Pulmonary alveolar proteinosis in children

A Case Report of Pulmonary Alveolar Proteinosis Masquerading as Respiratory Distress Syndrome in Preterm Neonates

A rare and challenging case of a preterm neonate with clinical and radiological signs of respiratory distress syndrome (RDS) since the first hour of life but was refractory to its standard treatment regimes like surfactant therapy and ventilation. Postmortem lung biopsy led us to the diagnosis of congenital pulmonary alveolar proteinosis (PAP). It occurs due to the aggregation of abnormal surfactant proteins and lipids in the alveoli, which hampers gas diffusion across the alveoli. It presents as respiratory distress at birth, and its diagnosis is often missed due to its resemblance with RDS. Although the exact etiology remains elusive, mutations in genes encoding surfactant and granulocyte-macrophage colony-stimulating factor (GM-CSF) pathway components have been implicated in the pathogenesis of PAP. Treatment options are limited and only supportive. Among all these, whole-lung lavage is the most widely used management modality but with limited success in neonates.

Interstitial lung disease in infancy and early childhood: a clinicopathological primer

Children's interstitial lung disease (chILD) encompasses a wide and heterogeneous spectrum of diseases substantially different from that of adults. Established classification systems divide chILD into conditions more prevalent in infancy and other conditions occurring at any age. This categorisation is based on a multidisciplinary approach including clinical, radiological, genetic and histological findings. The diagnostic evaluation may include lung biopsies if other diagnostic approaches failed to identify a precise chILD entity, or if severe or refractory respiratory distress of unknown cause is present. As the majority of children will be evaluated and diagnosed outside of specialist centres, this review summarises relevant clinical, genetic and histological findings of chILD to provide assistance in clinical assessment and rational diagnostics.

ILD of childhood is comparable by name only to lung disease in adults. A dedicated interdisciplinary team is required to achieve the best possible outcome. This review summarises the current clinicopathological criteria and associated genetic alterations.https://bit.ly/3mpxI3b

Pediatric bronchoscopy: recent advances and clinical challenges

Introduction: During the last 40 years equipment has been improved with smaller instruments and sufficient size working channels. This has ensured that bronchoscopy offers therapeutic and interventional options.Areas covered: We provide a review of recent advances and clinical challenges in pediatric bronchoscopy. This includes single-use bronchoscopes, endobronchial ultrasound, and cryoprobe. Bronchoscopy in persistent preschool wheezing and asthma is included. The indications for interventional bronchoscopy have amplified and included balloon dilatation, endoscopic intubation, the use of airway stents, whole lung lavage, closing of fistulas and air leak, as well as an update on removal of foreign bodies. Others include the use of laser and microdebrider in airway surgery. Experience with bronchoscope during the COVID-19 pandemic has been included in this review. PubMed was searched for articles on pediatric bronchoscopy, including rigid bronchoscopy as well as interventional bronchoscopy with a focus on reviewing literature in the past 5 years.Expert opinion: As the proficiency of pediatric interventional pulmonologists continues to grow more interventions are being performed. There is a scarcity of published evidence in this field. Courses for pediatric interventional bronchoscopy need to be developed. The COVID-19 experience resulted in safer bronchoscopy practice for all involved.

[Interstitial lung disease in infancy and early childhood]

Diffuse interstitial lung disease of infancy (chILD) shows a spectrum of disease substantially different from that of adults. Established classification systems divide chILD into conditions that are more prevalent in infancy and conditions that occur at any age. The classification is based on a multidisciplinary approach including clinical, radiological, genetic, and histological findings. Lung biopsies become necessary if other diagnostic investigations have not identified a precise chILD or if severe or refractory respiratory distress of unknown cause is present. As the majority of pediatric lung biopsies will be received first by pathologists outside of specialist centers this review summarizes relevant clinical and histological findings of chILD.

Heterogeneous colonic content: A prenatal sonographic manifestation of lysinuric protein intolerance

We report a fetus with heterogeneous colonic content, an isolated sonographic prenatal sign of lysinuric protein intolerance, a very rare metabolic disease. Familial genetic enquiries confirmed heterozygote mutation in the implicated gene in parents. The prenatal diagnosis led to neonatal dietary adaptation and avoided acute complications.

