Rapid, simple, and sensitive immunoagglutination assay with SiO2 particles and quartz crystal microbalance for quantifying Schistosoma japonicum antibodies.
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BACKGROUND: The resurgence of the parasitic disease schistosomiasis calls for more efficient diagnostic tests. We developed a rapid, simple, portable, and sensitive immunoagglutination assay that uses SiO(2) particles and quartz crystal microbalance (QCM) for quantifying Schistosoma japonicum (Sj) antibodies (SjAb). METHODS: We prepared submicrometer-sized silica particles derivatized with Sj antigens as replacements for traditional latex microspheres to specifically agglutinate in the presence of SjAb targets, and we used the QCM monitor to measure the resulting frequency shifts. We optimized the assay medium by adding poly(ethylene glycol) (PEG) as a response accelerator of immunoagglutination. To minimize or eliminate any nonspecific agglutination or adsorption interferences, we conducted appropriate sealing procedures separately for silica particles and the QCM probe. RESULTS: The measured frequency changes were linearly related to the SjAb concentrations in infected rabbit serum. The PEG-assisted immunoagglutination system was quantitatively sensitive to SjAb concentrations ranging from approximately 0.70 to 32.31 mg/L, with a detection limit of approximately 0.46 mg/L. The obtained linear regression equation was: y=43.61 x+80.44 (r=0.9872). Several serum specimens were evaluated with the developed QCM immunoassay and the results were compared with ELISA, validating the feasibility of practical applications. CONCLUSIONS: This novel immunoagglutination-based QCM detection format is rapid, simple to use, and more portable than conventional diagnostic immunoassays, thus offering a promising alternative tool that can be used for point-of-care clinical diagnosis of schistosomiasis, particularly in epidemic situations. (+info)
Sigmoid colonic carcinoma associated with deposited ova of Schistosoma japonicum: a case report.
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We report a case of sigmoid colonic carcinoma associated with deposited ova of Schistosoma japonicum. A 57-year old woman presented with a 10-mo history of left lower quadrant abdominal pain and a 2-mo history of bloody stools. She had a significant past medical history of asymptomatic schistosomiasis japonica and constipation. A colonoscopy showed an exophytic fragile neoplasm with an ulcerating surface in the sigmoid colon. During the radical operative procedure, we noted the partially encircling tumor was located in the distal sigmoid colon, and extended into the serosa. Succeeding pathological analysis demonstrated the diagnosis of sigmoid colonic ulcerative tubular adenocarcinoma, and showed deposited ova of Schistosoma japonicum in both tumor lesions and mesenteric lymph nodes. Three days after surgery the patient returned to the normal bowel function with one defecation per day. These findings reveal that deposited schistosome ova play a possible role in the carcinogenesis of colorectal cancer. (+info)
Pro-inflammatory cytokines and C-reactive protein are associated with undernutrition in the context of Schistosoma japonicum infection.
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Schistosomiasis is associated with undernutrition, but the mechanisms involved remain unknown. We analyzed baseline and follow-up data from a longitudinal treatment-reinfection study in N = 477 Schistosoma japonicum-infected subjects 7-20 years of age from Leyte, the Philippines. After baseline treatment with praziquantel, follow-up visits were scheduled every 3 months for 18 months; stool, venous blood, and anthropometric measurements were collected at each visit. Cytokine production by peripheral blood mononuclear cells (PBMCs) stimulated with specific S. japonicum antigens was measured once 4 weeks after treatment. After adjustment for confounders, S. japonicum intensity was associated with decreased serum albumin and Z-scores (all P < 0.05) and with increased serum C-reactive protein (CRP) and interleukin (IL)-6. CRP was associated with decreased albumin and Z-scores (all P < 0.01). Production of IL-1b and tumor necrosis factor (TNF)-alpha in response to worm antigen was associated with decreased albumin (both P < 0.005) and height-for-age Z-score (TNF-alpha only, P = 0.05). S. japonicum-associated undernutrition may, in part, result directly from inflammation. (+info)
Cytokine mRNA profiles in pigs exposed prenatally and postnatally to Schistosoma japonicum.
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The pig is a natural host for Schistosoma japonicum and a useful animal model of human infection. The aim of the present study was to assess the differences between the cytokine profiles in prenatally or postnatally S. japonicum exposed pigs. Seven prenatally exposed pigs, 7 postnatally exposed pigs and 4 uninfected control pigs were compared 27 weeks post exposure. Variables included worm burdens, tissue egg counts, liver pathology and mRNA levels of IL-2, IL-4, IL-10, IL-12, TNF-alpha, TGF-beta1 and IFN-gamma in the liver and the caecum, assessed by RT-PCR. Infection intensity and level of septal fibrosis were significantly higher in the postnatal group compared to the prenatal group (P < 0.05). A significant increase of IL-4 (P < 0.01), IL-10 (P < 0.01), IL-12 (P < 0.01) and TNF-alpha (P < 0.05) mRNA level was also observed in the caecum of prenatally infected animals compared to the control group (P < 0.01). The prenatal group showed higher levels of TGF-beta1 in the liver compared with the postnatally infected group (P< 0.05) and the control group (P< 0.01). This suppressive immune response correlated with previously reported low hepatic pathogenesis in prenatally exposed pigs. (+info)
CD4+ T-cell counts, CD4+/CD8+ T-cell count ratios, and antibody levels in migrant fishermen infected with Schistosoma japonicum in the Dongting Lake, China.
