Pulmonary alveolar proteinosis (PAP) in exogenous toxic alveolitis (ETA) patients

PAP is a rare lung disease. It can be autoimmune (about 90 % of all PAP), congenital and secondary in patients with hematological malignancies, after occupational exposure and other. Aim: to demonstrate 3 cases of PAP in patients with ETA, approaches to treatment. Methods: 3 male patients (37, 32, 39 yrs. old) with PAP associated by ETA were investigated. X-ray,computed tomography (CT), complex lung function examination, broncholoalveolar lavage (BAL), PAS staining of BAL fluid (BALF), lung biopsy were performed. The patients had an occupational exposure to paints, corrosive and irritant substances, aluminium, resin, lubricants, hardeners. The duration of the exposure was 1-8-12 yrs. Results: In 2 patients PAP was diagnosed 2-4 yrs. after first manifestations of ETA (dyspnoea, CT signs: interstitial or “ground glass”; restrictive type of functional disorders, crepitation on auscultation). 1 patient had a cough for 4 yrs. before acute onset of the disease (dyspnoea, fever, weight loss, reduction of vital capacity, crepitation). CT revealed “crazy paving”. Morphological signs: thickening of interalveolar septum, filling of the alveoli by PAS-positive substancein all samples, lymphoid infiltration (1 patient), alveolar macrophages in the lumen of the alveoli (1 patient). The course of segmental BALs was performed to all patients with clinical and CT improvement. 2 patients continued systemic corticosteroid treatment. Conclusion: Secondary PAP induced by exposure to harmful aerosols may develop on the background of ETA or, less frequently, precede it. In that cases several segmental BALs are preferable to the whole BAL. Corticosteroids should be administrated in ETA progression.