Double umbilical cord blood transplantationNavneet S Majhail, Claudio G Brunsand John E Wagn
Unrelated umbilical cord blood (UCB) is an alternative donor
identifying an unrelated adult donor takes many weeks to
source for allogeneic haematopoietic cell transplantation and,
compared with unrelated donor bone marrow, has theadvantages of rapid availability, greater tolerance of HLA
To expand the donor pool, unrelated umbilical cord blood
disparity and lower incidence of severe graft-versus-host
(UCB) has been investigated as an alternate haemato-
disease. Graft cell dose is an important determinant of
poietic stem cell source. In vitro and in vivo studies have
haematopoietic recovery and overall outcome following UCB
shown that, compared with adult bone marrow, UCB has a
transplantation, and the limited cell dose of single UCB units
greater proportion of primitive haematopoietic progenitor
has been a major barrier to its more widespread use.
cells that have a higher potential for expansion and
Transplantation with two unrelated UCB units is feasible, safe
proliferation []. Although the first successful transplant
and effective and can overcome the limitation of cell dose of
using a HLA-matched UCB donor was reported by
Gluckman et al. in 1989 the clinical applications of
unrelated umbilical cord blood transplantation (UCBT),
1 Department of Medicine, Blood and Marrow Transplant Program,
especially in adults, have become more evident only
University of Minnesota, Minneapolis, MN 55455, USA
2 Department of Pediatrics, Blood and Marrow Transplant Program,University of Minnesota, Minneapolis, MN 55455, USA
UCB offers certain advantages over unrelated adult
donors ]. Because UCB is collected from the pla-centa after delivery there is no risk to the donor. Also,HLA typing of UCB units is performed before storage
Current Opinion in Immunology 2006, 18:571–575
and, once identified, banked units are immediately avail-
able for transplantation. UCB grafts also have a lower risk
of transmission of infectious organisms; a prototypical
example is cytomegalovirus, because nearly all donorunits are negative for this virus. Furthermore, despite
the use of grafts with greater donor–recipient HLA dis-
parity, UCBT has been shown to be associated with a
# 2006 Elsevier Ltd. All rights reserved.
similar or even lower risk of acute and chronic graft-versus-host disease (GVHD) Whereas grafts from
unrelated adult or sibling donors have to be matched tothe recipient at least at five of six HLA-A, -B and -DRB1antigens, UCB units matched at only four of these six
HLA foci have been found to be acceptable for trans-
Allogeneic haematopoietic cell transplantation offers the
plantation with comparable rates of GVHD and trans-
potential for curing a variety of high-risk hematological
plant-related mortality. However, the presence of a
malignancies. However, lack of suitable donors is one of
limited number of haematopoietic progenitor cells in
the major limitations to successful transplantation
a single unit, lack of access to donor lymphocytes for
because almost half of all eligible patients who need an
donor lymphocyte infusion if needed, and the brief
allogeneic transplant will not have a human leukocyte
clinical experience to date are some of the limitations
antigen (HLA)-matched donor. Although an HLA-
of UCBT compared with the use of unrelated adult
matched sibling is the preferred donor source, it is not
available for $70% of all patients ]. An HLA-matchedunrelated donor, however, can be identified for another
In order to take advantage of the proven benefits of UCB,
30% of patients from the pool of almost 10 million adult
the aim of this review is to address one potential strategy
volunteers registered with donor registries worldwide.
for overcoming the cell dose limitation, namely the use of
The probability of finding a suitable donor also depends
upon the ethnic and racial background, with the lowestrate in patients of ethnic and racial minority descent [].
Furthermore, a significant proportion of patients being
The total nucleated cell (TNC) and CD34+ cell dose has
considered for unrelated donor transplantation will die,
been shown to be a crucial determinant of haematopoietic
have progressive disease or otherwise become ineligible
recovery and overall outcome following UCBT
before they can get a transplant because the process of
and the limited cell dose of single UCB units is clearly the
Current Opinion in Immunology 2006, 18:571–575
most important barrier to its more widespread use, espe-
(2 Â 105). Although different patterns of engraftment
cially in adults. Currently, a TNC dose of 2.5 Â 107 cells/
were observed in mice that received double UCBT, it
kg is generally considered to be the threshold, with
was dominated by one donor in the majority of their
significantly higher rates of graft failure and transplant-
related mortality reported in patients transplanted withsingle UCB units that contain lower numbers of TNCs.
