Bone Marrow Transplantation (2001) 28, 935–940
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Cytokines
The kinetics of circulating cytokines including IL-6, TNF-
, IL-8 and
IL-10 following allogeneic hematopoietic stem cell transplantation
C-K Min1, WY Lee2, D-J Min3, D-G Lee4, Y-J Kim4, YH Park1, HJ Kim1, S Lee1, DW Kim1,
JW Lee1, WS Min1 and CC Kim1
1The Catholic Hemopoietic Stem Cell Transplantation Center, College of Medicine, The Catholic University of Korea, Seoul, Korea;
2Department of Endocrinology, College of Medicine, The Catholic University of Korea, Seoul, Korea; 3Department of Rheumatology,
College of Medicine, The Catholic University of Korea, Seoul, Korea; and 4Department of Infectious Diseases, College of Medicine,
The Catholic University of Korea, Seoul, Korea
Summary:
Pro-inflammatory (IL-6, TNF
and IL-8) and anti-
inflammatory (IL-10) cytokines were determined in
weekly samples from 52 patients undergoing allogeneic
hematopoietic stem cell transplantation (HSCT). IL-6
increased immediately after transplant peaking at week
+3, but IL-8 concentrations were elevated only during
week +1. After a slight decrease in week +1, TNF-
sig-
nificantly increased from week +2 and peaked at week
+3, whereas, IL-10 values started to rise in week +2 and
peaked during week +4. IL-6 and TNF-
were positively
correlated from week +2 to week +4, and IL-6 levels at
week +1 were related with fever and severe stomatitis.
Serum levels of IL-6 at week +1 and IL-10 at week +4
were significantly higher in patients with early trans-
plant-related complications, such as fever, severe stoma-
titis or acute GVHD
overall grade II than in those
without the complications. We conclude that a high
serum IL-6 level at week +1 may be an early predictor
of transplant-related complications and that it seems to
trigger pro- and anti-inflammatory cytokine release.
Kinetic patterns of IL-6 and IL-10 were more exagger-
ated in those with complications after HSCT. Bone Mar-
row Transplantation (2001) 28, 935–940.
Keywords: allogeneic HSCT; cytokines; complications
Allogeneic hematopoietic stem cell transplantation (HSCT)
is the most common treatment for hematologic malig-
nancies and severe immunodeficiency. During the 3–4
weeks following transplantation, many patients develop
mucositis, fever, hepatic veno-occlusive disease (VOD) and
acute graft-versus-host disease (GVHD). It is generally
recognized that the cross-linking of the cytokine network
plays a major role in inflammatory processes including
these complications, for example, the dysregulation of cyto-
Correspondence: Dr WS Min, Catholic Hemopoietic Stem Cell Transplan-
tation Center, Department of Internal Medicine, St. Mary’s Hospital, #62,
Youido-Dong, Youngdungpo-Gu, Seoul 150–713, Korea
Received 4 June 2001; accepted 10 September 2001
kine production may initiate and perpetuate tissue damage
in those receiving bone marrow and solid organ transplan-
tation.1
Interleukin (IL)-6, tumor necrosis factor (TNF)-, and
IL-8 are well known pro-inflammatory cytokines, which are
involved in local and systemic inflammatory reactions.
These cytokines have been found to be involved in many
adverse conditions initiated by HSCT.2–6 IL-10 is a Th2
cytokine that inhibits cytokine production by Th1 cells, and
IL-10 is reported to block the production of the monokines
(IL-1, IL-6 and TNF-) in response to lipopolysaccharide
or other stimuli.7,8 High spontaneous IL-10 production in
transplant recipients is associated with fewer transplant-
related complications, and is believed to have a major role
in maintaining immunobalance in the allogeneic HSCT
setting.9,10
The levels of IL-6, TNF- and IL-8 in serum after HSCT
have been reported by many groups, but little attention has
been paid to their correlation with IL-10. In order to ident-
ify a diagnostic parameter for the prediction of early clini-
cal complications and to define their role in the pathogen-
esis, we studied the relationship between the serum
concentrations of pro- and anti-inflammatory cytokines and
transplantation-related complications in a series of 52
patients undergoing allogeneic HSCT.
Material and methods
Patients and transplant characteristics
Fifty-two allogeneic HSCT patients were continuously
enrolled in our institute; 19 had chronic myelogenous leu-
kemia (CML), 18 acute myelogenous leukemia (AML),
eight acute lymphocytic leukemia (ALL), four severe aplas-
tic anemia (SAA) and three had refractory anemia with
excess blasts in transformation (RAEBT), as shown in
Table 1. Eight patients received bone marrow (BM) from
human leukocyte antigen (HLA)-matched unrelated donors
and two patients from one-locus mismatched related donors
at the HLA-B or the -DR loci. Thirty patients (57.7%)
received total body irradiation (TBI) as a conditioning regi-
men. All the patients received 300–450 g of granulocyte

Cytokine kinetics after allogeneic HSCT
C-K Min et al
936
Bone Marrow Transplantation
Table 1 Description of patients’ characteristics, conditioning regimen
and GVHD prophylaxis
Characteristics n (%)
Age, median (range), years 32.5 (19–54)
Sex, M/F 29/23
Transplant type
Sibling, matched 42 (80.8)
Unrelated matched 8 (15.4)
Sibling, mismatched 2 (3.8)
Underlying disease
CML 19 (36.5)
AML 18 (34.6)
ALL 8 (15.4)
Aplastic anemia 4 (7.7)
MDS 3 (5.8)
Conditioning regimen
TBI/CY 20 (38.5)
BU/CY 6 (11.5)
CY/Thio/MPL 6 (11.5)
TBI/AraC/CY 6 (11.5)
BU/Thio/MPL 5.(9.6)
CY/ATG/Procarbazine 4 (7.7)
BU/TBI 3 (5.8)
TBI/CY/BU 1 (1.9)
Flud/BU/ATG 1 (1.9)
Stem cell sources
BM 46 (88.5)
BM+PBSCa 5 (9.6)
PBSC 1 (1.9)
GVHD prophylaxis
CsA+MTX 41 (78.9)
FK506+MTX 11 (21.1)
aT cell-depleted PBSC.
