好中球対リンパ球のレベルが高いことが重症COVID-19と関連している

Higher level of neutrophil-to-lymphocyte is associated with severe COVID-19.

• Man Kong
• Hongmei Zhang
• Xiaocui Cao
• Xiaoli Mao
• Zhongxin Lu

抄録

2019年12月、重症コロナウイルス2019（COVID-19）感染例が急性呼吸不全に急速に進行した。本研究は、好中球対リンパ球比（NLR）と重症COVID-19感染症の発生率との関連を評価することを目的としている。2020 年 1 月 27 日から 2020 年 3 月 9 日までに武漢中央病院に入院した COVID-19 感染症患者 210 例を対象にレトロスペクティブコホート研究を実施した．末梢血サンプルを採取し，フローサイトメトリーでリンパ球サブセットを調べた．COVID-19患者210人のうち87人が重症と診断された。重症者の平均NLRは軽症者よりも高かった（6.6 vs. 3.3, P < 0.001）。NLRの最高三分位（5.1～19.7）は、年齢、糖尿病、高血圧およびその他の交絡因子を調整した後、最下位三分位（0.6～2.5）と比較して、重症化の発生率が5.9倍（95％CI 1.3～28.5）に増加していた。T細胞数は重症群で有意に減少した（0.5対0.9、P＜0.001）。COVID-19は主にリンパ球、特にTリンパ球に作用する可能性がある。NLRは重症COVID-19病の初期危険因子として同定された。NLRが上昇した患者は隔離病棟に入院し、呼吸器モニタリングと支持療法を行うべきである。

In December 2019, cases of severe coronavirus 2019 (COVID-19) infection rapidly progressed to acute respiratory failure. This study aims to assess the association between the neutrophil-to-lymphocyte ratio (NLR) and the incidence of severe COVID-19 infection. A retrospective cohort study was conducted on 210 patients with COVID-19 infection who were admitted to the Central Hospital of Wuhan from 27 January 2020 to 9 March 2020. Peripheral blood samples were collected and examined for lymphocyte subsets by flow cytometry. Associations between tertiles of NLR and the incidence of severe illness were analysed by logistic regression.Of the 210 patients with COVID-19, 87 were diagnosed as severe cases. The mean NLR of the severe group was higher than that of the mild group (6.6 vs. 3.3, P < 0.001). The highest tertile of NLR (5.1-19.7) exhibited a 5.9-fold (95% CI 1.3-28.5) increased incidence of severity relative to that of the lowest tertile (0.6-2.5) after adjustments for age, diabetes, hypertension and other confounders. The number of T cells significantly decreased in the severe group (0.5 vs. 0.9, P < 0.001). COVID-19 might mainly act on lymphocytes, particularly T lymphocytes. NLR was identified as an early risk factor for severe COVID-19 illness. Patients with increased NLR should be admitted to an isolation ward with respiratory monitoring and supportive care.