However, only 25% of adult patients meet this cell dose
We first reported haematopoietic cell transplantation
requirement and hence the majority are ineligible for
using two UCB units in an adult patient who had accel-
UCBT [Also, because of the limited inventory of
erated phase chronic myeloid leukaemia, and subse-
suitable UCB units, most adults have access to only four
quent experience in a larger cohort of patients has
out of six HLA-matched grafts and there is increasing
established the safety and efficacy of double UCBT
evidence to show that increasing HLA disparity might
using both myeloablative and reduced-intensity condi-
lead to poorer engraftment with UCBT []. A variety
of approaches are being studied to overcome the nega-
no study has conducted a head-to-head comparison of
tive impact of low cell dose on engraftment following
double UCBT with transplantation using unrelated
single unit UCBT. These include ex vivo expansion
donor bone marrow, the outcomes from reported series
culture to increase the number of haematopoietic pro-
genitor cells, use of intra-bone marrow injection of UCBto minimize nonspecific loss of circulating haematopoie-
Patients who receive UCBT using two UCB units,
tic stem cells and the infusion of multiple UCB units.
because of the unavailability of a single unit that has a
This review focuses on the current results with double
satisfactory TNC dose, do as well as patients transplanted
with a single adequately sized UCB unit. Importantly, noincrease in the incidence of severe acute GVHD has been
noted with the use of two partially HLA-matched UCB
Cotransplantation of two or more partially HLA-matched
units instead of one. In a recent analysis that compared
unrelated UCB units is one approach that is being
single unit (n = 21) and double unit (n = 50) UCBT in
explored to overcome the limitation of low cell dose in
consecutive adult patients using myeloablative condition-
single unit UCBT. Preclinical studies in nonobese dia-
ing of Flu/Cy/TBI (fludarabine 25 mg/m2 intravenously
betic/severe combined immunodeficient (NOD/SCID)
daily from days À8 through À6, cyclophosphamide
mice have shown enhanced engraftment by the addition
60 mg/kg intravenously on days À7 and À6, and
165 cGy total body irradiation [TBI] twice-daily fromdays À4 to À1), we found no significant difference in
Liu et al. [investigated the effect of donor competition
the rates of transplant-related mortality, acute GVHD,
on haematopoietic progenitors during methylcellulose
neutrophil and platelet engraftment, disease-free survival
and long-term culture-initiating cells coculture of equal
or overall survival (JEW et al., unpublished data). In a
numbers of mononuclear cells from two units. Using
similar analysis in adult patients undergoing UCBT with
colony-forming unit analysis during mixed UCB culture,
reduced-intensity conditioning using Flu/Cy/TBI regi-
they demonstrated an early and progressive dominance
men (fludarabine 40 mg/m2 intravenously daily from
of one donor; the predominating unit had a higher
days À6 through À2, cyclophosphamide 50 mg/kg intra-
CD3+ content. They proposed that an immediate and
venously on day À6, and 200 cGy TBI on day À1), we
protracted T-cell effector mechanism along with a
observed comparable outcomes for recipients of either
single (n = 17) or double (n = 93) UCB units (JEW et al.,
effect promotes and mediates the rapid engraftment of
Interestingly, sustained hematopoiesis after double
Nauta et al. [] have reported increased engraftment in
UCBT is usually derived from a single donor. In our
NOD/SCID mice transplanted with human haemato-
initial report of 21 patients who received double UCBT
poietic progenitor cells derived from two unrelated
using myeloablative conditioning [], single donor
UCB units. Mice were transplanted with CD34+ cells
accounted for hematopoiesis in 76% and 100% of evalu-
derived from single UCB units (1 Â 105), with a combina-
able patients at days 21 and 100 post-transplant, respec-
tion of two UCB units (1 Â 105 each), or with a single
tively. The relative percent viability, the infused TNC
UCB unit that had a cell dose equivalent to that of the
and CD34+ cell dose, and the donor–recipient HLA-
double unit group (2 Â 105). Engraftment of a single UCB
disparity were not helpful in predicting which of the
unit was significantly enhanced with the cotransplanta-
two UCB units would predominate. Although early data
tion of a second UCB unit. This was comparable to the
suggested that the dominant unit had a higher median
engraftment achieved by a single UCB unit that had the
infused CD3+ cell dose, this observation has not persisted
same number of cells as the double UCBT group
with investigation of a larger cohort of patients. Order of
Current Opinion in Immunology 2006, 18:571–575
Double umbilical cord blood transplantation Majhail, Brunstein and Wagner
Clinical experience with double UCBT.
