Association of lipid-laden alveolar macrophages and gastroesophageal reflux in children

Bronchoalveolar lavage cytology in children with chronic unexplained cough and severely neurologically impaired children

OBJECTIVE

We aimed to compare the cellular composition of bronchoalveolar lavage (BAL) fluids in children with chronic unexplained cough (group 1) and severely neurologically impaired children with chronic or recurrent respiratory problems (group 2) with the BAL cytology of children without pulmonary or systemic diseases (group 3).

METHODS

Bronchoscopy with BAL fluid analysis was performed in all subjects. Children with respiratory symptoms underwent 24-hour multichannel intraluminal impedance monitoring.

RESULTS

A significant difference was found between the groups in the total number of cells in BAL fluid cytology (191 [range, 24-12,747], 747 [range, 53-13,000], and 105 [range, 41-233] cells/μL, P = .015), in the percentage of neutrophils (21.2 [SD = 32.4], 49.4 [SD = 36.6], and 3.6 [SD = 2.4], P < .001), and in the percentage of lipid-laden macrophages (10.3 [SD = 11.4], 13.7 [SD = 15.8] and 0.44 [SD = 1.0], P < .001).

CONCLUSION

The BAL fluid cytology provides useful data for determining the cause of chronic unexplained cough and chronic or recurrent respiratory problems in severely neurologically impaired children.

Utilization of Oil Red O staining for assessing aspiration risk in lung transplant patients: A multidisciplinary prospective study with clinical practice insights

BACKGROUND

Gastroesophageal reflux disease with microaspiration has been associated with graft dysfunction in lung transplant patients. Identifying patients with aspiration is clinically important because it enables implementation of appropriate interventions like antireflux therapy. Oil Red O (ORO) staining with determination of the lipid-laden macrophage index (LLMI) has been proposed as a noninvasive surrogate marker in the detection of aspiration. The aim of this study was to prospectively evaluate clinical utilization of ORO staining in the assessment of aspiration risk.

METHODS

All transbronchial surgical pathology biopsies obtained in lung transplant patients undergoing routine surveillance from August 2020 through November 2021 were included in this study. Clinical team members prospectively ascertained the aspiration risk category (ARC) of each patient both before and after biopsy findings and recorded reasons for change in ARC.

RESULTS

A total of 132 transbronchial biopsies with concurrent LLMI were included in the study. LLMI was low in 51 cases (38.6%), including 21 of the 54 cases (38.9%) where aspiration was suggested based on the transbronchial biopsy findings. In total, 19 cases (14.4%) underwent a change in ARC post-biopsy including 10 that were upgraded and nine cases that were downgraded. Transbronchial biopsy findings were noted as the reason for change in ARC in the majority (15/19; 79%) of cases; only a minority (2/19; 10.5%) were due to the LLMI. Notably, 16 cases (12.1%) had a low LLMI with high-risk post-biopsy ARC and nine cases (6.8%) had a high LLMI with low-risk post-biopsy ARC.

CONCLUSIONS

This study observed that clinical evaluation for aspiration relied more heavily on transbronchial biopsy findings. Although LLMI may retain clinical utility in some scenarios, reevaluation of the clinical value of ORO testing would be prudent.

Correlation between cytology Oil Red O staining and lung biopsy specimens: utility of the lipid-laden macrophage index

INTRODUCTION

Oil Red O staining is used for enumeration of the lipid-laden macrophage index (LLMI) as a surrogate for aspiration. As part of quality improvement efforts aimed at optimizing resource utilization, the utility of this stain in current cytopathology practice was re-evaluated. The objective of this study was to explore the clinical utility of Oil Red O staining in bronchoalveolar lavage (BAL) samples by correlating the LLMI with findings in concurrent histologic tissue samples.

MATERIALS AND METHODS

Lung transbronchial biopsy specimens that suggested aspiration that were submitted with concurrent BAL cytology samples were retrieved. Lung tissue biopsies were reviewed for the presence of foamy alveolar macrophages (graded as 0, 1+, and 2+), foreign material, and giant cells. The concurrent BAL was reviewed with consensus determination of the LLMI.

RESULTS

A total of 53 cases were identified. On histology, 13 cases (24.5%) were found to have no foamy alveolar macrophages, 23 cases (43.4%) were found to have 1+ foamy alveolar macrophages, and 17 cases (32.1%) were found to have 2+ foamy alveolar macrophages. Six cases (11.3%) were found to have foreign material, and 10 cases (18.9%) were found to have multinucleated giant cells. The average LLMI score was 16, with 44 (83.0%) in the low range (LLMI &lt;40) and 9 (17.0%) in the intermediate range (LLMI of 40-90).

CONCLUSIONS

None of the cases in our study had an LLMI that exceeded the cutoff value for which aspiration would be suspected. We found no correlation of the LLMI with lung biopsies that suggested aspiration.

Oil red O staining for lipid-laden macrophage index of bronchoalveolar lavage: interobserver agreement and challenges to interpretation

INTRODUCTION

Oil Red O (ORO) staining on cytologic specimens with calculation of the lipid-laden macrophage index (LLMI) is used as a part of the workup in a number of clinical settings, particularly when aspiration is of concern. As a part of ongoing internal quality improvement measures, the objective of the present study was to evaluate the interobserver agreement of the LLMI calculation and to identify factors that affect the variability of the calculation.

MATERIALS AND METHODS

There were 9 study participants, which included 3 trainees, 3 cytotechnologists, and 3 cytopathologists. Each participant reviewed 100 ORO-stained bronchoalveolar lavage slides and assigned an LLMI score to each case. The scores were categorized into 3 groups according to the associated aspiration risk: low, LLMI <40; intermediate, LLMI 40 to 90; and high, LLMI >90. The participants were also requested to note any challenges to the calculation for each case.

RESULTS

The interobserver agreement among all participants was fair (κ = 0.23). Stratified by participant group, the interobserver agreement among the trainees was fair (κ = 0.24), among cytotechnologists was fair (κ = 0.32), and among cytopathologists was moderate (κ = 0.60). In 70 cases, at least one participant scored the case at least one category higher than the other participants; in 47 cases there was a two category difference. A primary diagnostic challenge reported by participants was macrophage pigmentation (hemosiderin, anthracosis).

CONCLUSIONS

We found only fair interobserver agreement among all 9 participants in the study. Hemosiderin and anthracotic pigmentation was a major factor impeding LLMI calculation resulting in overestimation of the LLMI.

Testing for lipid-laden macrophages in bronchoalveolar lavage fluid to diagnose vaping-associated pulmonary injury. Are we there yet?

