Combined sputum hypermethylation and eNose analysis for lung cancer diagnosis.

AIMS: The aim of this study is to explore DNA hypermethylation analysis in sputum and exhaled breath analysis for their complementary, non-invasive diagnostic capacity in lung cancer. METHODS: Sputum samples and exhaled breath were prospectively collected from 20 lung cancer patients and 31 COPD controls (Set 1). An additional 18 lung cancer patients and 8 controls only collected exhaled breath as validation set (Set 2). DNA hypermethylation of biomarkers RASSF1A, cytoglobin, APC, FAM19A4, PHACTR3, 3OST2 and PRDM14 was considered, and breathprints from exhaled breath samples were created using an electronic nose (eNose). RESULTS: Both DNA hypermethylation markers in sputum and eNose were independently able to distinguish lung cancer patients from controls. The combination of RASSF1A and 3OST2 hypermethylation had a sensitivity of 85% with a specificity of 74%. eNose had a sensitivity of 80% with a specificity of 48%. Sensitivity for lung cancer diagnosis increased to 100%, when RASSF1A hypermethylation was combined with eNose, with specificity of 42%. Both methods showed to be complementary to each other (p≤0.011). eNose results were reproducible in Set 2. CONCLUSIONS: When used in concert, RASSF1A hypermethylation in sputum and exhaled breath analysis are complementary for lung cancer diagnosis, with 100% sensitivity in this series. This finding should be further validated.

A comparison of two skin test methodologies and allergens from two different manufacturers.

BACKGROUND: Skin prick tests (SPTs) are a frequently used method for evaluation of atopy. A variety of standard allergen preparations are available, together with a number of different methods of application. OBJECTIVE: The objective of this study was to compare SPT reactivity 1) using Soluprick SQ allergens (ALK Allergologisk Laboratorium A/S, Hørsholm, Denmark) and Bayer allergens [Bayer Corporation, West Haven, CT], and 2) using two common methods of application, a standard prick lancet and a Quintest, both produced by Bayer. METHODS: SPTs were undertaken on 22 adult volunteers (mean age 40 years, 17 female, 5 male). Wheal size was recorded as mean diameters (mm) and area (mm2). RESULTS: Bayer allergens produced larger mean diameters and areas to dust mites than ALK allergens, with the differences significant when allergens were applied with the lancet. There was a tendency for the ALK cat allergen to produce larger reactions than the Bayer product. The method of application also influenced the wheal size, with the lancet producing significantly larger mean diameters than the Quintest for the histamine and allergens from both manufacturers, except the ALK cat allergen. There were similar differences between methods of application for reactions measured as an area. CONCLUSIONS: SPTs that use different allergens or different methods of application will not provide comparable assessments of atopy.