A Rare Case of Pulmonary Alveolar Proteinosis Complicated With Pulmonary Tuberculosis Treated With Colorimetry Guided Whole Lung Lavage and Anti Tuberculosis Treatment

Abstract Introduction Pulmonary Alveolar Proteinosis (PAP) is a rare syndrome of lipoproteinaceous deposits in the alveoli, resulting in various lung issues including lung failure. PAP is a restrictive lung pathology and in most cases, it is of autoimmune in nature, with increased presence of GM-CSF autoantibodies. Although the treatment comprehensively involves immunotherapy, clinical improvement and symptomatic relief is best achieved by Whole Lung Lavage (WLL) under general anesthesia. Case report In this case report, is a 46 year old female diagnosed with PAP complicated with pulmonary tuberculosis. Clinically, the patient presented with acute on chronic dyspnea and cough with Arterial Blood Gas(ABG) showing Pao2 – 49mmHg (severe PAP). Radiographic findings include diffuse ground-glass opacity with interlobular septal thickening with crazy-paving pattern. Bronchoscopy was performed from right lower lobe which stained positive for PAS suggestive of PAP. In view of hypoxemia respiratory failure, sequential Whole Lung Lavage (WLL) was performed on separate occasions. Right lung lavage was followed by left lung with one week interval. A total of 13 cycles were carried out during for each lung lavage. The drain was assessed for color, sedimentation and quantity. Optical density (OD) was measured using colorimetric method on each cycle. Inflow and outflow quantity tabulated. A standardized colorimeter (CL 223; Elico R) was used and the samples were run at 410 nanometer. Procedure was suspended when the outflow became less opaque (OD<0.5), and the same findings were confirmed with spectrophotometry. Post procedure radiography improved and ABG showed improved Pao2-70mmHg and clinically on 6 Minute Walk Test patient could walk without desaturation for 200 meters. On one month follow up the Mycobacteria Growth Indicator Tube (MGIT) grew Mycobacterium tuberculosis. Hence this case was diagnosed to be rare case of TB complicated PAP and was started on Anti Tuberculosis Treatment. Discussion Several etiological agents have been identified for PAP in this population but the association of alveolar proteinosis and pulmonary tuberculosis has been rarely reported. WLL has been effectively carried out to provide clinical improvement of the symptoms in our case. We utilized Optical density by colorimeter as a surrogate marker to decide on suspending the lavage. Single lung ventilation was maintained during the procedure and no complications were encountered. In conclusion, superinfection of M. tuberculosis may raise risk of complications in patients with PAP. Therefore, these patients should be monitored for superinfections and appropriate treatment for co infections should be initiated on time.