We tested correlations between anti-Helicobacter pylori IgG and IgA levels and the urease test, anti-CagA protein antibody, degree of gastritis, and age. In total, 509 children (0-15 years) were enrolled. Subjects were stratified as 0-4 years (n = 132), 5-9 years (n = 274), and 10-15 years (n = 103) and subjected to the urease test, histopathology, ELISA, and western blot using whole-cell lysates of H. pylori strain 51. The positivity rate in the urease test (P = 0.003), the degree of chronic gastritis (P = 0.021), and H. pylori infiltration (P < 0.001) increased with age. The median titer for anti-H. pylori IgG was 732.5 IU/mL at 0-4 years, 689.0 IU/mL at 5-9 years, and 966.0 IU/mL at 10-15 years (P < 0.001); the median titer for anti-H. pylori IgA was 61.0 IU/mL at 0-4 years, 63.5 IU/mL at 5-9 years, and 75.0 IU/mL at 10-15 years (P < 0.001). The CagA-positivity rate was 26.5% at 0-4 years, 36.5% at 5-9 years, and 46.6% at 10-15 years for IgG (P = 0.036), and 11.3% at 0-4 years, 18.6% at 5-9 years, and 23.3% at 10-15 years for IgA (P < 0.001). Anti-H. pylori IgG and IgA titers increased with the urease test grade, chronic gastritis degree, active gastritis, and H. pylori infiltration. Presence of CagA-positivity is well correlated with a high urease test grade and high anti-H. pylori IgG/IgA levels.
Adolescent ; Antibodies, Bacterial/*blood ; Antigens, Bacterial/*analysis/immunology ; Bacterial Proteins/*analysis/immunology/metabolism ; Blotting, Western ; Child ; Child, Preschool ; Chronic Disease ; Enzyme-Linked Immunosorbent Assay ; Female ; Gastritis/pathology ; Helicobacter Infections/blood/microbiology/*pathology ; Helicobacter pylori/isolation & purification/*metabolism ; Humans ; Immunoglobulin A/*blood ; Immunoglobulin G/*blood ; Infant ; Infant, Newborn ; Male ; Severity of Illness Index ; Urease/metabolism

OBJECTIVES: The seroprevalence of hepatitis E virus (HEV) among high-risk groups overseas is high, but studies in these groups are rare in South Korea. We conducted the present study from April to November 2012 to obtain data on the seroprevalence and associated risk factors for HEV among slaughterhouse workers in South Korea. METHODS: Slaughterhouse workers from 80 workplaces nationwide were surveyed in South Korea in 2012. The subjects comprised 1848 cases: 1434 slaughter workers and 414 residual products handlers. By visiting 80 slaughterhouses, which were mixed with 75 of which also performed residual products handling, we conducted a questionnaire survey for risk factors and obtained blood samples in order to determine the seropositivity and seroprevalence of HEV. Anti-HEV IgG and IgM were measured using HEV IgG and IgM enzyme-linked immunospecific assay kits and HEV antigen was measured by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The seropositivity of anti-HEV IgG was 33.5% (slaughter workers 32.8% and residual products handlers 36.2%), and among the seropositive individuals the seroprevalence of anti-HEV IgM was 0.5% (slaughter workers 0.5%, residual products handlers 0.7%). The response rate of HEV-antigen as measured by RT-PCR was 0.2%. Risk factors significantly related to anti-HEV IgG seropositivity were age, sex , and working duration (slaughter workers only). CONCLUSIONS: There were significant risk factors (sex, age, and working duration) for HEV identified in our study. All three positive cases for HEV-antigen by RT-PCR were related to pig slaughter but without statistical significance. To prevent HEV, an educational program and working guidelines may be needed for high risk groups.
Abattoirs ; Adult ; Aged ; Enzyme-Linked Immunosorbent Assay ; Female ; Hepatitis Antibodies/blood ; Hepatitis E/*diagnosis/epidemiology/virology ; Hepatitis E virus/genetics/*immunology/metabolism ; Humans ; Immunoglobulin G/blood ; Immunoglobulin M/blood ; Male ; Middle Aged ; Multivariate Analysis ; Prevalence ; Republic of Korea/epidemiology ; Reverse Transcriptase Polymerase Chain Reaction ; Risk Factors ; Workplace

