Cytokeratin 19 fragment is associated with severity and poor prognosis of interstitial lung disease in anti-MDA5 antibody-positive dermatomyositis

Potential and application of abortive transcripts as a novel molecular marker of cancers

Abortive transcript (AT) is a 2-19 nt long non-coding RNA that is produced in the abortive initiation stage. Abortive initiation was found to be closely related to RNA polymerase through in vitro experiments. Therefore, the distribution of AT length and the scale of abortive initiation are correlated to the promoter, discriminator, and transcription initiation sequence, and can be affected by transcription elongation factors. AT plays an important role in the occurrence and development of various diseases. Here we summarize the discovery of AT, the factors responsible for AT formation, the detection methods and biological functions of AT, to provide new clues for finding potential targets in the early diagnosis and treatment of cancers.

Autoimmunity against melanoma differentiation-associated gene 5 induces interstitial lung disease mimicking dermatomyositis in mice

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM) is characterized by amyopathic DM with interstitial lung disease (ILD). Patients with anti-MDA5 antibody-associated ILD frequently develop rapidly progression and present high mortality rate in the acute phase. Here, we established a murine model of ILD mediated by autoimmunity against MDA5. Mice immunized with recombinant murine MDA5 whole protein, accompanied with complete Freund's adjuvant once a week for four times, developed MDA5-reactive T cells and anti-MDA5 antibodies. After acute lung injury induced by intranasal administration of polyinosinic-polycytidylic acid [poly (I:C)] mimicking viral infection, the MDA5-immunized mice developed fibrotic ILD representing prolonged respiratory inflammation accompanied by fibrotic changes 2 wk after poly (I:C)-administration, while the control mice had quickly and completely recovered from the respiratory inflammation. Treatment with anti-CD4 depleting antibody, but not anti-CD8 depleting antibody, suppressed the severity of MDA5-induced fibrotic ILD. Upregulation of interleukin (IL)-6 mRNA, which was temporarily observed in poly (I:C)-treated mice, was prolonged in MDA5-immunized mice. Treatment with anti-IL-6 receptor antibody ameliorated the MDA5-induced fibrotic ILD. These results suggested that autoimmunity against MDA5 exacerbates toll-like receptor 3-mediated acute lung injury, and prolongs inflammation resulting in the development of fibrotic ILD. IL-6 may play a key role initiating ILD in this model.

Predicting the death of patients with anti-melanoma differentiation-associated protein-5-positive dermatomyositis-associated interstitial lung disease: A systematic review and meta-analysis

OBJECTIVES

To investigate the risk factors for death in anti-melanoma differentiation-associated protein-5-positive dermatomyositis-associated interstitial lung disease (ILD).

METHODS

Studies were identified by searching PubMed, Embase, Web of Science, and Cochrane Library. We calculated pooled risk ratios (RRs) or standardized mean differences (SMDs) and 95% confidence intervals (CIs) using random-effects models.

RESULTS

Twenty studies were selected. Factors that may increase death risk included older age (SMD: 0.62, 95% CI: 0.42-0.81), elevated Krebs von den Lungen-6 (SMD: 0.66, 95% CI: 0.47-0.86), lactate dehydrogenase (SMD: 0.87, 95% CI: 0.72-1.02), C-reactive protein (SMD: 0.62, 95% CI: 0.44-0.80), ferritin (SMD: 0.93, 95% CI: 0.71-1.15), creatine kinase (SMD: 0.28, 95% CI: 0.13-0.44), neutrophil (SMD: 0.34, 95% CI: 0.04-0.64), neutrophil-to-lymphocyte ratio (SMD: 0.52, 95% CI: 0.24-0.79), aspartate aminotransferase (SMD: 0.70, 95% CI: 0.45-0.94), shorter disease duration (SMD: -0.44, 95% CI: -0.67 to -0.21), rapidly progressive ILD (RR: 4.08, 95% CI: 3.01-5.54), fever (RR: 1.98, 95% CI: 1.46-2.69), dyspnoea (RR: 1.63, 95% CI: 1.32-2.02), and anti-Ro52 antibody positive (RR: 1.28, 95% CI: 1.11-1.49). Female (RR: 0.86, 95% CI: 0.78-0.94), increased albumin (SMD: -1.20, 95% CI: -1.76 to -0.64), lymphocyte (SMD: -0.49, 95% CI: -0.67 to -0.30), and arthralgia (RR: 0.53, 95% CI: 0.37-0.78) were protective factors.

