Changes in Seroprevalence of Helicobacter pylori Infection over 20 Years in Jinju, Korea, from Newborns to the Elderly.

BACKGROUND: The objective of this study was to examine changes in the prevalence of cytotoxic-associated gene A (CagA) positive Helicobacter pylori infection in Jinju, Korea, over the last 20 years. METHODS: Three cross-sectional analyses were conducted concurrently. A total of 1,305 serum samples were collected from 1994-1995, 2004-2005, and 2014-2015, respectively. The presence of immunoglobulin (Ig) G, IgA, and IgM antibodies against H. pylori CagA protein was examined by western blotting. RESULTS: Overall, seropositivity for anti-CagA IgG antibody was significantly decreased from 63.2% to 42.5% over the last 20 years (P < 0.001). Anti-CagA IgG seropositivities in children and young adults aged 10-29 years decreased from 1994 (60.0%-85.0%) to 2015 (12.5%-28.9%). The age when plateau of increasing IgG seropositivity was reached in each study period shifted from the 15-19 year-old group in 1994-1995 (85.0%) to the 40-49 year-old group in 2014-2015 (82.5%). Overall seropositive rates of anti-CagA IgA and IgM antibodies did not change significantly either over the last 20 years. CONCLUSION: H. pylori infection rate in children and young adults declined over 20 years in Jinju, probably due to improved sanitation, housing, or economy.

A Pilot Study Evaluating Cerebral Vasculitis in Kawasaki's Disease.

Cerebral vasculitis is thought to be a possible underlying mechanism of severe neurological complications of Kawasaki's disease (KD), such as cerebral infarct or aneurysm rupture. To evaluate the intracranial inflammatory response in patients with acute-stage KD, we measured the levels of cytokines (interleukin [IL]-6 and tumor necrosis factor [TNF]-α) and pentraxin-3 (PTX3) in the cerebrospinal fluid of patients with KD (n = 7) and compared the levels to those of the age- and sex-matched febrile control patients (bacterial meningitis [n = 5], enteroviral meningitis [n = 10], nonspecific viral illness without central nervous system involvement [n = 10]). PTX3 and TNF-α were rarely detected and only in trace concentration in KD, and the levels of IL-6 were not different from those of nonspecific viral illnesses. These mediators are not established biomarkers for cerebral vasculitis but might reflect vascular inflammation in various diseases including KD. Therefore, intracranial inflammation including vasculitis seems to be insignificant in our patients with KD. However, our results might be attributed to the fact that these patients lacked any clinical signs of cerebral or coronary vessel involvement. None of them underwent brain imaging. To clarify this issue, further studies involving patients with neurologic symptoms and proven involvement of cerebral vessels are needed.

Helicobacter pylori Antigens Inducing Early Immune Response in Infants.

To identify the Helicobacter pylori antigens operating during early infection in sera from infected infants using proteomics and immunoblot analysis. Two-dimensional (2D) large and small gel electrophoresis was performed using H. pylori strain 51. We performed 2D immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin M (IgM) antibody immunoblotting using small gels on sera collected at the Gyeongsang National University Hospital from 4-11-month-old infants confirmed with H. pylori infection by pre-embedding immunoelectron microscopy. Immunoblot spots appearing to represent early infection markers in infant sera were compared to those of the large 2D gel for H. pylori strain 51. Corresponding spots were analyzed by matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MALDI-TOF-MS). The peptide fingerprints obtained were searched in the National Center for Biotechnology Information (NCBI) database. Eight infant patients were confirmed with H. pylori infection based on urease tests, histopathologic examinations, and pre-embedding immunoelectron microscopy. One infant showed a 2D IgM immunoblot pattern that seemed to represent early infection. Immunoblot spots were compared with those from whole-cell extracts of H. pylori strain 51 and 18 spots were excised, digested in gel, and analyzed by MALDI-TOF-MS. Of the 10 peptide fingerprints obtained, the H. pylori proteins flagellin A (FlaA), urease ß subunit (UreB), pyruvate ferredoxin oxidoreductase (POR), and translation elongation factor Ts (EF-Ts) were identified and appeared to be active during the early infection periods. These results might aid identification of serological markers for the serodiagnosis of early H. pylori infection in infants.

