MANIFESTASI KLINIS INFEKSI DENGUE

Infeksi virus dengue (DENV) bermanifestasi klinik mulai asimptomatis, dengue fever (DF), dengue haemoraghic fever (DHF), sampai dengue shock syndrome (DSS).1-5 Virus dengue dibedakan menjadi empat serotype yaitu DENV-1, DENV-2, DENV-3 dan DENV-4,2 3 ditularkan oleh nyamuk Aedes aegypty dan Aedes albopictus.3 6 Mekanisme imunologis dan virulensi berperan dalam patogenesis dan manifestasi klinis dengue, dikaitkan dengan ketidakseimbangan antara sitokin proinflamasi dan anti inflamasi.1-3 6 Terapi spesifik terhadap DENV masih belum ada sedangkan penelitian kurang berhasil dalam penggunaan kortikosteroid, antivirus dan substansi penurun permeabilitas kapiler.4 7-15

Infeksi DENV banyak diderita penduduk di daerah tropis dan sub tropis, diperkirakan 50 juta orang terinfeksi setiap tahun dan lebih dari 2,5 milyar berisiko.3 16 Infeksi DENV di Asia didominasi oleh anak di bawah 15 tahun,3 17-19 sedangkan kejadian di Amerika lebih banyak ditemukan pada dewasa dengan manifestasi klinis lebih ringan.3 20 21 Penyakit DHF telah menyerang semua provinsi di Indonesia (1997) yang awalnya setiap 5 tahun sekali, meningkat 3 tahun, dan akhirnya setiap tahun. Jumlah korban DHF tahun 2002 sebanyak 40.377 orang dan tahun 2003 sebanyak 50.131 orang. Kejadian DHF cenderung meningkat antara tahun 1994-1998, meskipun case fatality rate (CFR) berhasil diturunkan dari 2.5% (1994) menjadi 2% (1998).22

Infeksi DENV tidak selalu menimbulkan gejala klinis. Gejala klinis biasanya ringan di daerah endemis bahkan tidak menunjukkan gejala.1 Keadaan ini didapatkan pada 53% penderita di bawah usia 15 tahun,23 tetapi pada penderita dewasa hanya sekitar 14% yang asimptomatis.24 Penampilan klinis infeksi DENV bervariasi dari asimptomatis, undifferentiated fever, dengue fever (DF; demam dengue, DD), dengue hemorrhagic fever (DHF; demam berdarah dengue, DBD), dan yang disertai dengan kebocoran plasma (plasma leakage) sampai dengan terjadinya syok (dengue shock syndrome, DSS; sindroma renjatan dengue, SRD).25-28 Gejala klinis timbul pada 4-7 hari setelah gigitan nyamuk yang terinfeksi. Perjalanan penyakit dengue melaui 3 fase yaitu demam (febrile phase), fase kritis (critical phase) dan fase perbaikan (recovery phase).24-26 29

A. Fase Demam

Fase demam pada infeksi dengue ditandai dengan demam tinggi antara 39-40oC selama 2-7 hari (pada DHF terjadi 3 hari sebelum fase krisis).24 26 30 Sebanyak 5-6% penderita menunjukkan tipe demam yang khas yaitu pola bifasik (saddleback fever, pelana kuda, gambar 7) yang ditandai oleh demam beberapa hari pada awal sakit, diikuti dengan hilangnya demam selama beberapa hari dan diakhiri dengan demam selama 12-24 jam.1 24

Demam sering disertai nyeri kepala, nyeri retro-orbita, mialgia dan antragia, kemerahan pada muka, eritema kulit, nyeri telan, kemerahan pada faring dan konjungtiva, anoreksia, mual dan muntah. Gejala tersebut tidak seluruhnya didapatkan pada anak di bawah 15 tahun dengan frekuensi gejala demam sebanyak 90%, dan nyeri kepala, nyeri retroorbita, mialgia, antralgia (63-78%). Gejala saluran nafas berupa batuk, nyeri telan dan kongesti hidung (33%). Fase awal infeksi dengue sulit dibedakan dengan penyakit demam akut yang lain. Tes tourniquet positif pada fase ini meningkatkan kemungkinan infeksi DENV.3 24 26

