Anti-CMV Cellular Immunity Quantification Using an IGRA Test in Kidney Transplant récipients and Hemodialysis Patients, Comparison to Control Patients

Quantification de l'immunité T Anti-CMV à l'Aide d'un Test IGRA Chez Des Patients greffés rénaux et Des Patients dialysés, Comparaison Avec Une Population de témoins

Evaluation of anti-CMV T cellular immunity using an IGRA test (Quantiferon-CMV test) in kidney transplant recipients and hemodialysis patients, comparison to control patients.

Cytomegalovirus (CMV) infection is a common opportunistic complication after kidney transplantation (KT). It has been associated with high morbidity and mortality in kidney transplant recipients (KTR). Its actual management is only based on the humoral immunity : the main risk factor for CMV infection after KT is the association of a seropositive donor and a seronegative recipient (so-called "D+/R- mismatch").

However several studies have highlighted the essential role of cellular immunity to control CMV infection. The Quantiferon-CMV (QF-CMV) is an IGRA test (Interferon Gamma Releasing Assay) which evaluates T CD8 lymphocytes production of Interferon Gamma (IFNy) exposed to CMV antigens. Some studies have shown the possible interest of the QF-CMV in predicting CMV infection after antiviral prophylaxis discontinuation or when CMV viremia is detected.

However some limits have been underlined. First its positivity threshold hasn't been approved in KTR. Hemodialysis patients (HP) called to receive a renal allograft also suffered from altered immunity. No study has directly compared the QF-CMV value in KTR, HP and control patients.

That's why we propose evaluating the expression of basal cellular immunity against CMV (far from any active infection) in KTR and HP using the QF-CMV and comparing it to control patients population (not suffering from kidney dysfunction or immunosuppression).

Inclusion Criteria :

• For all patients :

  • to be seropositive for CMV
  • to not be opposed to the study

• For kidney transplant recipients :

  • to have received a kidney graft for over 1 year
  • to have received an induction therapy at transplantation time by anti-lymphocytes antibodies and steroids
  • to be currently receiving immunosuppressive therapy by calcineurins inhibitors (tacrolimus or cyclosporine), mycophenolic acid with or without steroids
  • to not suffer from another cause of immunosuppression

• For hemodialysis patients :

  • to be treated by hemodialysis for end stage renal disease
  • without prior solid organ transplant history
  • to not suffer from another cause of immunosuppression

• For control patients :

  • with normal kidney function (estimated GFR > 90 ml/min)
  • to not suffer from another cause of immunosuppression

Exclusion Criteria :

• patient under guardianship or deprived of his liberty