Leukocyte CMV antigen levels in renal allograft recipients

ABSTRACT

Thirty-eight [38] new kidney recipients, and 12 normal controls were included in this study to determine the value of various immunologic parameters in the early monitoring of active CMV infection. CMV antigen and IgG and IgM antibodies were measured weekly in both recipient and control groups. In addition, the level of Soluble Interleukin 2 Receptor [SIL2R] and T cell subsets were measured at monthly intervals. This was correlated to their clinical condition. Eight [8] of the 38 recipients became positive for CMV antigen in peripheral blood leukocytes. This usually preceded the appearance of CMV IgM antibodies by at least one week. On further follow-up, CMV IgM decreased to normal levels in 4 to 6 weeks in 5 recipients. The remaining 3 died from CMV syndrome. In addition, the serum SIL2R level in the recipients before transplantation was significantly higher than in the control group. One month after transplantation, the CMV negative antigen group showed a significant lowering of the SIL2R level, while the CMV positive group showed a significant rise in this level. One month later, SIL2R decreased significantly. Finally, T cell subset determination in the CMV positive group showed a slight lowering of helper T cells and a marked elevation of the suppressor cells compared to the CMV negative group. This was also associated with a significant decrease in the helper/suppressor ratio. CMV antigenaemia is a sensitive and specific marker of CMV infection that significantly precedes the appearance of CMV antibodies. It is of great value in the monitoring of renal transplant recipients who are at high risk of CMV infection