A Marruchella1, M Tondini. 1. Division of Pneumology, Civic Hospital, Piacenza, Italy. almx@libero.it
Abstract
BACKGROUND: The aim of the study was to evaluate the reliability of bronchoalveolar lavage in the routine clinical assessment of patients with sarcoidosis. STUDY DESIGN: retrospective analysis. SETTING: 2 Divisions of Respiratory Medicine, both in the context of a public general hospital (Ospedale Morelli, Sondalo, Italy and Ospedale Civile, Piacenza, Italy). PATIENTS: 89 patients with definitely diagnosed diffuse infiltrative lung disease, who underwent bronchoalveolar lavage as part of their initial diagnostic work-up in the period 1991-2001. Fifty-one of them had biopsy-proven sarcoidosis. Diagnostic procedures were: transbronchial lung biopsy (n=26), bronchial biopsy (n=11), skin biopsy (n=6), surgical lung biopsy (n=4), superficial lymph node biopsy (n=3), mediastinal lymph node biopsy (n=1). In 38 patients various interstitial lung diseases were diagnosed, according to established criteria. MEASURES: we compared the percentage of BAL lymphocytes and CD4/CD8 ratio in the 2 groups. Sensitivity, specificity, positive and negative predictive value of BAL parameters were calculated with a cut-off value of 28% for BAL lymphocytes and 3.5 for CD4/CD8 ratio. RESULTS: The percentage of lymphocytes was similar in the 2 groups (p=0.19); CD4/CD8 ratio was 5.7+/-4.9 in sarcoidosis and 2.0+/-3.3 in the other patients (p=0.0001). BAL CD4/CD8 ratio in sarcoidosis had sensitivity 58%, specificity 86%, positive predictive value 85%, negative predictive value 61%. CONCLUSIONS: BAL has a low sensitivity in patients with sarcoidosis; CD4/CD8 ratio >or=3.5 strongly suggests sarcoidosis but is not specific enough if considered alone.
BACKGROUND: The aim of the study was to evaluate the reliability of bronchoalveolar lavage in the routine clinical assessment of patients with sarcoidosis. STUDY DESIGN: retrospective analysis. SETTING: 2 Divisions of Respiratory Medicine, both in the context of a public general hospital (Ospedale Morelli, Sondalo, Italy and Ospedale Civile, Piacenza, Italy). PATIENTS: 89 patients with definitely diagnosed diffuse infiltrative lung disease, who underwent bronchoalveolar lavage as part of their initial diagnostic work-up in the period 1991-2001. Fifty-one of them had biopsy-proven sarcoidosis. Diagnostic procedures were: transbronchial lung biopsy (n=26), bronchial biopsy (n=11), skin biopsy (n=6), surgical lung biopsy (n=4), superficial lymph node biopsy (n=3), mediastinal lymph node biopsy (n=1). In 38 patients various interstitial lung diseases were diagnosed, according to established criteria. MEASURES: we compared the percentage of BAL lymphocytes and CD4/CD8 ratio in the 2 groups. Sensitivity, specificity, positive and negative predictive value of BAL parameters were calculated with a cut-off value of 28% for BAL lymphocytes and 3.5 for CD4/CD8 ratio. RESULTS: The percentage of lymphocytes was similar in the 2 groups (p=0.19); CD4/CD8 ratio was 5.7+/-4.9 in sarcoidosis and 2.0+/-3.3 in the other patients (p=0.0001). BAL CD4/CD8 ratio in sarcoidosis had sensitivity 58%, specificity 86%, positive predictive value 85%, negative predictive value 61%. CONCLUSIONS: BAL has a low sensitivity in patients with sarcoidosis; CD4/CD8 ratio >or=3.5 strongly suggests sarcoidosis but is not specific enough if considered alone.