Vaping-associated pulmonary injury (VAPI) is a severe respiratory disorder associated with the inhalation of nicotine, tetrahydrocannabinol, cannabidiol, or other active substances through a personal vaporizer ("vaping"). Within 2 months after its description, the disease has reached epidemic proportion, affecting over 2000 people and resulting in a number of fatalities. The substance(s) responsible for the lung injury are still unknown, and the pathophysiology of the disease is still incompletely understood. The manifestations of the disease are protean, and the insidiously starting respiratory, gastrointestinal, and constitutional symptoms may initially resemble a viral flu-like illness. The disease may increase in severity, requiring hospitalization, and in more severe cases, mechanical ventilation. The diagnosis of VAPI currently relies on the identification of pulmonary infiltrates on imaging studies in patients who have used vaping products, after excluding infections and other plausible alternative diagnoses. Because VAPI is currently a diagnosis of exclusion, some authors have suggested the use of lipid-laden macrophages (LLM) as a diagnostic test to confirm the disease. We review the current state of the knowledge about the pathologic basis of VAPI, and the literature on the analytic performance of the LLM test to better understand the potential utility of this test in the diagnosis of VAPI. Our review finds little evidence to suggest the use of LLM in the diagnosis of VAPI, since its underlying pathology is acute lung injury, which is unrelated to LLM, and the frequency of their detection varies greatly in different reported series.

Pepsin levels and oxidative stress markers in exhaled breath condensate of patients with gastroesophageal reflux disease

AIM

To evaluate the pepsin and oxidative stress markers in exhaled breath condensate (EBC) in patients with gastroesophageal reflux disease (GERD).

PATIENTS AND METHOD

Patients with a presumptive diagnosis of GERD with recurrent respiratory and gastrointestinal problems aged between 2 and 14 years were included in the study. All patients underwent pH monitoring. Patients with a reflux index (RI) ≥4 were assessed as the reflux group, and those with an RO <4 were assessed as the non-reflux group. Pepsin levels and oxidative stress markers [NO metabolites (NOX) and total sulphydrile (TSH) levels] were measured in the EBC.

RESULTS

There were 24 patients in the reflux group [RI 17.6 (6.6-46.4)] [median, interquartile range] and 23 in the non-reflux group [RI 0.8 (0.5-1.9) (p<0.001). Pepsin levels in the EBC were below the level of detection. The median levels of NOx in the EBC of children with reflux [13.7 μmol/L (7.3-24.5)] were lower in than non-reflux group [21.0 μmol/L (14.0-25.2)] (p=0.034). There was a negative correlation between reflux index and NOX levels in EBC (rs: -0.331, p=0.023). In contrast, there was no difference in TSH levels between the reflux and non-reflux groups [37.4 μmol/L (30.2-44.6) vs 40.1 μmol/L (37.4-44.9), respectively, (p>0.05)].

CONCLUSION

Decreased levels of NOX in patients with GER disease suggest increased oxidative stress in airways of these patients.

Biomarkers for gastroesophageal reflux in respiratory diseases

Gastroesophageal reflux (GER) is commonly associated with respiratory symptoms, either through a vagal bronchoconstrictive reflex or through microaspiration of gastric contents. No diagnostic test is available, however, to diagnose when respiratory illnesses are caused by GER and when not, but research in this field has been moving forward. Various biomarkers in different types of biosamples have been studied in this context. The aim of this review is to summarize the present knowledge in this field. GER patients with respiratory diseases seem to have a different biochemical profile from similar patients without GER. Inflammatory biomarkers differ in asthmatics based on GER status, tachykinins are elevated in patients with GER-related cough, and bile acids are elevated in lung transplant patients with GER. However, studies on these biomarkers are often limited by their small size, methods of analysis, and case selections. The two pathogenesis mechanisms are associated with different respiratory illnesses and biochemical profiles. A reliable test to identify GER-induced respiratory disorders needs to be developed. Bronchoalveolar lavage is too invasive to be of use in most patients. Exhaled breath condensate samples need further evaluation and standardization. The newly developed particles in exhaled air measurements remain to be studied further.

Laryngopharyngeal reflux: Current opinion

The increasing importance of LPR is being recognized day by day in ENT practice. LPR has a significant negative impact in the quality of lives of the patients. Although its impact is similar in some respects to that of laryngopharyngeal disease, LPR has a more significant impact on patient's social functioning and vitality.([23]) All ear, nose and throat practitioners need to be sensitised to the presence of LPR and the need for starting treatment wherever required. Lot of hitherto symptoms of unknown aetiology are being increasingly of treating patients with atypical reflux symptoms such as hoarseness (unexplained cause), globus, throat clearing, cough, etc., with antireflux therapy.([24]).

Reduction of lipid-laden macrophage index after laparoscopic Nissen fundoplication in cystic fibrosis patients after lung transplantation

BACKGROUND

Lipid-laden macrophage (LLM) index could be potentially useful in assessing gastroesophageal (GE) reflux and aspiration after lung transplantation (LT) in patients with cystic fibrosis (CF).

METHODS

A retrospective review of CF patients undergoing LT and/or laparoscopic Nissen fundoplication (LNF) from January 1, 2009, to December 31, 2011, was performed.

RESULTS

Seventeen CF patients (nine women), mean (± SD) age 27.9 ± 7.5 yr, underwent LT with mean (± SD) pre-transplant FEV(1) of 20.9 ± 5.0% predicted. Seventy percentage (12/17) of patients underwent LNF without complications within 1-2 wk of LT. After LT, but prior to antireflux surgery, there was no significant difference in the mean (± SD) baseline LLM index (154 ± 41 vs. 146 ± 51, p = NS) between patients who were to undergo LNF and patients who did not. After LNF, a significant reduction in the mean (± SD) LLM index occurred following the procedure (154 ± 41-74 ± 54, p < 0.0001) while each patient reported resolution of symptoms of GE reflux, whereas 40% (2/5) undergoing only medical treatment reported resolution of symptoms.

CONCLUSIONS

Significant reduction in the LLM index occurred after LNF in CF patients after LT that correlated with resolution of clinical symptoms of GE reflux.

Gastroesophageal reflux in cystic fibrosis: current understandings of mechanisms and management

Cystic fibrosis (CF) is an inherited disease that affects both the lungs and the digestive system in children and adults. Thick mucus fills the gut and blocks lumens of the pancreas and hepatobiliary systems, creating insufficient pancreas function and liver disease. Chronic gastrointestinal (GI) complications, including intestinal obstruction, occur in neonates, and poor digestion and gastroesophageal reflux disease (GERD) in children. Although GI symptoms tend to improve with age, CF and associated GERD eventually create respiratory insufficiency; the only available treatment option at this stage is a bilateral lung transplant, which carries considerable morbidity and mortality. While GERD may reoccur as a complication of lung transplantation, GERD symptoms are often reduced following a fundoplication.

Lipid-Laden Alveolar Macrophages and pH Monitoring in Gastroesophageal Reflux-Related Respiratory Symptoms

Lipid-laden alveolar macrophages and pH monitoring have been used in the diagnosis of chronic aspiration in children with gastroesophageal reflux (GER). This study was conducted to prove a correlation between the detection of alimentary pulmonary fat phagocytosis and an increasing amount of proximal gastroesophageal reflux. It was assumed that proximal gastroesophageal reflux better correlates with aspiration than distal GER. Patients from 6 months to 16 years with unexplained recurrent wheezy bronchitis and bronchial hyperreactivity, or recurrent pneumonia with chronic cough underwent 24-hour double-channel pH monitoring and bronchoscopy with bronchoalveolar lavage (BAL). Aspiration of gastric content was determined by counting lipid laden alveolar macrophages from BAL specimens. There were no correlations between any pH-monitoring parameters and counts of lipid-laden macrophages in the whole study population, even when restricting analysis to those with abnormal reflux index expressing clinically significant GER. Quantifying lipid-laden alveolar macrophages from BAL in children with gastroesophageal-related respiratory disorders does not have an acceptable specificity to prove chronic aspiration as an underlying etiology. Therefore, research for other markers of pulmonary aspiration is needed.

Utilization of lipid-laden macrophage index in evaluation of aerodigestive disorders

OBJECTIVES/HYPOTHESIS

The utility of the lipid-laden macrophage index (LLMI) in the evaluation of airway inflammatory processes remains controversial. There is a paucity of normative data in both pediatric and adult populations, and there is wide variability in the reported cases. The goal of this project was to review the LLMI levels in a large series of patients with a wide range of well-documented pulmonary and airway diseases (cystic fibrosis, aspiration, tracheo/bronchomalacia, recurrent pneumonia, asthma, immunosuppressed conditions, and laryngeal clefts) to develop a better understanding of the clinical utility of the LLMI.

STUDY DESIGN

This study is a retrospective analysis of patients who underwent initial bronchoscopy with broncheoalveolar lavage (BAL) and had specimens sent for determination of LLMI. This study was performed at a major pediatric tertiary care medical center from April 12, 2006 to July 13, 2009.

METHODS

Medical charts were reviewed for major diagnoses, indications for bronchoscopy, the side of lung (right versus left), documented aspiration, suspected aspiration, neutrophil counts, and patient age. These qualitative and quantitative variables were considered in relation to the LLMI.

RESULTS

The cohort of patients examined were 4.9 ± 4.3 years (4 days to 18 years of age). Forty-two percent were female and 58% were male. The highest median LLMI was in immunocompromised patients with a median of 78. Recurrent pneumonia, aspiration, tracheo/bronchomalacia, and cystic fibrosis had median LLMI levels of 55, 49, 40, and 50, respectively. There was a wide range of LLMI within each primary diagnosis. There was no significant correlation between neutrophils percentage in the BAL and LLMI. There were no significant differences between BAL specimens obtained from the right or left side.

CONCLUSIONS

To our knowledge, this is the largest series of patients reported in the literature to have an LLMI compared with underlying diagnoses. Based on our data and analyses, there is wide variability between the range of LLMI and the primary diagnosis. As such, the diagnostic utility of the LLMI is limited and should be interpreted with caution.

The lipid laden macrophage index as a marker of aspiration in patients with type I and II laryngeal clefts

OBJECTIVES

Laryngeal clefts are uncommon congenital anomalies that may cause pulmonary aspiration, leading to considerable morbidity including recurrent pneumonias. The lipid laden macrophage index (LLMI) is a potential marker of pulmonary aspiration. The objective of this study was to assess the utility of the lipid laden macrophage index as a marker of severity of pulmonary aspiration in children with laryngeal clefts and its role in the management of these patients.

METHODS

An institutional review board approved retrospective review of all patients with laryngeal cleft who had also underwent direct laryngoscopy with rigid bronchoscopy and flexible bronchoscopy with bronchoalveolar lavage. The LLMI was measured from the lavage and compared to clinical and radiological data.

RESULTS

Forty-four patients with laryngeal clefts (31 type I clefts and 13 type II clefts) underwent assessment with flexible bronchoscopy and bronchoalveolar lavage. The median age at first outpatient visit in our Center for Aero-digestive Disorder was 0.92 years in patients with type I clefts and 1.66 years in patients with type 2 clefts. All patients in this study had at least one modified barium swallow (MBS) performed to assess for aspiration. The mean LLMI was significantly higher in patients with type II (mean+/-SEM) 81.8+/-11.9 clefts compared to type I clefts 44.9+/-5.6.

CONCLUSIONS

We recommend obtaining LLMI in patients with laryngeal cleft. The lipid laden macrophage index is increased in patients with more severe laryngeal clefts, thus potentially predicting those patients whom would most benefit from early surgical intervention.

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.

Biomarkers in the diagnosis of aspiration syndromes

Recognizing and managing the different types of aspiration events remain a challenging task due to the lack of distinguishing clinical or laboratory characteristics. Numerous biomarkers in serum, sputum and bronchoalveolar lavage have been studied, and their role in the recognition of aspiration remains controversial at this time. Recent animal investigations using an array of biomarkers based on distinct pathogenic features of each aspiration event have produced promising results; however, they have not been validated in humans. Newer markers are being introduced as diagnostic and prognostic tools in conditions such as community-acquired pneumonia and sepsis, but they have not been examined in aspiration. The present review summarizes the different biomarkers that have been studied in aspiration and those who might have a potential clinical use in the future.

Pediatric gastroesophageal reflux clinical practice guidelines: joint recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN)

OBJECTIVE

To develop a North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) international consensus on the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

METHODS

An international panel of 9 pediatric gastroenterologists and 2 epidemiologists were selected by both societies, which developed these guidelines based on the Delphi principle. Statements were based on systematic literature searches using the best-available evidence from PubMed, Cumulative Index to Nursing and Allied Health Literature, and bibliographies. The committee convened in face-to-face meetings 3 times. Consensus was achieved for all recommendations through nominal group technique, a structured, quantitative method. Articles were evaluated using the Oxford Centre for Evidence-based Medicine Levels of Evidence. Using the Oxford Grades of Recommendation, the quality of evidence of each of the recommendations made by the committee was determined and is summarized in appendices.

RESULTS

More than 600 articles were reviewed for this work. The document provides evidence-based guidelines for the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

CONCLUSIONS

This document is intended to be used in daily practice for the development of future clinical practice guidelines and as a basis for clinical trials.

Aspiration lung disease

The term aspiration lung disease describes several clinical syndromes, with massive aspiration and chronic lung aspiration being at two extremes of the clinical spectrum. Over the years, significant advances have been made in understanding the mechanisms underlying dysphagia, gastroesophageal function, and airway protective reflexes and new diagnostic techniques have been introduced. Despite this, characterizing the presence or absence of aspiration, and under what circumstances a child might be aspirating what, is extremely challenging. Many children are still not adequately diagnosed or treated for aspiration until permanent lung damage has occurred. A multidisciplinary approach is mandatory for a correct diagnosis in addition to timely and appropriate care.

Abnormal Sensorimotor Integrative Function of the Larynx in Congenital Laryngomalacia: A New Theory of Etiology

OBJECTIVES/HYPOTHESIS

Laryngomalacia is an enigmatic disease in which laryngeal tone is weak, resulting in dynamic prolapse of tissue into the larynx. Sensorimotor integrative function of the brainstem and peripheral reflexes are responsible for laryngeal tone and airway patency. The goal of this study was to elucidate the etiology of decreased laryngeal tone through evaluating the sensorimotor integrative function of the larynx. The secondary goal was to evaluate factors and medical comorbidities that contribute to the wide spectrum of symptoms and outcomes.