Reduced-intensity conditioningUniversity of
Abbreviations: ANC, absolute neutrophil count; Ara-C, cytosine arabinoside; Cy, cyclophosphamide; DFS, disease-free survival; Flu, fludarabine;GVHD, graft-versus-host disease; Mel, melphalan; PFS, progression-free survival; Pr graft fail, primary graft failure; TBI, total body irradiation; TNC,total nucleated cell; TRM, transplant related mortality; UCBT, umbilical cord blood transplantation. a Includes studies with more than 10 patients. b Includes unpublished data. c Method of CD34+ cell analysis not known.
infusion, location of HLA mismatch, ABO blood group or
Transplantation of two cord blood units can potentially
sex mismatch also did not have a predictive effect on
augment the graft-versus-leukemia (GVL) effect. We
reported recently a reduced risk of relapse in patientswith acute leukemia who received double unit UCBT
In another analysis of 93 patients who received double
]. We compared the outcome of patients with acute
UCBT using reduced-intensity conditioning the
leukemia who received myeloablative UCBT using
predominant unit and nonsustained units had similar
either one (n = 67) or two (n = 29) UCB units that had
median infused TNC dose (1.8 Â 107 cells/kg versus
similar HLA disparity. Adjusting for factors potentially
1.7 Â 107 cells/kg, p = 0.10), CD34+ cell dose (2.6 Â 105
influencing outcome, double unit UCBT was associated
cells/kg versus 2 Â 105 cells/kg, p = 0.22) and CD3+ cell
with a reduced chance of relapse (relative risk 0.3,
p = 0.03) in Cox regression. This effect was most promi-
p = 0.06). The predominant unit, however, had a higher
nent in patients undergoing transplantation in their first or
median granulocyte-macrophage colony-forming unit con-
second complete clinical remission; the overall risk of
tent (2.2 Â 104 cells/kg versus 2.0 Â 104 cells/kg, p = 0.02).
relapse was 11% (95% cumulative incidence [CI], 0–25%)
Haspel et al. ] have also reported the presence of single
in recipients of two UCB units compared with 54% (95%
unit predominance in 21 patients who received double
CI, 23–85%) in those receiving one unit (p < 0.01). It is
UCBT with non-myeloablative conditioning. In contrast
not known whether this enhanced GVL effect is mainly
to our practice of infusing the two UCB units simulta-
the result of increased HLA disparity from the use of two
neously, they infused them sequentially 1–6 h apart. The
mismatched units or if it is owing to the presence of
first infused unit predominated in 76% of the transplants.
additional graft–graft or graft–patient immune effects.
Again, the TNC and CD34+ cell dose were not predictors
Our observations also need to be investigated and con-
of which of the two UCB units would eventually predo-
minate, and they did not investigate the impact of CD3+cells. Although the precise biologic mechanisms for single-
donor predominance in double UCBT are not understood
Our current UCBT protocols at the University of Min-
to date, reported studies suggest at least a partial role for
nesota select UCB units based on cryopreserved TNC
T-cell mediated immune effects. Other putative expla-
dose and HLA-A, -B and -DRB1 match using intermedi-
nations could be the inclusion of a larger number of
ate resolution antigen level typing for A and B and for
supporting mesenchymal stem cells and the presence of
DRB1 allele level typing. Single unit UCBT is performed
a graft-versus-graft alloreactivity.
if a 5–6 out of 6 HLA-matched UCB unit is available that
Current Opinion in Immunology 2006, 18:571–575
has an NC dose of >3.0 Â 107 cells/kg, otherwise patients
Confer DL: The National Marrow Donor Program. Meetingthe needs of the medically underserved. Cancer 2001,
Mayani H, Lansdorp PM: Biology of human umbilical cord
As of 2006, the method of unit selection for double UCBT
blood-derived hematopoietic stem/progenitor cells.
is complex and there are no currently available data that
specifically address their optimal selection. Because it is
Gluckman E, Broxmeyer HA, Auerbach AD, Friedman HS,
becoming increasingly clear that HLA match has an
Douglas GW, Devergie A, Esperou H, Thierry D, Socie G,Lehn P: Hematopoietic reconstitution in a patient with
impact on relapse and that HLA match and cell dose
Fanconi’s anemia by means of umbilical-cord blood
have an impact on transplant-related mortality, we pre-
from an HLA-identical sibling. N Engl J Med 1989,321:1174-1178.
ferentially select a 5–6 out of 6 HLA-matched unit,regardless of the TNC dose as long as it exceeds
Brunstein CG, Wagner JE: Umbilical cord blood transplantationand banking. Annu Rev Med 2006, 57:403-417.
