The prevalence of pulmonary airway lesions is high in HTLV-1-positive rheumatoid arthritis: a cross-sectional observational study.

OBJECTIVE

To investigate whether human T cell leukaemia virus type 1 (HTLV-1) infection increases the risk of respiratory complications in patients with RA, focusing on high-resolution computed tomography (HRCT) findings and clinical features.

METHODS

We retrospectively analysed 30 HTLV-1-positive patients with RA enrolled in the HTLV-1 RA Miyazaki Registry who had undergone chest HRCT. For each patient, three age- and sex-matched HTLV-1-negative RA patients (n = 90) were recruited as controls. We compared pulmonary abnormalities on HRCT, RA disease activity, medication use and systemic complications between the groups. In the HTLV-1-positive group, we also assessed the relationship between HTLV-1 proviral load (PVL) and pulmonary findings.

RESULTS

Although age and disease duration were similar between groups at the time of HRCT, HTLV-1-positive patients had significantly higher disease activity (CDAI: 6.4 vs 3.3, P = 0.01; SDAI: 7.28 vs 3.46, P = 0.01), greater glucocorticoid use (70% vs 36%) and lower biologics use (33% vs 61%). Abnormal pulmonary findings were observed in ≈50% of both groups; however, bronchiolitis was more frequent in HTLV-1-positive patients, while interstitial lung disease patterns were comparable. HTLV-1 PVL did not differ significantly based on the presence or absence of pulmonary lesions.

CONCLUSION

HTLV-1 infection may link to an increased prevalence of airway lesions, such as bronchiolitis and bronchiectasis, in RA patients. These findings suggest that screening for HTLV-1 should be considered in RA patients, especially those with respiratory symptoms or complications.