STUDY DESIGN

Prospective and retrospective collection of evaluative data on infants with congenital laryngomalacia at two tertiary care pediatric referral centers.

METHODS

Two hundred one infants with laryngomalacia were divided into three groups on the basis of disease severity (mild, moderate, severe). Patients were followed prospectively every 8 to 12 weeks until symptom resolution or loss to follow-up. Sensorimotor integrative function of the larynx was evaluated in 134 infants by laryngopharyngeal sensory testing (LPST) of the laryngeal adductor reflex (LAR) by delivering a duration- (50 ms) and intensity- (2.5-10 mm Hg) controlled air pulse to the aryepiglottic fold to induce the LAR. Medical records were retrospectively reviewed for medical comorbidities.

RESULTS

The initial LPST was higher (P < .001) in infants with moderate (6.8 mm Hg) and severe disease (7.4 mm Hg) compared with those with mild disease (4.1 mm Hg). At 1, 3, and 6 months, infants with moderate and severe disease continued to have a higher LPST compared with those with mild disease. At 9 months, the LPST decreased in all subjects (3.1-3.5 mm Hg, P = .14), which also correlated with symptom resolution. Neurologic, genetic, and cardiac diseases were more common in infants with severe disease (P < .001). Gastroesophageal reflux disease (GERD) and feeding problems more common in those with moderate and severe disease (P < .001). Apgar scores were lower in those with severe disease (P < .001). Most symptoms resolved within 12 months of presentation. Those with GERD benefited from treatment. Supraglottoplasty resulted in few complications. Multiple comorbidities (>3) influenced the need for tracheotomy.

CONCLUSIONS

Laryngeal tone and sensorimotor integrative function of the larynx is altered. The degree of alteration correlated with disease severity, indicating that factors that alter the peripheral and central reflexes of the LAR have a role in the etiology of signs and symptoms of laryngomalacia. GERD, neurologic disease, and low Apgar scores influenced disease severity and clinical course, explaining the spectrum of disease symptoms and outcomes. Sensorimotor integrative function improved as symptoms resolved.

Lipid-laden macrophage index is not an indicator of gastroesophageal reflux-related respiratory disease in children

BACKGROUND

The lipid-laden macrophage index has been used to evaluate for gastroesophageal reflux-related respiratory disease, but the relationship between reflux detected by pH probe and the lipid-laden macrophage index is uncertain despite widespread use of the lipid-laden macrophage index in clinical decision-making. It was the aim of this study to correlate reflux as detected by multichannel intraluminal impedance with the lipid-laden macrophage index.

METHODS

Patients undergoing both pH multichannel intraluminal impedance testing and bronchoscopy between January 2002 and January 2006 were identified. Baseline characteristics were compared by using parametric and nonparametric testing. Reflux profiles were correlated with the lipid-laden macrophage index by using Spearman correlations.

RESULTS

There was no significant correlation between the lipid-laden macrophage index and the number of acid or nonacid reflux events. There also was no significant correlation between the lipid-laden macrophage index and the amount of full-column reflux. There was no significant difference between the mean lipid-laden macrophage index in patients with and without esophagitis. Finally, in patients who underwent fundoplication (n = 13) for intractable respiratory disease, there was no significant difference in any of the reflux parameters between patients who did and did not experience clinical improvement after fundoplication. There was, however, a higher lipid-laden macrophage index in patients with no symptomatic improvement compared with patients with symptomatic improvement.

CONCLUSIONS

Lipid-laden macrophage index lacks the specificity necessary to detect reflux-related respiratory disease.

Increased laryngeal lavage lipid-laden macrophage index during acute bronchiolitis

AIM

To investigate aspiration risks associated with bronchiolitis in infants using the lipid-laden macrophage index (LLMI) from laryngeal lavages.

METHODS

Laryngeal lavages from 29 infants with acute bronchiolitis caused by respiratory syncytial virus were evaluated (acute stage). Repeated studies were then performed at 3-4 weeks after the initial study (remission stage). Lavage cell counts and differentials were determined. The amount of lipid per single macrophage was evaluated and the LLMI was determined by evaluating 100 cells. In addition, 24-h pH monitoring (pHm) was performed in 16 patients.

RESULTS

The LLMIs in the acute stage were significantly higher than those in the remission stage (p < 0.05). The neutrophil percentage of the laryngeal lavage correlated significantly with the LLMI (r = 0.707, p < 0.0001) during the acute stage of bronchiolitis. When patients were divided into pHm-positive (n = 5) and pHm-negative (n = 11) subgroups, a significant decrease in LLMI between acute and remission stages was noted among the pHm-positive (p < 0.01) subgroup, but not in the pHm-negative subgroup.

CONCLUSION

These findings suggest that there is a transient increased LLMI in patients with bronchiolitis, which could be caused by gastroesophageal reflux.

Cutoff value of lipid-laden alveolar macrophages for diagnosing aspiration in infants and children

Chronic passage of gastric and/or alimentary material into the airways is a frequent and difficult-to-diagnose condition. Because alveolar macrophages phagocytose aspirated material, it has been suggested that their identification is a useful diagnostic method. To know the usefulness of the lipid-laden alveolar macrophages (LLAM) index as a diagnostic tool for aspiration, children from 1 month to 16 years of age were included in three groups: G-I, children with pulmonary pathology and suspicion of aspiration by clinic or image evaluation; G-II, with pulmonary pathology without suspicion of aspiration; and G-III, without respiratory symptoms nor suspicion of aspiration. Bronchoalveolar lavage was obtained through bronchoscopy in G-I and G-II, and through endotracheal tube in G-III, and the LLAM index (0-400) was determined. A total of 112 patients (41, 30, and 41 in G-I to III, respectively) were studied. LLAM index (mean +/- SEM) was highest in G-I (233.2 +/- 5.5), as compared with G-II (187.8 +/- 11.6, P < 0.05), and G-III (108.5 +/- 13.5, P < 0.001). However, notable overlap of LLAM values was observed between G-I and G-II, and between G-II and G-III. When patients from G-I and G-III were jointly analyzed, the area under the ROC curve for diagnosing aspiration was 0.92, with a best cutoff value of >165 (98.6% sensitivity, 78.0% specificity, 87.8% overall accuracy). LLAM index, with a cutoff value of >165 is a useful diagnostic test for aspiration when there is suspicion of this condition. However, due to its low specificity, it does not discriminate other causes of chronic lung disease.

Lipid-laden macrophage index in healthy canines

BACKGROUND

The quantity of lipids in alveolar macrophages is used clinically as an indicator of aspiration, which is associated with increased lung inflammation. This is determined in the macrophages obtained from bronchoalveolar lavage (BAL) and is expressed as lipid-laden macrophage index (LLMI). Although there is ample data on LLMI in human subjects, there is no published data pertaining to the baseline measures of the LLMI in canines, which are extensively used for experimental studies on gastroesophageal reflex (GER) and airway diseases. Primary aim of the present study was to collect data pertaining to the cytology and LLMI in BAL fluids obtained from healthy dogs.

