Israel Medical Association Journal

Background: The exposure to ambient particulate matter (PM) is associated with increased morbidity and mortality from respiratory, cardiovascular, and other causes. A major contribution to this adverse effect is attributed to particles at the nanoscale range (ultrafine particles [UFP] particles < 100 nm). Most of the information about human exposure to PM has been collected by environmental monitoring of inhaled particles.

Objectives: To evaluate the use of direct measuring of UFP in the sputum as a biomarker for lung inflammation and functional impairment.

Methods: The study population included 121 patients who underwent an induced sputum (IS) test as a part of a clinical evaluation for respiratory symptoms. Cell differential count was performed, and the UFP content was measured in each IS sample. The UFP content in the sputum was compared among patients with different inflammatory phenotypes based on IS granulocytes levels: eosinophilic inflammation (EI) IS eosinophils > 2.7%, neutrophilic inflammation (NI) IS neutrophils > 65%, and mixed granulocytic inflammation (MGI) including both IS eosinophils > 2.7% and IS neutrophils > 65%. The association between the IS-UFP content and pulmonary function test (PFT) parameters was also tested.

Results: Patients with MGI had a distinct profile of particles in IS, which was characterized by the highest percentage of UFP (relative to larger particles) compared to patients with EI, NI, or normal IS cell count. Furthermore, EI and NI were found to have an interaction effect regarding the IS–UFP profile, as demonstrated by the significantly different IS–UFP profile of patients with MGI compared to the profile associated with EI and NI independently. Last, the profile of UFP in the IS samples was also correlated with patient PFT. Reduced forced mid-expiratory flow (FEF) 25–75 or FEV1 were correlated with a higher IS–UFP mean size. Reduced FEF25–75 was correlated with a lower IS–UFP concentration and percentage relative to larger particles.

Conclusions: To the best of my knowledge, this study is the first to report a distinct IS–UFP profile in patients with MGI, which suggest an interaction effect of EI and NI on the IS–UFP content. This finding may further support the consideration of MGI as a distinct inflammatory phenotype, beyond the simple combination of EI and NI independently. In addition, reduced PFT parameters were associated with a specific change in the IS–UFP profile. The results of this study may shed light on the use of IS–UFP content as a biomarker for lungs inflammation and functional impairment. Further prospective studies are needed to establish a cause and effect relationship between lungs inflammation and functional impairment to the IS–UFP content.

Background: Dyspnea may be a presenting symptom of type I food hypersensitivity, and bronchial hyper-reactivity, without known asthma, can coexist in patients with food allergy.

Objective: To evaluate airway involvement in young adult patients with food allergy and no asthma and compare the findings to those of patients with food allergy and asthma, with food allergy and allergic rhinitis, with asthma and no food allergy, and of apparently healthy controls.

Methods: The evaluation involved prick skin test to food (65 allergens) and inhalants (24 allergens), spirometry, methacholine inhalation challenge, and induced sputum for cell analysis. The five groups consisted of 18 patients with food allergy alone, 11 with food allergy and asthma, 13 with food allergy and allergic rhinitis, 10 with asthma alone, and 10 controls.

Results: Patients with food allergy alone were mainly (86%) skin sensitive to pollens. Those with either asthma or allergic rhinitis were mainly (95%) sensitive to mites. BHR was detected in 40% of the patients with food allergy alone, 55% of the patients with allergic rhinitis, and 100% of the patients with asthma. Cell counts in the sputum of patients with asthma and in those with food allergy and asthma showed higher eosinophil counts compared to those with food allergy and allergic rhinitis. Patients with food allergy and no asthma, regardless of BHR status, had mainly neutrophils in the sputum.

Conclusions: Patients with food allergy are highly likely to have concomitant asymptomatic BHR. Mite sensitivity in patients with food allergy predicts respiratory allergy (either asthma or allergic rhinitis). High eosinophil levels in the sputum of food allergy patients predict respiratory involvement.

The induced sputum technique allows sampling of the airways in a non-invasive manner and thus offers a unique opportunity to identify biomarkers of potential clinical utility in respiratory medicine. Sputum cells were originally examined in stained smears and the procedure was applied in both research and clinical settings from the 1950s through the 1970s. The cells, recovered from spontaneous coughing, were used to study lung cancer and respiratory infections and, later on, to diagnose Pneumocystis carinii pneumonia in patients infected with human immunodeficiency virus. The method was largely improved by the induction of sputum with aerosol of hypertonic saline and was extended to become part of the assessment of airway inflammation in bronchial asthma and chronic obstructive pulmonary disease. It was recently shown that induced sputum can be used to study interstitial lung diseases and, more specifically, sarcoidosis, non-granulomatous ILD[1], occupational lung diseases and other systemic diseases with lung involvement.

____________________________________