全血細胞計數(complete blood count)是臨床照護常用的實驗室檢查。此研究比較康復及死亡的COVID-19患者之全血細胞計數結果,提出臨床上簡易可行的預後預測模型。其中患者發病後淋巴球(lymphocyte)的比例,是評估病情是否惡化的關鍵指標;淋巴球低下(lymphopenia)可做為COVID-19嚴重度的預測因子。

預測模型如下:

  1. 發病後10-12天,若淋巴球比例 >20%,表示病情將好轉;淋巴球比例 <20%,表示病情嚴重。
  2. 發病後17-19天,若淋巴球比例 >20%,表示病情好轉中;淋巴球比例介於5%–20%之間,表示病情仍危急,須密切觀察;淋巴球比例<5%,表示病情危殆,死亡率極高,需重症加護照顧。

此外,作者也提出SARS-CoV-2感染患者淋巴球低下的可能原因,不過這些假說仍待實驗證明。

  1. 病毒直接感染具ACE2受體的淋巴球,導致其死亡。
  2. 病毒直接破壞淋巴器官,如胸腺、脾臟等,此有待病理切片驗證。
  3. 病毒引發的促發炎細胞激素釋放,如TNFα、IL-6等,會導致淋巴球凋亡。
  4. 感染造成的代謝性失調,如高乳酸血(hyperlactic academia),會抑制淋巴球的增殖。

(財團法人國家衛生研究院 吳綺容醫師摘要整理)

An outbreak of an unknown infectious pneumonia has recently occurred in Wuhan, China.1 The pathogen of the disease was quickly identified as a novel coronavirus (SARS-CoV-2, severe acute respiratory syndrome coronavirus 2), and the disease was named coronavirus disease-19 (COVID-19).2 The virus has so far caused 78,959 confirmed cases and 2791 deaths in China according to the reports of government. COVID-19 has been spreading in many countries such as Japan, Korea, Singapore, Iran, and Italia. The clinical manifestation of COVID-19 include fever, cough, fatigue, muscle pain, diarrhea, and pneumonia, which can develop to acute respiratory distress syndrome, metabolic acidosis, septic shock, coagulation dysfunction, and organ failure such as liver, kidney, and heart failure.1,3,4 Unfortunately, there is no effective medication other than comprehensive support. However, the mild type of COVID-19 patients can recover shortly after appropriate clinical intervention. The moderate type patients, especially the elderly or the ones with comorbidity, can worsen and became severe, indicating high mortality rate.3,4 However, efficient indicators for the disease severity, therapeutic response and disease outcome have not been fully investigated. Once such indicators are present, reasonable medication and care can be inclined, which is believed to significantly reduce the mortality rate of severe patients.

Author:Li Tan, Qi Wang, Duanyang Zhang, et al.
原文連結:https://www.nature.com/articles/s41392-020-0148-4