A WORKING FORMULATION FOR THE STANDARDIZATION OF NOMENCLATURE AND FORCLINICAL STAGING OF CHRONIC DYSFUNCTION IN LUNG ALLOGRAFTS

A clinically applicable, standardized method for assessing functional results after lung transplantation is required to evaluate factors tha t may affect long-term outcome, to permit comparison of results from d ifferent centers, and to evaluate results of clinical trials. An ad ho c working group was established under the auspices of the Internationa l Society for Heart and Lung Transplantation for the purpose of develo ping such a clinically applicable system. Chronic allograft dysfunctio n is often associated with pathologic findings of obliterative bronchi olitis, the cause of which has not been defined. Physiologically, such dysfunction is associated with obstructive airways disease. The group concluded that the forced expiratory volume in 1 second was the most reliable and consistent indicator of graft dysfunction, excluding othe r identifiable causes. The term bronchiolitis obliterans syndrome was adopted to describe such dysfunction, recognizing that there may or ma y not be pathologic evidence of bronchiolitis obliterans present. Four stages of bronchiolitis obliterans syndrome were defined, each with t wo subcategories to indicate whether pathologic evidence of obliterati ve bronchiolitis had been identified. This working formulation will re quire reappraisal in the future to reassess its practical application and to make such adjustments as may seem appropriate.