Clinical Significance And Detection Of Cytokines And SVCAM-1 Levels In Serum From Dengue Fever Patients

Dengue fever is an acute infectious disease caused by dengue virus infection and transmitted by infected mosquito. It has threatened 2.5 billion populations from over 100 countries throughout the tropical and subtropical areas, and its severe form like dengue hemorrhagic fever and dengue shock syndrome resulted in approximately 22,000 deaths every year. Dengue fever has become an important disease which impacted developing countries'public health. Dengue epidemic mainly along the coast area in China, especially in Guangdong province for there were dengue reported almost every year. Early diagnose and treatment timely is the key to cure severe dengue fever and reduce the mortality. But we still have not specific clinical and experimental markers for early diagnose or warning severe dengue by far. Pathogenesis of dengue virus infection, especially for severe dengue is still not clearly elucidated. Some small proteins like cytokines and adhesion molecular are the focus of research about immunopathogenesis in diseases recently. By far, there have been no reports about detection of cytokines and soluble vascular cell adhesion molecule-1 in serum from dengue patients in China. So, further research on the immunopathogenesis in dengue fever and selecting clinical or experimental marker for severe dengue fever is very important to its prevention and treatment.ObjectsTo analyze clinical and experimental characteristics of dengue fever patients and select warning markers for the dengue fever patients with severe manifestation. To further elucidate the immunopathogenesis of dengue fever by detect cytokines and sVCAM-1 levels in serum from dengue fever patients. Study subjectsOf the 2006 dengue outbreak in Guangzhou, we chose 29 dengue fever patients with severe manifestation who had been stored series serum samples as severe group. We also selected 22 dengue fever patients without severe manifestation as mild group for comparison at the same time. There were no differences in age and sex between two study groups.Methods1. Accumulate all dates of symptoms, signs and laboratories from dengue fever patients, then analyze and choose markers from above which can warn the happen of dengue fever patients with severe manifestation.2. Detect levels of cytokines( IL-6,IL-10,IL-17A,IFN-γ,TNF-αand sTNFRI ) in series serum from dengue fever patients by ELISA.3. Detect levels of soluble vascular cell adhesion molecule-1 (sVCAM-1) in series serum from dengue fever patients by ELISA.4. Detect levels of viral load in serum from dengue fever patients by real-time PCR.Results1. In comparison to the mild group, severe dengue group had higher rate of nausea (41.4%:13.6%, P=0.031), diarrhea (20.7%:0%, P=0.031), petechiae (41.4%:13.6%, P=0.031), and positive tourniquet test (48.3%:0%, P=0.000). 2. Severe dengue group had significantly lower levels of neutrophil (1.11:1.5, P=0.0434) and platelet counts (49.5:108, P=0.000), but higher levels of ALT(87:25.5, P=0.000), AST(136:41, P=0.000), creatine kinase (CK) (249:98.5, P=0.003) and LDH (349:222,P=0.000) in comparison to those with mild DF.3. Severe group had persistently higher sVCAM-1 levels compared to those with mild DF, while all cytokines levels except for IL-17A were significantly higher in severe DF than in mild DF, but the time points at which their differences were observed are distinct.4. sVCAM-1 levels in dengue fever patients were positively correlated with ALT (r=0.49, P=0.000), AST (r=0.516, P=0.000), CK(r=0.298, P=0.035), LDH (r=0.472, P=0.001), IL-6 (r=0.287, P=0.041) and TNF-α(r=0.313, P=0.026) levels, but negatively correlated with neutrophil counts (r=-0.384, P=0.005), platelet counts (r=-0.479, P=0.000) , and viral load (r=-0.431, P=0.005).5. Platelet counts were negatively correlated with IL-6(r=-0.372, P=0.007) and TNF-α(r=-0.406,P=0.003) levels, viral load were positively correlated with IL-10(r=0.334,P=0.033) and sTNFRI(r=0.493,P=0.001) levels. In addition, CK levels were positively correlated with IL-17A levels(r=0.322,P=0.023), and AST levels were positively correlated with TNF-αlevels(r=0.310,P=0.027). 6. Viral load between two dengue fever groups were no differences.Conclusions1. Dengue patients with nausea, diarrhea, petechiae and positive tourniquet test, or laboratory show high levels of aminotransaferase and decreased levels of neutrophil and platelet counts could act as warning signs of dengue fever patients with severe manifestation.2. Levels of sVCAM-1 in serum may act as an experimental warning marker of dengue fever patients with severe manifestation.3. IL-6, IL-10, IFN-γ, TNF-αand sTNFRI in serum from dengue fever patients may play an important part in the immunopathogenesis of dengue fever.