Cytomegalovirus Infectivity in Whole Blood Following Leukocyte Reduction by Filtration

Abstract

Cytomegalovirus (CMV) may be transmitted by transfusion of whole blood and cellular components processed according to standard processing procedures. A need exists to develop new procedures to remove CMV and other leukocyte-borne viruses from donor blood. Ten patients (AIDS/bone marrow transplants) who were CMV antigenemic (virus subsequently confirmed by isolation), donated 50 mL of venous blood within 24 to 72 hours of the initial antigen detection. Twenty-five-milliliter aliquots of each specimen were passed through Purecell Neo Neonatal Leukocyte Reduction Filters (Pall, East Hills, NY). The remaining 25-mL nonfiltered aliquots, as well as the blood filtrates, were subjected to infectivity endpoint determinations. The Purecell Neo filter effected a 3 to 4 log10 leukocyte reduction. CMV input titers ranged from less than 10 to 7.3 x 10(1) median tissue culture infectious dose (TCID50) per milliliter. CMV was not isolated from any postfiltration effluent (i.e., leukocytes, erythrocytes, or plasma). CMV DNA was not detected by nested polymerase chain reaction in 8 of 10 postfiltrate blood specimens. The Purecell Neo filter was efficacious in eliminating or significantly reducing viral (CMV) load in venous blood.

Response 6

“…Most centres utilize leucodepletion as a fall‐back, when CMV‐negative blood products are not available. This is in line with evidence indicating that leucocyte‐filtered transfusions considerably reduce levels of white cells [1], and experimental studies that show reduced levels of infectious CMV and CMV DNA in blood postfiltration [2].…”

Effect of serum and CTL on focal growth of human cytomegalovirus

“…Several lines of evidence indicate that a strictly cellassociated mode of HCMV infection more accurately reflects the in vivo situation than a cell-free mode of infection: (i) HCMV infectivity in the blood is almost exclusively cellassociated (Lipson et al, 2001;Spector et al, 1999). (ii) Clinical HCMV isolates grow strictly cell-associated after primary isolation (Yamane et al, 1983) and start to release cell-free virus only after extended propagation in cell-culture (Sinzger et al, 1999).…”

Virion Glycoprotein-Mediated Immune Evasion by Human Cytomegalovirus: a Sticky Virus Makes a Slick Getaway

“…In vivo, CMV most often displays a cell-associated method of dissemination. For example, in patients with acute CMV infection, virus is found in the white blood cell compartment but not in plasma or serum (167). Furthermore, low-passage-number clinical viruses display a highly cell-associated phenotype (168)(169)(170).…”