Correlations between the CagA Antigen and Serum Levels of Anti-Helicobacter pylori IgG and IgA in Children.

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.

Immunohistochemical Expressions of MUC2, MUC5AC, and MUC6 in Normal, Helicobacter pylori Infected and Metaplastic Gastric Mucosa of Children and Adolescents.

OBJECTIVES: The aim of this study was to investigate expression of gastric mucins in children and adolescents and to assess their relations with age and Helicobacter pylori (H. pylori) infection. METHODS: Gastric biopsies were collected from 259 pediatric and adulthood patients with gastrointestinal symptoms among all of patients undergone gastroduodenoscopy from 1990 to 2004 at Gyeongsang National University hospital and assorted based on H. pylori infection, age, and intestinal metaplasia as follows; H. pylori infection before 5 years of age or not, H. pylori infection between 5 and 9 years of age or not, H. pylori infection between 10 and 14 years of age or not, H. pylori infection between 20 and 29 years of age or not and intestinal metaplasia between 21 and 35 years of age. Total 810 tissue slides from the subjects were examined regarding expressions of Mucin2 (MUC2), Mucin5AC (MUC5AC), and Mucin6 (MUC6) in nine groups using immunohistochemical stains. A semiquantitative approach was used to score the staining extent of tissue slide. RESULTS: Increased expressions of MUC2, MUC5AC, and MUC6 were noted in intestinal metaplasia compared with subjects infected with H. pylori between 20 and 29 years. Gastric expressions of MUC5AC were decreased in older than 5 years with H. pylori compared with in older than 5 years without H. pylori (p < .001). Expressions of MUC2 and MUC6 did not change significantly by H. pylori status. Some nuclear expressions of MUC2 and MUC6 were noted in children without intestinal metaplasia. CONCLUSIONS: MUC5AC might be affected by chronic H. pylori infection. In addition to biomarkers for intestinal metaplasia or prognostic factors for gastric cancer in adults, MUC2 and MUC6 in children might have an another role, based on ectopic gastric nuclear expressions of MUC2 and MUC6 in children without intestinal metaplasia.

Mediation Effect of Social Distancing on Neonatal Vitamin D Status and Related Clinical Outcomes during the Coronavirus Disease-19 Pandemic.

BACKGROUND: We analyzed the impact of social distancing (SD) on vitamin D status and associated morbidity in neonates during the coronavirus disease (COVID-19) pandemic. METHODS: Serum levels of 25-hydroxy vitamin D (25OHD) and clinical characteristics of newborn infants before (2019) and during SD (2021) were compared. RESULTS: A total of 526 neonates (263 in 2019 and 263 in 2021) were included. The rate of vitamin D deficiency in neonates (47.1% vs. 35.4 %, p = 0.008) decreased and the rate of maternal vitamin D intake increased (6.8% vs. 37.6%, p < 0.001), respectively, during SD compared to those in 2019. The rates of hypocalcemia (12.5% vs. 3.8%, p < 0.001) and respiratory illness (57.0% vs. 43.0%, p = 0.002) decreased during SD. Neonatal vitamin D deficiency during SD was associated with maternal vitamin D supplementation (odds ratio [OR] = 0.463, p = 0.003) but was not associated with SD (OR = 0.772, p = 0.189). The mediation effect of SD on neonatal morbidity by neonatal vitamin D status was statistically insignificant. CONCLUSIONS: SD might affect the increased maternal vitamin D intake and decreased neonatal vitamin D deficiency. However, neonatal morbidity was not affected by SD, even with neonatal vitamin D status changes.

Identification of Autoantigens in Pediatric Gastric Juices.

