Introduction: Seropositive status and the use of T cell depleted grafts are major risk factors for CMV reactivation due to delayed immune reconstitution. However, not all recipients of T cell depleted grafts experience CMV reactivation. Thus identification of risk factors which contribute towards recurrent CMV reactivation is mandatory
Patients and Methods: A retrospective study was performed from January 2004 to February 2014 at University Hospital of Wales, UK. CMV viral load was determined by real time PCR and T cell recovery was determined by flow-cytometry.
Results: 124 (42%) were CMV seropositive. (R+/D+) were 53% while 46% were (R+/D-). All patients received T cell depletion . 21% had no CMV episodes reactivation during the first 100 days, 31.5% had one r episode and 42.5% had a median of 2 episodes. A CD4 count at day + 100 of <50 cell/ul was the most significant risk factor in predicting CMV reactivation p=0.002. We found that patients who were refractory to first and/or second line of chemotherapy but subsequently responded to salvage therapy achieving either CR or PR showed significant correlation with recurrent CMV reactivation and low CD4 count at day + 100 following transplant (p=0.031) Also AML as the underlying disease was associated with both failure of recovery of CD4 count and an increased risk of recurrent CMV reactivation p=0.001. On the other hand, we didn't find any significant association with other factors like recipient age (p=0.489), time from diagnosis to transplant (p=0.203), conditioning regimens (p=0.093), presence of acute GVHD (p=0.410) and concomitant fungal infection (p=0.675).
Conclusion: Failure of response to first and/or second line therapy and underlying diagnosis of AML are associated with a lower CD4 count at day + 100 and increased risk of CMV reactivation in CMV seropositive recipients following T cell depleted graft.