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17th International Congress on Infectious Diseases / International Journal of Infectious Diseases 45S (2016) 1–477 439
Type: Poster Presentation
Final Abstract Number: 43.196
Session: Poster Session III
Date: Saturday, March 5, 2016
Time: 12:45-14:15
Room: Hall 3 (Posters & Exhibition)
Expansion of regulatory T cells in acute dengue
infection does not associate with disease
severity
H.E. Jayaratne1,∗, N. Wickramasinghe2, T.N.
Adikari3, L. Gomes3, A. Kamaladasa3, G.S. Ogg4,
G.N. Malavige5
1University of Sri Jayewardenepure, Nugegoda, Sri
Lanka
2University of Sri Jayewardanapura, Colombo, Sri
Lanka
3University of Sri Jayawardanapura, Nugegoda, Sri
Lanka
4University of Oxford, Oxford, United Kingdom
5University of Sri Jayawardenapura, Nugegoda, Sri
Lanka
Background: Regulatory T cells (Tregs) with suppressive func-
tion were shown to expand in acute dengue and were speculated
to contribute to milder disease. However, as more recent data point
towards a protective role of dengue virus (DENV) specific T cells in
acute dengue, we proceeded to determine if the expansion of Tregs
in acute dengue was associated with milder clinical disease.
Methods & Materials: 58 adult patients with acute dengue
infection were recruited and disease severity classified according to
2011 WHO guidelines. Convalescent samples were obtained from
10 of these patients 30 days after onset of illness. Tregs were iden-
tified in both patients and in 13 healthy individuals by staining for
CD4 + T cells expressing Foxp3 and CD25. Quantitative ELISA was
done to determine plasma levels of IL-10, TGFand IL-17. Intracel-
lular cytokine staining for IL-17 was carried out and TH17 subset of
CD4 +T cells was identified as those expressing, IL-17 and CD161.
Results: Tregs were significantly expanded in patients with
acute dengue (p < 0.0001) when compared to healthy individuals
and the frequency of Tregs significantly reduced during conva-
lescence (p = 0.01). The frequency of Tregs were not significantly
higher in those with milder forms of dengue and did not asso-
ciate with the extent of fluid leakage, presence of shock or liver
derangements. The frequency of Tregs in acute dengue, did not
correlate with either plasma levels of IL-10 or TGF. Expression
of CD25, which is the IL-2 receptor, on CD4 + T cells was signifi-
cantly lower (p = 0.006) in patients with acute dengue and CD25
expression inversely correlated with IL-10 and TGFlevels. Both
plasma IL-10 (p < 0.0001) and TGFlevels (p< 0.0001) were signifi-
cantly elevated. However, no difference in plasma IL17 levels were
observed and the frequency of TH17 subset of CD4 + T cells and Treg:
TH17 ratios were similar in both patients and healthy individuals.
Conclusion: Although Tregs are increased in frequency during
acute dengue, they do not appear to associate with milder clini-
cal disease. Immunosuppressive cytokines (IL-10 and TGF) were
significantly elevated in patients with acute dengue and inversely
correlated with CD25, which suggests that they possibly suppress
T cell proliferation.
http://dx.doi.org/10.1016/j.ijid.2016.02.932
Type: Poster Presentation
Final Abstract Number: 43.197
Session: Poster Session III
Date: Saturday, March 5, 2016
Time: 12:45-14:15
Room: Hall 3 (Posters & Exhibition)
Obesity and the presence of asthma are
associated with hospitalization due to dengue
infection
K.C. Jeewandara1, L. Gomez1, S.A. Paranavitane1,
M.C.K. Jayarathne2, M. Tantirimudalige1,S.
Fernando1,∗, R. Fernando1, S. Prathapan1, G.S.
Ogg3, G.N. Malavige1
1Center for Dengue Reserach, Nugegoda, Sri Lanka
2Department of Family Medicine, Nugegoda, Sri
Lanka
3Weatherall Institute of Molecular Medicine, Oxford
NIHR Biomedical Research Centre and Department of
Dermatology, Churchill Hospital, Oxford, Oxford,
United Kingdom
Background: Although dengue infections can lead to severe
clinical disease sometimes resulting in fatalities, the major-
ity of both primary and secondary dengue infections result in
mild/asymptomatic disease that is usually not diagnosed as dengue.
Therefore, we proceeded to investigate epidemiological and co-
morbid risk factors associated with hospitalization when infected
with dengue.
Methods & Materials: 1689 healthy individuals who were
attending the primary health care facility of the university were
recruited. Information regarding their co-morbid illnesses and
anthropometric measurements were recorded. The dengue anti-
body status was determined in all individuals.
Results: Although 1152/1689 (68.2%) individuals were seropos-
itive for dengue and only133/1152 (11.5%) of them had been
hospitalized to due to dengue. We found that obesity (BMI > 22.9
in adults and above the 85th percentile BMI for age for children),
asthma, allergic rhinitis and a waist circumference of > 80cm in
women was significantly associated with increased risk of hos-
pitalization. The association of hospitalization due to dengue and
obesity was stronger for females (P < 0.0001, odds ratio= 3.33, 95%
CI = 1.8 to 6.1), when compared to males (p value = 0.04, odds
ratio = 2.2, 95% CI= 1.1 to 4.5). Although female children were sig-
nificantly more likely (p = 0.006) to be hospitalized due to dengue
(odds ratio 2.4, 95% CI = 1.3 to 4.4) when compared to male chil-
dren, no such association was observed in adults. The presence of
diabetes, hypercholesterolaemia or hypertension were not signifi-
cantly associated with hospitalization due to dengue.
Conclusion: Obesity, a high waist circumference in women,
asthma and allergic rhinitis appear to be associated with a higher
risk of hospitalization when infected with the dengue virus.
http://dx.doi.org/10.1016/j.ijid.2016.02.933