Gambar 7. Pola demam pada infeksi dengue

Manifestasi perdarahan dapat terjadi pada DF dan DHF sehingga perdarahan bukan merupakan gejala pembeda antara keduanya. Perdarahan muncul pada 9-22% kasus DF, biasanya ringan berupa ptekie, epistaksis dan perdarahan guzi. Perdarahan gastrointestinal (melena) dan menorhagia yang berat dapat ditemukan pada penderita DF.3 31 Ptekie dan ekimosis spontan terjadi pada 50% kasus DHF diikuti hematemesis (15-30%), melena (5-10%) dan epistaksis (10%). Perdarahan dapat disebabkan oleh trombositopenia, vaskulopati, koagulopatie dan gangguan fibrinolisis serta diperberat oleh adanya disseminated intravascular coagulation (DIC).24 26 32

Hepatomegali ditemukan pada 37-52% kasus DF dan 75% kasus DHF. Hepatomegali dapat disertai nyeri tekan tetapi tidak berbanding lurus dengan severitas penyakit. Enzim transaminase sering meningkat yang mana aspartate aminotranspherase (AST) lebih tinggi pada DHF dibanding DF.24 26 Penurunan progresif jumlah leukosit, neutrofilia relatif dan limfopenia dengan jumlah trombosit normal seringkali ditemukan pada fase awal demam.24 26 32 30

B. Fase Kritis

Penderita infeksi DENV memiliki 2 kemungkinan setelah melewati fase demam yaitu pada hari ke-3 sampai ke-7. Penderita dapat berangsur sembuh atau memasuki fase kritis. Fase kritis biasanya terjadi pada hari ke-3 sakit dan berlangsung selama 24-48 jam yang ditandai dengan peningkatan permeabilitas kapiler dan kebocoran plasma.24 26 Peningkatan permeabilitas kapiler akan menyebabkan terjadinya efusi pleura dan asites. Efusi pleura dapat ditemukan mulai hari ke-2 dan ke-3 (6%) serta meningkat pada hari ke-5 dan ke-7 (62-65%). Asites dapat ditemukan pada hari ke-5 dan ke-7 (52-53%) tetapi jarang ditemukan pada hari awal sakit.24

Nyeri abdomen hebat dan muntah disertai perubahan mendadak dari demam ke hipotermia, letargi atau gelisah menunjukkan tanda awal terjadinya syok (DSS). Syok akan berlangsung selama 24-48 jam sehingga diperlukan resusitasi cepat dan adekuat serta pengawasan ketat untuk mencegah syok berulang/berkepanjangan.24

Pemeriksaan laboratorium menunjukkan peningkatan hematokrit >20% (hemokonsentrasi) disertai trombositopenia <100.000/uL. Leukopenia yang progresif dan penurunan trombosit biasanya mendahului kebocoran plasma. Limfositosis relatif yang terdiri dari 15% limfosit atipik dapat terjadi pada DHF. Delapan puluh persen penderita DHF menunjukkan peningkatan AST/ALT (umumnya tidak lebih dari 100 U/dL) dan kadar AST meningkat 2-3 kali ALT. Sebagian besar kasus menunjukkan pemanjangan activated partial tromboplastin time (APTT), trombin time (TT), dan protrombin time (PT).24 26

C. Fase Perbaikan

Reabsorbsi cairan ekstraseluler ke dalam intravaskuler terjadi pada 48-72 jam setelah fase kritis pada fase perbaikan. Keadaan umum anak membaik disertai perbaikan napsu makan, gejala gastrointestinal, hemodinamik dan terjadi diuresis. Beberapa penderita menunjukkan ruam penyembuhan (convalesencence rash) di seluruh tubuh, terutama dorsum manus dan pedis yang sering disertai pluritus. Fase penyembuhan berlangsung beberapa hari sampai minggu.24 26

Kadar hematokrit kembali normal atau menurun akibat efek dilusi dari reabsorbsi cairan ekstravaskuler. Jumlah leukosit dan trombosit meningkat, tetapi peningkatan trombosit terjadi setelah peningkatan leukosit. Pada fase ini perlu diperhatikan kemungkinan kelebihan cairan dengan gejala distres nafas akibat adanya efusi pleura dan asites serta edema paru. 24 26

DAFTAR PUSTAKA

1. Gubler DJ. Epidemic dengue/dengue hemorrhagic fever as a public health, social and economic problem in the 21st century. Trends Microbiol 2002;10(2):100-3.