CONCLUSION

Older age, shorter disease duration, rapidly progressive ILD, fever, dyspnoea, anti-Ro52 antibody positive, and some inflammatory markers were risk factors for death in patients with anti-melanoma differentiation-associated protein-5-positive dermatomyositis-associated ILD.

Anti-MDA5 antibody-positive dermatomyositis: pathogenesis and clinical progress

Anti-melanoma differentiation-associated protein 5 (MDA5) antibody-positive dermatomyositis (MDA5-DM) is a subtype of dermatomyositis. Although the aetiology and pathology remain unclear, increasing evidence suggests that viral infection is a potential trigger of MDA5-DM. Multiple factors, including T cells, B cells, neutrophils and macrophages, are implicated in the pathophysiology of MDA5-DM. Distinctive skin rashes, rapidly progressive interstitial lung disease, peripheral lymphopenia and elevated serum ferritin levels are the most prominent clinical and laboratory features of MDA5-DM. Concomitant infection is a common complication of MDA5-DM. The proper evaluation of patients with MDA5-DM requires knowledge of the disease heterogeneity and clinical course variability. Several biomarkers, including serum levels of anti-MDA5 antibodies and biomarkers related to macrophage activation, have been identified as useful tools for monitoring disease activity and prognosis. MDA5-DM shows a poor response to conventional glucocorticoid and immunosuppressant therapy and has a poor overall prognosis. Therefore, there is an urgent need to explore the key pathogenic mechanisms of MDA5-DM and develop novel therapeutic options for patients. This Review discusses recent clinical progress and pathogenic findings of MDA5-DM.

Analysis of characteristics related to interstitial lung disease or pulmonary hypertension in patients with dermatomyositis

INTRODUCTION

Dermatomyositis (DM) is often associated with interstitial lung disease (ILD) or pulmonary hypertension (PH). The aim of this study was to investigate the clinical characteristics of DM patients with ILD or PH.

METHODS

This study retrospectively analysed the clinical characteristics of 372 patients with DM, including cytokines, lymphocyte subsets, immunoglobulin and complement. The DM patients were divided into different groups according to whether complicated with ILD, PH or anti-melanoma differentiation-associated gene 5 antibodies (MDA5). A qualitative and quantitative data analysis was performed.

RESULTS

IgG, IgA and IgM in the DM-associated ILD (ILD-DM) were higher than that of the DM non-complicating ILD (Non-ILD-DM) (p = 0.022, 0.002 and 0.029, respectively). Meanwhile, IL-6 (p = 0.008) and IL-10 (p = 0.001) were increased in the DM-associated PH (PH-DM) than in the DM non-complicating PH (Non-PH-DM), while IL-17 (p = 0.004), double positive (DP) cell ratio and B lymphocyte ratio were reduced in the PH-DM. Moreover, the incidence of ILD and levels of C4 were higher in the DM with MDA5 (MDA5+ DM) than that of the DM without MDA5.

CONCLUSION

ILD-DM has higher IgG, IgA and IgM than that of Non-ILD-DM. PH-DM has higher IL-6, IL-10 and lower IL-17, DP cell ratio and B lymphocyte ratio than that of Non-PH-DM.

