Screening for CMV-specific T cell proliferation to identify patients at risk of developing late onset CMV disease.

Thirty patients undergoing allogeneic BMT were screened post-transplant together with their marrow donors for CMV-specific T cell proliferation and the occurrence of CMV disease. Twenty-one of these patients received a marrow transplant from an HLA-matched sibling donor, and nine from an HLA-matched unrelated donor. All these patients were either CMV seropositive and/or had received a transplant from a CMV-seropositive donor. Patients were monitored for CMV-viraemia until day +100 post-BMT by PCR and virus culture, and thereafter by virus culture only when clinically indicated. The proliferative T cell response was investigated at regular monthly intervals beginning on day +30. A proliferative response to HCMV (median, day +123) was documented in these patients between day +37 and +730 post-BMT. None of the patients with a documented CMV-specific T cell proliferation on day 120 (n = 17) developed CMV disease in the later post-transplant period, but of the patients lacking CMV-specific proliferation (n = 13), 30.8% developed CMV disease after day 120. Thus, patients lacking a CMV-specific T-helper cell response might benefit from sensitive screening for CMV infection and pre-emptive therapy after day +100.