colony-stimulating factor (G-CSF) from day +7 until the
absolute neutrophil count exceeded 3.0 × 109/l.
GVHD prophylaxis and treatment
For GVHD prophylaxis, 41 patients (78.8%) received a
combination of cyclosporin A (CsA) and methotrexate
(MTX). CsA was administered i.v. at a dose of 3 mg/kg as
a continuous infusion from days −1 to +21. Thereafter CsA
was given orally at 5 mg/kg/day divided into two doses, to
maintain a blood concentration between 200 and 500 ng/ml.
MTX was administered at 10 mg/m2 on days +1, +3, +6
and +11. FK-506 and MTX were used for GVHD prophy-
laxis in 11 patients (21.2%). FK-506 was given i.v. at a
dose of 0.03 mg/kg as a continuous infusion from days −1
to +21 and orally at 0.12 mg/kg/day divided into two doses,
to maintain a blood concentration between 10 and
30 ng/ml.11 Acute GVHD was based on clinical signs and
graded on a four-point scale (I indicated mild disease, and
IV severe disease).12 Methylprednisolone 4 mg/kg/day for
4–7 days with gradual taper was used to treat acute GVHD

grade II.
Complications after HSCT
Complications observed in this group of patients included:
(1) acute GVHD
grade II, diagnosed on clinical findings;
(2) fever of unknown origin, defined as fever
38.3°C for
at least 2 consecutive days; (3) oral mucositis
grade III,
scored in accordance with the NCI criteria; (4) hepatic
VOD. The diagnosis of hepatic VOD required the presence
of hyperbilirubinemia (3.0 mg/dl), weight gain (2.5%
of initial weight) and right upper quadrant pain with or
without the presence of hepatomegaly.13
Ten (19.2%) patients developed acute GVHD
grade II
at a median of 21 days (range, 11–38). Eleven (21.2%)
patients developed fever, as defined above, and nine
(17.3%) developed stomatitis of grade III or more. One
patient who fulfilled the severe hepatic VOD criteria, as
classified by McDonald et al,14 was included. Twenty-eight
(58.3%) patients did not have any complications.
Blood sample collection and the cytokine level
determination
In order to measure the biochemical markers and cytokines,
venous blood samples were taken between 7 am and 9 am
following an overnight fast, aseptically in tubes containing
EDTA and sodium citrate. Following centrifugation for 10
min, aliquots of serum were stored at −20°C until analysis.
In all patients, blood was sampled before the conditioning
and at 1, 2, 3 and 4 weeks and 3 months after the transplant.
IL-6, TNF-, IL-8 and IL-10 were measured in duplicate
using a sandwich ELISA kit (Hyundae Pharm. Institute,
Incheon, Korea). Detection limits were 4, 8, 10 and
10.4 pg/ml, respectively. The maximum inter- and intra-
assay CV for the range of concentrations evaluated were:
8.3% and 6.2% for IL-6; 8.2% and 7.0% for TNF-; 7.4%
and 7.6% for IL-8; and 9.8% and 5.6% for IL-10, respect-
ively. In order to investigate the possibility of a correlation
with renal or hepatic function, serum total bilirubin (TB),
creatinine (Cr) and lactic dehydrogenase (LDH) levels
were determined using an autoanalyser (747 Automatic
Analyser, Hitachi, Japan).
Statistical analysis
Wilcoxon’s signed rank test was used to analyze the cyto-
kine profiles in matched pairs during the pre- and post-
transplant period. The Mann–Whitney U test or the Moses
test was used to compare cytokine profiles according to the
occurrence of complications. Correlations between numeri-
cal variables were assessed using the Spearman rank test.
Differences were considered statistically significant when
P  0.05.
Results
Cytokine levels during the early course of HSCT
IL-6 levels increased significantly from week +1 to week
+4 after HSCT compared with pre-transplant levels (mean
± s.e.m.: baseline, 36.9 ± 8.6 pg/ml; 1st week, 105.7 ±
15.9 pg/ml, P  0.001; 2nd week, 142.5 ± 26.2 pg/ml, P
 0.001; 3rd week, 159.8 ± 29.0 pg/ml, P  0.001; 4th
week, 148.3 ± 19.2 pg/ml, P = 0.002). The IL-6 level on
week +12 (mean ± s.e.m.: 113.4 ± 21.6 pg/ml) was not sig-
nificantly different from the pretransplant level (P = 0.061).
After a slight decrease on week +1, TNF- increased from