Cytomegalovirus Infection in Immunocompetent and Renal Transplant Patients : Clinical Aspects and T-cell Specific Immunity

• Cytomegalovirus (CMV) is a β-herpesvirus that, after primary infection, establishes a life-long persistence in the human host. Up to 90% of humans are infected with CMV, that is kept under control by CMV-specific CD8+ and CD4+ T cells. In patients with an impaired cellular immunity, however, CMV infections can be life-threatening. Thus, it is vital to identify risk factors and target high-risk patients. In this thesis we have evaluated low-dose valacyclovir prophylaxis in renal transplant patients and studied CMV-specific T cell immunity in healthy and renal transplant patients. In renal transplant patients, the CMV serostatus of both the recipient (R) and the donor (D) has a major impact on the risk of developing CMV disease. In the high-risk D+/R- population, >50% are likely to develop CMV disease in the absence of prophylaxis and/or pre-emptive therapy. We have used low-dose valacyclovir prophylaxis for high-risk renal transplant patients, and graft and patient survival up to 5 years after transplantation was comparable to data reported for other prophylactic protocols. The incidence of CMV disease and graft rejection during the first year after transplantation was also comparable to that achieved with other protocols, and without the adverse effects reported for other therapies. In the D+/R+ population, with a 15-35% risk of developing CMV disease, it is important to identify those individuals that are subject to a higher risk because of risk factors other than CMV serostatus. We therefore measured several immunologic parameters in renal transplant patients and in immunocompetent individuals with latent and primary CMV infection. In patients with a primary symptomatic CMV infection, CMV-specific CD8+ T cells peaked within a month after onset of symptoms but declined rapidly. In renal transplant patients, we found that the reduction in IFNγ-producing CMV-specific CD4+ T cells at 2 months post-transplantation may predict high-grade CMV DNAemia.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Infektionsmedicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Infectious Medicine (hsv//eng)

Nyckelord

Cytomegalovirus

renal transplantation

cellular immunity

valacyclovir

mismatched

prophylaxis

tetramer

CD4 T cells

CD8 T cells

Infectious diseases

Infektionssjukdomar

Publikations- och innehållstyp

vet (ämneskategori)

dok (ämneskategori)