Autoimmune pulmonary alveolar proteinosis (aPAP) is an ultra-rare pulmonary disease. Due to heterogeneity and small patient cohorts, no standardized treatment protocol exists. Whole lung lavage (WLL) is considered the gold standard therapy and aims to remove the highest protein amount by flushing the lung with the lowest possible instilled volume. We report a new protocol for a new modified lavage technique (nMLT) in which controlled repetitive manual hyperinflation (MH) and intermittent chest percussion are used to enhance WLL efficacy.
We included all patients with aPAP treated with nMLT between 2013 and 2018. nMLT consisted of repetitive MH with intermittent chest percussion every third wash cycle. We reported: instilled and recovered volume, protein concentration, and optical density (OD) using spectrophotometry. Pulmonary function (FVC %predicted and DLCO %predicted) and serum biomarkers (LDH, CA 15 − 3, SP-D, and YKL-40) two months prior and post nMLT, and one year after nMLT treatment were evaluated. Data are displayed as mean (± SD) or median [IQR]. Comparisons were made using Student t-test and Wilcoxon test.
We included 11 patients (64% male) in whom a total of 65 nMLTs were performed. One nMLT consisted of 15 [12–18] wash cycles. Protein removal was 9.80 [7.52–12.66] grams per nMLT. After 3–4, 6–7, and 9-10L of instilled and recovered volume 56 [49–61] %, 81 [77–84] % and 91 [88–94] % of protein was removed respectively. OD was measured 116 times and increased from 1.13 (± 0.52) to 1.31 (± 0.52) after MH (p < 0.001). Our study also showed that pulmonary function improves after WLL with nMLT. Improvement of biomarkers was only reflected by CA 15 − 3. No adverse events related to the procedure were observed.
Efficacy of WLL seems to be enhanced by using manual hyperinflation and applying this every third cycle. Our technique of WLL with nMLT could be used to increase the amount of protein recruited while instilling the lung with the smallest volume of fluid as possible. The duration of anesthesia and the risk of complications is thereby reduced.