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In this study, CD4(+) and CD8(+) T cells and antibody levels were measured in 94 migrant fishermen infected with Schistosoma japonicum from Dongting Lake, China. Prevalence among these fishermen was high (63.8%), with a mean infection intensity of 61.4 +/- 3.8 epg, and included a high proportion of individuals (39.4%) with substantial parenchymal fibrosis (stages > or = 2/3). The CD4(+)/CD8(+) ratio in men (1.34 +/- 0.11) was significantly lower than that of women (1.58 +/- 0.15). CD4(+) T cells and the ratio of CD4(+)/CD8(+) were significantly decreased both in subjects infected with S. japonicum and those with parenchymal fibrosis. However, levels of total IgA, IgM, and anti-schistosome egg antigen IgG correlated positively with infection intensity and pathologic lesion number. These results suggest an imbalance between cell-mediated and humoral immunity in these fishermen, the precise cause of which remains undetermined. (+info)
Comparison of immune repertoires of Chinese and Philippine patients infected with Schistosoma japonicum.
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Chinese and Philippine patients exhibited detectable titers of serum antibodies to Schistosoma japonicum worm and egg antigens. Western blot (immunoblot) data revealed differing antigenic profiles. Antigen inhibition studies showed low and high levels of cross-reactivity with anti-worm and anti-egg antibodies, respectively, derived from both Chinese and Philippine patients. Thus, anti-egg antibodies and egg antigens are more conserved than anti-worm antibodies and worm antigens. (+info)
Th2 cytokines are associated with persistent hepatic fibrosis in human Schistosoma japonicum infection.
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We conducted a prospective cohort study in Leyte, the Philippines, among 611 Schistosoma japonicum-infected participants 7-30 years old, all of whom were treated with praziquantel at baseline. To detect hepatic fibrosis, abdominal ultrasound was performed at baseline and 12 months after treatment. Stool for assessment of S. japonicum infection was collected at baseline and at 3, 6, 9, and 12 months after treatment. Cytokines (interleukin [IL]-4, IL-5, IL-10, IL-13, tumor necrosis factor- alpha , and interferon- gamma ) produced by peripheral-blood mononuclear cells in response to soluble worm antigen preparation (SWAP), soluble egg antigen (SEA), and control medium were measured once 4 weeks after treatment. IL-4 to SWAP and IL-10 to both SWAP and SEA were associated with the presence of baseline fibrosis after adjustment for potential confounding variables (P<.03, for all). In participants with fibrosis at baseline, IL-4 to SWAP and IL-5 and IL-13 to both SWAP and SEA were associated with persistent fibrosis at 12 months after treatment (P<.05, for all). Males showed consistently stronger T helper 2 (Th2) cytokine responses to both SWAP and SEA than did females (P<.02, for all). These results suggest an independent role for Th2-biased cytokine responses to S. japonicum antigens in persistent hepatic fibrosis and indicate that Th2 cytokines may contribute to the male-biased prevalence of fibrosis. (+info)
Vaccination against Schistosoma japonicum infection by DNA vaccine encoding Sj22.7 antigen.
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To observe the in vitro expression of DNA vaccine pcDNA3-Sj22.7 and its immunological effect in mice, the recombinant plasmid pcDNA3-Sj22.7 was used to transfect HeLa cells with liposome-mediated method and the expression of Sj22.7 mRNA and protein was examined using reverse transcription-polymerase chain reaction, sodium dodecylsulfate-polyacrylamide gel electrophoresis and Western blot. Then, the ability of pcDNA3-Sj22.7 to protect against Schistosoma japonicum challenge infections was analyzed according to worm reduction rate and egg reduction rate after vaccination of mice. The serum levels of specific IgG antibody and T lymphocyte proliferation response were also determined. After the challenge infection, Sj22.7-driven interferon (IFN)-gamma and interleukin (IL)-4 was also quantified. Results showed that pcDNA3-Sj22.7 could express Sj22.7 mRNA and protein in vitro. Immunization resulted in a worm reduction rate of 29.70%, egg reduction rate of 47.25% (liver) and 51.73% (intestine), and egg reduction rate of 25.90% (eggs per female), suggesting induction of significant anti-fecundity in the pcDNA3-Sj22.7 group. Enzyme-linked immunosorbent assay and Western blot analysis indicated that immunized mice generated specific IgG against Sj22.7. T lymphocytes from mice immunized with pcDNA3-Sj22.7 showed a significant proliferation response to rSj22.7. The culture of spleen cells showed that secretion of IFN-gamma increased but IL-4 decreased. The results indicate hat DNA vaccination by pcDNA3-Sj22.7 is sufficient to elicit significant levels of protective immunity against S. japonicum infection. The DNA vaccine could induce significant cellular and humoral immune response, and display predominant T helper cell type 1 type immune responses, which contribute to the protective immunity against challenge infection in mice. (+info)