2.5 Â 107 cells/kg. Also, because immunological rejection
Rocha V, Labopin M, Sanz G, Arcese W, Schwerdtfeger R,
is hypothesized to account for loss of one unit over time,
Bosi A, Jacobsen N, Ruutu T, de Lima M, Finke J et al.:
our practice has always required partial HLA matching
Transplants of umbilical-cord blood or bone marrowfrom unrelated donors in adults with acute leukemia.
between the two units. This requirement often results in
the selection of units that are not necessarily the two units
Laughlin MJ, Eapen M, Rubinstein P, Wagner JE, Zhang MJ,
that have the greatest cell dose. HLA disparity between
Champlin RE, Stevens C, Barker JN, Gale RP, Lazarus HM et al.:
each unit and the recipient and between the two units
Outcomes after transplantation of cord blood or bone marrowfrom unrelated donors in adults with leukemia. N Engl J Med
does not necessarily have to be at the same loci. Each unit
is required to have a cryopreserved TNC dose of at least
Barker JN, Davies SM, DeFor T, Ramsay NK, Weisdorf DJ,
1.5 Â 107 cells/kg, such that the total graft dose is
Wagner JE: Survival after transplantation of unrelated donor
3.0 Â 107 cells/kg or more. We do not use CD34+ cell
umbilical cord blood is comparable to that of human leukocyteantigen-matched unrelated donor bone marrow: results of a
dose routinely for UCB unit selection, unless two units of
matched-pair analysis. Blood 2001, 97:2957-2961.
equal HLA match that have a TNC dose within 0.3 Â 107
10. Barker JN, Scaradavou A, Stevens CE, Rubinstein P: Analysis of
cells/kg of each other are available. The unit with larger
608 umbilical cord blood (UCB) transplants: HLA-match is a
CD34+ cell dose is then selected for UCBT. It is not
critical determinant of transplant-related mortality (TRM) inthe post-engraftment period even in the absence of acute
known whether these selection criteria are optimal, but
graft-vs-host disease (aGVHD). ASH Annual Meeting Abstracts
they represent the practice used at our institution to date.
11. Wagner JE, Barker JN, DeFor TE, Baker KS, Blazar BR,
Eide C, Goldman A, Kersey J, Krivit W, MacMillan ML et al.:Transplantation of unrelated donor umbilical cord blood
Double UCBT is a feasible, safe and effective transplan-
in 102 patients with malignant and nonmalignant diseases:
tation strategy for patients that have life-threatening
influence of CD34 cell dose and HLA disparity ontreatment-related mortality and survival
haematological disorders who need a haematopoietic
stem cell transplant but lack a HLA-matched related or
12. Laughlin MJ, Barker J, Bambach B, Koc ON, Rizzieri DA,
unrelated donor. It is an attractive option, especially for
Wagner JE, Gerson SL, Lazarus HM, Cairo M, Stevens CE et al.:
adults who are typically not eligible for single UCBT
Hematopoietic engraftment and survival in adult recipients ofumbilical-cord blood from unrelated donors. N Engl J Med
because of limitations of cell dose. Besides being rapidly
available, an acceptable double unit graft can be identi-
13. Gluckman E, Rocha V, Boyer-Chammard A, Locatelli F, Arcese W,
fied for the majority of patients. The rates of engraftment,
Pasquini R, Ortega J, Souillet G, Ferreira E, Laporte JP et al.:
transplant-related mortality, GVHD and survival are simi-
Outcome of cord-blood transplantation from related andunrelated donors. Eurocord Transplant Group and the
lar to those seen with single UCBT and unrelated donor
European Blood and Marrow Transplantation Group.
bone marrow. Ongoing studies are investigating the more
general applicability of double UCBT in a multi-institu-
14. Nauta AJ, Kruisselbrink AB, Lurvink E, Mulder A, Claas FH,
Noort WA, Willemze R, Fibbe WE: Enhanced engraftment ofumbilical cord blood-derived stem cells in NOD/SCID miceby cotransplantation of a second unrelated cord blood unit.
Papers of particular interest, published within the annual period of
15. Kim DW, Chung YJ, Kim TG, Kim YL, Oh IH: Cotransplantation of
third-party mesenchymal stromal cells can alleviate single-donor predominance and increase engraftment from double
cord transplantation. Blood 2004, 103:1941-1948.
16. Liu M, Reese JS, Jaroscak JJ, Gerson SL: Progressive
emergence of a dominant unit during dual unit umbilical cord
Barker JN, Krepski TP, DeFor TE, Davies SM, Wagner JE,
blood (UCB) culture. ASH Annual Meeting Abstracts 2005.
