HEART TRANSPLANTATION
Anti-CD25 Therapy Impairs Donor-Specific Th1 and Th2 Cytokine-
Producing Peripheral Blood Cells After Clinical Heart Transplantation
N.M. van Besouw, A.H.M.M. Balk, M. van Vliet, P.H. van der Meide, A.P.W.M. Maat, T. van Gelder,
C.C. Baan, and W. Weimar
R
EJECTION episodes after transplantation are associ-
ated with increased levels of intragraft IL-2, CD25
mRNA expression and protein production.
1–3
The target of
the Anti-CD25 mAbs is the -chain of the IL-2R complex
(CD25); these antibodies are used to prevent acute rejec-
tion after organ transplantation.
4
Alloactivated T cells
express the IL-2 receptor complex (CD25) and secrete Th1
and Th2 cytokines. Thus, blockade of the IL-2 signalling
pathway may affect other cytokine systems as well (e.g.,
down-regulating Th2 cytokines) and may impair graft ac-
ceptance.
In a pilot study, we determined the effect of treatment
with daclizumab (a humanized anti-CD25mAb) on donor-
specific IFN- (Th1) and IL-4 (Th2) producing cells in
peripheral blood by Elispot-assay in the first 4 months after
heart transplantation; at that time no circulating CD3
+
CD25
+
cells were detected by flowcytometry.
PATIENTS AND METHODS
Patients were treated with cyclosporine (CsA), prednisone, 1.5 g
twice daily mycophenolate mofetil (MMF), and five doses of
daclizumab 1.0 mg/kg IV or matching placebo every 2 weeks
starting at the time of heart transplantation.
We tested PBMC from 9 patients treated with anti-CD25 mAbs
and 10 patients treated with placebo for the frequency of IFN-
and IL-4 producing cells by Elispot (U-CyTech, Utrecht, The
Netherlands). We stimulated 1 10
5
(IL-4: 2 10
5
) PBMC with
1 10
5
(IL-4: 2 10
5
) irradiated donor spleen cells. After 40 hours
of incubation, the nonadherent cells were transferred to the Elispot
plate precoated with anti-human IFN- or IL-4 mAb. Within the
Elispot plate the cells were incubated for 5 or 18 hours, respec-
tively, to allow spot formation.
RESULTS AND DISCUSSION
After stimulation with irradiated donor spleen cells, we
found significant numbers of IFN-–producing cells in all
patients from the placebo group; only 5 out of 9 patients
treated with anti-CD25 mAbs had significant numbers (
50/10
6
PBMC) of donor-specific IFN-–producing cells in
peripheral blood (Fischer’s Exact test; P = .03). The
median number of donor-specific IFN-–producing cells
was 245/10
6
PBMC (range, 50 to 870) in the placebo group
and 230/10
6
PBMC (range, 0 to 1560) in the group of patients
treated with anti-CD25 mAb therapy. In addition, all patients
treated with placebo had donor-specific IL-4 –producing cells
( 0/10
6
PBMC), while during anti-CD25 mAb therapy 5 out
of 9 patients had no IL-4 –producing cells after donor stimu-
lation (Fisher’s Exact test; P = .01). The median number of
donor-specific IL-4 –producing cells was 63/10
6
PBMC (range,
5 to 295) in the placebo group and 0/10
6
PBMC (range, 0 to
225) in the group of patients treated with anti-CD25 mAb
therapy (Mann-Whitney test, P = .09).
From the Departments of Internal Medicine (N.M.v.B., M.v.V.,
T.V.G., C.C.B., W.W.), Cardiology (A.H.M.M.B.), and Thoracic
Surgery (A.P.W.M.M.), University Hospital Rotterdam-Dijkzigt,
Rotterdam, and U-CyTech (P.H.v.d.M.), Utrecht, The Nether-
lands.
Supported by grant NHS99064 from the Netherlands Heart
Foundation.
Address reprint requests to Dr N.M. van Besouw, University
Hospital Rotterdam-Dijkzigt, Department of Internal Medicine-
Transplantation, Room Ee559, P.O. Box 2040, 3000 CA Rotter-
dam, The Netherlands. E-mail: vanbesouw@inw1.azr.nl
0041-1345/02/$–see front matter © 2002 by Elsevier Science Inc.
PII S0041-1345(02)03498-X 360 Park Avenue South, New York, NY 10010-1710
2942 Transplantation Proceedings, 34, 2942–2943 (2002)