Risk factors for mortality in patients with anti-MDA5 antibody-positive dermatomyositis: A meta-analysis and systematic review

OBJECTIVES

To determine the prognostic factors of dermatomyositis with anti-melanoma differentiation-associated gene 5 (MDA5) antibody, a rare disease and often complicated by life-threatening, rapidly progressive interstitial lung disease.

METHODS

Herein, we searched the Medline, Embase, and Cochrane Library databases and extracted studies published before August 23, 2022. Pooled analysis of hazard ratios (HRs) or odds ratios was used to identify prognostic factors for mortality among patients with anti-MDA5 antibody-positive dermatomyositis (MDA5+ DM).

RESULTS

Twenty-nine cohorts with 2,645 patients were included in this meta-analysis. Factors related to poor prognosis included old age (HR 1.54, 95% confidence interval (CI) 1.41-1.69, p < 0.01), male sex (HR 2.07, 95% CI 1.34-3.18, p < 0.01), rapidly progressive interstitial lung disease (RP-ILD) (HR 9.34, 95% CI 6.39-13.6, p < 0.01), high levels of ferritin (HR 1.05, 95% CI 1.01-1.08, p < 0.01), C-reactive protein (CRP) (HR 1.12, 95% CI 1.06-1.19, p < 0.01), creatine kinase (HR 1.05, 95% CI 1.03-1.07, p < 0.01), and lactate dehydrogenase (LDH) (HR 1.27, 95% CI 1.12-1.45, p < 0.01), whereas oxygen index (HR 0.990, 95% CI 0.988-0.992, p < 0.01), partial pressure of oxygen (HR 0.933, 95% CI 0.906-0.961, p < 0.01), forced vital capacity (HR 0.962, 95% CI 0.928-0.998, p = 0.038), and lymphocyte count (HR 0.421, 95% CI 0.282-0.629, p < 0.01) were associated with better outcomes.

CONCLUSIONS

Old age, male sex, hypoxemia, low forced vital capacity, lymphocytopenia, and high levels of ferritin, CRP, creatine kinase, and LDH are risk factors for mortality in patients with MDA5+ DM. However, a cautious interpretation of these results and further quality investigation are warranted.

Clinical significance of interleukin-6, total bilirubin, CD3 + CD4 + T cells counts in the acute exacerbation of connective tissue disease-associated interstitial lung disease: a cross-sectional study

OBJECTIVE

Interstitial lung disease (ILD) is a severe complication of connective tissue disease (CTD) that can significantly impact patients' prognosis and quality of life. However, the current diagnostic arena lacks reliable biomarkers for detecting and monitoring the progression and exacerbation of CTD-ILD. This study aimed to investigate the clinical value of 12 serum cytokines in the diagnosis of CTD-ILD and prediction of the risk of acute exacerbation (AE) in this disease.

METHODS

This study was a cross-sectional investigation. Ninety-one hospitalized CTD patients were allocated into two groups: CTD-ILD group (n = 61) and CTD-non-ILD group (n = 30), and 30 sex-age matched healthy volunteers were enrolled as controls. The serum concentrations of interferon (IFN)-α, IFN-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17A, and IL-1β were measured by Luminex suspension arrays. Logistic regression was employed to determine the significance of variables in the occurrence of AE-CTD-ILD. A nomogram was constructed to visualize the independent variables.

RESULTS

Elevated levels of IL-6, IL-8, and TNF-α were observed and compared in the CTD-ILD group with CTD-non-ILD (all P < 0.05). Similarly, the levels of IL-6, IL-8 and TNF-α were higher in the acute exacerbation (AE-CTD-ILD) group compared with stable CTD-ILD (S-CTD-ILD) (P < 0.001, P < 0.001, and P = 0.022). Significant correlations between serum IL-6 and PaO2/FiO2 ratio (r = - 0.463, P < 0.001), percent predicted forced vital capacity (FVC%; r = - 0.362, P < 0.05), and total ground-glass opacity (GGO) score (r = 0.439, P < 0.001) were observed in CTD-ILD patients. Multivariate logistic regression analysis revealed that elevated IL-6 levels, total bilirubin (TBil), and decreased CD3 + CD4 + T cells counts were independent risk factors for the occurrence of AE-CTD-ILD (OR = 1.121, P = 0.024; OR = 1.865, P = 0.047; OR = 0.983, P = 0.037, respectively). Furthermore, by employing these three variables in combination for the prediction of AE status, their collective impact surpasses the independent effects of any single biomarker.