Aminoacyl-tRNA synthetase deficiencies in search of common themes

Purpose

Pathogenic variations in genes encoding aminoacyl-tRNA synthetases (ARSs) are increasingly associated with human disease. Clinical features of autosomal recessive ARS deficiencies appear very diverse and without apparent logic. We searched for common clinical patterns to improve disease recognition, insight into pathophysiology, and clinical care.

Methods

Symptoms were analyzed in all patients with recessive ARS deficiencies reported in literature, supplemented with unreported patients evaluated in our hospital.

Results

In literature, we identified 107 patients with AARS, DARS, GARS, HARS, IARS, KARS, LARS, MARS, RARS, SARS, VARS, YARS, and QARS deficiencies. Common symptoms (defined as present in ≥4/13 ARS deficiencies) included abnormalities of the central nervous system and/or senses (13/13), failure to thrive, gastrointestinal symptoms, dysmaturity, liver disease, and facial dysmorphisms. Deep phenotyping of 5 additional patients with unreported compound heterozygous pathogenic variations in IARS, LARS, KARS, and QARS extended the common phenotype with lung disease, hypoalbuminemia, anemia, and renal tubulopathy.

Conclusion

We propose a common clinical phenotype for recessive ARS deficiencies, resulting from insufficient aminoacylation activity to meet translational demand in specific organs or periods of life. Assuming residual ARS activity, adequate protein/amino acid supply seems essential instead of the traditional replacement of protein by glucose in patients with metabolic diseases.

ERS statement: interventional bronchoscopy in children

Paediatric airway endoscopy is accepted as a diagnostic and therapeutic procedure, with an expanding number of indications and applications in children. The aim of this European Respiratory Society task force was to produce a statement on interventional bronchoscopy in children, describing the evidence available at present and current clinical practice, and identifying areas deserving further investigation. The multidisciplinary task force panel performed a systematic review of the literature, focusing on whole lung lavage, transbronchial and endobronchial biopsy, transbronchial needle aspiration with endobronchial ultrasound, foreign body extraction, balloon dilation and occlusion, laser-assisted procedures, usage of airway stents, microdebriders, cryotherapy, endoscopic intubation, application of drugs and other liquids, and caregiver perspectives. There is a scarcity of published evidence in this field, and in many cases the task force had to resort to the collective clinical experience of the committee to develop this statement. The highlighted gaps in knowledge underline the need for further research and serve as a call to paediatric bronchoscopists to work together in multicentre collaborations, for the benefit of children with airway disorders.

A pediatric case of relapsed pulmonary alveolar proteinosis despite successful whole lung lavage

Pulmonary alveolar proteinosis (PAP) is a rare disease in children characterized by intra-alveolar accumulation of surfactant proteins, which severely reduces gaseous exchange. Whole lung lavage (WLL) is the preferred technique for the treatment of severe PAP. Herein, we present a pediatric case of PAP treated with WLL. An 11-year-old boy was admitted with the chief complaint of a dry cough lasting 6 months. He developed symptoms of dyspnea on exertion and had difficulty in climbing stairs. He was ultimately diagnosed with PAP through video-assisted thoracoscopic lung biopsy. As first-line of treatment for PAP, he underwent therapeutic WLL for each of his lungs on separate days. After a brief recovery, his symptoms gradually worsened; therefore, he underwent a second WLL. This is the first pediatric case of PAP relapse despite successful WLL in Korea.

Congenital Pulmonary Alveolar Proteinosis: From Birth to Ten-years of Age

Pulmonary alveolar proteinosis is a rare lung disease in which lipoproteinaceous material accumulates within the alveoli, interfering with gas exchange. The disease is classified into congenital, secondary, and acquired. The congenital form includes inborn errors of surfactant metabolism, lysinuric protein intolerance and mutations in the components of granulocyte-macrophage colony-stimulating factor receptor. The main symptoms are non-specific. The radiologic appearance of pulmonary alveolar proteinosis is bilateral, symmetric and perihilar airspace consolidation. Bronchoalveolar lavage is crucial for diagnosis of the disease. There is only one ten-year-old patient with diagnosed congenital form in Croatia. What makes him different from other children in the world is that since the ninth month of his life he has been mechanically ventilated. Diagnosis of postnatal alveolar proteinosis should be considered in every infant with respiratory distress with diffuse alveolar and interstitial infiltrate.