MATERIALS AND METHODS

Eight dogs underwent a bronchoscopy with BAL collection, and esophageal pH monitoring to determine the reflux index (RI). The BAL fluid was processed and reviewed under a microscope to determine the proportions of the various cell types and the LLMI.

RESULTS

The median RI among the subjects was found to be 0.6 (0.0, 1.2). The BAL cytology analysis showed 77.5% (71.0, 83.5) macrophages, 21.0 (13.0, 24.5) lymphocytes and 2.5 (1.5, 5.0) neutrophils. The median LLMI was found to be 156 (111, 208).

CONCLUSIONS

Although the differential cell counts in the dogs' BAL fluid was comparable to that of other experimental animals and humans, the LLMI was distinctly higher than the corresponding value reported for other species. As LLMI is a valuable modality for evaluation of intrapulmonary pathophysiology, these data on LLMI can be used as a species-specific standard for canine subjects used for experimental studies on GER and airway diseases.

Lipid-laden alveolar macrophage index in sputum is not useful in the differential diagnosis of pulmonary symptoms secondary to gastroesophageal reflux

BACKGROUND

Gastroesophageal reflux (GER) is frequently associated with pulmonary diseases. Esophageal acid-induced bronchoconstriction and recurrent microaspirations of gastric content are the proposed mechanisms. At present there is not a sensitive test available to prove a causal relationship between pulmonary symptoms and GER. In this study we aimed to investigate the value of a marker of aspiration: lipid-laden alveolar macrophage index (LLAM) in induced sputum, in the diagnosis of pulmonary symptoms highly suspected to be due to GER.

METHODS

Twenty-two patients with the endoscopic diagnosis of erosive esophagitis who had various pulmonary symptoms that could not be attributed to any apparent etiology constituted the study group. Fifteen healthy volunteers with no prior diagnosis of gastroesophageal and lung disease constituted the control group. Subjects were questioned for pulmonary and abdominal symptoms and underwent physical examination, chest radiography, pulmonary function tests, and sputum induction. Prepared cytospins were stained with oil red-O to detect cytoplasmic lipid droplets and LLAM index was calculated.

RESULTS

There was no statistically significant difference between the LLAM indexes of the study (1.9 +/- 3.3) and control group (4.2 +/- 4.5). LLAM index had a significant positive correlation with the duration of reflux symptoms (p=0.01, r=0.5).

CONCLUSIONS

LLAM index is not found to be a valuable method in the differential diagnosis of pulmonary symptoms suspected to be due to GER.

Safety evaluation of an α-cyclodextrin glycosyltranferase preparation

Alpha-cyclodextrin glucosyltransferase (alpha-CGTase, EC 2.4.1.19) is an amylolytic enzyme used for the production of alpha-cyclodextrin (alpha-CD), a novel, soluble dietary fiber, from food-grade starch. The safety of an alpha-CGTase preparation obtained by batch fermentation from a recombinant strain of Escherichia coli K12 harboring the alpha-CGTase gene from Klebsiella oxytoca strain M5a1 was examined. In a 13-week subchronic toxicity study in rats, the administration by gavage of the alpha-CGTase preparation at levels of up to 20 ml/kg bw/day, corresponding to a total organic solids dosage of 260 mg/kg bw/day, did not cause any systemic toxic effect. Some signs of irritation were observed in the respiratory tract which occurred, however, in one sex only and/or were not dose-related. Accordingly, these changes were considered to be an unspecific consequence of the reflux and aspiration of the dosing solution. There was no evidence of a genotoxic activity in Ames tests and a chromosome aberration test in cultured human lymphocytes. It is concluded that the examined alpha-CGTase preparation is safe when used for the production of alpha-CD.

Supra-oesophageal manifestations of gastro-oesophageal reflux disease

Since the early 1960s, many studies have been published that consider the possible relationship between gastro-oesophageal (acid) reflux (GORD) and various other complaints, including dental erosions, ear, nose and throat problems, chronic cough and asthma. Although a high coincidence of GORD and these supra-oesophageal complaints have been noted, there is no consensus on the pathophysiology and management of such complications. In this article we review the literature published between 1966 and 2000 on this subject. We also analyse the available information on the incidence, pathophysiological mechanisms, diagnostic approach and therapeutic options in the various subgroups of disorders.

Exhaled breath condensates: a potential novel technique for detecting aspiration

There is an urgent need for diagnostic procedures that can detect aspiration of oral and gastrointestinal (GI) secretions into the respiratory tract. Current approaches are limited by poor sensitivity and specificity. These techniques include (1) adding indicators to feedings; (2) recovery of lipid-filled macrophages in respiratory secretions; (3) measurement of changes in the pH of the upper GI and respiratory tracts; (4) endoscopic visualization of reflux events; and (5) measurement of increased glucose concentrations in respiratory secretions. Ideally, specific markers from various sites in the oral and GI tracts might be discovered in respiratory secretions, but conventional bronchoalveolar lavage for sampling respiratory secretions is not practical and involves some risk. Noninvasive measurements of indicators in the exhaled breath condensates could be used to detect aspiration, but a number of theoretical and practical aspects of such studies must be considered before this approach can be applied to the problem of aspiration.

Supraesophageal complications of gastroesophageal reflux in children: challenges in diagnosis and treatment

Gastroesophageal reflux (GER) occurs throughout the day in healthy infants, children, and adolescents, as well as in adults. However, regurgitation into the pharynx and vomiting are more common in infants than in adults. This places the infant at particular risk for supraesophageal complications of GER. Despite recognition of this risk, a lack of good control data in children and an absence of placebo-controlled treatment trials provide only marginal evidence to support GER as a cause of any supraesophageal disorder in infants or children. An association of GER with "awake apnea," reactive airway disease, and recurrent pneumonia has been demonstrated. Although there is no good evidence to support the efficacy of medical therapy, surgical therapy for GER has been demonstrated to improve symptoms in selected cases with each of these symptom presentations. Although clinical experience and case series suggest that GER may possibly contribute to laryngeal disorders, sinusitis, and otitis media, convincing data are lacking. No studies have definitively demonstrated symptom improvement with medical or surgical therapy for the latter symptom presentations.

Gastroesophageal reflux and the upper airway

EER is a disorder commonly seen in otolaryngologic practice and differs from GERD in its clinical manifestations, pathophysiology, and response to treatment. Its association with numerous disorders in children should lead otolaryngologists to consider this diagnosis in all patients with voice, airway, and swallowing complaints.