CONCLUSIONS

Elevated levels of serum IL-6, IL-8, and TNF-α were associated with the complication of ILD in CTD patients and the occurrence of AE in CTD-ILD patients. IL-6 could be a promising serum biomarker of severity and the occurrence of AE in CTD-ILD patients. The combination of the three variables (IL-6 level, TBil and CD3 + CD4 + T cells) predicted the AE-CTD-ILD better.

Peripheral lymphocyte count defines the clinical phenotypes and prognosis in patients with anti-MDA5-positive dermatomyositis

OBJECTIVE

To explore the role of peripheral lymphocyte count in phenotyping and prognosis prediction in dermatomyositis (DM) patients with anti-MDA5 antibodies.

METHODS

In total, 1669 patients with idiopathic inflammatory myopathy (IIM) were retrospectively enrolled. Clinical characteristics and prognosis of patients with anti-MDA5+ DM were analyzed in association with peripheral lymphocyte counts and clusters determined by unsupervised machine learning.

RESULTS

The peripheral lymphocyte count was significantly lower in the anti-MDA5+ DM group (N = 421) than in the other IIM serotype groups. The anti-MDA5+ DM patients were divided into three groups; the severe lymphopenia group had skin ulcers and rapidly progressive interstitial lung disease (RP-ILD); patients with a normal lymphocyte count had a younger age of onset, more frequent arthritis, and normal serum ferritin levels, whereas mild lymphopenia group showed a moderate increase of serum ferritin and intermediate incidence of RP-ILD. Survival analysis revealed that the 3- and 6-month mortality rates were significantly higher in the severe lymphopenia group (29.0% and 42.1%, respectively) than in the mild lymphopenia group and normal lymphocyte count group (p value <0.001). Consistently, unsupervised machine learning identified three similar groups; the arthritis cluster shows the highest lymphocyte counts and best prognosis; the RP-ILD cluster presents the lowest peripheral lymphocyte, high incidence of RP-ILD, and poor prognosis; the typical DM rash cluster had a moderate peripheral lymphocyte count and an intermediate prognosis.

CONCLUSIONS

Lymphopenia is a unique manifestation of anti-MDA5+ DM. Peripheral lymphocyte count can define clinical phenotypes and predict prognosis in anti-MDA5+ DM.

Predictors of progression in idiopathic inflammatory myopathies with interstitial lung disease

The idiopathic inflammatory myopathies (IIMs) are a group of connective tissue diseases that afect multiple organ systems, including the lungs. Interstitial lung disease (ILD) is the most common and heterogeneous complication of IIMs, with its degree ranging from mild to fatal. Thus, it is critical to identify clinical features and validated biomarkers for predicting disease progression and prognosis, which could be beneficial for therapy adjustment. In this review, we discuss predictors for rapid progression of IIM-ILD and propose guidance for disease monitoring and implications of therapy. Systematic screening of myositis-specific antibodies, measuring serum biomarker levels, pulmonary function tests, and chest high-resolution computer tomography will be beneficial for the evaluation of disease progression and prognosis.

