Chintana Chirathaworn

Serum IL-18 and IL-18BP Levels in Patients with Chikungunya Virus Infection

Chikungunya virus infection has recently emerged in several countries. The inflammatory response is suggested to be involved in the pathology observed in this infectious disease. Interleukin-18 (IL-18) is an inducer of interferon-gamma (IFN-gamma) production and has been shown to play a role in several inflammatory diseases. IL-18 binding protein (IL-18BP) is a natural regulator of IL-18. In this study, we determined the levels of IL-18 and IL-18BP in patients with Chikungunya virus infection. Acute and convalescent sera were collected from each patient. The levels of both IL-18 and IL-18BP were measured by ELISA assays. IL-18 and IL-18BP levels were higher in patients than in controls. In addition, the level of IL-18 was higher in convalescent than in acute sera. However, the level of IL-18BP was lower in convalescent than in acute sera. These data suggest that production of both IL-18 and IL-18BP was induced following Chikungunya virus infection. IL-18BP was increased to regulate the activity of IL-18. The ratio of IL-18 to IL-18BP was higher in convalescent than in acute sera. The lower level of IL-18BP in convalescent sera was probably due to loss following IL-18 neutralization. Our data suggest that Chikungunya virus infection promotes the T helper-1 (Th-1) response by inducing IL-18 production. Manipulation of IL-18 and IL-18BP levels could be a promising therapeutic approach to alleviate symptoms in patients with Chikungunya virus infection.

Long-term humoral and cellular immune response to hepatitis B vaccine in high-risk children 18-20 years after neonatal immunization.

Eighty-seven high-risk individuals in Thailand who had received a complete course of recombinant HBV vaccine 18-20 y ago were investigated with regard to their immunological memory. To evaluate humoral immunity, anti-HBs antibody titers were measured. Cellular immunity was determined by ELISPOT to detect HBV-specific IFN-gamma-producing cells. Overall 83.9% of participants developed circulating anti-HBs (titer > or = 1 mIU/mL) and 58.6% were seroprotected (titer > or = 10 mIU/mL). As for cellular immunity, 50.6% were positive on ELISPOT. Moreover, there was no correlation between the level of anti-HBs and positive ELISPOT results. However, the majority of participants (81.8%) who were positive for IFN-gamma-producing cells were seropositive, but only 50% of seropositive participants were ELISPOT-positive. Thus, 18-20 y after immunization, it appears that a second booster dose should be considered, especially in high-risk groups.

Cytokine levels in patients with chikungunya virus infection.

OBJECTIVE To investigate cytokine profile in patients with chikungunya virus (CHIKV) infection. METHODS Twenty eight pairs of serum samples collected from CHIKV infected patients during the outbreak of chikungunya fever in South Thailand in 2008 were obtained. A multiple cytokine assay for detection of 17 cytokines was performed. RESULTS In the acute stage of CHIKV infection, the patients had significantly higher levels of interleukin-6, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, monocyte chemotactic protein 1 and tumor necrosis factor alpha than the control (P<0.001, P=0.023, P=0.015, P<0.001 and P=0.024, respectively). When the disease developed to the recovery stage, the patients had significantly lower levels of interleukin-6, granulocyte-macrophage colony-stimulating factor, monocyte chemotactic protein 1 and macrophage inflammatory protein beta than in the acute stage (P<0.001). CONCLUSIONS This study provides additional information that these cytokines could play roles in pathogenesis of CHIKV infection and could be used as disease biomarkers or drug targets.

Expression of TNF-α, TGF-β, IP-10 and IL-10 mRNA in kidneys of hamsters infected with pathogenic Leptospira

Leptospirosis is a worldwide zoonosis caused by pathogenic Leptospira. Although several components of this organism have been identified, the molecular mechanisms underlying pathogenesis of this infectious disease are still poorly understood. Besides, direct injury by microbial factors, cytokines produced in response to infection have been proposed to be involved in pathogenesis of leptospirosis. In this study, cytokine gene expression in kidneys was investigated. Hamsters were injected with pathogenic Leptospira interrogans serovar Pyrogenes and were sacrificed on days 3, 5 and 7 after infection. RNA was extracted from kidney tissues. Real-time PCR was performed to demonstrate expression of TNF-alpha, TGF-beta, IP-10 and IL-10 mRNA in kidneys. TNF-alpha, TGF-beta and IP-10 expression could be demonstrated since day 3 post-infection whereas IL-10 expression was detected later on day 5. Leptospira infection resulted in not only expression of a proinflammatory cytokine, TNF-alpha, but also a T cell chemokine, IP-10. Detection of IP-10 suggested the involvement of T cell recruitment in the immune response or pathology in infected kidneys. Expressions of anti-inflammatory cytokines, TGF-beta and IL-10 were also observed. However, the level of TGF-beta expression was prominent since day 3 post-infection whereas IL-10 expression was clearly observed on day 5. Further experiments will provide additional information whether there is a correlation between the expression of these cytokines and pathologies found in an affected organ.

