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Elimination of CD13 positive cells — an approach to prevent transmission of HCMV in bone marrow transplantation
Abstracts
175
Intervention Studies- Posters G6-17 Diagnostic and prognostic value of human cytomegalovirus (HCMV) load and IgM antibody in blood of fetuses and newborns with congenital HCMV infection LAVINIA SIMONCINI IRCCS Policlinico S. Matteo, Pavia, Italy HCMV load (pp65-antigenemia, viremia and leukoDNAemia) and virus-specific IgM were determined in blood of 22 HCMV-infected and 15 uninfected fetuses (diagnosed by virus isolation from and DNA detection in amniotic fluid), and of 40 HCMV-infected newborns/infants and 34 uninfected newborns (diagnosed by virus isolation from urine at birth). In HCMV-infected fetuses, sensitivities of antigenemia, viremia, leukoDNAemia and IgM were 60%, 52.6%, 83.3% and 60%, respectively. Specificity was 100% for all assays. At amniocentesis, 12 HCMV-infected fetuses (group A) showed abnormal hematologic/biochemical findings, whereas 7 (group B) had normal values. Although only antigenemia and IgM reached significance (p=0.05 and 0.02, respectively), higher values of all viral parameters were observed in group A compared to group B. At birth, 2/5 newborns from group A were symptomatic, whereas all 6 newborns from group B were subclinically infected. Compared to virus isolation from urine, sensitivities of leukoDNAemia, antigenemia, viremia, and IgM assay were 100°/,, 42.5%, 28.2%, and 70.7%, respectively. Specificity was 100% for all assays. HCMV load was significantly higher and persisted longer in newborns with symptomatic infection compared to subclinically infected babies. No difference was observed for virus-specific IgM. In conclusion: i) combined virologic, laboratory and ultrasound findings may contribute to a better prognostic definition of fetal conditions; ii) determination of leukoDNAemia appears a new sensitive and specific marker of congenital HCMV infection; iii) significantly higher HCMV load was detected in symptomatic infants; iv) virus clearance from blood occurs spontaneously both in symptomatic and subclinically infected infants.
G6-18 Elimination of CD13 positive cells - an approach to prevent transmission of HCMV in bone marrow transplantaion SARI FELD Dept. of Biosciences, Karolinska Institute at Novum, Huddinge, Stockholm, Sweden CD13 (aminopeptidase N) is a common denominator for cells that can be HCMV infected in vitro. We have previously demonstrated that HCMV virions carry host-cell derived CD13. HCMV infection induces an autoimmune response against CD13, which is associated with chronic GVHD following bone marrow (BM) transplantation. Our earlier findings provide the basis for prevention of CMV transmission. Here, we investigated whether depletion of CD13 + cells from BM samples would affect the BM from forming colonies of the granulocyte/monocyte lineage (CFU-CM) and burst-forming units of the erythroid lineage (BFU-E). BM samples were obtained from 11 healthy donors and separated using CD13-specific monoclonal antibodies and magnetic beads. The purity was analysed using flow cytometry. CD13+ cells comprised 9-27% of the total cell population in the BM samples tested. The CD13 negative cell fractions contained 1-7"/o of contaminating CD13+ cells. The cell fractions were frozen or used directly for further analyses. On average, CD13 negative cells generated 90% of the number of BFU-E produced by total cells. When assaying the CFU-GM, CD13 negative cells generated 52% of the number of colonies produced by total cells. The reduction was more pronounced in 4/11 CD13 negative cell fractions tested which generated 34% of the number of CFU-GM produced by total cells. This would imply thatCD13 negative BM has the ability to mature into both erythrocytes and granulocytes/monocytes. Therefore, CD13 negative BM may be used for BM transplantation to reduce the risk of transferring HCMV infection with the graft.
175
Intervention Studies- Posters G6-17 Diagnostic and prognostic value of human cytomegalovirus (HCMV) load and IgM antibody in blood of fetuses and newborns with congenital HCMV infection LAVINIA SIMONCINI IRCCS Policlinico S. Matteo, Pavia, Italy HCMV load (pp65-antigenemia, viremia and leukoDNAemia) and virus-specific IgM were determined in blood of 22 HCMV-infected and 15 uninfected fetuses (diagnosed by virus isolation from and DNA detection in amniotic fluid), and of 40 HCMV-infected newborns/infants and 34 uninfected newborns (diagnosed by virus isolation from urine at birth). In HCMV-infected fetuses, sensitivities of antigenemia, viremia, leukoDNAemia and IgM were 60%, 52.6%, 83.3% and 60%, respectively. Specificity was 100% for all assays. At amniocentesis, 12 HCMV-infected fetuses (group A) showed abnormal hematologic/biochemical findings, whereas 7 (group B) had normal values. Although only antigenemia and IgM reached significance (p=0.05 and 0.02, respectively), higher values of all viral parameters were observed in group A compared to group B. At birth, 2/5 newborns from group A were symptomatic, whereas all 6 newborns from group B were subclinically infected. Compared to virus isolation from urine, sensitivities of leukoDNAemia, antigenemia, viremia, and IgM assay were 100°/,, 42.5%, 28.2%, and 70.7%, respectively. Specificity was 100% for all assays. HCMV load was significantly higher and persisted longer in newborns with symptomatic infection compared to subclinically infected babies. No difference was observed for virus-specific IgM. In conclusion: i) combined virologic, laboratory and ultrasound findings may contribute to a better prognostic definition of fetal conditions; ii) determination of leukoDNAemia appears a new sensitive and specific marker of congenital HCMV infection; iii) significantly higher HCMV load was detected in symptomatic infants; iv) virus clearance from blood occurs spontaneously both in symptomatic and subclinically infected infants.
G6-18 Elimination of CD13 positive cells - an approach to prevent transmission of HCMV in bone marrow transplantaion SARI FELD Dept. of Biosciences, Karolinska Institute at Novum, Huddinge, Stockholm, Sweden CD13 (aminopeptidase N) is a common denominator for cells that can be HCMV infected in vitro. We have previously demonstrated that HCMV virions carry host-cell derived CD13. HCMV infection induces an autoimmune response against CD13, which is associated with chronic GVHD following bone marrow (BM) transplantation. Our earlier findings provide the basis for prevention of CMV transmission. Here, we investigated whether depletion of CD13 + cells from BM samples would affect the BM from forming colonies of the granulocyte/monocyte lineage (CFU-CM) and burst-forming units of the erythroid lineage (BFU-E). BM samples were obtained from 11 healthy donors and separated using CD13-specific monoclonal antibodies and magnetic beads. The purity was analysed using flow cytometry. CD13+ cells comprised 9-27% of the total cell population in the BM samples tested. The CD13 negative cell fractions contained 1-7"/o of contaminating CD13+ cells. The cell fractions were frozen or used directly for further analyses. On average, CD13 negative cells generated 90% of the number of BFU-E produced by total cells. When assaying the CFU-GM, CD13 negative cells generated 52% of the number of colonies produced by total cells. The reduction was more pronounced in 4/11 CD13 negative cell fractions tested which generated 34% of the number of CFU-GM produced by total cells. This would imply thatCD13 negative BM has the ability to mature into both erythrocytes and granulocytes/monocytes. Therefore, CD13 negative BM may be used for BM transplantation to reduce the risk of transferring HCMV infection with the graft.