Roles of biomarkers in anti-MDA5-positive dermatomyositis, associated interstitial lung disease, and rapidly progressive interstitial lung disease

BACKGROUND

Anti-melanoma differentiation-associated gene 5 (MDA5)-positive dermatomyositis (MDA5⁺ DM) is significantly associated with interstitial lung disease (ILD), especially rapidly progressive ILD (RPILD) due to poor prognosis, resulting in high mortality rates. However, the pathogenic mechanism of MDA5⁺ DM-RPILD is unclear. Although some MDA5⁺ DM patients have a chronic course of ILD, many do not develop RPILD. Therefore, the related biomarkers for the early diagnosis, disease activity monitoring, and prediction of the outcome of RPILD in MDA5⁺ DM patients should be identified. Blood-based biomarkers are minimally invasive and can be easily detected.

METHODS

Recent relative studies related to blood biomarkers in PubMed were reviewed.

RESULTS

An increasing number of studies have demonstrated that dysregulated expression of blood biomarkers related to ILD such as ferritin, Krebs von den Lungen-6 (KL-6), surfactant protein-D (SP-D), and cytokines, and some tumor markers in MDA5⁺ DM may provide information in disease presence, activity, treatment response, and prognosis. These studies have highlighted the great potentials of blood biomarker values for MDA5⁺ DM-ILD and MDA5⁺ DM-RPILD. This review provides an overview of recent studies related to blood biomarkers, besides highlighted protein biomarkers, including antibody (anti-MDA5 IgG subclasses and anti-Ro52 antibody), genetic (exosomal microRNAs and neutrophil extracellular traps related to cell-free DNA), and immune cellular biomarkers in MDA5⁺ DM, MDA5⁺ DM-ILD, and MDA5⁺ DM-RPILD patients, hopefully elucidating the pathogenesis of MDA5⁺ DM-ILD and providing information on the early diagnosis, disease activity monitoring, and prediction of the outcome of the ILD, especially RPILD.

CONCLUSIONS

Therefore, this review may provide insight to guide treatment decisions for MDA5⁺ DM-RPILD patients and improve outcomes.

Prediction model for the pretreatment evaluation of mortality risk in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis with interstitial lung disease

Background

Anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis with interstitial lung disease (anti-MDA5 DM-ILD) is a disease with high mortality. We sought to develop an effective and convenient prediction tool to estimate mortality risk in patients with anti-MDA5 DM-ILD and inform clinical decision-making early.

Methods

This prognostic study included Asian patients with anti-MDA5 DM-ILD hospitalized at the Nanjing Drum Hospital from December 2016 to December 2020. Candidate laboratory indicators were retrospectively collected. Patients hospitalized from 2016 to 2018 were used as the discovery cohort and applied to identify the optimal predictive features using a least absolute shrinkage and selection operator (LASSO) logistic regression model. A risk score was determined based on these features and used to construct the mortality risk prediction model in combination with clinical characteristics. Results were verified in a temporal validation comprising patients treated between 2019 and 2020. The primary outcome was mortality risk within one year. The secondary outcome was overall survival. The prediction model’s performance was assessed in terms of discrimination, calibration, and clinical usefulness.

Results

This study included 127 patients, (72 men [56.7%]; median age, 54 years [interquartile range, 48-63 years], split into discovery (n = 87, 70%) and temporal validation (n=37, 30%) cohorts. Five optimal features were selected by LASSO logistic regression in the discovery cohort (n = 87) and used to construct a risk score, including lymphocyte counts, CD3+CD4+ T-cell counts, cytokeratin 19 fragment (CYFRA21-1), oxygenation index, and anti-Ro52 antibody. The retained predictive variables in the final prediction model were age, Heliotrope, fever, and risk score, and the most predictive factor was the risk score. The prediction model showed good discrimination (AUC: 0.915, 95% CI: 0.846–0.957), good calibration (Hosmer–Lemeshow test, P = 0.506; Brier score, 0.12), and fair clinical usefulness in the discovery cohort. The results were verified among patients in the temporal validation cohort (n = 38). We successfully divided patients into three risk groups with very different mortality rates according to the predictive score in both the discovery and validation cohorts (Cochran-Armitage test for trend, P < 0.001).

