Diagnostic significance of carcinoembryonic antigen and anti-MDA5 antibodies in polymyositis/dermatomyositis-associated rapidly progressive interstitial lung disease.

OBJECTIVES

To explore relationship between lung cancer-related biomarkers and polymyositis/dermatomyositis (PM/DM) complicated with interstitial pneumonia, so as to identify serological markers for PM/DM rapidly progressing interstitial pneumonia (RP-ILD).

METHODS

This study was a control study in which clinical and laboratory data were collected from the Fujian Medical University Affiliated Second Hospital between August 2019 and January 2024. The tumor markers assessed included carcinoembryonic antigen (CEA), cytokeratin-19 fragment (CYFRA21-1), and neuron-specific enolase (NSE). The study aimed to compare clinical indicators and lung cancer biomarker differences among patients with PM/DM exhibiting varying characteristics. Data analysis was conducted using Spearman's rank correlation, logistic regression analysis, and receiver operating characteristic (ROC) curve analysis.

RESULTS

The study included a total of 130 patients, of whom 99 (76.15%) were diagnosed with interstitial lung disease (ILD). Among these, 73 patients had chronic ILD, while 26 exhibited RP-ILD. The remaining 31 individuals (23.85%) did not have ILD. In terms of clinical symptoms, the incidence of Gottron's sign and shortness of breath was significantly higher in the RP-ILD group compared to the chronic ILD and non-ILD groups. In terms of clinical markers, RP-ILD patients had much higher levels of serum ferritin, CEA, and CYFRA21-1 than those with chronic ILD (C-ILD) and non-ILD (N-ILD). Conversely, the RP-ILD group showed significantly reduced values for the oxygenation index, forced vital capacity, carbon monoxide diffusion capacity, and CD3CD4 T cell counts compared to the other groups. A significant correlation was observed between the presence of anti-melanoma differentiation-associated gene 5 (MDA5) antibodies, serum CEA levels, CD3CD4 T cell ratio, and oxygenation index with PM/DM complicated by RP-ILD. The combination of serum CEA levels and anti-MDA5 antibodies demonstrated the highest diagnostic value for PM/DM-RPILD, demonstrating a sensitivity of 88.9% and a specificity of 81.6%, with an area under the curve of 0.923 (P<0.001).

CONCLUSIONS

Elevated serum concentrations of lung cancer-associated biomarkers, notably CEA, alongside the presence of anti-MDA5 antibodies, exhibit a significant correlation with PM/DM complicated by RP-ILD. This combination of biomarkers could enhance the identification of RP-ILD subtypes in PM/DM patients.