Fig. 1

Scoring system for BALF NETs quantification. a-d NETs on cytospins BALF were evaluated using a blind scoring system. Scores 0 (no NETs), 1 (rare NETs), 2 (moderate NETs) and 3 (widely distributed NETs) were attributed to each of the 27 fields from the peripheral areas of the cytospin. Scale bars represent 100 μm. e-h Representative images illustrating NETs in the BALF of a horse with severe asthma. BALF cells were labeled with anti-myeloperoxidase antibody (red), anti-Histone H3 (Green) and DAPI (nucleus; blue), then observed by fluorescence microscopy at a magnification of 200X. Scale bar represents 10 μm. Arrowheads indicate profuse NETs appearing as a web-like extracellular structure