Conclusions

We developed and validated a mortality risk prediction tool with good discrimination and calibration for Asian patients with anti-MDA5 DM-ILD. This tool can offer individualized mortality risk estimation and inform clinical decision-making.

Interstitial Lung Disease in Dermatomyositis Without Myositis-Specific and Myositis-Associated Autoantibodies: Study of a Series of 72 Patients From a Single Cohort

Objective

The clinical features of interstitial lung disease (ILD) in patients with dermatomyositis (DM) and negative myositis autoantibodies had not been exactly demonstrated previously. This study aimed to describe and expand the phenotype of interstitial lung disease (ILD) in this cohort of patients.

Methods

A total of 1125 consecutive Chinese patients with idiopathic inflammatory myopathies (IIM) between 2006 and 2020 were screened retrospectively. All proven cases of isolated ILD with both negative myositis-specific autoantibodies (MSA) and negative myositis-associated autoantibodies (MAA) were selected for inclusion. The clinical features and outcome among this group, MDA5⁺DM (DM patients with positive anti-MDA5 antibody) and ASS (patients with positive anti-aminoacyl tRNA synthetases antibodies were recorded and compared.

Results

Of 1125 IIM patients with an average follow-up of 6 years, 154 DM patients with negative MSA and MAA (MSA/MAA) were identified, with an ILD incidence of 46.8%. DM-ILD Patients with negative MSA/MAA presented younger age at onset (p<0.001), lower incidence of elevated CA153 (p=0.03) and fever (p=0.04)than those ILD patients with MDA5⁺DM and ASS.The estimated high-resolution computed tomography patterns of ILD showed non-specific interstitial pneumonia (66.6%), followed by organizing pneumonia in patients with negative MSA/MAA. OP pattern was more common in patients with MDA5⁺DM (69.7%), and the ratios of the OP (48.7%) and NSIP (51.3%) patterns were almost equal in patients with ASS. Of these DM-ILD patients with negative MSA/MAA, 25% developed rapidly progressive interstitial lung disease (RP-ILD). Patients with RP-ILD had a shorter disease duration (p=0.002), higher percentage of positive ANA(p=0.01) and organizing pneumonia patterns (p=0.04), elevated CYFRA211(p=0.04) and decreased FiO2/PaO2 (p<0.001) than those with chronic progressive ILD. The incidence of OP pattern in RP-ILD patients with negative MSA/MAA was lower than in those RPILD patients with MDA5⁺ DM (75%) and ASS (89%) (p=0.006). The cumulative 5- and 10-year survival rates in the DM-ILD patients with negative MSA/MAA were 91% and 88%, respectively, during the long-term follow-up study. And they had more favorable survival rate compared with ILD patients with MDA5⁺DM and ASS (p<0.001). An independent prognostic factor was identified as decreased PaO2/FiO2 (hazard ratio, 0.97; p=0.004].

Conclusions

This study indicates DM-ILD patients with negative MSA/MAA had favorable long-term outcomes. Decreased baseline PaO2/FiO2 acted as an independent prognostic factor for this group of patients.

A Matrix Prediction Model for the 6-Month Mortality Risk in Patients With Anti-Melanoma Differentiation-Associated Protein-5-Positive Dermatomyositis

Objectives

The purpose of this study was to investigate the baseline independent risk factors for predicting 6-month mortality of patients with anti-melanoma differentiation-associated gene 5 (anti-MDA5)-positive dermatomyositis (DM) and develop a matrix prediction model formed by these risk factors.

Methods

The hospitalized patients with DM who completed at least 6-month follow-up were recruited as a derivation cohort. The primary exposure was defined as positive anti-MDA5 at the baseline. The primary outcome was all-cause 6-month mortality after enrollment. A matrix prediction model was developed in the derivation cohort, and another published cohort was used for external validation.

