In a cross-sectional study, these researchers investigated the relationship of RA with type and severity of pulmonary function test (PFT) abnormalities in comparison to the general population, accounting for smoking. Two acceptable measurements were obtained from all individuals: % predicted values of FEV1 and FVC (calculated on the basis of age, sex, race and height).
RA cases were identified by self-report and current DMARD use, as previously published in the UK Biobank. They compared RA cases with general population controls in the UK Biobank who denied having RA or another systemic rheumatic disease. Outcomes were continuous PFT results, type of PFT abnormality (i.e., restrictive pattern [% predicted FVC<80], obstructive pattern [FEV1/FVC <0.7] or either abnormality), and level of severity (i.e., mild, moderate or severe) according to standard clinical PFT cutpoints from population prediction equations. Covariates included age, sex, smoking status and pack-years. The researchers used linear regression to compare RA cases with controls for continuous PFT results. They used logistic regression to estimate adjusted odds ratios for type and severity of PFT abnormality, comparing RA cases with controls.
The bottom line: RA patients were more likely than general population controls to have restrictive (36% increased risk) or obstructive pattern (28% increased risk) abnormalities on PFTs obtained for research purposes. In addition to restriction, said Ms. Prisco, obstructive lung diseases may be a pulmonary manifestation of RA not explained by smoking.
Leaky Gut
Characterized by damage to the lining of the intestine, leaky gut leads to increased intestinal permeability. According to researcher Carolin Brandl of the Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany, the purpose of this study was to test whether a leaky gut occurs before the onset of human RA and experimental arthritis, and to seek for evidence that immune cells from the gut migrate to the joints (abstract 0492).4
The data in this study show that intestinal barrier dysfunction does precede the onset of RA and allows the trafficking of immune cells from the gut to the joints. Targeting intestinal tight junction function may, therefore, provide a way to prevent the onset of RA.
Can a Computer Score Joint Space in Hand Radiographs?
The final presentation in this abstract session took a turn away from RA complications. Yun-Ju Huang, MD, of the Chang Gung Memorial Hospital, Taoyuan City, Taiwan (Republic of China), discussed the results of a study intended to assess the performance of a deep-learning model for detecting and scoring joint space automatically in comparison to physician performance (abstract 0493).5
