Bone marrow transplantation (BMT) has been used to treat haematological malignancies, as well as congenital anemia and immunodeficiency disorders. Recently, medical centers have begun to harvest hematopoietic stem cells from umbilical cord blood (UCB) immediately after birth. Viral infections are major causes of morbidity and mortality in patients undergoing stem cell transplantation. We examined the patterns of viral infections that might be transmitted from bone marrow or UCB donors to hematopoietic stem cell transplant (HSCT) recipients.
A total of 790 clinical samples consisted of plasma, leukocyte and bone marrow were collected from the 30 allogenic bone marrow and 34 UCB donors. Total viral DNA was extracted and purified from plasma, peripheral blood leukocytes, cord blood, and bone marrow hematopoietic stem cell. Extracted DNA were processed with simple and nested polymerase chain reaction (PCR) for detection of human parvovirus B19 (HPV B19), human herpesvirus-6 (HHV-6), varicella-zoster virus (VZV), human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) The HCMV and HPV B19 serology status of the donor was determined prior to transplantation by EIA method.
Using simple and nested PCR, HPV B19 DNA was detected in plasma samples collected from 4 (13.3%) of 30 bone marrow and in 1 (2.9%) of 34 UCB donors respectively. EBV DNA was demonstrated in 7 (23.3%) of 30 bone marrow and in 5 (14.7%) of 34 UCB donors. VZV DNA on the other hand, wad detected in 1 (3.3%) of 30 bone marrow and in 1 (2.9%) of 34 UCB donors respectively. No HHV-6 DNA was found in any bone marrow or UCB donors. Twenty (66.7%) of 30 bone marrow and 23 (67.5%) of 34 UCB donors tested positive for HPV B19 antibodies. Twenty eight (93.3%) of 30 serum samples collected from bone marrow donors were tested positive for HCMV antibodies. Using nested PCR HCMV-DNA was found in 22 (73.3%) of bone marrow progenitor cells samples and in 9 (30%) of bone marrow donors’ buffy coats. HCMV- DNA on the other hand, was detected in 8 (23.5%) of 34 UCB hematopoietic stem cells.
Results indicate that the risk of viral transmission via umbilical cord blood is less than to those recognized in bone marrow progenitor cells. However, where a viral etiology is considered possible, or where there is a significant risk of viral transmission, donation should be exclusions.