Results

In derivation cohort, 82 patients with DM were enrolled (mean age of onset 50 ± 11 years and 63% women), with 40 (49%) showing positive anti-MDA5. Gottron sign/papules (OR: 5.135, 95%CI: 1.489–17.708), arthritis (OR: 5.184, 95%CI: 1.455–18.467), interstitial lung disease (OR: 7.034, 95%CI: 1.157–42.785), and higher level of C4 (OR: 1.010, 95%CI: 1.002–1.017) were the independent associators with positive anti-MDA5 in patients with DM. Patients with anti-MDA5-positive DM had significant higher 6-month all-cause mortality than those with anti-MDA5-negative (30 vs. 0%). Among the patients with anti-MDA5-positive DM, compared to the survivors, non-survivors had significantly advanced age of onset (59 ± 6 years vs. 46 ± 9 years), higher rates of fever (75 vs. 18%), positive carcinoma embryonic antigen (CEA, 75 vs. 14%), higher level of ferritin (median 2,858 ug/L vs. 619 ug/L, all p < 0.05). A stepwise multivariate Cox regression showed that ferritin ≥1,250 μg/L (HR: 10.4, 95%CI: 1.8–59.9), fever (HR: 11.2, 95%CI: 2.5–49.9), and positive CEA (HR: 5.2, 95%CI: 1.0–25.7) were the independent risk factors of 6-month mortality. A matrix prediction model was built to stratify patients with anti-MDA5-positive DM into different subgroups with various probabilities of 6-month mortality risk. In an external validation cohort, the observed 6-month all-cause mortality was 78% in high-risk group, 43% in moderate-risk group, and 25% in low-risk group, which shows good accuracy of the model.

Conclusion

Baseline characteristics such as fever, ferritin ≥1,250 μg/L, and positive CEA are the independent risk factors for 6-month all-cause mortality in patients with anti-MDA5-positive DM. A novel matrix prediction model composed of these three clinical indicators is first proposed to provide a chance for the exploration of individual treatment strategies in anti-MDA5-positive DM subgroups with various probabilities of mortality risk.

Correlation Between Serum Tumor Marker Levels and Connective Tissue Disease-Related Interstitial Lung Disease

Objective

The main aims of this study were to explore the relationships between serum tumor markers and connective tissue disease-related interstitial lung disease (CTD-ILD) and to evaluate the clinical value of tumor markers for investigating interstitial lung disease (ILD) in patients with connective tissue disease (CTD).

Methods

The study included 235 patients with CTD (90 CTD without ILDs, 145 CTD-ILD). Clinical information and the levels of inflammatory and tumor markers, including carbohydrate antigen (CA) 19-9, CA125, carcinoembryonic antigen (CEA), CA153, and cytokeratin 19 fragments (CYFRA21-1), were obtained in all the patients.

Results

A significant difference between CTD with or without ILD and higher levels of tumor markers was observed in the CTD-ILD group, including CA19-9 (p<0.001), CEA (p<0.001), CA153 (p<0.001), and CYFRA21-1 (p<0.001). There was no significant difference in serum tumor marker levels in the various types of CTD (rheumatoid arthritis, systemic lupus erythematosus, Sjogren's syndrome, inflammatory myositis, systemic sclerosis, and mixed connective tissue disease). The levels of CA153 [odds ratio (OR)=1.159] and CYFRA21-1 (OR=2.269) were clearly related to the risk of CTD-ILD. The diagnostic value of CA153 [area under receiver operating characteristic curve (AUC)=0.736] and CYFRA21-1 (AUC=0.718) was confirmed for ILDs in CTD patients, at cut-off values of 9.45 U/mL and 2.13 ng/mL, respectively.

Conclusion

There is a positive correlation between serum tumor marker levels and CTD-ILD. Higher levels of CA153 and CYFRA21-1 suggest an increased risk of developing ILD and may therefore be useful as biomarkers for detecting CTD-ILD in the clinical setting.