Elevated Myl9 reflects the Myl9-containing microthrombi in SARS-CoV-2–induced lung exudative vasculitis and predicts COVID-19 severity

• DOI: 10.1073/pnas.2203437119
• Publication Date: 2022-07-27T17:40:05Z
• Authors: Chiaki Iwamura; Kiyoshi Hirahara; Masahiro Kiuchi; Sanae Ikehara; Kazuhiko Azuma; Tadanaga Shimada; Sachiko Kuriyama; Syota Ohki; Emiri Yamamoto; Yosuke Inaba; Yuki Shiko; Ami Aoki; Kota Kokubo; Rui Hirasawa; Takahisa Hishiya; Kaori Tsuji; Tetsutaro Nagaoka; Satoru Ishikawa; Akira Kojima; Haruki Mito; Ryota Hase; Yasunori Kasahara; Naohide Kuriyama; Tetsuya Tsukamoto; Sukeyuki Nakamura; Takashi Urushibara; Satoru Kaneda; Seiichiro Sakao; Minoru Tobiume; Yoshio Suzuki; Mitsuhiro Tsujiwaki; Terufumi Kubo; Tadashi Hasegawa; Hiroshi Nakase; Osamu Nishida; Kazuhisa Takahashi; Komei Baba; Yoko Iizumi; Toshiya Okazaki; Motoko Y. Kimura; Ichiro Yoshino; Hidetoshi Igari; Hiroshi Nakajima; Takuji Suzuki; Hideki Hanaoka; Taka-aki Nakada; Yuzuru Ikehara; Koutaro Yokote; Toshinori Nakayama
• Keywords: Pathogenesis

The mortality of coronavirus disease 2019 (COVID-19) is strongly correlated with pulmonary vascular pathology accompanied by severe acute respiratory syndrome 2 (SARS-CoV-2) infection–triggered immune dysregulation and aberrant activation platelets. We combined histological analyses using field emission scanning electron microscopy energy-dispersive X-ray spectroscopy the lungs from autopsy samples single-cell RNA sequencing peripheral blood mononuclear cells to investigate pathogenesis vasculitis immunothrombosis in COVID-19. found that SARS-CoV-2 accumulated vessels, causing exudative emergence thrombospondin-1–expressing noncanonical monocytes formation myosin light chain 9 (Myl9)–containing microthrombi lung COVID-19 patients fatal disease. amount plasma Myl9 was clinical severity, measuring together other markers allowed us predict severity more accurately. This study provides detailed insight into immunothrombosis, which may lead optimal medical treatment for