2. Reis SR, Sampaio AL, Henriques MG, Gandini M, Azeredo EL, Kubelka CF. An in vitro model for dengue virus infection that exhibits human monocyte infection, multiple cytokine production and dexamethasone immunomodulation. Mem Inst Oswaldo Cruz 2007;102(8):983-90.

3. Martina BEE, Koraka P, Osterhaus ADME. Dengue virus pathogenesis: an integrated view. Clin Microbiol Rev 2009;22(4):564-81.

4. Panpanich R, Sornchai P, Kanjanaratanakorn K. Corticosteroids for treating dengue shock syndrome. Cochrane Database Syst Rev 2006;3:CD003488.

5. Bozza FA, Cruz OG, Zagne SM, Azeredo EL, Nogueira RM, Assis EF, et al. Multiplex cytokine profile from dengue patients: MIP-1beta and IFN-gamma as predictive factors for severity. BMC Infect Dis 2008;8:86.

6. Rajapakse S. Corticosteroids in the treatment of dengue illness. Trans R Soc Trop Med Hyg 2009;103(2):122-6.

7. Tassniyom S, Vasanawathana S, Chirawatkul A, Rojanasuphot S. Failure of high-dose methylprednisolone in established dengue shock syndrome: a placebo-controlled, double-blind study. Pediatrics 1993;92(1):111-5.

8. Pea L, Roda L, Moll F. Desmopressin treatment for a case of dengue hemorrhagic fever/dengue shock syndrome. Clin Infect Dis 2001;33(9):1611-2.

9. Gibbons RV, Vaughn DW. Dengue: an escalating problem. BMJ 2002;324(7353):1563-6.

10. Ligon BL. Dengue fever and dengue hemorrhagic fever: a review of the history, transmission, treatment, and prevention. Semin Pediatr Infect Dis 2005;16(1):60-5.

11. Sumarmo, Talogo W, Asrin A, Isnuhandojo B, Sahudi A. Failure of hydrocortisone to affect outcome in dengue shock syndrome. Pediatrics 1982;69(1):45-9(ABSTRAK).

12. Futrakul P, Poshyachinda M, Mitrakul C, Kwakpetoon S, Unchumchoke P, Teranaparin C, et al. Hemodynamic response to high-dose methyl prednisolone and mannitol in severe dengue-shock patients unresponsive to fluid replacement. Southeast Asian J Trop Med Public Health 1987;18(3):373-9.

13. Futrakul P, Vasanauthana S, Poshyachinda M, Mitrakul C, Cherdboonchart V, Kanthirat V. Pulse therapy in severe form of dengue shock syndrome. J Med Assoc Thai 1981;64(10):485-91.

14. Min M, U T, Aye M, Shwe TN, Swe T. Hydrocortisone in the management of dengue shock syndrome. Southeast Asian J Trop Med Public Health 1975;6(4):573-9.

15. Pongpanich B, Bhanchet P, Phanichyakarn P, Valyasevi A. Studies on dengue hemorrhagic fever. Clinical study: an evaluation of steroids as a treatment. J Med Assoc Thai 1973;56(1):6-14.

16. Guha-Sapir D, Schimmer B. Dengue fever: new paradigms for changing epidemiology. Emerg. Themes Epidemiol 2005;2:1.

17. Kittigul L, Pitakarnjanakul P, Sujirarat D, Siripanichgon K. The differences of clinical manifestations and laboratory findings in children and adults with dengue virus infection. J Clin Virol 2007;39(2):76-81.

18. Guzman MG, Garcia G, Kouri G. [Dengue and dengue hemorrhagic fever: research priorities]. Rev Panam Salud Publica 2006;19(3):204-15.

