major challenge. This study aimed to retrospectively investigate occurrences of AEs in patients with ILDs, including idiopathic pulmonary fibrosis (IPF), non-IPF (iNSIP: idiopathic nonspecific interstitial pneumonia), and connective tissue disease (CTD)-associated ILDs (CTD-ILDs), at a single tertiary center before and after the coronavirus disease 2019 (COVID-19) pandemic. The study aimed to clarify the seasonal and regional trends of AEs of ILDs, assess the roles of viral and bacterial infections, and identify key prognostic factors for patient outcomes. Methods: We conducted a retrospective review of hospitalized adult patients with AEs of ILDs from January 2019 to February 2024. Results: A total of 93 patients were enrolled: IPF (n = 42), iNSIP (n = 37), and CTD-ILDs (n = 14). The median age was 80 years (interquartile range: 74.0-86.0 years), with males comprising 64.5% (n = 60). AEs of ILDs predominantly occurred in winter and were particularly notable after summer 2023, coinciding with the lifting of COVID-19-related travel restrictions in Japan. Patient referrals from different areas (Northern Tama, East and/or Southern Tama, and other Tokyo metropolitan areas) were evenly distributed throughout the study period. Viral infections were detected in only two patients (SARS-CoV-2), and bacterial infections included methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. The Cox regression analysis identified serum lactate dehydrogenase levels ≥350 IU/L and tachypnea (respiratory rate ≥ 30 breaths per min) on admission as prognostic factors for mortality, with a hazard ratio [HR] of 2.783 (95% confidence interval [CI]: 1.480-5.235, p = 0.001) and an HR of 3.332 (95% CI: 1.710-6.492, p < 0.001), respectively. Conclusions: AEs of ILDs predominantly occur in winter, and viral and bacterial infections are infrequently detected. Elevated serum LDH levels and tachypnea are crucial prognostic markers for mortality. This study highlights the seasonal trend in the AE of ILD and emphasizes the importance of specific prognostic indicators in clinical practice.

Undercover lung damage in pediatrics - a hot spot in morbidity caused by collagenoses

Connective tissue represents the support matrix and the connection between tissues and organs. In its composition, collagen, the major structural protein, is the main component of the skin, bones, tendons and ligaments. Especially at the pediatric age, its damage in the context of pathologies such as systemic lupus erythematosus, scleroderma or dermatomyositis can have a significant negative impact on the development and optimal functioning of the body. The consequences can extend to various structures (e.g., joints, skin, eyes, lungs, heart, kidneys). Of these, we retain and reveal later in our manuscript, mainly the respiratory involvement. Manifested in various forms that can damage the chest wall, pleura, interstitium or vascularization, lung damage in pediatric systemic inflammatory diseases is underdeveloped in the literature compared to that described in adults. Under the threat of severe evolution, sometimes rapidly progressive and leading to death, it is necessary to increase the popularization of information aimed at physiopathological triggering and maintenance mechanisms, diagnostic means, and therapeutic directions among medical specialists. In addition, we emphasize the need for interdisciplinary collaboration, especially between pediatricians, rheumatologists, infectious disease specialists, pulmonologists, and immunologists. Through our narrative review we aimed to bring up to date, in a concise and easy to assimilate, general principles regarding the pulmonary impact of collagenoses using the most recent articles published in international libraries, duplicated by previous articles, of reference for the targeted pathologies.

Current views on lupus in children

PURPOSE OF REVIEW

This manuscript provides an update on clinical and pathophysiological features of juvenile-onset systemic lupus erythematosis (jSLE), challenges applying adult-derived classification criteria, and recent advances in treatment and care.

RECENT FINDINGS

Significant scientific advances have improved the understanding of genetic factors (both genetic causes and risk alleles) and associated phenotypic features. Panels of urine/blood biomarker candidates aid in diagnosing jSLE, monitoring disease activity and predicting treatment response. Available classification criteria have been extensively assessed, with differences in clinical and immunological phenotypes of patients across age groups and ethnicities affecting their performance in jSLE. Therapeutic options remain limited and are based on protocols for adult-onset SLE patients. International efforts to inform development of a treat-to-target (T2T) approach for jSLE have yielded cohort-level evidence that target attainment reduces the risk of severe flare and new damage, and treatment compliance.

SUMMARY

Recent studies have significantly improved our understanding of jSLE pathogenesis, highlighting important differences between jSLE and adult SLE, and providing the basis of biomarker development and target-directed individualized treatment and care. Future work focused on development of a T2T approach in jSLE is eagerly awaited.

Pirfenidone inhibits cell fibrosis in connective tissue disease-associated interstitial lung disease by targeting the TNF-α/STAT3/KL6 pathway

Background

To explore the effect and mechanism of pirfenidone in inhibiting pulmonary fibrosis in connective tissue disease-associated interstitial lung disease (CTD-ILD).

Methods

From 2018 to 2020, 50 CTD-ILD patients were enrolled in the clinical study. Based on whether pirfenidone was used during treatment, patients were enrolled into the pirfenidone group and the control group. Pulmonary function tests were compared before and after treatment. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the expression of tumor necrosis factor-α (TNF-α), signal transducer and activator of transcription 3 (STAT3), and Krebs Von den Lungen-6 (KL-6) in venous blood before and after treatment. Rat type II (RLE-6TN) lung epithelial cells were cultivated for in vitro experiments, and they were sorted into the control group, bleomycin group, pirfenidone group, TNF-α group, Stattic group, and TNF-α/Stattic combined treatment group. For the in vitro experiments, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests were used to evaluate cell proliferation, Reverse Transcription-Polymerase Chain Reaction(RT–PCR) was performed to detect STAT3 and KL-6 mRNA expression levels, ELISA was utilized to detect TNF-α and E-cadherin expression levels, and Western blotting (WB) was performed to determine α-smooth muscle actin (α-SMA), vimentin, TNF-α, STAT3, phosphorylated signal transducer and activator of transcription 3 (PSTAT3) and KL-6 expression.

Results

In the clinical study, the pulmonary function indices including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC, peak expiratory flow (PEF) and partial pressure (PaO₂) of the patients in the study group were superior to those in the control group (P<0.05). The serum TNF-α, STAT3 and KL-6 levels in the study group were significantly lower than those in the control group (P<0.05). In the in vitro experiments, the α-SMA, vimentin, STAT3 and KL-6 levels in the treatment group were significantly lower than those in the bleomycin group (P<0.05). Compared with those in the pirfenidone group, the α-SMA, vimentin, STAT3 and KL-6 levels in the TNF-α-treated group were significantly upregulated (P<0.05). Meanwhile, cell viability was further upregulated (P<0.05), and the expression of STAT3 and KL-6 was further decreased in the Stattic-treated group (P<0.05). In the group treated with infliximab combined with Stattic, TNF-α expression was significantly increased (P<0.05), cell activity was significantly restored (P<0.05), and the STAT3, KL-6 and E-cadherin expression levels were inhibited (P<0.05).

Conclusions

Pirfenidone improved pulmonary function 1 and decreased TNF-α, STAT3, and KL-6 expression in CTD-ILD patients. Moreover, pirfenidone inhibits cell fibrosis through the TNF-α/STAT3/Mucin 1(MUC1) pathway.