A case of autoimmune pulmonary alveolar proteinosis during the course of treatment of rapidly progressive interstitial pneumonia associated with anti-MDA5 antibody-positive dermatomyositis.

BACKGROUND: Autoimmune pulmonary alveolar proteinosis (APAP) is a diffuse lung disease that causes abnormal accumulation of lipoproteins in the alveoli; however, its pathogenesis remains unclear. Recently, APAP cases have been reported during the course of dermatomyositis. The combination of these two diseases may be coincidental; however, it may have been overlooked because differentiating APAP from a flare-up of interstitial pneumonia associated with dermatomyositis is challenging. This didactic case demonstrates the need for early APAP scrutiny. CASE PRESENTATION: A 50-year-old woman was diagnosed with anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody-positive dermatitis and interstitial pneumonia in April 2021. The patient was treated with corticosteroids, tacrolimus, and cyclophosphamide pulse therapy for interstitial pneumonia complicated by MDA5 antibody-positive dermatitis, which improved the symptoms and interstitial pneumonia. Eight months after the start of treatment, a new interstitial shadow appeared that worsened. Therefore, three additional courses of cyclophosphamide pulse therapy were administered; however, the respiratory symptoms and interstitial shadows did not improve. Respiratory failure progressed, and 14 months after treatment initiation, bronchoscopy revealed turbid alveolar lavage fluid, numerous foamy macrophages, and numerous periodic acid-Schiff-positive unstructured materials. Blood test results revealed high anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antibody levels, leading to a diagnosis of APAP. The patient underwent whole-lung lavage, and the respiratory disturbance promptly improved. Anti-GM-CSF antibodies were measured from the cryopreserved serum samples collected at the time of diagnosis of anti-MDA5 antibody-positive dermatitis, and 10 months later, both values were significantly higher than normal. CONCLUSIONS: This is the first report of anti-MDA5 antibody-positive dermatomyositis complicated by interstitial pneumonia with APAP, which may develop during immunosuppressive therapy and be misdiagnosed as a re-exacerbation of interstitial pneumonia. In anti-MDA5 antibody-positive dermatomyositis, APAP comorbidity may have been overlooked, and early evaluation with bronchoalveolar lavage fluid and anti-GM-CSF antibody measurements should be considered, keeping the development of APAP in mind.

Alveolar macrophage lipid burden correlates with clinical improvement in patients with pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a life-threatening, rare lung syndrome for which there is no cure and no approved therapies. PAP is a disease of lipid accumulation characterized by alveolar macrophage foam cell formation. While much is known about the clinical presentation, there is a paucity of information regarding temporal changes in lipids throughout the course of disease. Our objectives were to define the detailed lipid composition of alveolar macrophages in PAP patients at the time of diagnosis and during treatment. We performed comprehensive mass spectrometry to profile the lipid signature of alveolar macrophages obtained from three independent mouse models of PAP and from PAP and non-PAP patients. Additionally, we quantified changes in macrophage-associated lipids during clinical treatment of PAP patients. We found remarkable variations in lipid composition in PAP patients, which were consistent with data from three independent mouse models. Detailed lipidomic analysis revealed that the overall alveolar macrophage lipid burden inversely correlated with clinical improvement and response to therapy in PAP patients. Specifically, as PAP patients experienced clinical improvement, there was a notable decrease in the total lipid content of alveolar macrophages. This crucial observation suggests that the levels of these macrophage-associated lipids can be utilized to assess the efficacy of treatment. These findings provide valuable insights into the dysregulated lipid metabolism associated with PAP, offering the potential for lipid profiling to serve as a means of monitoring therapeutic interventions in PAP patients.

