Skip to main content
  • Poster presentation
  • Published:

Regulatory T cells are persistently enriched in the peripheral blood of head-injury patients


We have previously shown that a significant proportion of patients have increased numbers of lymphocytes proliferating in response to myelin basic protein 10 days post traumatic brain injury (TBI); associated with a trend for more favourable outcome [1]. This suggests that the adaptive immune response may have a protective role following TBI, as demonstrated in animal models [2]. In this study, we further explored this process by examining the effect of TBI on regulatory T cell (Treg) numbers, and determining whether a change in Treg frequency was long lived.


We recruited 12 patients with severe or moderate TBI who required protocol-driven therapy to maintain cerebral perfusion and intracranial pressure. Blood samples were taken within 72 hours and 10 days post TBI. A separate group of patients was studied 6 months post TBI. Age-matched and sex-matched healthy volunteers were used as controls. Peripheral blood mononuclear cells (PBMCs) were isolated. Flow cytometry was used to identify Tregs according to the surface expression of markers (CD4/CD25high/CD45ROhigh/CD127low).


When compared with controls, patients at 10 days and at 6 months post TBI showed a greater proportion of PBMCs with a Treg phenotype (Mann–Whitney U test; P < 0.01 and P < 0.05, respectively). The proportion of Treg cells at 72 hours was higher than controls, but this difference did not reach significance. See Figure 1.

Figure 1
figure 1

Treg frequency post TBI.


We have shown that TBI upregulates CD4+ T cells with a regulatory phenotype. This effect is sustained for at least 6 months, and may modulate protective autoimmunity. Better understanding of the functional capacity and specificity of lymphocytes identified as Tregs may provide therapeutic targets.


  1. Cox AL, et al.: J Neuroimmunol. 2006, 174: 180-186. 10.1016/j.jneuroim.2006.01.007

    Article  PubMed  CAS  Google Scholar 

  2. Hauben E, et al.: Lancet. 2000, 354: 286-287. 10.1016/S0140-6736(99)05140-5

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and permissions

About this article

Cite this article

Galtrey, E., Cox, A., Chatfield, D. et al. Regulatory T cells are persistently enriched in the peripheral blood of head-injury patients. Crit Care 13 (Suppl 1), P82 (2009).

Download citation

  • Published:

  • DOI: