Patients with chronic kidney disease (CKD) often have reduced immune function, which can leave them vulnerable to infections and illnesses.

This may be worse in CKD patients who have received a kidney transplant as they have to take medications to suppress their immune system to prevent the kidney from being rejected.

Exercise may help to promote immune function and prevent infections, but this relationship has not been investigated in kidney patients. It is also unclear how exercise will interact with the immunosuppressive drugs taken by transplant recipients.

The PINK study assesses how a 20-minute bout of relatively fast walking exercise affects various immune and inflammatory cells in healthy people, kidney disease patients and those with a kidney transplant. Blood samples are obtained before, after and one hour after the exercise bout to investigate how the immune cells react to and recover from exercise. Flow cytometry is used to analyse immune and inflammatory cells in the blood samples.


  • As expected, the transplant group displayed some negative alterations in their immune cells – these include a reduced number and concentration of regulatory T cells (T-Regs), which can reduce inflammation and help to maintain graft tolerance. However, the response to exercise does not appear to differ from the control group.
  • Moderate intensity aerobic exercise does not negatively influence the immune system of kidney transplant patients, and may even promote immune health as it does in the general population. Investigation of responses in kidney disease patients who do not have a kidney transplant is currently underway.