The effect of D-penicillamine on lung function parameters (diffusion capacity) in rheumatoid arthritis

Sequential lung function tests were performed on 28 rheumatoid arthritis (RA) patients who were treated with D-penicillamine (total of 101 treatment years) and on 42 control RA patients who were not treated or who were treated with NSAIDs, chloroquine, gold salts, corticosteroids, salazopyrine or methotrexate. A decline in lung function parameters was found in both groups, although it was only significant for the carbon monoxide diffusing capacity corrected for lung volume (DLCO/VL). This decrease in DLCO/VL was less pronounced in the D-penicillamine group (mean -6.9%) than in the control group (mean -11.3%). This difference could not be attributed to smoking, which was more frequent in the control group. When reviewing only the patients with an initial DLCO/VL < 80% of the predicted value and having, with some exceptions, chest X-ray abnormalities, we even observed an amelioration in the mean DLCO/VL in the D-penicillamine group, in contrast with a deterioration in the control group (+5.1% versus -5.6%).