The pathology of interstitial lung disease in nylon flock workers

lengths of synthetic fibers are applied to backing fabric to produce plush material. In response to an apparent outbreak of interstitial lung disease in flock workers, the Centers for Disease Control hosted a clinical-patholo gical workshop to identify the defining characteristics of the disease and possible etiologic agents. Six pathologists reviewed 15 biopsies of 15 case s (out of a clinical caseload of 20 patients) and assessed the pattern, ext ent and degree of pulmonary inflammation, fibrosis, and other changes. A co nsensus clinical-pathologic diagnosis was reached for each patient and corr elated with clinical and radiologic findings. Four of eight open lung biops ies and one of seven closed (transbronchial) lung biopsies demonstrated a c haracteristic pattern to which the descriptive terminology lymphocytic bron chiolitis and peribronchiolitis with lymphoid hyperplasia was applied. The other biopsies showed nonspecific inflammatory changes, airspace organizati on, and diffuse alveolar damage. One open lung biopsy demonstrated respirat ory bronchiolitis with lymphoid hyperplasia. None of the lung biopsies show ed more than mild interstitial fibrosis and no granulomas were identified. The consensus of the workshop was that lymphocytic bronchiolitis and peribr onchiolitis with lymphoid hyperplasia was a characteristic and distinctive pattern of injury in the flock workers' lung biopsies. Although the etiolog y of this disease remains undefined at present, the injury pattern and envi ronmental studies suggest a chronic immunologic response to inhaled materia l.