Therapeutic lung lavages in children and adults

Emerging Treatments for Childhood Interstitial Lung Disease

Childhood interstitial lung disease (chILD) is a large and heterogeneous group of disorders characterized by diffuse lung parenchymal markings on chest imaging and clinical signs such as dyspnea and hypoxemia from functional impairment. While some children already present in the neonatal period with interstitial lung disease (ILD), others develop ILD during their childhood and adolescence. A timely and accurate diagnosis is essential to gauge treatment and improve prognosis. Supportive care can reduce symptoms and positively influence patients' quality of life; however, there is no cure for many of the chILDs. Current therapeutic options include anti-inflammatory or immunosuppressive drugs. Due to the rarity of the conditions and paucity of research in this field, most treatments are empirical and based on case series, and less than a handful of small, randomized trials have been conducted thus far. A trial on hydroxychloroquine yielded good safety but a much smaller effect size than anticipated. A trial in fibrotic disease with the multitargeted tyrosine kinase inhibitor nintedanib showed similar pharmacokinetics and safety as in adults. The unmet need for the treatment of chILDs remains high. This article summarizes current treatments and explores potential therapeutic options for patients suffering from chILD.

How We Do It: Whole Lung Lavage

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disorder characterized by the accumulation of surfactant in the alveolar spaces resulting in hypoxemic respiratory failure. Whole lung lavage (WLL), the preferred treatment for PAP, physically removes the lipoproteinaceous material from the alveolar spaces. Since its initial description in 1963, the WLL procedure has undergone various modifications. However, the procedure has not been standardized yet. After securing a double lumen endotracheal tube, we perform WLL under general anesthesia. One lung is ventilated, while the other is lavaged using one-liter aliquots of pre-warmed saline. We use gravity-assisted drainage of the lavaged lung after each cycle till the milky white and opaque fluid becomes clear (usually 15-20 cycles). Herein, we describe the step-by-step procedure, precautions, and monitoring of WLL. We also provide videos demonstrating one-lung ventilation and bronchoscopic confirmation of lung isolation.

Lung injury induced by different negative suction pressure in patients with pneumoconiosis undergoing whole lung lavage

Background

Pneumoconiosis is a diffuse interstitial fibronodular lung disease, which is caused by the inhalation of crystalline silica. Whole lung lavage (WLL) is a therapeutic procedure used to treat pneumoconiosis. This study is to compare the effects of different negative pressure suction on lung injury in patients with pneumoconiosis undergoing WLL.

Materials and methods

A prospective study was conducted with 24 consecutively pneumoconiosis patients who underwent WLL from March 2020 to July 2020 at Emergency General Hospital, China. The patients were divided into two groups: high negative suction pressure group (group H, n = 13, negative suction pressure of 300–400 mmHg) and low negative suction pressure group (group L, n = 11, negative suction pressure of 40–50 mmHg). The arterial blood gas, lung function, lavage data, oxidative stress, and inflammatory responses to access lung injury were monitored.

Results

Compared with those of group H, the right and left lung residual were significantly increased in the group L (P = 0.04, P = 0.01). Potential of hydrogen (pH), arterial partial pressure of oxygen (PaO₂), arterial partial pressure of carbon dioxide (PaCO₂), lactic acid (LAC) and glucose (GLU) varied from point to point in time (P < 0.01, respectively). There was statistical difference in the trend of superoxide dismutase (SOD) and interleukin-10 (IL-10) over time between the two groups (P < 0.01, P = 0.02). In comparison with the group H, the levels of IL-10 (P = 0.01) and SOD (P < 0.01) in WLL fluid were significantly increased in the group L. There was no statistical difference in the trend of maximal volumtary ventilation (MVV), forced vital capacity (FVC), forced expiratory volume in one second (FEV1%), residual volume (RV), residual volume/total lung capacity (RV/TLC), carbon monoxide dispersion factor (DLCO%), forced expiratory volume in one second/ forced vital capacity (FEV1/FVC%) over time between the two groups (P > 0.05, respectively).