19. Carlos CC, Oishi K, Cinco MT, Mapua CA, Inoue S, Cruz DJ, et al. Comparison of clinical features and hematologic abnormalities between dengue fever and dengue hemorrhagic fever among children in the Philippines. Am J Trop Med Hyg 2005;73(2):435-40.

20. Halstead SB. Dengue in the Americas and Southeast Asia: do they differ? Rev Panam Salud Publica 2006;20(6):407-15.

21. Halstead SB. Measuring dengue enhancing antibodies: caveats. J Infect Dis 2006;193(4):601.

22. Soegijanto S. Patogenesis infeksi virus dengue. Applied management of dengue viral infection in children. Kediri: IDA Jatim komisariat Jatim IV, 2010:11-45(fulltext).

23. Endy TP, Yoon IK, Mammen MP. Prospective cohort studies of dengue viral transmission and severity of disease. Curr Top Microbiol Immunol 2010;338:1-13.

24. Soemakto, Yuliarto S, Rridewi I. Mengenal tanda awal dan tanda bahaya infeksi dengue. Aplied Management of dengue viral infection in children. Kediri: IDAI Jatim komisariat Jatim IV, 2010:47-61.

25. WHO. Dengue hemorrhagic fever: diagnosis, treatment, prevention and control. 2 ed. Geneva: World Health Organization, 1997.

26. Basuki PS. Diagnosis infeksi virus dengue: penuntun bagi petugas kesehatan di daerah. Applied management of dengue viral infection in children. Kediri: IDAI Jatim komisariat Jatim IV, 2010:63-81.

27. WHO. Guidelines for treatments of dengue fever/dengue hemorrhagic fever in small hospital. New Delhi: World Health Organization, 1999.

28. WHO. Dengue, dengue hemorrhagic fever and dengue shock sundrome in the context of integrated management of childhood ilness. Geneva: World Health Organization, 2005.

29. WHO. Clinical management and delivery clinical service. Dengue guidelines for diagnosis, treatment, prevention and control. Geneva: World Health Organization, 2009.

30. Nimmannitya S. Dengue fever/dengue hemorrhagic fever: case management. Trop med 1994;36:249-56.

31. Balmaseda A, Hammond SN, Perez MA, Cuadra R, Solano S, Rocha J, et al. Short report: assessment of the World Health Organization scheme for classification of dengue severity in Nicaragua. Am J Trop Med Hyg 2005;73(6):1059-62.

32. Anonim. Infeksi virus dengue. In: Soedarmo SSP, Garna H, Hadinegoro SRS, Satari HI, editors. Buku ajar infeksi & pediatri tropis. 2 ed. Jakarta: Badan Penerbit IDAI, 2010:155-8.

IN VITRO MODEL OF CORTICOSTEROIDS IN DENGUE INFECTION (CYTOKINES RELEASED)

Dengue Virus (DENV) infection can result in significant morbidity and mortality in the world. Treatment approach is believed to be supportive to regulate the provision of fluids and there is no specific therapy for DENV. (1-11) Corticosteroids are not recommended by the WHO in the management of dengue but empirically been used by clinicians based on immunological mechanisms in the pathogenesis of Dengue infection. (12) Evidence of the benefits and safety of corticosteroids for DENV infection is still limited in number and methodologies with varying results. (2, 5, 12-22)

Cytokine play an important role in the pathogenesis and severity DENV infection, especially TNF alpha, IL-1B, and IL-8. (23-28) Cytokines are associated with bleeding manifestations, activation of coagulation and fibrinolysis, (29-30) involved in the increased vascular permeability and disease morbidity. (31) Changes in cytokine levels have occurred in DENV infections changed significantly in mild and severe clinical conditions. (32-33)

Mononuclear phagocyte, such as dendritic cells and monocyte are a good cell to study dengue infection in vitro and in vivo. (34-37) Monocyte is DENV-infected leukocytes, although often in patients with DHF is often atypical lymphocytes and PMN obtained. (34) Monocytes from patients in the acute phase showed DENV-Ag during natural infection DF. (38)

