[Pulmonary sarcoidosis. Study of the distribution of active alveolitis assessed by comparison of data from radiological examination, gallium 67 scintigraphy and double bronchoalveolar lavage].

Abnormal uptake of gallium in alveolar structures, raised lymphocyte levels, ECA and, to a lesser degree, proteins in alveolar washings are the principal currently known criteria used to recognise cases of sarcoidosis with persistent immunological activity. The contribution of data concerning broncho-alveolar washings (BAW) in the context of this diagnostic assessment has never been the subject of a critical evaluation. It would nevertheless seem that the distribution of sarcoidosis lesions is not always diffuse and homogeneous, leading to the possibility of errors of assessment in this technique. The aim of the present study was to assess the true existence, degree and consequences of this risk. It was based upon the study of 41 cases of active pulmonary sarcoidosis. Search for homogeneity and heterogeneity between lesions and active alveolitis involved precise radiological study, gallium isotope scan with determination of the index of uptake as well as the quality of the latter, and double BAW carried out in the most radioactive and least radioactive regions respectively. Comparative study of the results obtained showed that zones of active alveolitis were distributed unevenly and heterogeneously in more than half of the patients (71% for gallium and 54% for BAW). This would explain the fact that in 14 cases (34%) criteria of alveolar activity were present in only one of the two specimens of washings. Identification of the zones which should be included in BAW cannot be determined accurately by radiological analysis, regardless of the degree and distribution of radiological abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)