Image of the cytokine IP-10
I have been reading some reports about cytokine storms in patients with COVID-19 that fare poorly and end up on ventilators in the ICU.
Here is one such study which was submitted for publication on March 6th:
Exuberant elevation of IP-10, MCP-3 and IL-1ra during SARS-CoV-2 infection is associated with disease severity and fatal outcome
Yang Yang, Chenguang Shen, Jinxiu Li, Jing Yuan, Minghui Yang, Fuxiang Wang, Guobao Li, Yanjie Li, Li Xing, Ling Peng, Jinli Wei, Mengli Cao, Haixia Zheng, Weibo Wu, Rongrong Zou, Delin Li, Zhixiang Xu, Haiyan Wang, Mingxia Zhang, Zheng Zhang, Lei Liu, Yingxia Liu
Here are the key findings and cautions:
They analyzed levels of 48 cytokines (!) in COVID-19 patients and healthy controls.
Key Findings:
• Many cytokines were elevated with COVID-19
(IFNy, IL-1Ra, IL-2Ra, IL-6, IL-10, IL-18, HGF, MCP-3, MIG, M-CSF, G-CSF, MIG-1a, and IP-10).
IP-10, IL-1Ra, and MCP-3 (esp. together) were associated with disease severity and fatal outcome.
• IP-10 was correlated to patient viral load (r=0.3006, p=0.0075).
• IP-10, IL-1Ra, and MCP-3 were correlated to loss of lung function (PaO2/FaO2 (arterial/atmospheric O2) and Murray Score (lung injury) with MCP-3 being the most correlated (r=0.4104 p<0.0001 and r=0.5107 p<0.0001 respectively).
• Viral load (Lower Ct Value from qRT-PCR) was associated with upregulated IP-10 only (not IL-1Ra or MCP-3) and was mildly correlated with decreased lung function: PaO2/FaO2 (arterial/atmospheric O2) and Murray Score (lung injury).
• Lymphopenia (decreased CD4 and CD8 T cells) and increased neutrophil correlated w/ severe patients.
Caution: Collection time of clinical data and lab results was not reported directly making it very difficult to determine if cytokines were predictive of patient outcome or reflective of patient compensatory immune response. Small numbers for cytokine analysis (N=2 fatal and N=5 severe/critical, and N=7 moderate or discharged). @sinaiimmunologyreviewproject
What is IP-10? Also known as CXCL10: it is a chemoattractant for various types of white blood cells and promotes inflammation.
What is IL-1Ra? The interleukin-1 receptor antagonist (IL-1Ra) blocks the IL-1 receptor and is a natural inhibitor of the pro-inflammatory effect of IL1 (which causes fever for example). A slightly modified version of IL-1Ra, called anakinra, is used in the treatment of rheumatoid arthritis, an autoimmune disease in which IL-1 plays a key role
What is MCP-3? Also known as CCL7. It is a chemokine that attracts monocytes, a type of white blood cell.
It is beginning to look like a familiar scenario. Too much of an immune response is not a good thing. Cytokine storms have famously contributed to the lethality of influenza such as the Spanish flu of 1918.
It is important, because there are a number of drugs that can block specific cytokines. For example, anti-IP-10 is a possible therapeutic (Eldelumab).
It may be premature, but it is the best available data to explain why some with COVID-19 have a minor disease and others have life threatening disease.
About D. Posnett MD
Emeritus Prof. of Medicine, Weill Cornell Medical College
R&R - Reachout and Rebuild 
Thanks David
Krae from my iPhone
Thank you, David, for these very interesting posts on covid.
I just want to warn everybody that the knowledge on COVID is VERY fluid and preliminary. These reports should not be viewed as “proven” or set in stone. Scientific reports are being released before they are vetted by the review process and therefore prone to error. They are released early only because of the COVID-19 threat to all of mankind.