A newly identified novel variant in the CSF2RA gene in a child with pulmonary alveolar proteinosis: a case report

BACKGROUND

The congenital form of pulmonary alveolar proteinosis due to colony stimulating factor 2 receptor alpha gene mutations is a rare disease with only a few cases reported worldwide. In this study we report a new case of pulmonary alveolar proteinosis with a novel variant in colony stimulating factor 2 receptor alpha gene.

CASE PRESENTATION

A 5-year-old Saudi boy presented with a history of progressive dyspnea over 6 months; he was diagnosed as having pulmonary alveolar proteinosis. A molecular study revealed a novel variation in colony stimulating factor 2 receptor alpha gene. His clinical condition showed significant improvement after whole lung lavage.

CONCLUSIONS

This case has the typical presentation of congenital pulmonary alveolar proteinosis due to colony stimulating factor 2 receptor alpha defect with a novel variant in this gene likely to be pathogenic.

Pulmonary alveolar proteinosis in a 10-year-old girl masquerading as tuberculosis

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disease. Diagnosis is established by bronchoalveolar lavage (BAL), which has macroscopic ‘milky appearance’, and in the presence of typical computed tomography, findings are diagnostic of PAP but, however, the feature of periodic acid–Schiff-positive eosinophilic proteinaceous fluid raises the confidence of the diagnosis. We report late-onset PAP in a 10-year-old girl who had acid fast bacilli on an initial BAL examination, but was subsequently diagnosed as PAP.

Biallelic Mutations of Methionyl-tRNA Synthetase Cause a Specific Type of Pulmonary Alveolar Proteinosis Prevalent on Réunion Island

Methionyl-tRNA synthetase (MARS) catalyzes the ligation of methionine to tRNA and is critical for protein biosynthesis. We identified biallelic missense mutations in MARS in a specific form of pediatric pulmonary alveolar proteinosis (PAP), a severe lung disorder that is prevalent on the island of Réunion and the molecular basis of which is unresolved. Mutations were found in 26 individuals from Réunion and nearby islands and in two families from other countries. Functional consequences of the mutated alleles were assessed by growth of wild-type and mutant strains and methionine-incorporation assays in yeast. Enzyme activity was attenuated in a liquid medium without methionine but could be restored by methionine supplementation. In summary, identification of a founder mutation in MARS led to the molecular definition of a specific type of PAP and will enable carrier screening in the affected community and possibly open new treatment opportunities.

Lung involvement in children with lysinuric protein intolerance

BACKGROUND AND OBJECTIVES

Lysinuric protein intolerance (LPI) is a rare multisystemic metabolic disease. The objective of the study was to describe presentation and course of lung involvement in a cohort of ten children.

PATIENTS AND METHODS

Retrospective review of patients followed at Necker-Enfants Malades University Hospital between 1980 and 2012 for a LPI. In patients with lung involvement, clinical data, chest radiographs, pulmonary function tests, bronchoalveolar lavages, and lung biopsies were analyzed. The first and last high-resolution computed tomography (HRCT) were also reviewed.

RESULTS

Lung involvement was observed in ten of 14 patients (71 %). Five patients had an acute onset of respiratory symptoms, three had a progressive onset and two were free of symptoms. During the period studied, six patients (60 %) died, all in a context of respiratory failure. Clinical presentation and course were highly variable, even in the same family. HRCT were performed in seven cases, showing in all cases an interstitial pattern and fibrosis in four. All ten patients had pulmonary alveolar proteinosis (PAP) confirmed by histopathological analysis. Five patients had pulmonary fibrosis (at biopsy and/or HRCT scan). Two patients underwent whole lung lavages, without efficiency.

