Characterization and outcomes of pulmonary alveolar proteinosis in Brazil: a case series

Pathogenesis-driven treatment of primary pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a syndrome that results from the accumulation of lipoproteinaceous material in the alveolar space. According to the underlying pathogenetic mechanisms, three different forms have been identified, namely primary, secondary and congenital. Primary PAP is caused by disruption of granulocyte-macrophage colony-stimulating factor (GM-CSF) signalling due to the presence of neutralising autoantibodies (autoimmune PAP) or GM-CSF receptor genetic defects (hereditary PAP), which results in dysfunctional alveolar macrophages with reduced phagocytic clearance of particles, cholesterol and surfactant. The serum level of GM-CSF autoantibody is the only disease-specific biomarker of autoimmune PAP, although it does not correlate with disease severity. In PAP patients with normal serum GM-CSF autoantibody levels, elevated serum GM-CSF levels is highly suspicious for hereditary PAP. Several biomarkers have been correlated with disease severity, although they are not specific for PAP. These include lactate dehydrogenase, cytokeratin 19 fragment 21.1, carcinoembryonic antigen, neuron-specific enolase, surfactant proteins, Krebs von Lungen 6, chitinase-3-like protein 1 and monocyte chemotactic proteins. Finally, increased awareness of the disease mechanisms has led to the development of pathogenesis-based treatments, such as GM-CSF augmentation and cholesterol-targeting therapies.

Alveolar Proteinosis Secondary to M. tuberculosis, in a Patient with Transient CD4 Lymphocytopenia Due to Cryptococcus neoformans Infection: First Case in the Literature

Transient CD4 lymphocytopenia is defined as the transitory presence of CD4+ T lymphocyte fewer than 300 cells/mm³ or less than 20% of T cells without HIV infection. It can occur due to multiple causes; however, it is rare for it to occur due to opportunistic infections. Few cases have been described in the literature where antimicrobial treatment normalizes the CD4 count, being more frequent in Mycobacterium tuberculosis infections. To date, this phenomenon has not been described in Cryptococcus neoformans infections. This would be the first reported case according to our knowledge, of a patient who normalizes CD4 count after antifungal treatment, later developing alveolar proteinosis due to M. Tuberculosis.

Granulocyte Macrophage Colony-Stimulating Factor-Specific Autoantibodies and Cerebral Nocardia With Pulmonary Alveolar Proteinosis

In this study, we report the history of a 40-year-old man with a primary cerebral abscess caused by Nocardia abscessus that led to the discovery of autoimmune pulmonary alveolar lipoproteinosis (anti-granulocyte-macrophage colony-stimulating factor [GM-CSF] autoantibodies). Anti-GM-CSF autoantibodies promote immunodeficiency and should be monitored to prevent opportunistic and disseminated infections and to diagnose asymptomatic pulmonary alveolar lipoproteinosis.

Pulmonary alveolar proteinosis: A single center retrospective analysis of 14 cases

INTRODUCTION

Pulmonary alveolar proteinosis (PAP) is a rare lung disease, characterized by abnormal alveolar accumulation of enlarged foamy macrophages and periodic acid-Schiff (PAS)-positive materials. Knowledge of the disease characteristics is still lacking.

OBJECTIVE

To help clinicians gain a better understanding of this rare disease.

METHODS

We undertook a retrospective analysis of 14 adult patients with PAP, treated in Zhongshan Hospital, Fudan University.

RESULTS

Serum lactate dehydrogenase (LDH) was correlated with the arterial partial pressure of oxygen (PaO2) and diffusion capacity for carbon monoxide (DLCO). Transbronchial lung biopsy (TBLB) established a definitive diagnosis for a positive rate of 100%. The patients underwent whole lung lavage (WLL) and exhibited varying degrees of remission. The patients with mild symptoms received only supportive care and observation, and remained stable during follow-up.

CONCLUSION

LDH may correlate with disease severity. Bronchoscopy is sufficiently sensitive for a definite diagnosis. Conventional bilateral whole lung lavage proved a reliable treatment for indicated patients, but selective unilateral lung lavage or observation may be a rational choice in certain patients.

Pulmonary Alveolar Proteinosis Due to Pneumocystis carinii in Type 1 Hyper-IgM Syndrome: A Case Report

Background: Pulmonary alveolar proteinosis (PAP) is a rare diffuse lung disease. Reports of rare cases of PAP due to Pneumocystis jirovecii (P. jirovecii) exist in infants with immunodeficiency diseases, but no cases have been reported to date in pediatric patients with type 1 hyper-IgM syndrome (HIGM1). Case Presentation: Herein, we present a case of PAP secondary to P. jirovecii on an infant with HIGM1. He was admitted to our unit because of cough and tachypnea. Lung biopsy confirmed the diagnosis of PAP, whereas hexamine-silver staining of the bronchoalveolar lavage fluid identified P. jirovecii infection. No other probable cause of PAP was observed. Whole exome sequencing indicated a novel c.511dupA (p.I171N^*30) hemizygous mutation in the CD40 ligand (CD40LG) gene. He was cured with bronchoalveolar lavage and compound sulfamethoxazole tablets. Conclusions: To our knowledge, this is the first reported case of P. jirovecii infection as a reversible cause of PAP in an infant with HIGM1.