Lymphocyte Counts and COVID-19

Already since the SARS (2002-2003) and MERS (2011) outbreaks, an association between the number of lymphocytes ("cellular immune status") and the course of a corona virus infection has been discussed.


Recent studies from the current SARS-CoV-2 pandemic confirm this relationship (Zhao et al., 2020). For example, patients with severe COVID-19 disease show a significant decrease in lymphocytes compared to infected patients with mild or no symptoms.


Recent studies also show that there are differences between individual immune cell subtypes (Liu et al., 2020; Wang et al., 2020).

These studies show that, among other things, the decrease in CD8+ T cells, neutrophils and B cells differs in patients with varying degrees of COVID-19 progression. Regular monitoring of the cellular immune status could thus provide early indications of a severe course of the disease.


Epimune's i.Mune™ TBNK test allows the determination of individual lymphocyte subtypes using a drop of blood from the fingertip, which can be dried on paper and sent to a laboratory for evaluation.

This opens up the perspective of regularly checking the cellular immune status after a confirmed SARS-CoV-2 virus detection using our i.Mune™ TBNK test.  Early detection of a drop in individual immune cell types would indicate a severe course of the disease and would indicate that these high-risk patients should be admitted to hospital  and receive intensive medical treatment if necessary. 


These examinations can be carried out from home in the case of home quarantine. It is also possible to retrospectively analyse frozen blood samples collected at clinical centers during the corona pandemic. 


  • Thevarajan I, et al. Breadth of concomitant immune responses prior to patient recovery: a case report of non-severe COVID-19. Nat Med. 2020 Apr;26(4):453-455.
  • Tan L, et al. Lymphopenia predicts disease severity of COVID-19: a descriptive and predictive study. Signal Transduct Target Ther. 2020 Mar 27;5(1):33. 
  • Ruan Q, et al. Clinical predictors of mortality due to COVID-19 based on an analysis of data of 150 patients from Wuhan, China. Intensive Care Med. 2020 Mar 3.
  • Prompetchara E, et al. Immune responses in COVID-19 and potential vaccines: Lessons learned from SARS and MERS epidemic. Asian Pac J Allergy Immunol. 2020 Mar;38(1):1-9.