Bronchoalveolar lavage fluid evaluation in rheumatoid arthritis.

Rheumatoid arthritis (RA), a systemic disorder of unknown cause, is associated with a variety of well-recognized pulmonary abnormalities including interstitial lung disease. To investigate possible pathogenic events in this disorder, we performed bronchoalveolar lavage (BAL) in 24 patients with classic or definite RA. Using radiographic and physiologic parameters as well as BAL cell differentials, 3 distinct groups emerged. Group I consisted of 9 patients with evidence of clinical interstitial lung involvement. Group II consisted of 5 patients without evidence of clinical interstitial lung disease (normal chest roentgenogram and functional testing) but who had abnormal BAL cellular differentials. The 10 remaining patients (Group III) had no evidence of clinical interstitial lung disease and had normal BAL cell differentials. Bronchoalveolar lavage in Group I had a significantly increased percentage of neutrophils (12.4 +/- 4.2; p less than 0.05) compared with Group II (2.4 +/- 0.8) and Group III (2.9 +/- 0.6). All patients in Group II had elevated BAL lymphocytes (24.4 +/- 6.4) compared with Group I (10.1 +/- 3.8; p greater than 0.05) and Group III (5.4 +/- 0.7; p less than 0.01). Both Groups I and II had detectable IgM in BAL (0.02 +/- 0.01 and 0.04 +/- 0.02 mg/mg of albumin, respectively), whereas Group III patients and normal control subjects did not (p less than 0.01). There was a marked reduction in BAL T-lymphocyte Leu 3/Leu 2A (helper/suppressor) cell ratios in Group I (0.92 +/- 0.02; p less than 0.05) compared with Group II (2.6 +/- 0.6) and Group III (1.6 +/- 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)