Roundworms of Toxocara canis and Toxascaris leonina are common gastrointestinal helminths of canids over the world. Humans are infected with T. canis larvae through ingestion of infective eggs in contaminated environments or larvae by consumption of raw or uncooked meat or livers. Recently, patients of clinically diagnosed toxocariasis are increasing and require correct diagnosis in Korea. The present study investigated serological cross-reactivity between crude antigens of T. canis (TCLA) and T. leonina (TLLA) larvae. We collected serum specimens from 177 toxocariasis patients who were clinically suspected in the Seoul National University Hospital and 115 healthy controls. An ELISA method for toxocariasis was used to evaluate diagnostic efficacy of TLLA for serodiagnosis of human toxocariasis. The IgG ELISA using TLLA gave 14 (14.3%) positives of 98 TCLA positive specimens among 177 suspected toxocariasis patients. Most of them showed high absorbances with TCLA. In conclusion, there is a partial cross reaction between serum specimens of toxocariasis and TLLA.
Animals ; Antibodies, Helminth/blood ; Antigens, Helminth/*immunology ; Cross Reactions ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunoglobulin G/blood ; Larva/immunology/metabolism ; Toxascaris/growth & development/*immunology/isolation & purification ; Toxocara canis/growth & development/*immunology/isolation & purification ; Toxocariasis/*diagnosis/parasitology

BACKGROUND/AIMS: Visceral larva migrans, caused by Toxocara canis and Toxocara cati, has emerged as a significant cause of eosinophilic liver abscess (ELA). Differentiation of ELA associated with toxocariasis (ELA-T) from metastasis or primary liver malignancy is sometimes difficult. However, the role of albendazole treatment remains uncertain in this condition. The aim of this study was to evaluate whether albendazole can enhance the radiologic resolution of ELA-T. METHODS: We retrospectively reviewed the medical records of the patients diagnosed with ELA-T at our institution between January 2008 and December 2011. ELA-T was diagnosed based on the imaging findings on computed tomography or magnetic resonance imaging and the presence of positive serum IgG antibody for Toxocara canis. Among a total of 163 patients, 32 patients received albendazole (albendazole group) and 131 did not (control group). Baseline characteristics and fate of liver nodules were compared between the two groups. RESULTS: Baseline characteristics (age, sex, number and maximal size of lesions, eosinophil count) were similar between the two groups. Median duration for achieving radiologic resolution in the albendazole group was significantly shorter than in the control group (207 days [range 186-228] vs. 302 days [range 224-380], p=0.023). In Cox regression analysis of the cumulative rates of radiologic resolution, the hazard ratio for albendazole treatment was 1.99 (95% confidence interval, 1.22-3.23). CONCLUSIONS: Radiologic resolution of ELA-T can be accelerated with albendazole treatment. Hence, inconvenience associated with long-term follow-up and unnecessary worries among patients can be eliminated with albendazole treatment.
Adult ; Aged ; Aged, 80 and over ; Albendazole/*therapeutic use ; Animals ; Antiprotozoal Agents/*therapeutic use ; Eosinophils/*immunology ; Female ; Humans ; Immunoglobulin G/blood ; Larva Migrans, Visceral/*drug therapy/parasitology ; Liver/enzymology/metabolism ; Liver Abscess/*etiology ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Proportional Hazards Models ; Retrospective Studies ; Tomography, X-Ray Computed ; Toxocara canis/immunology/isolation & purification

BACKGROUND: Without appropriate culture systems for hepatitis E virus (HEV), sufficient natural viral proteins are difficult to generate for use in serological tests. Therefore, it is important to produce large amounts of HEV recombinant proteins in an economical way. The present study developed ELISAs using 2 truncated forms of the HEV open reading frame (ORF) 2 protein in order to detect anti-HEV IgG in serum samples. METHODS: Two truncated forms of the ORF2 protein were expressed in Escherichia coli and were purified by Ni2+-chelate-affinity chromatography (Qiagen, Germany). Two ELISAs were developed using these proteins and were compared with DIA.PRO HEV IgG ELISA kit (DIA.PRO. Italy) in 220 serum samples. RESULTS: High yields of the target proteins were obtained through codon optimization. The concentration and purity of the proteins were improved with Amicon filters (EMD Millipore, USA). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting analysis of the resultant proteins showed a protein band of approximately 60 kDa corresponding to ORF2.1 (amino acids 112-660) and a protein band of approximately 55 kDa corresponding to ORF2.2 (amino acids 112-607). Positive agreement, negative agreement, and concordance of the 2 in-house ELISAs compared with DIA.PRO HEV IgG ELISA kit were 87%, 99.5%, and 98.1%, respectively (kappa=0.899, P=0.625). CONCLUSIONS: The newly developed ELISAs are useful for detecting anti-HEV IgG in serum samples and are highly concordant with DIA.PRO HEV IgG ELISA kit.
Amino Acid Sequence ; Antibodies/*blood ; *Enzyme-Linked Immunosorbent Assay ; Escherichia coli/metabolism ; Hepatitis E virus/*metabolism ; Humans ; Immunoglobulin G/*blood ; Molecular Sequence Data ; Recombinant Proteins/biosynthesis/immunology/isolation & purification ; Sequence Alignment ; Viral Proteins/chemistry/*immunology/metabolism