Limited reliability of lipid-laden macrophage index restricts its use as a test for pulmonary aspiration: comparison with a simple semiquantitative assay

The lipid-laden macrophage index (LLMI) is a semiquantitative evaluation of alveolar macrophage lipid content used in diagnosis of pulmonary aspiration. To date, there are no published reports regarding the reliability of LLMI. We sought to evaluate the interobserver and intraobserver variability and validity of LLMI and to compare it to a simpler macrophage lipid content index (LCI). To evaluate reliability we compared both the LLMI and LCI of 26 bronchoalveolar lavage (BAL) specimens from 14 aspirators and 12 non-aspirators on 10 separate occasions by two observers. The ranges of means and standard deviations (SD) of LLMI for observer 1 (Obs 1) were 19-160 (5-31) for aspirators, and 0-48 (0-15) for non-aspirators; and those of observer 2 (Obs 2) were 77-249 (13-33) for aspirators and 47-170 (8-37) for non-aspirators. The ranges of means and SD of LCI for Obs 1 were 2-8 (0-2) for aspirators and 0-4 (0-1) for non-aspirators, compared with 2-9 (0-2) for aspirators and 1-6 (0-2) for non-aspirators for Obs 2. No statistical significance was found between LLMI and LCI by comparing coefficients of variation (CV) in either groups or observers. Poor agreement between the two observers was found using a Bland Altman analysis, with the difference of the two observations mostly exceeding zero and becoming larger as the average of the two observations became bigger. The combined sensitivity, specificity, and positive and negative predictive value (PPV and NPV) for both observers of the LLMI were 57%, 75%, 84%, and 69% and those of LCI were 58%, 92%, 93%, and 69%. We conclude that there is poor reliability for both methods. The LCI is simpler and appears to be at least as good as the LLMI.

Gavaging the infant lung

An 8-month-old female infant was hospitalized for persistent bilateral infiltrates, failure to thrive, and tachypnea. An extensive diagnostic workup was negative, except for strong oil-red O staining of the white-turbid bronchoalveolar lavage fluid and borderline esophageal pH monitoring. Conservative treatment failed, and she was scheduled for gastrostomy and Nissen-fundoplication until the family physician found that the anxious mother was feeding the child forcibly, which caused chronic aspiration pneumonitis. The mother was given psychological support and was supervised, and the child recovered completely.

Fat laden macrophages in tracheal aspirates as a marker of reflux aspiration: a negative report

OBJECTIVES

Refluxed gastric material aspirated into the lungs is an important cause of acute and chronic pulmonary disease. Currently, the presence of fat-laden macrophages (FLM) in tracheobronchial secretions of children is a conventional marker for reflux aspiration. However, this assay is limited by its apparent lack of specificity. The aim of this study was to reevaluate the role of this assay in diagnosing reflux aspiration.

METHODS

The tracheal aspirates of sixty-four consecutive children with clinically significant gastroesophageal reflux undergoing upper gastrointestinal endoscopy under general anesthesia, and 34 other children from the routine operative schedule were evaluated. Both groups were further subdivided on the basis of presence or absence of associated respiratory symptoms. After intubation, tracheal aspirates were collected, fixed, and stained for FLM. By grading the amount of intracellular fat present, a semiquantitative lipid index was computed. Tracheal aspirates with a lipid index of 100 or greater were considered positive.

RESULTS

Twenty-four of the 64 children with reflux symptoms and 14 of 34 children without reflux symptoms were positive for FLM. Sixteen of 37 children with both gastroesophageal reflux and respiratory symptoms and 10 of 26 children negative for both tested positive for FLM. The mean lipid index of the subgroup of children with both reflux and respiratory symptoms was not significantly different from that of the subgroup that was negative for both conditions. Despite computing a semiquantitative lipid index, an index of 100 or greater only had a sensitivity of 38% and specificity of 59%.

CONCLUSION

Assay of FLM in the tracheal aspirates of children considered at risk of reflux aspiration is not a sensitive or specific as a marker for reflux aspiration.

Pediatric fiberoptic bronchoscopy: Clinical experience with 2,836 bronchoscopies

OBJECTIVE: To report 21 yrs of experience with pediatric flexible fiberoptic bronchoscopy in infants and children, explore newer applications, delineate potential complications, and make recommendations for its future application. DESIGN: Retrospective review. SETTING: A 20-bed pediatric critical care unit in a tertiary care, university-based children's hospital. PATIENTS: A total of 2,836 pediatric and infant fiberoptic bronchoscopies, performed over a course of 21 yrs, were reviewed. Measurement and MAIN RESULTS: A total of 2,836 children (1,536 girls) were subjected to flexible fiberoptic bronchoscopy. Of those, laryngeal mask airway was incorporated in 92 procedures (3.2%) and general anesthesia was applied in 198 cases (7%). The youngest subject was a 1-wk-old, 600-g, premature infant. The procedure resulted in diagnoses that modified patient care, particularly in tracheostomized infants and those with upper airway obstruction, plastic bronchitis of acute chest syndrome, dyskinetic cilia syndrome, immunocompromised individuals, and those with unexplained chronic cough and recurrent pulmonary infiltrates. Microbiologic and cytologic data from bronchoalveolar lavage helped confirm the diagnoses of pulmonary hemosiderosis and gastroesophageal reflux and validated the presence, or lack of, bacterial or viral pathogens. A total of 21 patients (<1%) experienced life-threatening hypoxemia, prompting termination of the procedure. Laryngospasm or bronchospasm was observed in 17 individuals (<1%) undergoing bronchoalveolar lavage, and 4% of the total population experienced mild nasopharyngeal bleeding. No fatalities were encountered. CONCLUSIONS: Pediatric flexible fiberoptic bronchoscopy is a safe diagnostic and interventional tool, even in young or extremely premature infants. Although the rate of serious complications in this report is low, general anesthetic agents and incorporation of laryngeal mask airway is advocated for severe mucoid impaction, transbronchial biopsy, and chronic pulmonary infiltrates, which may necessitate extensive bronchoalveolar lavage.

Guidelines for evaluation and treatment of gastroesophageal reflux in infants and children: recommendations of the North American Society for Pediatric Gastroenterology and Nutrition

Gastroesophageal reflux (GER), defined as passage of gastric contents into the esophagus, and GER disease (GERD), defined as symptoms or complications of GER, are common pediatric problems encountered by both primary and specialty medical providers. Clinical manifestations of GERD in children include vomiting, poor weight gain, dysphagia, abdominal or substernal pain, esophagitis and respiratory disorders. The GER Guideline Committee of the North American Society for Pediatric Gastroenterology and Nutrition has formulated a clinical practice guideline for the management of pediatric GER. The GER Guideline Committee, consisting of a primary care pediatrician, two clinical epidemiologists (who also practice primary care pediatrics) and five pediatric gastroenterologists, based its recommendations on an integration of a comprehensive and systematic review of the medical literature combined with expert opinion. Consensus was achieved through Nominal Group Technique, a structured quantitative method. The Committee examined the value of diagnostic tests and treatment modalities commonly used for the management of GERD, and how those interventions can be applied to clinical situations in the infant and older child. The guideline provides recommendations for management by the primary care provider, including evaluation, initial treatment, follow-up management and indications for consultation by a specialist. The guideline also provides recommendations for management by the pediatric gastroenterologist. This document represents the official recommendations of the North American Society for Pediatric Gastroenterology and Nutrition on the evaluation and treatment of gastroesophageal reflux in infants and children. The American Academy of Pediatrics has also endorsed these recommendations. The recommendations are summarized in a synopsis within the article. This review and recommendations are a general guideline and are not intended as a substitute for clinical judgment or as a protocol for the management of all patients with this problem.

