PMC7149861_01
Time course images of immunostaining of tracheal aspirates and changes of PaO2/FiO2 ratio, white blood cell count (WBC), and C-reactive protein (CRP) in case 1. Methylprednisolone (150 mg/day) was given intravenously from hospital days 8 to 18. Triple staining was performed with 4',6-diamidino-2-phenylindole (DAPI), anti-human histone H3 mouse monoclonal antibody, and anti-human Cit-H3 rabbit polyclonal antibody. Blue: DAPI; red: histone H3; green: citrullinated histone H3. White arrowheads indicate NETs. Scale bar = 30 mum
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PMC7149861_01_40560_2020_444_Fig1_HTML.jpg
Fig1
However, Cit-H3 was rarely observed and NETs almost completely disappeared by hospital day 14 (Fig. 1).
PMC7149861_02
Time course images of immunostaining of tracheal aspirates and changes of PaO2/FiO2 ratio, white blood cell count (WBC), and C-reactive protein (CRP) in case 2. Steroids were not given over the course of hospitalization. Blue: DAPI; red: histone H3; green: citrullinated histone H3. White arrowheads indicate NETs. Scale bar = 30 mum
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PMC7149861_02_40560_2020_444_Fig2_HTML.jpg
Fig2
The expression of Cit-H3 and NETs were found to diminish on hospital days 7 and 17, but they increased significantly on hospital days 24 and 28 (Fig. 2).
PMC7149861_03
Time course images of immunostaining of tracheal aspirates and changes of PaO2/FiO2 ratio, white blood cell count (WBC), and C-reactive protein (CRP) in case 3. Methylprednisolone (1000 mg/day) was given intravenously from hospital days 6 to 8, and prednisolone (100 mg/day) was given through feeding tube from hospital days 4 to 8. Blue: DAPI; red: histone H3; green: citrullinated histone H3. White arrowheads indicate NETs. Scale bar = 30 mum
40560_2020_444_Fig3_HTML.jpg
PMC7149861_03_40560_2020_444_Fig3_HTML.jpg
Fig3
Immunostaining of her sputum showed abundant expression of Cit-H3 and NETs from hospital day 5 that persisted until hospital day 14 (Fig. 3).