CONCLUSION

PAP is a constant feature in children with LPI and lung involvement. Pulmonary fibrosis is frequent and these two pathologies may develop independently. This study shows the heterogeneity of presentation and outcome. Lung injury could be secondary to impaired phagocytic function and abnormal inflammatory and immune responses intrinsic to the SLC7A7 mutant phenotype. HRCT is recommended to detect lung involvement.

An official American Thoracic Society clinical practice guideline: classification, evaluation, and management of childhood interstitial lung disease in infancy

BACKGROUND

There is growing recognition and understanding of the entities that cause interstitial lung disease (ILD) in infants. These entities are distinct from those that cause ILD in older children and adults.

METHODS

A multidisciplinary panel was convened to develop evidence-based guidelines on the classification, diagnosis, and management of ILD in children, focusing on neonates and infants under 2 years of age. Recommendations were formulated using a systematic approach. Outcomes considered important included the accuracy of the diagnostic evaluation, complications of delayed or incorrect diagnosis, psychosocial complications affecting the patient's or family's quality of life, and death.

RESULTS

No controlled clinical trials were identified. Therefore, observational evidence and clinical experience informed judgments. These guidelines: (1) describe the clinical characteristics of neonates and infants (<2 yr of age) with diffuse lung disease (DLD); (2) list the common causes of DLD that should be eliminated during the evaluation of neonates and infants with DLD; (3) recommend methods for further clinical investigation of the remaining infants, who are regarded as having "childhood ILD syndrome"; (4) describe a new pathologic classification scheme of DLD in infants; (5) outline supportive and continuing care; and (6) suggest areas for future research.

CONCLUSIONS

After common causes of DLD are excluded, neonates and infants with childhood ILD syndrome should be evaluated by a knowledgeable subspecialist. The evaluation may include echocardiography, controlled ventilation high-resolution computed tomography, infant pulmonary function testing, bronchoscopy with bronchoalveolar lavage, genetic testing, and/or lung biopsy. Preventive care, family education, and support are essential.

Congenital pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare syndrome characterized by pulmonary surfactant accumulation within the alveolar spaces. It occurs with a reported prevalence of 0.1 per 100,000 individuals. Two clinically different pediatric types have been defined as congenital PAP which is fatal and a late-onset PAP which is similar to the adult form and less severe. The clinical course of PAP is variable, ranging from spontaneous remission to respiratory failure. Whole-lung lavage is the current standard treatment for PAP patients. We report a new congenital case of PAP.

Long-term follow-up and treatment of congenital alveolar proteinosis

Background

Clinical presentation, diagnosis, management and outcome of molecularly defined congenital pulmonary alveolar proteinosis (PAP) due to mutations in the GM-CSF receptor are not well known.

Case presentation

A 2 1/2 years old girl was diagnosed as having alveolar proteinosis. Whole lung lavages were performed with a new catheter balloon technique, feasible in small sized airways. Because of some interstitial inflammation in the lung biopsy and to further improve the condition, empirical therapy with systemic steroids and azathioprin, and inhaled and subcutaneous GMCSF, were used. Based on clinical measures, total protein and lipid recovered by whole lung lavages, all these treatments were without benefit. Conversely, severe respiratory viral infections and an invasive aspergillosis with aspergilloma formation occurred. Recently the novel homozygous stop mutation p.Ser25X of the GMCSF receptor alpha chain was identified in the patient. This mutation leads to a lack of functional GMCSF receptor and a reduced response to GMCSF stimulation of CD11b expression of mononuclear cells of the patient. Subsequently a very intense treatment with monthly lavages was initiated, resulting for the first time in complete resolution of partial respiratory insufficiency and a significant improvement of the overall somato-psychosocial condition of the child.

Conclusions

The long term management from early childhood into young adolescence of severe alveolar proteinosis due to GMCSF receptor deficiency requires a dedicated specialized team to perform technically demanding whole lung lavages and cope with complications.