Recombinant antigenic proteins of Toxoplasma gondii are alternative source of antigens which are easily obtainable for serodiagnosis of toxoplasmosis. In this study, highly antigenic secretory organellar proteins, dense granular GRA2 and GRA3, rhoptrial ROP2, and micronemal MIC2, were analyzed by bioinformatics approach to express as water-soluble forms of antigenic domains. The transmembrane region and disorder tendency of 4 secretory proteins were predicted to clone the genes into pGEX-4T-1 vector. Recombinant plasmids were transformed into BL21 (DE3) pLysS E. coli, and GST fusion proteins were expressed with IPTG. As a result, GST fusion proteins with GRA225-105, GRA339-138, ROP2324-561, and MIC21-284 domains had respectively higher value of IgG avidity. The rGST-GRA225-105 and rGST-GRA339-138 were soluble, while rGST-ROP2324-561 and rGST-MIC21-284 were not. GRA231-71, intrinsically unstructured domain (IUD) of GRA2, was used as a linker to enhance the solubility. The rGST-GRA231-71-ROP2324-561, a chimeric protein, appeared to be soluble. Moreover, rGST-GRA231-71-MIC21-284 was also soluble and had higher IgG avidity comparing to rGST-MIC21-284. These 4 highly expressed and water-soluble recombinant antigenic proteins may be promising candidates to improve the serodiagnosis of toxoplasmosis in addition to the major surface antigen of SAG1.
Animals ; Antibodies, Protozoan/immunology ; Antibody Affinity ; Antigens, Protozoan/chemistry/*diagnostic use/genetics/immunology ; *Gene Expression ; Immunoglobulin G/blood/immunology ; Mice, Inbred BALB C ; Recombinant Proteins/chemistry/*diagnostic use/genetics/immunology ; Serologic Tests/methods ; Solubility ; Toxoplasma/genetics/immunology/*metabolism ; Toxoplasmosis/diagnosis

BACKGROUND: The dramatic increase in use of the IgG test for toxoplasma, rubella, cytomegalovirus (CMV), and herpes simplex virus (HSV) [TORCH] has led to the requirement for a high-efficiency method that can be used in the clinical laboratory. This study aimed to compare the results of BGI-Array ELISA TORCH IgG (BGI-GBI, China) screening method to those of Virion/Serion TORCH IgG ELISA (Virion/Serion, Germany). METHODS: Serum specimens (n=400) submitted for routine IgG testing by Virion/Serion ELISA were also tested using the BGI-Array ELISA method. The agreements of these two kinds of method were analyzed by kappa-coefficients calculation. RESULTS: Following repeat testing, the BGI-Array ELISA TORCH IgG assays demonstrated agreements of 99.5% (398/400 specimens), 98% (392/400 specimens), 99% (396/400 specimens), and 99.5% (398/400 specimens), respectively. The BGI-Array ELISA IgG assays provided results comparable to Virion/Serion ELISA results, with kappa-coefficients showing near-perfect agreement for the HSV (kappa=0.87), rubella (kappa=0.92) and CMV (kappa=0.93) and substantial agreement for the toxoplasma (kappa=0.80) IgG assays. The use of the BGI-Array ELISA TORCH IgG assays could reduce the turnaround time (1.5 hr vs. 5 hr by Virion/Serion ELISA for 100 specimens) and were easy to use. CONCLUSIONS: BGI-Array ELISA TORCH IgG shows a good agreement with Virion/Serion ELISA methods and is suitable for clinical application.
Antibodies, Viral/blood ; Cytomegalovirus/immunology/*metabolism ; *Enzyme-Linked Immunosorbent Assay ; Humans ; Immunoglobulin G/*analysis/blood ; Protozoan Infections/diagnosis ; Reagent Kits, Diagnostic ; Rubella virus/immunology/*metabolism ; Sensitivity and Specificity ; Simplexvirus/immunology/*metabolism ; Toxoplasma/immunology/*metabolism ; Virion/*immunology/metabolism ; Virus Diseases/diagnosis