Déficit congénito de proteína de surfactante: caso clínico / Deficiency of surfactant protein: Case report

Introducción: El déficit congénito de surfactante es una entidad de diagnóstico inhabitual en recién nacidos. Se reporta un caso clínico de déficit de proteína B del surfactante, se revisa el estudio, tratamiento y diagnóstico diferencial de los déficit de proteínas del surfactante y enfermedad crónica intersticial de la infancia. Caso clínico: Recién nacido de término que cursa dificultad respiratoria, con velamiento pulmonar recurrente y respuesta transitoria a administración de surfactante. El estudio inmunohistoquímico y genético confirmaron diagnóstico de déficit de proteína B de surfactante. Conclusiones: La enfermedad pulmonar congénita requiere un alto índice de sospecha. El déficit de proteína B de surfactante genera un cuadro clínico progresivo y mortal en la mayoría de los casos, al igual que el déficit de transportador ATP binding cassette, sub-family A member 3 (ABCA3). El déficit de proteína C es insidioso y puede presentarse con un patrón radiológico pulmonar intersticial. Debido a la similitud en el patrón histológico, el estudio genético permite una mayor certeza en el pronóstico y la posibilidad de entregar un adecuado consejo genético.

Introduction: Congenital surfactant deficiency is a condition infrequently diagnosed in newborns. A clinical case is presented of surfactant protein B deficiency. A review is performed on the study, treatment and differential diagnosis of surfactant protein deficiencies and infant chronic interstitial lung disease. Case report: The case is presented of a term newborn that developed respiratory distress, recurrent pulmonary opacification, and a transient response to the administration of surfactant. Immunohistochemical and genetic studies confirmed the diagnosis of surfactant protein B deficiency. Conclusions: Pulmonary congenital anomalies require a high index of suspicion. Surfactant protein B deficiency is clinically progressive and fatal in the majority of the cases, similar to that of ATP binding cassette subfamily A member 3 (ABCA3) deficiency. Protein C deficiency is insidious and may present with a radiological pulmonary interstitial pattern. Due to the similarity in the histological pattern, genetic studies help to achieve greater certainty in the prognosis and the possibility of providing adequate genetic counselling.

Proteinosis alveolar. Respuesta al tratamiento con factor estimulante de colonias de granulocitos y macrófagos por vía inhalada / Response to Inhaled Granulocyte-Macrophage Colony-Stimulating Factor in a Patient With Alveolar Proteinosis

La proteinosis alveolar pulmonar (PAP) es una rara enfermedad que se caracteriza por la acumulación en el alvéolo pulmonar de un material lipoproteico derivado del surfactante alveolar, lo que provoca el consiguiente deterioro del intercambio gaseoso. Su patogenia está relacionada con alteraciones en la capacidad fagocítica del macrófago alveolar. Desde hace pocos años existe un nuevo tratamiento para la PAP consistente en la administración de factor estimulante de colonias de granulocitos y macrófagos (GM-CSF) por vía subcutánea. El tratamiento comúnmente aceptado y que ha demostrado mayor eficacia en la PAP es el lavado pulmonar total. Una alternativa a este tratamiento es la administración por vía inhalada en aerosolterapia de este factor. La administración del GM-CSF por vía inhalada es segura y eficaz para el tratamiento de la PAP y supone una alternativa al tratamiento con lavado pulmonar total y GM-CSF por vía subcutánea. Presentamos un caso de PAP tratada con GM-CSF por vía inhalada y su evolución clínica y funcional tras un año de tratamiento(AU)

Pulmonary alveolar proteinosis is a rare disease characterized by the accumulation of lipoproteinaceous material derived from alveolar surfactant in the alveoli, with a consequent deterioration in gas exchange. Pathogenesis is related to impaired phagocytic function of alveolar macrophages. In recent years, a new treatment for pulmonary alveolar proteinosis—consisting of subcutaneous administration of granulocyte-macrophage colony-stimulating factor (GM-CSF)—has become available. The commonly accepted treatment, and the one to have shown greatest efficacy in pulmonary alveolar proteinosis, is whole lung lavage. Instead of subcutaneous administration, GM-CSF can also be inhaled as an aerosol. This route of administration of GM-CSF is safe and effective in the treatment of pulmonary alveolar proteinosis and represents an alternative to subcutaneous administration or whole lung lavage. We present a patient with pulmonary alveolar proteinosis who was treated with inhaled GM-CSF and describe her clinical and functional outcome after 1 year of treatment(AU)