Cell profile of BAL fluid in children and adolescents with and without lung disease

The objective of this study was to review the literature on bronchoalveolar lavage fluid cell profiles in healthy children and adolescents, as well as on the use of BAL as a diagnostic and follow-up tool for lung disease patients in this age bracket. To that end, we used the Medline database, compiling studies published between 1989 and 2009 employing the following MeSH descriptors (with Boolean operators) as search terms: bronchoalveolar lavage AND cytology OR cell AND child. In healthy children, the cell profile includes alveolar macrophages (> 80%), lymphocytes (approximately 10%), neutrophils (approximately 2%) and eosinophils (< 1%). The profile varies depending on the disease under study. The number of neutrophils is greater in wheezing children, especially in non-atopic children, as well as in those with pulmonary infectious and inflammatory profiles, including cystic fibrosis and interstitial lung disease. Eosinophil counts are elevated in children/adolescents with asthma and can reach high levels in those with allergic bronchopulmonary aspergillosis or eosinophilic syndromes. In a heterogeneous group of diseases, the number of lymphocytes can increase. Evaluation of the BAL fluid cell profile, when used in conjunction with clinical and imaging findings, has proven to be an essential tool in the investigation of various lung diseases. Less invasive than transbronchial and open lung biopsies, BAL has great clinical value. Further studies adopting standard international protocols should be carried out. Such studies should involve various age groups and settings in order to obtain reference values for BAL fluid cell profiles, which are necessary for a more accurate interpretation of findings in children and adolescents with lung diseases.

Whole-lung lavage in infants and children with pulmonary alveolar proteinosis

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare alveolar filling syndrome where the mainstay of treatment is therapeutic whole-lung lavage (WLL). WLL techniques used in adults have to be modified for children because of their small-diameter airways.

AIM

To describe a technique for WLL adapted for small children.

METHODS

We describe a WLL technique that combines safe single-lung ventilation with the use of an age-appropriate endotracheal tube and selective occlusion of the other main bronchus with a balloon catheter through which the lavage is performed. Effectiveness measured by change in oxygen requirements and adverse effects was noted.

RESULTS

We performed 64 WLL procedures in four children (age 13 months to 7 years; body weight 4.7-14 kg). Two children had idiopathic and two had secondary PAP. At referral, all children had dyspnoea at rest and required continuous oxygen supplementation. Two patients showed significantly decreased oxygen demands and radiological improvement after WLL. Two patients showed no significant response. The only adverse effect observed was transient hypoxemia. Complications comprised fluid leak at the balloon (4), balloon rupture (1), and pneumothorax (1).

CONCLUSIONS

This technique for WLL combining single-lung ventilation with an endotracheal tube and lung exclusion for lavage with a balloon catheter can be safely and effectively performed in small children with PAP.

Interstitial lung diseases in children

Interstitial lung disease (ILD) in infants and children comprises a large spectrum of rare respiratory disorders that are mostly chronic and associated with high morbidity and mortality. These disorders are characterized by inflammatory and fibrotic changes that affect alveolar walls. Typical features of ILD include dyspnea, diffuse infiltrates on chest radiographs, and abnormal pulmonary function tests with restrictive ventilatory defect and/or impaired gas exchange. Many pathological situations can impair gas exchange and, therefore, may contribute to progressive lung damage and ILD. Consequently, diagnosis approach needs to be structured with a clinical evaluation requiring a careful history paying attention to exposures and systemic diseases. Several classifications for ILD have been proposed but none is entirely satisfactory especially in children. The present article reviews current concepts of pathophysiological mechanisms, etiology and diagnostic approaches, as well as therapeutic strategies. The following diagnostic grouping is used to discuss the various causes of pediatric ILD: 1) exposure-related ILD; 2) systemic disease-associated ILD; 3) alveolar structure disorder-associated ILD; and 4) ILD specific to infancy. Therapeutic options include mainly anti-inflammatory, immunosuppressive, and/or anti-fibrotic drugs. The outcome is highly variable with a mortality rate around 15%. An overall favorable response to corticosteroid therapy is observed in around 50% of cases, often associated with sequelae such as limited exercise tolerance or the need for long-term oxygen therapy.

Therapeutic bilateral lung lavage in a child with pulmonary alveolar proteinosis

OBJECTIVE

Pulmonary alveolar proteinosis is a rare condition that can cause life-threatening respiratory failure attributable to excessive alveolar accumulation of surfactant proteins. The standard treatment for removing these secretions is through therapeutic bilateral lung lavage. Descriptions of procedures for performing therapeutic bilateral lung lavage and methods used to evaluate the overall effectiveness of this invasive procedure in children with pulmonary alveolar proteinosis have not been adequately described in the medical literature. We successfully and safely performed therapeutic bilateral lung lavage and obtained lung mechanics measurements in a child with pulmonary alveolar proteinosis.