Update on gastroesophageal reflux disease in pediatric airway disorders

In this article, the literature regarding the effects of gastroesophageal reflux disease (GERD) on otolaryngologic disorders in infants and children is reviewed. We specifically focus on studies that suggest how GERD may be associated with sinusitis, cough, laryngitis, airway obstruction, apnea, recurrent croup, laryngomalacia, stridor, and subglottic stenosis in children.

Screening of milk aspiration in 105 infant death cases by immunostaining with anti-human alpha-lactalbumin antibody

To determine the frequency and degree of milk aspiration in infant death cases, immunohistochemical examinations were performed on lung sections from 41 sudden death cases and 64 in-hospital death cases using anti-human alpha-lactalbumin antibody. Milk aspiration to some degree was detected in more than half of the sudden death cases and in about one-third of the in-hospital death cases. A semi-quantitative examination of the amount of aspirated milk was subsequently performed in the positive cases. The amount of aspirated milk in the sudden death cases was significantly higher than that in the in-hospital death cases. The frequency distribution of the amount of aspirated milk was similar in shape in both groups. In most cases, a very small amount of aspirated milk was detected. The aspirated milk was assumed to be a result of occasional gastroesophageal reflux or cardiopulmonary resuscitation. However, in five cases, much larger amounts of aspirated milk were found. In these cases, milk aspiration may have been an important part of the cause of death. We concluded that slight milk aspiration is not rare in infant death cases, and that in a few cases, the aspiration is lethal. An immunohistochemical screening test is available to perform a postmortem diagnosis in these cases.

The prevalence of gastroesophageal reflux in children with tracheomalacia and laryngomalacia

OBJECTIVE

We conducted a retrospective study to determine the relationship between gastroesophageal reflux (GER) and large airways malacia in infancy.

METHODS

One hundred sixteen children referred for chronic respiratory problems who were between the ages of 3 and 28 months were investigated. All of them underwent flexible bronchoscopy and chest radiography. Eighteen children had laryngomalacia, 13 had tracheomalacia, and 23 had combined laryngotracheomalacia. During bronchoscopy, BAL was performed. An analysis of macrophages in the BAL fluid for lipid content was performed. Fifty-four children with laryngomalacia and tracheomalacia constituted the study group, and 62 children were in the control group. Reflux studies were obtained for 40 children from the study group and 41 from the control group.

RESULTS

In the study group, 28 children (70%) had GER documented by reflux studies compared with 16 children (39%) in the control group (p < 0.01). In the control group, GER was found mainly among those with recurrent bilateral pneumonia. The lipid-laden macrophage score was correlated with the documented GER.

CONCLUSION

GER is prevalent among infants with large airways malacia, and treatment of this group with antireflux therapy should be considered.

Bronchoalveolar lavage and esophageal pH monitoring data in children with "difficult to treat" respiratory symptoms

Gastroesophageal reflux (GER) may be associated with chronic or recurrent asthma-like symptoms secondary to bronchoconstrictor reflexes and/or inhalation of gastric content. The presence of lipid-laden alveolar macrophages has been proposed as an index to establish the degree of gastric aspiration. We evaluated 20 children with "difficult to treat" respiratory symptoms and a clinical history suggestive of GER. All children underwent 24-hr esophageal pH monitoring (pHm) and fiberoptic bronchoscopy with bronchoalveolar lavage (BAL). The amount of lipid per single macrophage was determined by a semiquantitative method, using fluorescence microscopy to detect Nile-Red-stained BAL cells and calculating a lipid-laden macrophage index (LLMI). Eleven children had positive pHm recordings, suggesting the presence of GER (pH-positive patients), and 9 had negative pHm records (pH-negative patients). The pH-positive patients had higher percentages of neutrophils and higher LLMI than the pH-negative children (P < 0.05). There were no correlations between the pHm records and either % BAL neutrophils or LLMI in pH-positive or pH-negative patients (P > 0.05; each correlation). In contrast, a single correlation was found between % BAL neuytrophils and LLMI, both in the pH-positive and in the pH-negative patients (r = 0.72, P = 0.02 and r = 0.71, P = 0.04, respectively). These data demonstrate that a significant proportion of pH-positive patients with respiratory symptoms have BAL abnormalities that suggest airway inflammation and gastric content aspiration. However, the intensity of GER as indicated by pH monitoring does not correspond with BAL data in all patients.

Immunohistochemical examination of the lungs in infant death cases using antibodies against milk components

To examine the use of immunohistochemical staining with antibodies against milk components for detection of aspirated milk on lung sections, eighteen infant death cases were investigated. Immunostaining was performed with anti-human alpha lactalbumin, anti-human IgA, anti-human milk fat globulin 1, and anti-cow whey antibody. Reactivity with each antibody was examined, and semi-quantitative examinations were performed to compare the amount of aspirated milk using anti-human alpha lactalbumin antibody. Materials in the alveoli or bronchioli on lung sections suspected to be aspirated milk showed the most sensitive and clearest reaction with anti-human alpha lactalbumin antibody. Of the eighteen cases, ten cases showed positive reaction with this antibody. The amount of aspirated milk varied widely in each case. In conclusion, immunohistochemical staining with antibodies against human milk components, especially anti-human alpha lactalbumin antibody, can detect small amounts of milk. Using this method, we were able to compare the relative amount of aspirated milk among cases.

Why do the published data fail to clarify the relationship between gastroesophageal reflux and asthma?

The relationship between gastroesophageal reflux (GER) and asthma has troubled physicians for centuries and has been a source of debate among pulmonologists, allergists, and gastroenterologists for decades. Attempting to tie together the pieces of the puzzle, numerous investigators have struggled to show that in patients with asthma, GER symptoms occur too frequently, gastric acid dwells for too long in the esophageal lumen, and refluxed gastric acid injures the esophageal mucosa more than expected. Unfortunately, all of the work done by these fine investigators has failed to demonstrate a "cause and effect" relationship. Although they have succeeded in convincing us that GER occurs more frequently in asthmatics than in nonasthmatics, they still must continue until we all know how to predict which patients have gastroesophageal-induced or gastroesophageal-exacerbated asthma.

Esophageal biopsy for the diagnosis of gastroesophageal reflux-associated otolaryngologic problems in children

Recently, gastroesophageal reflux (GER) has been found to contribute to many types of otolaryngologic pathology in infants and children. The complaints may be intermittent and unresponsive to usual therapies, such as antimicrobial treatments. A high index of suspicion for GER and for the concept of "silent" GER (GER without overt symptoms) is necessary for accurate diagnosis and treatment of otolaryngologic manifestations of GER in these patients. In this prospective historical cohort study, the records were reviewed from 101 children who underwent esophagoscopy and biopsy as a diagnostic test for GER at the time of other otolaryngologic procedures. Significant associations were found between the presence of histologic esophagitis and asthma, recurrent croup, cough, apnea, sinusitis, stridor, laryngomalacia, subglottic stenosis, posterior glottic erythema, and posterior glottic edema. There were no complications. Esophageal biopsy is a rapid, safe and effective diagnostic test for GER that should be considered at the time of other procedures in children with selected GER-associated problems.

