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Lung ultrasound outperformed symptom-based screening questionnaires for ILD-RA detection, according to a recent study published in RMD Open.

Lung ultrasound outperformed symptom-based screening tools for the detection of interstitial lung disease associated with rheumatoid arthritis (ILD-RA), according to a study published in RMD Open.

The findings are based on a cross-sectional analysis conducted by Marie Vermant, MD, and colleagues that assessed the role of lung ultrasound, using a 72-zone approach, compared with symptom-based questionnaires to detect ILD in patients with RA.

The study included 116 adult patients diagnosed with RA. All patients underwent high-resolution CT, pulmonary function tests, and lung ultrasound. They also completed questionnaires about their pulmonary and rheumatologic symptoms. The questionnaires examined the presence of dyspnea and cough, and they included the modified Medical Research Council (mMRC) dyspnea scale and the Visual Analogue Scale for Cough (VAS Cough).

Kruskal-Wallis (KW) tests evaluated the correlation between clinical–radiological high-resolution CT score (no ILD, non-specific abnormalities, subclinical ILD or ILD) and the B-lines on lung ultrasound, predicated diffusion capacity (DLCO%pred), predicted forced vital capacity (FVC%pred), VAS Cough, and mMRC.

Most patients were women, seropositive, and ever-smokers. The majority were in remission, as shown by a median disease activity score 28-C-reactive protein of 2.2.

The researchers detected clinically relevant ILD in 11.8% and subclinical interstitial lung changes in 5.5% of patients. The researchers found B-lines (KW c²=41.2; P=<0.001) and DLCO%pred (KW χ2=27.4; P=<0.001) were significantly associated with the clinical–radiological score, in contrast to FVC%pred, mMRC, and VAS cough. When using the purely radiologic score, this correlation remained significant for B-lines (KW c²=24.16; P=<0.001) and DLCO%pred (KW χ2=19.7; P=<0.001).

Cough and dyspnea only weakly predicted the ILD score in the sensitivity–specificity analyses. The sensitivity and specificity for the presence of dyspnea to detect the clinical–radiological score 3 were 62% and 50%, respectively. For the presence of cough, the sensitivity and specificity to detect score 3 were 54% and 66%, respectively.

“While further collaborative research is necessary to define consensus protocols to identify subjects for screening, determine appropriate cut-offs for the number of B-lines, and define optimal screening intervals, our findings suggest that [lung ultrasound] could have a transformative role in the early detection of RA-ILD,” the investigators concluded.