DESIGN

Case report.

SETTING

Operating room within a pediatric hospital.

PATIENTS/SUBJECTS

A 13-yr-old boy with pulmonary alveolar proteinosis requiring serial therapeutic bilateral lung lavage for recurrent respiratory distress.

INTERVENTIONS

The patient presented to the hospital operating room for therapeutic lung lavage after a recent history of progressive dyspnea, respiratory distress, declining lung function measurements, and worsening radiographic abnormalities. We obtained baseline spirometric and respiratory system compliance measurements before and after therapeutic bilateral lung lavage. The left lung was lavaged on the first day and the right lung was lavaged on the third day using selective endobronchial intubation and selective lung ventilation.

RESULTS

The procedure was well-tolerated and resulted in the removal of a significant volume of accumulated secretions. After the lavage, the patient demonstrated improvement in respiratory distress, chest radiograph appearance, lung compliance, and spirometric measurements.

CONCLUSIONS

This case report demonstrates that therapeutic bilateral lung lavage can be performed safely and effectively in a pediatric patient with pulmonary alveolar proteinosis by isolating individual lungs using a dual-lumen endotracheal tube. In this patient, therapeutic bilateral lung lavage was found to have a significant impact on lung function and mechanics after this procedure.

Interstitial Lung Disease in Children Older Than 2 Years

The spectrum of childhood interstitial lung diseases (chILD) encompasses a group of heterogeneous, rare disorders in children characterized by diffuse pulmonary infiltrates and disordered gas exchange. Whereas the disorders that present in early life are unique to children, those that present in older children are also seen in adults. This review will concentrate on chILD presenting in children older than 2 years of age with a focus on the idiopathic interstitial pneumonias, connective tissue diseases, alveolar hemorrhage, and hypersensitivity pneumonitis. A systematic approach to diagnosis that includes a careful history and physical, computed tomography of the chest, bronchoalveolar lavage, and lung biopsy can be very helpful in establishing the correct diagnosis. Treatment approaches are described, including general supportive measures, indications for a trial of systemic corticosteroids, or other immunomodulating therapies, and when lung transplantation reserved for those with end-stage lung disease should be considered.

Genetic disorders of surfactant dysfunction

Mutations in the genes encoding the surfactant proteins B and C (SP-B and SP-C) and the phospholipid transporter, ABCA3, are associated with respiratory distress and interstitial lung disease in the pediatric population. Expression of these proteins is regulated developmentally, increasing with gestational age, and is critical for pulmonary surfactant function at birth. Pulmonary surfactant is a unique mixture of lipids and proteins that reduces surface tension at the air-liquid interface, preventing collapse of the lung at the end of expiration. SP-B and ABCA3 are required for the normal organization and packaging of surfactant phospholipids into specialized secretory organelles, known as lamellar bodies, while both SP-B and SP-C are important for adsorption of secreted surfactant phospholipids to the alveolar surface. In general, mutations in the SP-B gene SFTPB are associated with fatal respiratory distress in the neonatal period, and mutations in the SP-C gene SFTPC are more commonly associated with interstitial lung disease in older infants, children, and adults. Mutations in the ABCA3 gene are associated with both phenotypes. Despite this general classification, there is considerable overlap in the clinical and histologic characteristics of these genetic disorders. In this review, similarities and differences in the presentation of these disorders with an emphasis on their histochemical and ultrastructural features will be described, along with a brief discussion of surfactant metabolism. Mechanisms involved in the pathogenesis of lung disease caused by mutations in these genes will also be discussed.

