Placental blood as a source of hematopoietic stem cells for transplantation into unrelated recipients.
BACKGROUND
Transplantation of bone marrow from unrelated donors is limited by a lack of HLA-matched donors and the risk of graft-versus-host disease (GVHD). Placental blood from sibling donors can reconstitute hematopoiesis. We report preliminary results of transplantation using partially HLA-mismatched placental blood from unrelated donors.


METHODS
Twenty-five consecutive patients, primarily children, with a variety of malignant and non-malignant conditions received placental blood from unrelated donors and were evaluated for hematologic and immunologic reconstitution and GVHD. HLA matching was performed before transplantation by serologic typing for class I HLA antigens and low-resolution molecular typing for class II HLA alleles. In donor-recipient pairs who differed by no more than one HLA antigen or allele, high-resolution class II HLA typing was done retrospectively. Fordonor-recipient pairs who were mismatched for two HLA antigens or alleles, high-resolution typing was used prospectively to select the best match for HLA-DRB1.


RESULTS
Twenty-four of the 25 donor-recipient pairs were discordant for one to three HLA antigens. In 23 of the 25 transplant recipients, the infused hematopoletic stem cells engrafted. Acute grade III GVHD occurred in 2 of the 21 patients who could be evaluated, and 2 patients had chronic GVHD. In vitro proliferative responses of T cells and B cells to plant mitogens were detected 60 days after transplantation. With a median follow-up of 12 1/2 months and a minimal follow-up of 100 days, the overall 100-day survival rate among these patients was 64 percent, and the overall event-free survival was 48 percent.


CONCLUSIONS
HLA-mismatched placental blood from unrelated donors is an alternative source of stem cells for hematopoietic reconstitution in children.
Kurtzberg
J
J
Pediatric Bone Marrow Transplant Program, Duke University Medical Center, Durham, NC 27710, USA.
Laughlin
M
M
Graham
M L
ML
Smith
C
C
Olson
J F
JF
Halperin
E C
EC
Ciocci
G
G
Carrier
C
C
Stevens
C E
CE
Rubinstein
P
P
D000293:Adolescent; D000328:Adult; D001771:Blood Banks; D001782:Blood Donors; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D005260:Female; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology; D006086:Graft vs Host Disease / Q000209:etiology; D006680:HLA Antigens / Q000235:genetics; D006402:Hematologic Diseases / Q000628:therapy; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects; D006650:Histocompatibility Testing; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010920:Placenta / Q000098:blood supply; D015996:Survival Rate
D006680:HLA Antigens