Cellular immune parameters associated with spontaneous control of CMV in children who underwent transplantation

CD4(+) T-cell functions that best correlate with CMV control were evaluated by studying the relationship between CMV infection and CMV-specific immune recovery as determined by proliferation assay and intracytoplasmic-IFNgamma assay. A total of 30 children (mean age: 8.30 years) who received an allogeneic hematopoietic SCT (HSCT) were included. In total, 13 recipients were seronegative before HSCT. None developed CMV infection or CMV-specific immunity. A total of 17 recipients were seropositive: (i) four patients spontaneously controlled CMV. The median of CMV-specific IFNgamma-secreting CD4 T cells was 9.13/microl at month 3 in these four patients and three of the four patients evidenced optimal proliferative responses since month 1; (ii) in 10 patients who received anti-CMV chemotherapy because of prolonged viremia, lower (P=0.016) IFNgamma responses (0.39/microl), together with delayed and/or depressed proliferative responses, were observed; (iii) finally, one patient with early CMV-associated disease had undetectable proliferative and IFNgamma responses until month 3. In conclusion, both intense IFNgamma responses and early proliferative responses seem to be associated with optimal CMV control.