CHEST Guidelines-Response_chest

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This document highlights key issues in defining airway obstruction (AO) in patients with rheumatoid arthritis (RA) and the role of anticitrullinated protein antibodies (ACPA). The primary focus is on Matson et al.'s study, which diagnosed AO using the fixed FEV/FVC ratio of 0.70—considered outdated by current European Respiratory Society and American Thoracic Society guidelines, which favor a z-score method. The lack of consensus on AO definitions results in variable frequencies reported in RA patients.<br /><br />The response from Matson acknowledges this and re-evaluates their dataset using both methods, showing minimal difference in patient classification: 38 patients identified by the fixed ratio and 37 by the z-score, with an overlap of 30 patients. This suggests substantial agreement between methods, though Matson concedes the physiological z-score method accounts for factors like age, sex, height, and ethnicity, notwithstanding the operational simplicity of the fixed ratio for broader, diverse studies.<br /><br />Additionally, the critique points out the oversight of ACPA status in Matson’s study. Other findings, particularly from an Algerian study, have demonstrated significant differences in AO prevalence in ACPA-positive versus ACPA-negative RA patients, suggesting a link potentially driven by oxidative stress due to citrulline reactivity. Matson responds by defending their approach to antibody testing, highlighting variations in RA populations studied and suggesting these as factors influencing results.<br /><br />Overall, the document calls for standardized AO definitions in RA and the incorporation of ACPA status in future research, ensuring a more unified and thorough understanding of pulmonary implications in RA. This synthesis reflects a comprehensive exchange of scientific ideas, illustrating the complexity and evolving nature of medical research.

Keywords

airway obstruction

rheumatoid arthritis

anticitrullinated protein antibodies

FEV/FVC ratio

z-score method

Matson study

ACPA status

pulmonary implications

oxidative stress

standardized definitions