TNF alfa and IL-1B produced by monocytes is an early cytokine that appears on DENV infection. (39-40) Macrophages in vitro will release TNF-α, IFN-α, IL-1β, IL-8, IL-12, MIP-1, and RANTES after infection but not IL-6, IL-15, or nitric oxide. (41) The study by Reis et al. (2007) showed that human monocytes from 15 healthy donors in the Brazilian monocyte infected with DENV can induce cytokines TNF-α, IFN-α, IL-6, and IL-10 which occur also in patients with DF. (42) Cytokine IL-1β, IL-8, IL-12, and IL-15 were not detected in cultured monocytes in which cytokines are produced at least in patients with DF. (31, 42) Interferon alpha has increased dramatically during defervescence DHF. (43)

Research at the cellular level swowed that the corticosteroids effects on cytokine production. Corticosteroids enter the cell that will bind to the receptors and will be interacting with buclear factor - kB (NF-kB) caused negative regulation of IL-8 and RANTES. Intitute of corticosteroids on the GRE in the nucleus of cells would inhibit the transcription of several cytokines including IL-1B, TNF alpha, GM-CSF, IL-2 to IL-6, IL-8, RANTES and MIP-1 alpha. (44) Kurane et al. (1993) measured the levels of IFN-α in the serum of patients with DHF and DF. The highest levels of IFN-α in patients with DHF and DF occured on the first day of devervescence phase and gradually decreases during deververcence. The research results indicate that IFN-α produced in high amounts in acute phase of DHF and DF. IFN-α level remained high in patients with DHF after phase of fever but not for the DF. (43)

Inhibitory effect of dexamethasone occurred on cytokine production by DENV infected monocytes and viral load reduction. (42) Dexamethasone working on the production of cytokines TNF-α, IFN-α and IL-10 by monocytes after infection with DENV-2. Dexamethasone effects on the production of TNF-α and translocation of NF-kβ, which is an important step for the induction of TNF-α by monocytes. (42)

Interleukin 1β, IL-6, and IL-10 is inhibited by dexamethasone after monocytes induced by lipopolysaccharide (LPS) bacteria in shock septik. (42) Dexamethasone does not alter significantly the production of IL-6 during DENV infection in vitro. Other cytokines related to severity DENV infection, such as IL-18 and TGF-β, (29) and dexamethasone effects need to be studied. (42)

Pathogenesis of dengue was believed due to the dysregulation of immune response. Monocytes / macrophages infected with DENV will secrete monokin that play a role in the manifestations of DHF / DSS. During the acute phase, mononuclear cells proliferate poorly in response to mitogen and dengue antigens as detected by the radiolabel of timidine. During the convalescent phase, limfoploriferatif response returned to normal. (29)
Dexamethasone, inhibits expression of inflammatory mediators such as cytokines proinflamatory. (45) Corticosteroids inhibit monocyte function including the release of TNF alpha stimulated by endotoxin. Monocytes also release TNF receptor (cTNF-R) that modulates the bioactivity of TNF-α. Effect increased with increasing concentration of dexamethasone. Dexamethasone concentraton of 1 umol/L can inhibit the released of sTNF-RT75 by monocyte as much as 86% and 40% in culture. Dexamethasone also reduced TNF bioactivity in peripheral monocyte cultures, especially TNF-α. Dexamethasone also inhibits the release of IL-1β and IL-1ra by monocytes culture. (45)

The study by Reis et al (2007) have tested the effect of dexamethasone on cytokine production by monocytes infected by DENV in vitro. (42) TNF-α, IL-6, IL-10, and IFN-α was measured in cell supernatant PBML 10-15 different donors with immunoassay. Inhibition occurred significantly in monocyte cultures were added dexamethasone especially TNF-α, and IL-10. Interleukin 6 is not statistically different although 8 of the 15 donors PBML showed resistance> 35% (Figure 1). (42)

Figure 1. Inhibition by dexamethasone on the expression of DENV antigens in infected monocyte cultures DENV (42)
            

 Downregulation of IFN-α initiate immunomodulatory effects of dexamethasone. This effect is not related to different viral clearance with antiviral effects caused by other molecules such as nitric oxide, which is known for controlling DENV replication in monocytes. Interleukin 10 38 46 block in STAT-1 and IRF-1, activation factor for nosocomial infection, whose expression can lead to inhibition of nitric oxide effect on DENV replication. (47, 48) After the downregulation of IL-10 by dexamethasone, activation of nosocomial infection can occur, resulting in a more efficient nitric oxide to the antiviral effects on monocytes. (42)