Hepatitis E virus infection: Epidemiology and treatment implications

Hepatitis E virus (HEV) infection is now established as an emerging enteric viral hepatitis. Standard treatments in acute and chronic hepatitis E remain to be established. This study undertakes a review of the epidemiology, treatment implication and vaccine prevention from published literature. HEV infection is a worldwide public health problem and can cause acute and chronic hepatitis E. HEV genotypes 1 and 2 are primarily found in developing countries due to waterborne transmission, while the zoonotic potential of genotypes 3 and 4 affects mostly industrialized countries. An awareness of HEV transmission through blood donation, especially in the immunocompromised and solid organ transplant patients, merits an effective anti-viral therapy. There are currently no clear indications for the treatment of acute hepatitis E. Despite concerns for side effects, ribavirin monotherapy or in combination with pegylated interferon alpha for at least 3 mo appeared to show significant efficacy in the treatment of chronic hepatitis E. However, there are no available treatment options for specific patient population groups, such as women who are pregnant. Vaccination and screening of HEV in blood donors are currently a global priority in managing infection. New strategies for the treatment and control of hepatitis E are required for both acute and chronic infections, such as prophylactic use of medications, controlling large outbreaks, and finding acceptable antiviral therapy for pregnant women and other patient groups for whom the current options of treatment are not viable.

Plasma and synovial fluid connective tissue growth factor levels are correlated with disease severity in patients with knee osteoarthritis

Background: Connective tissue growth factor (CTGF) has been implicated in development of osteoarthritis (OA). Objective: To determine the correlation between plasma and synovial fluid CTGF levels and the severity in knee osteoarthritis patients. Methods: A total of 100 subjects were recruited into this study (75 OA patients and 25 controls). CTGF concentrations in plasma and synovial fluid were analyzed by enzyme-linked immunosorbent assay. Results: Plasma and synovial fluid CTGF concentrations were correlated with radiographic severity. There was a positive correlation between plasma and synovial fluid CTGF levels. Conclusion: CTGF could be useful for monitoring the severity and progression of OA.

Detection of Leptospira in urine using anti-Leptospira-coated gold nanoparticles.

Serological assays for antibody detection have been widely used for Leptospirosis diagnosis. However, antibody is usually undetectable during the first week after infection. Detection of Leptospira DNA can be done by PCR but this technique requires special equipments and the cost is still relatively high. Here we demonstrate that gold nanoparticles can be used to facilitate Leptospira detection. Gold nanoparticles were coated with rabbit antibody specific to Leptospira interrogans serovar Bratislava and these coated particles were used to detect Leptospira in urine. Agglutination of gold particles indicated the presence of Leptospira in samples tested. The sensitivity of detection was 10 leptospires/ml. No agglutination was observed when anti-Leptospira-coated particles were tested with urine containing the organisms commonly found in urine such as Klebsiella pneumoniae, Escherichia coli and Enterococcus faecalis. This assay is very easy to perform and results could be observed with the naked eyes. Fresh or frozen urine samples could be used. The stability of antibody-coated particles was at least 2 months when kept at 4°C. In conclusion, we have demonstrated that the technique using antibody-coated gold nanoparticles is a promising tool for further validation as a rapid assay for Leptospirosis diagnosis.

Herpes simplex virus 1 induced LOX-1 expression in an endothelial cell line, ECV 304.

Infections, such as by Chlamydophilia pneumoniae, cytomegalovirus, herpes simplex virus, and Helicobacter pylori, have been shown to be involved in atherogenesis. Herpes simplex virus I (HSV-1) could infect vascular endothelial cells, and it has been shown that, when endothelial cells were activated with oxidized LDL (oxLDL), a number of cellular events are occurred, leading to endothelial cell dysfunction. Since LOX-1 is a major receptor for oxLDL on endothelial cells and its expression was increased in atherosclerosis, we investigated whether HSV1 infection can lead to the increase expression of LOX-1 in endothelial cells. LOX-1 mRNA expression determined by RT-PCR and LOX-1 promoter activity measured by luciferase assay were increased in endothelial cells following HSV-1 infection. This suggests that one of the mechanisms by which HSV-1 is involved in atherogenesis maybe the enhanced uptake of oxLDL via the increased expression of LOX-1 in endothelial cells.

Immune responses to Leptospira infection: roles as biomarkers for disease severity

Various leptospiral components have been identified and shown to be involved in tissue destruction. In addition, immune responses to leptospires have been implicated in target organ damages in severe leptospirosis cases. Several inflammatory mediators were shown to be higher in susceptible animals than in resistant hosts. Moreover, cytokines/chemokines and serum proteins induced following Leptospira infection were suggested to be biomarkers for disease severity in human leptospirosis. This review focuses on the role of immune responses in the severity of leptospirosis. Studies in both animal models and humans are discussed.

Interpretation of microscopic agglutination test for leptospirosis diagnosis and seroprevalence

Determination of antibody titer by microscopic agglutination test (MAT) has been used as a tool for leptospirosis diagnosis. Four fold or greater rise in antibody titers between acute and convalescent sera suggests recent Leptospira infection. In addition, results obtained by MAT have been used to predict infecting serovars. However, cross reactivity among various Leptospira serovars have been reported when patient sera were tested with a battery of Leptospira serovars. This study demonstrates cross- reactivity among several Leptospira serovars when MAT was performed on leptospirosis sera. The data support a role of MAT as a tool for diagnosis. However, for information on infecting serovars, Leptospira isolation and molecular identification should be performed.