Relationship between cytomegalovirus infection of peripheral blood leukocytes and bone marrow cells in haematopoietic stem cell transplant recipients

Cytomegalovirus (CMV) disease may still develop in some hematopoietic stem cell transplant (HSCT) patients who have a negative pp65-antigenemia (pp65-AG) or undetectable DNA. CMV AG and DNA have been detected in cord blood and bone marrow (BM) CD34+ cells in vitro. We prospectively determined the relationship between the pp65-AG and CMV DNA in peripheral blood leukocytes (PBL) and BM samples pairs, simultaneously collected, from two groups of allogeneic HSCT patients at risk of CMV infection, undergoing BM suppression and with a preceding negative blood CMV DNA or pp65-AG. CMV pp65-AG was detected in 24 of 145 patients (16%) examined (Group I). A good correlation was found between the CMV pp65 antigen PBL and the number of BM cells(r= 0.83, p=0.00001, 95% confidence interval: 0.18-0.91). No difference was observed between the number of pp65-AG positive cells in PBL and BM cells,(p=1). CMV DNA was detected in 14 of 46 patients (30%) examined (Group II). A significant correlation was found between the positive CMV DNA in PBL and BM cells (r= 0.78, p=0.01, 95% confidence interval: 0.262-0.953). There was no difference between the CMV DNA load in PBL and BM cells (p=0.476). In conclusion, our study shows that during BM suppression CMV pp65-AG and DNA were both detectable in PBL and BM cells in a substantial proportion of allografted patients. A diagnostic evaluation of BM, including CMV PCR analysis may be indicated for patients at risk of CMV infection, undergoing BM suppression and a preceding negative blood CMV DNA or pp65-AG.