Salivary Amylase Level in Bronchoalveolar Fluid as a Marker of Chronic Pulmonary Aspiration in Children

Abstract

Background: Chronic pulmonary aspiration is a common cause of chronic respiratory symptoms in children. However, there is no gold standard diagnostic test for aspiration. In this study, we explore the diagnostic value of measuring salivary amylase in bronchoalveolar lavage (BAL) fluid as a marker of chronic aspiration in children with different chronic respiratory illnesses. Methods: Measurements of salivary amylase in BAL fluid were routinely done in patients undergoing flexible bronchoscopy. Patients' demographic and clinical data were extracted from records and reviewed by one of the investigators. Patients were classified into three different groups based on the reviewer's assessment of risk for aspiration. BAL amylase measurements were masked from the reviewer. Multiple regression analysis was used to determine the effect of the patients' clinical variables on BAL amylase. Results: Sixty-four patients (median age 2 years; range 0-14 years) were included. Indications for bronchoscopy included chronic cough (n = 20), chronic wheezing (n = 27), Cystic Fibrosis (n = 6), recurrent pneumonia (n = 5), and lung infiltrate in immunocompromised patients (n = 6). Young age, history of excessive drooling, and wet cough were predictive of high BAL amylase. Thirteen patients were considered at no risk of aspiration, 41 patients were at low risk, and 10 patients were at high risk based on clinical symptoms and other diagnostic tests. No significant differences in BAL amylase levels were found between the three groups. However, when high and low risk groups were combined and compared to the no risk group, there was a significantly higher BAL amylase level in the combined at risk groups (1,722 vs. 307 U/L; p = 0.03). Receiver operator curve analysis demonstrated that amylase cutoff value of 250 U/L differentiates between the two risk groups with sensitivity of 66.7% and specificity of 69.2%. Conclusion: Salivary amylase level in BAL can help identify children at risk for chronic pulmonary aspiration.

Is α-Amylase an Important Biomarker to Detect Aspiration of Oral Secretions in Ventilated Patients?

“…Median values of α-amylase in “tracheal” secretions varied widely from 0 in a small pilot study to over 22,000 U/L in patients with documented aspiration or VAP ( 10 , 11 , 15 ). Median values for “BAL” specimens ranged from 134 U/L to 927 U/L; a mean value of 1,722 U/L was reported in those at high risk for aspiration ( 17 – 20 ).…”

Bronchiectasis and Chronic Suppurative Lung Disease

“…Neutrophilic Acute viral infection 269 Soluble intercellular adhesion molecule-1 Bronchiectasis 116,128 Elevated IL-8, neutrophil elastase, TNF-α, IL-1β Cystic fibrosis 270 Elevated IL-8, neutrophil elastase, proteases Protracted bacterial bronchitis 11,257 Elevated IL-8, MMP-9, IL-1β and related mediators that reflect IL-1β pathway activation Chronic lung disease of prematurity 271 Proinflammatory cytokines and chemokines Severe bronchiolitis 272,273 Myeloperoxidase, CD11b RSV proteins and mRNA transcripts in severe RSV bronchiolitis Bronchiolitis obliterans 274 Elevated IL-6, IL-8, TNF-α, IL-1β Aspiration lung disease 275 Index of lipid-laden macrophages (nonspecific marker), amylase, pepsin (still needs validation) Eosinophilic Atopic asthma 276 Elevated nitric oxide in steroid naive Helminth infections 111 e.g., toxocara and strongyloides Allergic bronchopulmonary aspergillosis 277 Neutrophilic inflammation may also be present with elevated IL-8 and MMP-9 Hypersensitivity, eosinophilic pneumonia 278 Lymphocytic Acute viral infection 269 Soluble intercellular adhesion molecule-1 Bronchiolitis obliterans 279,274 CD8+T lymphocytes Autoimmune disease* 280…”

Impact of deep oropharyngeal suctioning on microaspiration, ventilator events, and clinical outcomes: A randomized clinical trial

“…Alpha‐amylase is an enzyme that initiates the digestive process and is normally present in saliva and oral secretions but not in the lungs. Several researchers have identified α‐amylase in tracheal secretions, indicating microaspiration of oral contents (Abu‐Hasan, Elmallah, Neal, & Brookes, ; Dewavrin et al, ; Filloux et al, ; Qu et al, ; Samanta et al, ; Sole et al, ; Tripathi, Mirant‐Borde, & Lee, ; Weiss, Moazed, DiBardino, Swaroop, & Wunderink, ).…”