Conclusion

Low negative suction pressure has the potential benefit to reduce lung injury in patients with pneumoconiosis undergoing WLL, although it can lead to increased residual lavage fluid. Despite differing suction strategies, pulmonary function parameters including FEV1%, RV and DLCO% became worse than before WLL.

Trial Registration Chinese Clinical Trial registration number ChiCTR2000031024, 21/03/2020.

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

Increased Efficacy of Whole Lung Lavage Treatment in Alveolar Proteinosis Using a New Modified Lavage Technique

BACKGROUND

Autoimmune pulmonary alveolar proteinosis is an ultra-rare pulmonary disease. Whole lung lavage (WLL) is considered the gold standard therapy. We report a protocol for a new modified lavage technique (nMLT) in which controlled repetitive manual hyperinflation (MH) and intermittent chest percussion are used to enhance WLL efficacy.

METHODS

We included all subjects with autoimmune pulmonary alveolar proteinosis treated with nMLT between 2013 and 2018. nMLT consisted of repetitive MH with intermittent chest percussion every third wash. We reported: instilled volume, protein concentration, and optical density using spectrophotometry. Pulmonary function (FVC %predicted and DLCO %predicted) at start of nMLT was recorded. Data are displayed as mean (±SD), median [interquartile range], or number (%). Comparisons within individuals were made using Students t test.

RESULTS

We included 11 subjects (64% male) in whom a total of 67 nMLTs were performed. One nMLT consisted of 15 [12-18] washes. Protein removal was 9.80 [7.52-12.66] g per nMLT. After the first, second, and third cycle of 3 washes, 56% [49% to 61%], 81% [77% to 84%], and 91% [88% to 94%] of the final protein yield was removed, respectively. Optical density was measured 116 times and increased from 1.13 (±0.52) to 1.31 (±0.52) after MH (P<0.001).

CONCLUSION

Efficacy of WLL seems to be enhanced by applying MH every 3 washes. Our technique of WLL with nMLT could be used to increase the amount of protein recruited while instilling the lung with the smallest volume of fluid as possible.

Whole lung lavage-technical details, challenges and management of complications

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by alveolar accumulation of surfactant material with resulting hypoxemia and reduced lung function. Whole lung lavage (WLL) to physically remove the proteinaceous material from the affected lung is the standard treatment. Since its original description in 1964, there have been increasing numbers of WLL procedures done worldwide and the technique has been variously refined and modified. When done in experienced centers, WLL provides long lasting benefit in the majority of patients. It is considered safe and effective. There are no guidelines standardizing the procedure. Our preferred method is to lavage one lung at a time, with the patient supine, filling to functional residual capacity (FRC) and repeating cycles of drainage and instillation with chest percussion until the effluent is clear. The aim of this article is to provide a detailed description of the technique, equipment needed and logistic considerations as well as providing a physiologic rationale for each step of WLL. We will also review the available data concerning variations of the technique described in the literature.

Successful Treatment of Autoimmune Pulmonary Alveolar Proteinosis in a Pediatric Patient

Patient: Male, 13

Final Diagnosis: Pulmonary alveolar protinosis (autoimmune subtype)

Symptoms: Dyspnea • general weakness • subfebrile episodes

Medication: Vincristine

Clinical Procedure: Bronchoscopy • bronchoalveolar lavage • CT scan • lung biopsy • GM CSF antibody testing • diagnosis confirmation • therapy with inhaled GM-CSF • bilateral lung transplantation • chemotherapy due to PTLD

Specialty: Pediatrics and Neonatology

Surfactant proteins in pediatric interstitial lung disease

BACKGROUND

Children's interstitial lung diseases (chILD) comprise a broad spectrum of diseases. Besides the genetically defined surfactant dysfunction disorders, most entities pathologically involve the alveolar surfactant region, possibly affecting the surfactant proteins SP-B and SP-C. Therefore, our objective was to determine the value of quantitation of SP-B and SP-C levels in bronchoalveolar lavage fluid (BALF) for the diagnosis of chILD.