Pediatric gastroesophageal reflux and laryngopharyngeal reflux

Pediatric gastroesophageal reflux (GER) and laryngopharyngeal reflux (LPR) have gained better recognition over the past few years. GER and LPR usually present as regurgitation, emesis, epigastric pain, failure to thrive, esophagitis, or stricture. Many patients suffer respiratory disorders associated with reflux. Classification of reflux, pathophysiology, manifestations of reflux, diagnosis, and management of the disease are discussed in this article.

A novel diagnostic method for pulmonary aspiration in a murine model. Immunocytochemical staining of milk proteins in alveolar macrophages

Aspiration of foreign material into the lungs has been implicated in the etiology of a variety of pulmonary disorders. Although aspiration is a common clinical problem, its diagnosis represents a major challenge due to the lack of sensitive and/or specific tests. In this study, we evaluated the sensitivity and specificity of a novel diagnostic method in a murine model of milk aspiration. Under light anesthesia, BALB/c mice received either single or repeated intranasal instillation of milk. Control animals received sterile physiologic saline or were infected with respiratory pathogens in a similar manner. After isolation and cannulation of the trachea, mouse lungs were lavaged with PBS at various time points after the last aspiration event. Cells were recovered for Oil Red O (ORO) staining as well as immunocytochemistry for milk proteins: alpha-lactalbumin and beta-lactoglobulin. After single aspiration of milk, a large number of alveolar macrophages displayed a strong immunoreactivity for alpha-lactalbumin for 2-96 h. After single and repeated aspiration, the percentage of positive cells for alpha-lactalbumin was significantly higher when compared with ORO staining at 24, 48, and 72 h (p < 0.05). No immunoreactivity for milk proteins was found in alveolar macrophages obtained from our control groups. These findings demonstrate that immunocytochemical staining of milk proteins within alveolar macrophages represents a novel, sensitive, and specific test for the diagnosis of aspiration in a murine model.

Chronic aspiration in children: evaluation of the lipid-laden macrophage index

Chronic pulmonary aspiration (CPA) causes significant morbidity, but is underdiagnosed because of difficulties in establishing a diagnosis. The lipid-laden macrophage index (LLMI) is said to differentiate between those with and without CPA. Records of 113 patients were reviewed to determine specificity and sensitivity of the LLMI for CPA. Diagnostic accuracy was inferred from treatment outcome. Mean LLMI for aspirators was 104 +/- 62 (range, 20-233), and for nonaspirators, 44 +/- 39 (range, 0-170) (P < 0.05). Sensitivity and specificity were 0.69 and 0.79, respectively. While the LLMI provides clinically helpful information, it does not stand alone as the gold standard for the diagnosis of CPA. Failure to thrive and neurological impairment correlated with CPA, using Fisher's exact test. CPA was not diagnosed in any patient with normal growth, normal neurological development, and an LLMI <86. No other clinical observation (cough, wheeze, vomiting, difficulty feeding, choking with feeding, recurrent pneumonia, bronchopulmonary dysplasia, chronic chest X-ray changes, endotracheal tube, tracheostomy tube, nasogastric feeding tube, or transpyloric feeding tube) or diagnostic study (upper gastrointestinal series, gastroesophageal scintigraphy, modified barium swallow, or pH probe) correlated with the diagnosis of CPA.

Lipid-laden macrophages in the tracheal aspirate of ventilated neonates receiving Intralipid: A pilot study

Lipid-laden macrophages (LLM) in tracheal aspirates are reported to be pathognomonic findings in exo- and endogenous lipoid pneumonia in adults. A pilot study was carried out to evaluate the effect of lipid infusion on the LLM index of the tracheal aspirates from ventilated neonates. All intubated infants were eligible for the study. Infants receiving parenteral nutrition had intravenous (IV) lipid introduced by 4-7 days of age; most samples after 7 days were from infants receiving IV lipid. Four infants received minimal gastric feeding; none had evidence of aspiration pneumonia. Tracheal aspirates from 28 infants were analyzed for the LLM index. Alveolar macrophages were graded 0-4 in direct relation to the amount of lipid per cell. One hundred macrophages were graded; the maximum possible LLM index was 400. Two hundred forty-five of 387 tracheal aspirate samples were acceptable for analysis. LLM indices increased during the first week after birth; the mean LLM index then continued in the same range, but with a wide distribution of individual values. The mean LLM index from infants receiving an IV lipid infusion during days 4-7 was 87.9 (SD = 44.8), and was significantly higher compared to 58.7 (SD = 40.8) in infants receiving no IV lipid (P < 0. 003). Tracheal aspirates from infants with and without IV lipid infusion yielded many LLM index values >100. These observations invalidate the use of the LLM index >100 as proof of aspiration pneumonia in this group of infants.

Antireflux surgery in children suffering from reflux-associated respiratory diseases

The aim of our study was to evaluate the success, complications, and morbidity following a modified Thal fundoplication in children with reflux-associated respiratory disease (RARD). We used a procedure consisting of retroesophageal hiatal plasty, wrapping the gastric fundus around the gastroesophageal junction 180 degrees, and fixation of the lesser curvature at the abdominal wall. Follow-up by questionnaire of 128 (77 male, 51 females) out of 196 antireflux procedures between 1992 and 1995 was achieved. Surgical therapy was considered justified whenever there was gastroesophageal reflux resulting in severe recurrent respiratory symptoms. Eleven percent of the children suffered from bronchiectasis. The diagnosis of RARD was based on a high index of suspicion, barium swallow with fluoroscopy, 24-hr two-level pH-monitoring, bronchoscopy, bronchoalveolar lavage and detection of lipid-laden alveolar macrophages, esophago-gastroscopy, and esophageal biopsy. Patients with bronchopulmonary diseases such as allergy, immunodeficiency, cystic fibrosis, primary ciliary dyskinesia, and malformation of the bronchial tree or vessels had been excluded. "Evident improvement" as a result of surgery was reported in 88%, "no change" in 10%, and a "change for the worse" in 2% of patients. Persistent mild difficulties in swallowing were observed in 11%. Paraesophageal hernia, gas-bloat syndrome, and dumping syndrome were not observed. Two children needed a second operation because of relapse. The use of emergency steroidal medication for acute respiratory distress decreased impressively (219 single doses/year before surgery vs. 30 single doses/year after surgery). The need for more than 4 times/year of antibiotic therapy before surgery was reduced from 52. 3% before to 14% after surgery. Most (90.6%) of the parents stated they would agree to have surgery done again if medically indicated. In conclusion, Thal fundoplication is sufficient, safe, and effective in the management of RARD. Complications of the procedure were minor and of little consequence to the patient.