Dexamethasone acts as immunomodulator DENV infection that can reduce viral load and reduces the inflammatory reaction caused by a virus. (49) Dexamethasone significantly inhibited expression of DENV antigens and reduce the number of infected cells in 11 of the 15 culture monocytes. DENV particles decreased significantly after administration of dexamethasone for 2 days (Figure 1). (42) Although dexamethasone has a very interesting effect on in vitro models of dengue infection, clinical evidence is insufficient to recommend the use of corticosteroids in managing DHF / DSS.

1. Anonim. Infeksi virus dengue. In: Soedarmo SSP, Garna H, Hadinegoro SRS, Satari HI, editors. Buku ajar infeksi & pediatri tropis. 2 ed. Jakarta: Badan Penerbit IDAI, 2010:155-81.

2. Azis AL, Kushartono H, Darmawati I. Tatalaksanan sindroma renjatan dengue. Applied management of dengue viral infection in children. Kediri: IDAI Jatim Komisariat Jatim IV, 2010:99-113.

3. Basuki PS. Diagnosis infeksi virus dengue: penuntun bagi petugas kesehatan di daerah. Applied management of dengue viral infection in children. Kediri: IDAI Jatim komisariat Jatim IV, 2010:63-81(fulltex).

4. Basuki PS. Dengue 2010: apa yang baru? Workshop & simposium tatalaksana muthakir kasus demam pada anak: IDAI Jatim Kosisariat Jember, 2010:80-109.

5. Husada D. Pearls dan pitfalls, gosip, fakta, serta kontroversi seputar infeksi virus dengue. Applied management of dengue viral infection in children. Kediri: IDAI  cabang Jatim Komisariat Jatim IV, 2010:125-46.

6. Ismudijanto. Epidemiologi infeksi virus dengue: broader coverage, older patient and higher mortality. Applied management of dengue viral infection in children. Kediri: IDAI Jatim komisariat Jatim IV, 2010:1-9.

7. Soemakto, Yuliarto S, Rridewi I. Mengenal tanda awal dan tanda bahaya infeksi dengue. Aplied Management of dengue viral infection in children. Kediri: IDAI Jatim komisariat Jatim IV, 2010:47-61.

8. WHO. Dengue hemorrhagic fever: diagnosis, treatment, prevention and control. 2 ed. Geneva: World Health Organization, 1997.

9. WHO. Guidelines for treatments of dengue fever/dengue hemorrhagic fever in small hospital. New Delhi: World Health Organization, 1999.

10. WHO. Dengue, dengue hemorrhagic fever and dengue shock sundrome in the context of integrated management of childhood ilness. Geneva: World Health Organization, 2005.

11. WHO. Clinical management and delivery clinical service. Dengue guidelines for diagnosis, treatment, prevention and control. Geneva: World Health Organization, 2009.

12. Rajapakse S, Ranasinghe C, Rodrigo C. Corticosteroid therapy in dengue infection- opinions of junior doctors. J Glob Infect Dis 2010;2(2):199-200.

13. Futrakul P, Poshyachinda M, Mitrakul C, Kwakpetoon S, Unchumchoke P, Teranaparin C, et al. Hemodynamic response to high-dose methyl prednisolone and mannitol in severe dengue-shock patients unresponsive to fluid replacement. Southeast Asian J Trop Med Public Health 1987;18(3):373-9.

14. Futrakul P, Vasanauthana S, Poshyachinda M, Mitrakul C, Cherdboonchart V, Kanthirat V. Pulse therapy in severe form of dengue shock syndrome. J Med Assoc Thai 1981;64(10):485-91.

15. Min M, U T, Aye M, Shwe TN, Swe T. Hydrocortisone in the management of dengue shock syndrome. Southeast Asian J Trop Med Public Health 1975;6(4):573-9.

