Lobar flexible fiberoptic lung lavage: therapeutic benefit in severe respiratory failure in pulmonary alveolar proteinosis and influenza A H1N1 pneumonia

CSF2RB mutation-related hereditary pulmonary alveolar proteinosis: the "long and winding road" into adulthood

Genetic analysis pre-lung transplantation diagnosed a case of hereditary pulmonary alveolar proteinosis (PAP) complicated by fibrosis in adulthood. The need for genetic testing in GM-CSF autoantibody negative and unclassifiable PAP is highlighted. https://bit.ly/3QcsYwM.

Autoimmune Pulmonary Alveolar Proteinosis That Improved after a COVID-19 Episode

Autoimmune pulmonary alveolar proteinosis (APAP) is caused by macrophage dysfunction owing to the presence of anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies. A 77-year-old man with APAP was referred to our hospital for whole-lung lavage (WLL) due to oxygenation exacerbation and pulmonary shadows. The patient had had coronavirus disease 2019 (COVID-19) during the APAP evaluation before WLL. About three months after COVID-19 resolved, his oxygenation and shadow reflecting APAP had obviously improved, thus avoiding the need for WLL. We suspected that the improvement in APAP was due to various immunological reactions induced by COVID-19.

Alveolar Proteinosis in COVID-19: Clinical Case

Pulmonary alveolar proteinosis (PAP) is a rare, diffuse lung disease characterized by accumulation of lipoprotein in lung surfactant in the alveolar space and terminal bronchioles, leading to impaired gas exchange and arterial hypoxemia. We present the case of a 51-year-old woman who was admitted with a diagnosis of severe SARS-CoV-2 pneumonia. Her condition did not improve with corticosteroids. A chest CT scan revealed ground-glass opacities in all lung lobes, with septal thickening. A differential diagnosis was proposed with other diseases. Bronchoscopy revealed milky bronchoalveolar lavage fluid, and staining with periodic acid-Schiff was positive, thus indicating PAP. Therefore, the patient underwent whole lung lavage, which led to clinical, radiological, and functional improvement. In the context of the COVID-19 pandemic, differential diagnosis ensures that appropriate attention is given to less prevalent entities such as PAP.

Viral pneumonia and pulmonary alveolar proteinosis: the cause and the effect, case report

Pulmonary alveolar proteinosis (PAP) is a rare lung disease characterized by the accumulation of amorphous lipoproteinaceous material in the distal air spaces due to defective surfactant clearance by alveolar macrophages. This leads to impaired gas exchange and arterial hypoxemia of varying degrees. Although autoimmune type of PAP is thought to be idiopathic, this focused report highlights the possible relationship between viral pneumonia and autoimmune PAP (APAP) in terms of causation, superinfection and effect of treatments. We report a newly diagnosed case of APAP with a possible viral causation "trigger" for the confirmed serum anti-granulocyte macrophage-colony stimulating factor (GM-CSF) antibody. To the best of our knowledge, this is the first report that describe and discuss this issue. The patient is a 38-year-old, ex-smoker woman who had had a progressively worsening dyspnea and a persistent, productive cough for more than 4 months. It was thought to be a community acquired pneumonia (CAP) case and was treated with multiple antibiotics which yielded no improvement in her condition. Physical examination revealed mild hypoxemia and minimal bilateral fine crepitations despite marked alveolar filling on chest X-ray (CXR). She underwent a bronchoscopic procedure that revealed PAP. The case also describes an acute flare up of the condition during the course of the disease caused by a confirmed H1N1 influenza infection. APAP should be considered in the differential diagnosis of recurrent pneumonia not responding to treatment. In this case report we suggest the possible role of viral causation "trigger" or cross-reactivity of GM-CSF antibodies that lead to APAP. We also describe the provided management, the response to the antiviral therapy and the diagnostic and management challenges that was encountered during the follow up.

Combined-modality therapy for pulmonary alveolar proteinosis in a remote setting: a case report

Background

Pulmonary alveolar proteinosis (PAP) is a rare lung disease characterized by accumulation of phospholipoproteinaceous material in the alveoli. The presentation is nonspecific but typically includes dyspnea; the spectrum of disease includes rapidly progressive hypoxic respiratory failure. Whole lung lavage (WLL) is the treatment of choice in symptomatic PAP, but transient worsening of oxygenation sometimes requires salvage modalities of support such as extracorporeal membrane oxygenation (ECMO). Granulocyte macrophage colony-stimulating factor (GM-CSF) plays a role in the pathophysiology of PAP. We highlight a case of severe PAP treated with exogenous GM-CSF and sequential lobar lavage due to the unavailability of salvage methods of oxygenation.

Case presentation

A 36 year old female was admitted with fevers, chills, and progressive dyspnea. On presentation she was tachypneic, tachycardic, and hypoxemic; labs revealed leukocytosis and lactic acidosis. Chest CT identified diffuse ground glass opacities in a ‘crazy-paving’ pattern. Following intubation due to impending respiratory failure, bronchoscopy with bronchoalveolar lavage was performed. The lavage return stained positive with Periodic Acid Schiff, confirming the diagnosis of PAP. Continued deterioration necessitated treatment; however, at this geographically remote center without ECMO services WLL was judged to carry significant risk. Nebulized GM-CSF was administered without significant improvement. Subcutaneous GM-CSF was administered and isolated subsegmental lavages of the bilateral upper lobes were performed, with rapid improvement in oxygenation. Additional sequential lobar lavage and continued GM-CSF therapy as an outpatient resulted in complete resolution of oxygen requirement and return to normal pulmonary physiology.

Conclusions

The autoimmune form of PAP is the most common, indicating that therapy with GM-CSF may play an important role for many patients. Treatment with WLL may be impractical in some clinical settings due to the expertise and salvage modalities required. Sequential lobar lavage requires less specialized expertise and may incur less risk of refractory hypoxemia. We posit that this combined-modality therapy is ideally suited to geographically-remote centers such as our own.

Rare Presentation of Pulmonary Alveolar Proteinosis Causing Acute Respiratory Failure

Pulmonary alveolar proteinosis (PAP) is a rare condition characterized by dysfunctional alveolar macrophages, which ineffectively clear surfactant and typically cause mild hypoxemia. Characteristic Computed Tomography findings are septal reticulations superimposed on ground-glass opacities in a crazy paving pattern, with a clear juxtaposition between affected and unaffected parenchyma. While traditionally PAP was diagnosed via biopsy, bronchoalveolar lavage (BAL) is usually sufficient; the fluid appears milky, and on microscopic examination there are foamy macrophages with eosinophilic granules and extracellular hyaline material that is Periodic Acid-Schiff positive. Standard therapy is whole lung lavage (WLL), although novel treatments are under development. The case presented is a 55-year-old woman with six months of progressive dyspnea, who developed hypoxemic respiratory failure requiring mechanical ventilation; she had typical findings of PAP on imaging and BAL. WLL was ultimately successful in restoring adequate oxygenation. Respiratory failure of this magnitude is a rare finding in PAP.