PURPOSE: Cefaclor is widely prescribed for various infectious diseases. As its consumption increases, the number of hypersensitivity reactions to cefaclor has increased. This study aimed to evaluate the immunologic findings of immediate hypersensitivity to cefaclor. MATERIALS AND METHODS: We enrolled 47 patients with immediate hypersensitivity to cefaclor from Ajou University Hospital and Asan Medical Center. Serum specific IgE, IgG1, and IgG4 antibodies to cefaclor-human serum albumin (HSA) conjugate were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The most common phenotype was anaphylaxis (Group I, 78.7%), followed by urticaria (Group II, 21.3%). The detection of specific IgE, IgG1, and IgG4 to cefaclor-HSA conjugate by ELISA tended to be higher in Group I (40.5%, 41.7%, 21.6%) than in Group II (20.0%, 20.0%, 0%) with no statistical significance. Significant associations were found between specific IgE and IgG1 or IgG4 (p<0.001, p=0.019). ELISA inhibition tests showed significant inhibitions by both free cefaclor and cefaclor-HSA conjugate. For basophil activation tests in patients having no specific IgE antibody, the CD63 expression level on basophils increased with incubations of free cefaclor. CONCLUSION: The most common manifestation of immediate hypersensitivity to cefaclor was anaphylaxis, most of which was mediated by IgE; however, a non-IgE mediated direct basophil activation mechanism was suggested in a subset of anaphylaxis patients.
Adolescent ; Adult ; Aged ; Anaphylaxis/*chemically induced/immunology ; Anti-Bacterial Agents/adverse effects/*immunology ; Antigens, CD63 ; Basophils/metabolism ; Cefaclor/*adverse effects/immunology ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Hypersensitivity, Immediate/chemically induced/diagnosis/*immunology ; Immunoglobulin E/*blood ; Immunoglobulin G/immunology ; Male ; Middle Aged ; Retrospective Studies ; Skin Tests ; Urticaria/chemically induced/diagnosis/immunology ; Young Adult

Radiation sensitive protein 23 (RAD23) is a nucleotide excision repair (NER) protein that plays an important role in Ubiquitin-proteasome pathway (UPP). Schistosoma japonicum radiation sensitive protein23 (SjRAD23) cDNA sequences were amplified by PCR and cloned into pET28a (+) vector to construct recombinant expression plasmid pET28a(+)-SjRAD23. The recombinant protein was expressed as both inclusion bodies and the supernatant in Escherichia coli BL21 (DE3) cell. Immunofluorescence observation shows that SjRAD23 was mainly distributed on the tegument surface of the worms. ELISA assay reveals that specific IgG, IgG1 and IgG2a antibodies could be detected in the sera of rSjRAD23 immunized mice. Western blotting analysis shows that the recombinant SjRAD23 could be recognized by serum specific to soluble adult worm antigen of S. japonicum. BALB/c mice vaccinated with rSjRAD23 combined with 206 adjuvant revealed 35.94% worm reduction and 40.59% liver egg reduction when compared with that of the adjuvant control
Animals ; Antibodies, Helminth ; blood ; Blotting, Western ; Cloning, Molecular ; DNA Repair Enzymes ; genetics ; metabolism ; DNA, Complementary ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli ; Genetic Vectors ; Helminth Proteins ; genetics ; immunology ; Immunoglobulin G ; blood ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; genetics ; immunology ; Schistosoma japonicum ; genetics ; metabolism ; Schistosomiasis japonica ; prevention & control ; Vaccines ; immunology

Diagnosis of scrub typhus is difficult because its symptoms are very similar to other acute febrile illnesses, such as leptospirosis, murine typhus, and other viral hemorrhagic fevers. To differentiate scrub typhus from other acute febrile diseases, a rapid and reliable serological diagnosis is important. We have developed a chimeric recombinant antigen cr56 and two other recombinant antigens, r21 and kr56, from various serotypes of Orientia tsutsugamushi. They were tested for the detection of antibodies against O. tsutsugamushi in the patient's serum samples using enzyme-linked immunosorbent assay (ELISA) and dot-blot analyses. As of conventional immunofluorescence assay (IFA), when the mixture of these three recombinant antigens was used, both sensitivity and specificity of the recombinant antigens were increased up to 98% in IgM and IgG at ELISA and dot blotting. Additionally, both sensitivity and specificity by detection of IgM and IgG antibodies at rapid diagnostic test (RDT), using the mixture of three antigens and gold conjugated antibodies, were 99%. Our results suggest the use of mixture of these recombinant antigen proteins in ELISA or RDT is suitable as a diagnostic test for scrub typhus.
Antibodies, Bacterial/blood/chemistry/immunology ; Antigens, Bacterial/diagnostic use/genetics/metabolism ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique, Indirect ; Gold/chemistry ; Humans ; Immunoassay ; Immunoglobulin G/blood ; Immunoglobulin M/blood ; Orientia tsutsugamushi/immunology/*metabolism ; Recombinant Proteins/biosynthesis/diagnostic use/genetics ; Scrub Typhus/*diagnosis ; Sensitivity and Specificity ; Serotyping