16. Panpanich R, Sornchai P, Kanjanaratanakorn K. Corticosteroids for treating dengue shock syndrome. Cochrane Database Syst Rev 2006;3:CD003488(fulltext).

17. Pongpanich B, Bhanchet P, Phanichyakarn P, Valyasevi A. Studies on dengue hemorrhagic fever. Clinical study: an evaluation of steroids as a treatment. J Med Assoc Thai 1973;56(1):6-14.

18. Rajapakse S. Corticosteroids in the treatment of dengue illness. Trans R Soc Trop Med Hyg 2009;103(2):122-6.

19. Sumarmo. The role of steroids in dengue shock syndrome. Southeast Asian J Trop Med Public Health 1987;18(3):383-9.

20. Sumarmo, Talogo W, Asrin A, Isnuhandojo B, Sahudi A. Failure of hydrocortisone to affect outcome in dengue shock syndrome. Pediatrics 1982;69(1):45-9.

21. Sumarmo, Widya MS, Martoatmodjo K. Cliical observations on dengue shoch syndrome (an evaluation of steroid treatment). Pediatr Indones 1975;15:151-60.

22. Tassniyom S, Vasanawathana S, Chirawatkul A, Rojanasuphot S. Failure of high-dose methylprednisolone in established dengue shock syndrome: a placebo-controlled, double-blind study. Pediatrics 1993;92(1):111-5.

23. Vitarana T, de Silva H, Withana N, Gunasekera C. Elevated tumour necrosis factor in dengue fever and dengue haemorrhagic fever. Ceylon Med J 1991;36(2):63-5.

24. Hober D, Poli L, Roblin B, Gestas P, Chungue E, Granic G, et al. Serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-1 beta (IL-1 beta) in dengue-infected patients. Am J Trop Med Hyg 1993;48(3):324-31.

25. Bethell DB, Flobbe K, Cao XT, Day NP, Pham TP, Buurman WA, et al. Pathophysiologic and prognostic role of cytokines in dengue hemorrhagic fever. J Infect Dis 1998;177(3):778-82.

26. Raghupathy R, Chaturvedi UC, Al-Sayer H, Elbishbishi EA, Agarwal R, Nagar R, et al. Elevated levels of IL-8 in dengue hemorrhagic fever. J Med Virol 1998;56(3):280-5.

27. Braga EL, Moura P, Pinto LM, Ignacio SR, Oliveira MJ, Cordeiro MT, et al. Detection of circulant tumor necrosis factor-alpha, soluble tumor necrosis factor p75 and interferon-gamma in Brazilian patients with dengue fever and dengue hemorrhagic fever. Mem Inst Oswaldo Cruz 2001;96(2):229-32.

28. Fink J, Gu F, Vasudevan SG. Role of T cells, cytokines and antibody in dengue fever and dengue haemorrhagic fever. Rev Med Virol 2006;16(4):263-75.

29. Azeredo EL, Zagne SM, Santiago MA, Gouvea AS, Santana AA, Neves-Souza PC, et al. Characterisation of lymphocyte response and cytokine patterns in patients with dengue fever. Immunobiology 2001;204(4):494-507.

30. Suharti C, van Gorp EC, Setiati TE, Dolmans WM, Djokomoeljanto RJ, Hack CE, et al. The role of cytokines in activation of coagulation and fibrinolysis in dengue shock syndrome. Thromb Haemost 2002;87(1):42-6.

31. Green S, Rothman A. Immunopathological mechanisms in dengue and dengue hemorrhagic fever. Curr Opin Infect Dis 2006;19(5):429-36.

32. Avila-Aguero ML, Avila-Aguero CR, Um SL, Soriano-Fallas A, Canas-Coto A, Yan SB. Systemic host inflammatory and coagulation response in the Dengue virus primo-infection. Cytokine 2004;27(6):173-9.

33. Nguyen TH, Lei HY, Nguyen TL, Lin YS, Huang KJ, Le BL, et al. Dengue hemorrhagic fever in infants: a study of clinical and cytokine profiles. J Infect Dis 2004;189(2):221-32.

34. Scott RM, Nisalak A, Cheamudon U, Seridhoranakul S, Nimmannitya S. Isolation of dengue viruses from peripheral blood leukocytes of patients with hemorrhagic fever. J Infect Dis 1980;141(1):1-6.

