Lower Incidence of CMV Reactivation Following Allogeneic Stem Cell Transplantation Despite a High Seroprevalence - a Single Centre Experience

Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality following allogeneic stem cell transplantation (SCT). We wanted to study the incidence of CMV reactivation following SCT is high in a population where previous exposure to CMV is high. This is a retrospective analysis of consecutive transplants done in the Department of Haematology, Christian Medical College, Vellore India between January 2008 and December 2012. Recipient and donor demographics along with transplant data were recorded. Patients were monitored for CMV reactivation weekly using a CMV DNA PCR in the first 100 days post SCT.

Four hundred and seventy five patients with a median age of 21 years (range: 1-59) underwent SCT for both malignant and non-malignant indications. Of these, 459 (97.2%) were CMV IgG positive. Donors were either sibling (n = 393) or matched unrelated (n= 82). CMV reactivation occurred in 36.6% at a median time of 41 days post SCT (range: 10 - 100). CMV disease occurred in 8 patients (1.68%). The use of a male donor (p=0.000), unrelated donor (p=0.000), degree of HLA mismatch (p=0.000), neutrophil recovery <15 days (p=0.005), acute GVHD (p=0.000) and steroid refractory GVHD (p=0.028) were identified as risk factors for CMV reactivation on univariate analysis. On multivariate analysis degree of HLA mismatch (p=0.009), early neutrophil recovery (p=0.014) and steroid refractory GVHD (p=0.014) remained independent risk factors. Most of the patients were treated with ganciclovir for a median duration of 16 days (14 – 21). The 5 year overall survival was significantly lower in patients who had CMV reactivation (58.2 ± 4.9%) compared to patients without reactivation (68.9 ± 3.7%, p=0.004).

The incidence of CMV reactivation after SCT is low despite a high seroprevalence in Indian patients undergoing allogeneic SCT. CMV reactivation however is associated with a lower overall survival following allogeneic SCT.