Specific bronchoalveolar lavage fluid T cells associate with disease in a pair of monozygotic twins discordant for sarcoidosis

A 49-year-old Caucasian woman had an acute onset of sarcoidosis. Bronchosco py with bronchoalveolar lavage (BAL) showed a pronounced accumulation of BA L fluid CD4(+) T cells expressing the T-cell receptor (TCR) AV2S3 gene. In line with this observation, the patient was HLA-DR17 positive, previously s hown to strongly correlate with lung compartmentalized AV2S3(+) T cells. At follow-up after recovery, reduced numbers of BAL fluid AV2S3(+) T cells we re found. Interestingly, BAL fluid of a healthy monozygotic twin sister con tained normal numbers of AV2S3(+) lung T cells. This report shows the T-cel l repertoire of BAL fluid T cells to correlate with the disease (sarcoidosi s), indicating a local and specific immune response triggered by an unknown antigen in sarcoidosis.