PURPOSE: Pulmonary alveolar proteinosis (PAP) is a rare disorder in which lipoproteinaceous material accumulates within alveoli and with variable natural history. Although there were some reviews and some case reports on the disease recent years, seldom of them were focus on the change of pulmonary function testing (PFT). The aim of the study was to analysis the characters of PFT for the diagnosis and treatment of PAP.
METHODS: All 25 patients (male 17, female 8, aged 15∼54 yrs) were confirmedly diagnosis of PAP by transbronchial lung biopsy, in which alveoli filled with abundant eosinophilic granular material that stains with positive periodic acid-Schiff and negative alcian blue, in our institute from 1997 to 2006. Spirometry and diffusion capacity were measured in all patients and lung volumes were tested in 10 patients in accordance with the procedure recommended by ATS. PFTs were impairment if parameters were less than 80% of prediction. 10 of 25 cases were treated with therapeutic lung lavage and their PFT were compared before and after lavage.
RESULTS: Percentage of prediction were 81.2±15.9 in FVC, 85.3±16.0 in FEV1,107.8±18.1 in PEF, 50.6±22.1 in DLCO, 71.1±20.5 DLCO/VA, 80.6±15.9 in TLC, and 82.9±26.8 in RV. The ratio of FEV1/FVC was 0.89±0.05, and RV/TLC was 32.1±6.7. Reduction of FVC, FEV1, FEV1/FVC, PEF, DLCO, DLCO/VA, were found in 12 (48%), 9 (36%), 0, 0, 22 (88%) and 14 (56%) out of 25 patients, respectively. Decrease of TLC and RV were found in 5 of 10 patients. After lung lavage treatment, significantly improvement were found in DLCO (20.4%, p=0.006) and DLCO/VA (14.2%, p=0.011), but not in FVC and FEV1 (5.4% and 5.2%, both p>0.2).
CONCLUSION: Impairment of pulmonary function was found in PAP with variable severity, the impairment of diffusion capacity was more severe than that of lung volumes. No airflow limitation was found in these PAP patients.
CLINICAL IMPLICATIONS: Pulmonary function testing is valuable in evaluation of lung function impairment in PAP, and it is good for the follow up study in particular.
DISCLOSURE: Jin-Ping Zheng, No Financial Disclosure Information; No Product/Research Disclosure Information