Recurrent pulmonary alveolar proteinosis secondary to agammaglobulinemia

Pulmonary alveolar proteinosis (PAP) is characterized by the accumulation of surfactant derived material in the lung of patients. PAP is rare in children. The patient presented with respiratory failure. In the history she was diagnosed with agammaglobulinemia at 8 months of age and has been treated by IVIG once in a month. She had two pulmonary alveolary proteinosis attacks before. Chest X-ray showed bilateral diffuse infiltrates. Initial diagnosis were pneumonia, ARDS, and lung edema. Whole-lung lavage revealed lipoproteinaceous material similar to surfactant. This findings and high level of LDH was as evaluated pulmonary alveolary proteinosis. She discharged from the hospital without any respiratory complication on the ninth day. This is the first case report recurrent PAP associated with agammaglobulinemia.

Successful whole lung lavage in pulmonary alveolar proteinosis secondary to lysinuric protein intolerance: a case report

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare disease characterised by accumulation of lipoproteinaceous material within alveoli, occurring in three clinically distinct forms: congenital, acquired and secondary. Among the latter, lysinuric protein intolerance (LPI) is a rare genetic disorder caused by defective transport of cationic amino acids. Whole Lung Lavage (WLL) is currently the gold standard therapy for severe cases of PAP.

CASE PRESENTATION

We describe the case of an Italian boy affected by LPI who, by the age of 10, developed digital clubbing and, by the age of 16, a mild restrictive functional impairment associated with a high-resolution computed tomography (HRCT) pattern consistent with pulmonary alveolar proteinosis. After careful assessment, he underwent WLL.

CONCLUSION

Two years after WLL, the patient has no clinical, radiological or functional evidence of pulmonary disease recurrence, thus suggesting that WLL may be helpful in the treatment of PAP secondary to LPI.

Matrix metalloproteinases in lung: multiple, multifarious, and multifaceted

The matrix metalloproteinases (MMPs), a family of 25 secreted and cell surface-bound neutral proteinases, process a large array of extracellular and cell surface proteins under normal and pathological conditions. MMPs play critical roles in lung organogenesis, but their expression, for the most part, is downregulated after generation of the alveoli. Our knowledge about the resurgence of the MMPs that occurs in most inflammatory diseases of the lung is rapidly expanding. Although not all members of the MMP family are found within the lung tissue, many are upregulated during the acute and chronic phases of these diseases. Furthermore, potential MMP targets in the lung include all structural proteins in the extracellular matrix (ECM), cell adhesion molecules, growth factors, cytokines, and chemokines. However, what is less known is the role of MMP proteolysis in modulating the function of these substrates in vivo. Because of their multiplicity and substantial substrate overlap, MMPs are thought to have redundant functions. However, as we explore in this review, such redundancy most likely evolved as a necessary compensatory mechanism given the critical regulatory importance of MMPs. While inhibition of MMPs has been proposed as a therapeutic option in a variety of inflammatory lung conditions, a complete understanding of the biology of these complex enzymes is needed before we can reasonably consider them as therapeutic targets.

Il lavaggio broncoalveolare (BAL) in età pediatrica

Il lavaggio broncoalveolare o BAL, permettendo di ottenere le cellule ed i soluti presenti sulla superficie epiteliale del tratto respiratorio distale, si è dimostrato una metodica di ricerca essenziale per lo studio dei meccanismi eziopatogenetici delle malattie del polmone profondo, come ad esempio lo studio delle interstiziopatie, su cui esiste una vastissima letteratura di dati ottenuti con il BAL. Oltre a questo aspetto di metodica di ricerca, il BAL rappresenta perè anche una procedura diagnostica insostituibile nella pratica clinica quotidiana.

Interstitial lung disease in children -- genetic background and associated phenotypes

Interstitial lung disease in children represents a group of rare chronic respiratory disorders. There is growing evidence that mutations in the surfactant protein C gene play a role in the pathogenesis of certain forms of pediatric interstitial lung disease. Recently, mutations in the ABCA3 transporter were found as an underlying cause of fatal respiratory failure in neonates without surfactant protein B deficiency. Especially in familiar cases or in children of consanguineous parents, genetic diagnosis provides an useful tool to identify the underlying etiology of interstitial lung disease. The aim of this review is to summarize and to describe in detail the clinical features of hereditary interstitial lung disease in children. The knowledge of gene variants and associated phenotypes is crucial to identify relevant patients in clinical practice.