METHODS

Levels of SP-B and SP-C in BALF from 302 children with chILD and in controls were quantified using western blotting. In a subset, single-nucleotide polymorphisms (SNPs) in the SFTPC promoter were genotyped by direct sequencing.

RESULTS

While a lack of dimeric SP-B was found only in the sole subject with hereditary SP-B deficiency, low or absent SP-C was observed not only in surfactant dysfunction disorders but also in patients with other diffuse parenchymal lung diseases pathogenetically related to the alveolar surfactant region. Genetic analysis of the SFTPC promoter showed association of a single SNP with SP-C level.

CONCLUSION

SP-B levels may be used for screening for SP-B deficiency, while low SP-C levels may point out diseases caused by mutations in TTF1, SFTPC, ABCA3, and likely in other genes involved in surfactant metabolism that remain to be identified. We conclude that measurement of levels of SP-B and SP-C was useful for the differential diagnosis of chILD, and for the precise molecular diagnosis, sequencing of the genes is necessary.

A mathematical model to predict protein wash out kinetics during whole-lung lavage in autoimmune pulmonary alveolar proteinosis

Whole-lung lavage (WLL) remains the standard therapy for pulmonary alveolar proteinosis (PAP), a process in which accumulated surfactants are washed out of the lung with 0.5-2.0 l of saline aliquots for 10-30 wash cycles. The method has been established empirically. In contrast, the kinetics of protein transfer into the lavage fluid has not been fully evaluated either theoretically or practically. Seventeen lungs from patients with autoimmune PAP underwent WLL. We made accurate timetables for each stage of WLL, namely, instilling, retaining, draining, and preparing. Subsequently, we measured the volumes of both instilled saline and drained lavage fluid, as well as the concentrations of proteins in the drained lavage fluid. We also proposed a mathematical model of protein transfer into the lavage fluid in which time is a single variable as the protein moves in response to the simple diffusion. The measured concentrations of IgG, transferrin, albumin, and β2-microglobulin closely matched the corresponding theoretical values calculated through differential equations. Coefficients for transfer of β2-microglobulin from the blood to the lavage fluid were two orders of magnitude higher than those of IgG, transferrin, and albumin. Simulations using the mathematical model showed that the cumulative amount of eliminated protein was not affected by the duration of each cycle but dependent mostly on the total time of lavage and partially on the volume instilled. Although physicians have paid little attention to the transfer of substances from the lung to lavage fluid, WLL seems to be a procedure that follows a diffusion-based mathematical model.

Surfactant protein B amount and kinetics in newborn infants: an optimized procedure

Surfactant protein B (SP-B) plays a key role in surfactant homeostasis affecting its biophysical properties and physiological function. Recently, a method to measure SP-B amount and kinetics from tracheal aspirates (TAs) became available. The main objective of this study was to improve the critical steps of the procedure to obtain a better SP-B sensitivity. We administered a 24 h continuous infusion of 1 mg/kg/h of 1(13)C-leucine to ten newborn infants. SP-B was isolated from serial TAs and its fractional synthesis rate, secretion time, peak time and half life were derived from (13)C enrichment curves obtained by gas chromatography mass spectrometry. SP-B amount in TAs was also assessed. During the extraction step, acidification and organic solvent ratio optimization doubled the recovery of SP-B from TAs, so did the elongation of the propylation time (from 20 min to 1 h) with enhanced leucine derivatization yield. Measurement of (13)C leucine enrichments, and therefore all SP-B kinetics parameters, were successfully calculated in all TAs samples due to the increase of SP-B yield. SP-B amount was 0.29 (0.16-0.41) % of total phospholipids with a minimum value of 0.08% belonging to one of the respiratory distress syndrome (RDS) patients. In conclusion, this new procedure enables accurate determination of SP-B kinetics even in the presence of low protein amount like in preterm RDS patients.