35. Hotta H, Wiharta AS, Hotta S, Homma M. Dengue type 2 virus infection in human peripheral blood monocyte cultures. Microbiol Immunol 1984;28(10):1099-109.

36. Halstead SB. Pathogenesis of dengue: challenges to molecular biology. Science 1988;239(4839):476-81.

37. Wu SJ, Grouard-Vogel G, Sun W, Mascola JR, Brachtel E, Putvatana R, et al. Human skin Langerhans cells are targets of dengue virus infection. Nat Med 2000;6(7):816-20.

38. Neves-Souza PC, Azeredo EL, Zagne SM, Valls-de-Souza R, Reis SR, Cerqueira DI, et al. Inducible nitric oxide synthase (iNOS) expression in monocytes during acute Dengue Fever in patients and during in vitro infection. BMC Infect Dis 2005;5:64.

39. Espina LM, Valero NJ, Hernandez JM, Mosquera JA. Increased apoptosis and expression of tumor necrosis factor-alpha caused by infection of cultured human monocytes with dengue virus. Am J Trop Med Hyg 2003;68(1):48-53.

40. Bosch I, Xhaja K, Estevez L, Raines G, Melichar H, Warke RV, et al. Increased production of interleukin-8 in primary human monocytes and in human epithelial and endothelial cell lines after dengue virus challenge. J Virol 2002;76(11):5588-97.

41. Chen YC, Wang SY. Activation of terminally differentiated human monocytes/macrophages by dengue virus: productive infection, hierarchical production of innate cytokines and chemokines, and the synergistic effect of lipopolysaccharide. J Virol 2002;76(19):9877-87.

42. Reis SR, Sampaio AL, Henriques MG, Gandini M, Azeredo EL, Kubelka CF. An in vitro model for dengue virus infection that exhibits human monocyte infection, multiple cytokine production and dexamethasone immunomodulation. Mem Inst Oswaldo Cruz 2007;102(8):983-90.

43. Kurane I, Innis BL, Nimmannitya S, Nisalak A, Meager A, Ennis FA. High levels of interferon alpha in the sera of children with dengue virus infection. Am J Trop Med Hyg 1993;48(2):222-9.

44. Harsono A, Endaryanto A. Penggunaan kortikosteroid di bidang alergi pada anak. In: Soegijanto S, Poerwodibroto S, Kaspan MF, Sarwono E, Soejoso DA, Noer MS, et al., editors. Continuing education ilmu kesehatan anak, krtikosteroid pada anak. Surabaya: Laboratorium/SMF Ilmu Kesehatan Anak Fakultas Kedokteran Universitas Airlangga, 1998:71-90.

45. Joyce DA, Kloda A, Steer JH. Dexamethasone suppresses release of soluble TNF receptors by human monocytes concurrently with TNF-alpha suppression. Immunol Cell Biol 1997;75(4):345-50.

46. Chareonsirisuthigul T, Kalayanarooj S, Ubol S. Dengue virus (DENV) antibody-dependent enhancement of infection upregulates the production of anti-inflammatory cytokines, but suppresses anti-DENV free radical and pro-inflammatory cytokine production, in THP-1 cells. J Gen Virol 2007;88(Pt 2):365-75.

47. Mahalingam S, Lidbury BA. Suppression of lipopolysaccharide-induced antiviral transcription factor (STAT-1 and NF-kappa B) complexes by antibody-dependent enhancement of macrophage infection by Ross River virus. Proc Natl Acad Sci U S A 2002;99(21):13819-24.

48. Dell'Albani P, Santangelo R, Torrisi L, Nicoletti VG, de Vellis J, Giuffrida Stella AM. JAK/STAT signaling pathway mediates cytokine-induced iNOS expression in primary astroglial cell cultures. J Neurosci Res 2001;65(5):417-24.

49. Moreno L, Jacoby DB, Fryer AD. Dexamethasone prevents virus-induced hyperresponsiveness via multiple mechanisms. Am J Physiol Lung Cell Mol Physiol 2003;285(2):L451-5.