Weisdorf DJ: Searching for unrelated donor hematopoietic
stem cells: availability and speed of umbilical cord bloodversus bone marrow. Biol Blood Marrow Transplant 2002,
17. Kai S, Misawa M, Iseki T, Takahashi S, Kishi K, Hiraoka A, Kato S,
Hara H: Double-unit cord blood transplantation in Japan. ASH Annual Meeting Abstracts 2004. 104:5166
Grewal SS, Barker JN, Davies SM, Wagner JE: Unrelated donorhematopoietic cell transplantation: marrow or umbilical cord
18. Barker JN, Weisdorf DJ, Wagner JE: Creation of a double
chimera after the transplantation of umbilical-cord blood from
Current Opinion in Immunology 2006, 18:571–575
Double umbilical cord blood transplantation Majhail, Brunstein and Wagner
two partially matched unrelated donors. N Engl J Med 2001,
23. Verneris MR, Brunstein CG, DeFor T, Barker J, Weisdorf DJ,
Blazar BR, Miller JS, Wagner JE: Risk of relapse after umbilicalcord blood transplantation in patients with acute leukemia:
19. Barker JN, Weisdorf DJ, DeFor TE, Blazar BR, McGlave PB,
marked reduction in recipients of two units. ASH Annual
Miller JS, Verfaillie CM, Wagner JE: Transplantation of 2 partially
HLA-matched umbilical cord blood units to enhanceengraftment in adults with hematologic malignancy.
24. Yoo KH, Kang HJ, Lee SH, Jung HL, Sung KW, Koo HH, Shin HY,
Ahn HS: Double unit cord blood transplantation in children with
This study describes preliminary results of double umbilical cord blood
acute leukemia. ASH Annual Meeting Abstracts 2005. 106:2043.
transplantation. This is the first report on the use of partially HLA matchedunits in the literature.
25. Ballen KK, Spitzer TR, Yeap B, Steve M, Dey BR, Attar E, Alyea E,
Cutler C, Ho V, Lee S et al.: Excellent disease free survival after
20. Brunstein CG, Barker J, DeFor T, French K, Weisdorf DJ,
double cord blood transplantation using a reduced intensity
Wagner JE: Non-myeloablative umbilical cord blood
chemotherapy only conditioning regimen in a diverse adult
transplantation: promising disease-free survival in 95
population. ASH Annual Meeting Abstracts 2005. 106:2048
consecutive patients. ASH Annual Meeting Abstracts 2005. 106:559.
26. Barker JN, Weisdorf DJ, DeFor TE, Brunstein CG, Wagner JE:
Umbilical cord blood (UCB) transplantation after non-
21. Barker JN, Weisdorf DJ, DeFor TE, Blazar BR, Miller JS,
myeloablative (NMA) conditioning for advanced follicular
Wagner JE: Rapid and complete donor chimerism in
lymphoma, mantle cell lymphoma and chronic lymphocytic
adult recipients of unrelated donor umbilical cord blood
leukemia: low transplant-related mortality and high
transplantation after reduced-intensity conditioning.
progression-free survival. ASH Annual Meeting Abstracts 2005.
22. Majhail NS, Weisdorf DJ, Wagner JE, Defor TE, Brunstein CG,
27. Haspel RL, Kao GS, Yeap B, Spitzer TR, Ritz J, Antin JH, Ballen K:
Burns LJ: Comparable results of umbilical cord blood and
Pre-infusion characteristics of the predominant cord blood
HLA-matched sibling donor hematopoietic stem cell
unit correlate with hematopoietic engraftment in the setting
transplantation after reduced-intensity preparative regimen
of non-myeloablative double cord blood transplant (DCBT).
for advanced Hodgkin lymphoma. Blood 2006, 107:3804-3807.
ASH Annual Meeting Abstracts 2005. 106:3027.
Current Opinion in Immunology 2006, 18:571–575
Aspirin Treatment Is Associated With a Significantly Decreased Risk of Staphylococcus aureus Bacteremia in Hemodialysis Patients With Tunneled Catheters Martin Sedlacek, MD,1,2 John M. Gemery, MD,1,2 Ambrose L. Cheung, MD,2 Arnold S. Bayer, MD,3,4 and Brian D. Remillard, MD1,2 Background: Hemodialysis patients with tunneled catheters are at increased risk of bacteremic Staphyl
Intercourse: Technique, enjoyment, orgasm1. Why was I unable to have sex the first time we tried?2. Why do I force him out just before orgasm?3. Why does the semen flow out of the vagina after intercourse?4. Are we following the correct technique for sex?5. How can my wife and I enjoy sexual pleasure at the same time?6. What is the cause of too much pain during intercourse?8. Does the