Pulmonary alveolar proteinosis: diagnostic and therapeutic challenges

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 and in distinct clinical forms: autoimmune (previously referred to as the idiopathic form, represents the vast majority of PAP cases, and is associated with Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) auto-antibodies; GMAbs), secondary (is a consequence of underlying disorders), congenital (caused by mutations in the genes encoding for the GM-CSF receptor), and PAP-like syndromes (disorders associated with surfactant gene mutations). The clinical course of PAP is variable, ranging from spontaneous remission to respiratory failure. Whole lung lavage (WLL) is the current standard treatment for PAP patients and although it is effective in the majority of cases, disease persistence is not an unusual outcome, even if disease is well controlled by WLL.In this paper we review the therapeutic strategies which have been proposed for the treatment of PAP patients and the progress which has been made in the understanding of the disease pathogenesis.

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.

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.

Pediatric bronchoalveolar lavage: practical considerations and future prospects

Despite the utilization of bronchoalveolar lavage (BAL) in children since the early 1970s, several challenges remain once the procedure is complete. These include little documentation on normal controls, the limitations due to the size of the patient, and uniform processes for assessment. It was not until 1995 that a taskforce on pediatric BAL was formed by the European Respiratory Society, and to our knowledge, they remain the only committee evaluating the process [1]. We examined our procedures and reviewed the literature in an attempt to document the most fruitful practices that would allow improved data comparison and introduce possible investigations.

Pulmonary alveolar proteinosis in children: a case series

Pulmonary alveolar proteinosis, (PAP) is a rare disease of unknown etiology, characterized by accumulation of intraalveolar proteinaceous material which is rich in lipid and positive on periodic acid-Schiff stain. Two clinically different pediatric types have been defined as congenital PAP which is fulminant and fatal, and a late-onset PAP which is similar to the adult form and less severe. Eight children with late-onset PAP were hospitalized from 1998 to 2005 in Mofid Children Hospital. Characteristics of these patients and the methods of diagnosis and treatment are presented in this case series.

SP-D counteracts GM-CSF-mediated increase of granuloma formation by alveolar macrophages in lysinuric protein intolerance

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a syndrome with multiple etiologies and is often deadly in lysinuric protein intolerance (LPI). At present, PAP is treated by whole lung lavage or with granulocyte/monocyte colony stimulating factor (GM-CSF); however, the effectiveness of GM-CSF in treating LPI associated PAP is uncertain. We hypothesized that GM-CSF and surfactant protein D (SP-D) would enhance the clearance of proteins and dying cells that are typically present in the airways of PAP lungs.

METHODS

Cells and cell-free supernatant of therapeutic bronchoalveolar lavage fluid (BALF) of a two-year-old patient with LPI were isolated on multiple occasions. Diagnostic BALF samples from an age-matched patient with bronchitis or adult PAP patients were used as controls. SP-D and total protein content of the supernatants were determined by BCA assays and Western blots, respectively. Cholesterol content was determined by a calorimetic assay or Oil Red O staining of cytospin preparations. The cells and surfactant lipids were also analyzed by transmission electron microscopy. Uptake of Alexa-647 conjugated BSA and DiI-labelled apoptotic Jurkat T-cells by BAL cells were studied separately in the presence or absence of SP-D (1 microg/ml) and/or GM-CSF (10 ng/ml), ex vivo. Specimens were analyzed by light and fluorescence microscopy.

RESULTS

Here we show that large amounts of cholesterol, and large numbers of cholesterol crystals, dying cells, and lipid-laden foamy alveolar macrophages were present in the airways of the LPI patient. Although SP-D is present, its bioavailability is low in the airways. SP-D was partially degraded and entrapped in the unusual surfactant lipid tubules with circular lattice, in vivo. We also show that supplementing SP-D and GM-CSF increases the uptake of protein and dying cells by healthy LPI alveolar macrophages, ex vivo. Serendipitously, we found that these cells spontaneously generated granulomas, ex vivo, and GM-CSF treatment drastically increased the number of granulomas whereas SP-D treatment counteracted the adverse effect of GM-CSF.

CONCLUSIONS

We propose that increased GM-CSF and decreased bioavailability of SP-D may promote granuloma formation in LPI, and GM-CSF may not be suitable for treating PAP in LPI. To improve the lung condition of LPI patients with PAP, it would be useful to explore alternative therapies for increasing dead cell clearance while decreasing cholesterol content in the airways.