Purpose: This study aimed to investigate the presence of autoantigens in the gastric juices of children. Methods: Gastric juice and serum samples were obtained from 53 children <15 years of age who underwent gastric endoscopy. Among these, 8, 22, and 23 participants were in the age groups 0-5, 6-10, and 11-15 years, respectively. These samples were analyzed using two-dimensional electrophoresis (2-DE), immunoblot analysis, and matrix-assisted laser desorption ionization-time of-flight mass spectrometry. Furthermore, we reviewed the histopathological findings and urease test results and compared them with the results of 2-DE and immunoblot analysis. Results: There were no statistically significant differences in urease test positivity, grades of chronic gastritis, active gastritis, or Helicobacter pylori infiltration of the antrum and body among the three age groups. Three distinct patterns of gastric juice were observed on 2-DE. Pattern I was the most common, and pattern III was not observed below the age of 5 years. Histopathological findings were significantly different among active gastritis (p=0.037) and H. pylori infiltration (p=0.060) in the gastric body. The immunoblots showed large spots at an approximate pH of 3-4 and molecular weights of 31-45 kDa. These distinct, large positive spots were identified as gastric lipase and pepsin A and C. Conclusion: Three enzymes, which are normally secreted under acidic conditions were identified as autoantigens. Further investigation of the pathophysiology and function of autoantigens in the stomach is required.

Changing pattern of antibiotic resistance of Helicobacter pylori in children during 20 years in Jinju, South Korea.

BACKGROUND: The antimicrobial resistance capability of Helicobacter pylori is one of the critical factors in the failure to treat this pathogen. The purpose of this study was to investigate the changing pattern of primary antibiotic resistance rates in children in the southern central part of South Korea from 1990 to 2009. METHODS: H. pylori strains were isolated from children who had undergone upper endoscopy at Gyeongsang National University Hospital, including 58 children from 1990-1994 and 33 children from 2005-2009. The susceptibility of H. pylori strains to erythromycin, clarithromycin, azithromycin, amoxicillin, tetracycline, metronidazole, furazolidone, levofloxacin, ciprofloxacin, moxifloxacin, and rifabutin was tested using the serial twofold agar dilution method. RESULTS: The resistance rate to erythromycin increased significantly from 13.8% in 1990-1994 to 33.3% in 2005-2009 (P = 0.032). Clarithromycin resistance increased from 6.9% to 18.2%. Metronidazole resistance decreased from 32.8% to 27.3%. The minimum inhibitory concentration of azithromycin and erythromycin showed definite shifts to higher concentrations in 2005-2009 compared with the strains sampled in 1990-1994 (P = 0.021 and P = 0.025, respectively). The frequency of both macrolide- and metronidazole-resistant strains was 13.8% in 1990-1994 and 15.2% in 2005-2009. No associations were detected between multidrug-resistant strains and the two study periods. CONCLUSIONS: The antibiotic resistance rates of H. pylori in Jinju had a different pattern to other regions. The antibiotic resistance rates of H. pylori showed geographic variation, and local data should be provided as a guideline for treating H. pylori infection.

Changes in anti-group a rotavirus antibody seroprevalence and levels in the Western Gyeongnam province of Korea over 16 years.

To observe how anti-group A rotavirus antibody seropositivity rates and levels have changed in the western region of Gyeongnam Province, 2,030 serum samples collected at four collection periods (1989-1990, 1994-1995, 1999-2000, and 2004-2005) were tested by Enzyme-Linked Immunosorbent Assay for IgG, and IgA antibodies reacting to recombinant VP6 protein. The seroprevalences exhibit no regular patterns over a 16-yr period. For all four collection periods, the anti-rVP6 IgG levels rose steadily during the first 5 months of life, after which they remained high. However, the 2-9 yr and 10-39 yr groups had significantly higher IgG levels in 1999-2000 and 2004-2005, respectively, than in the other collection periods. The 1-5 mo, 40- ≥ 60 yr, and 4-29 yr groups had significantly higher IgA levels in 1989-1990, 1999-2000, and 2004-2005, respectively. The 4 yr (25.0%), 5-9 yr (18.8%), 10-14 yr (41.1%), 20-29 yr (35.0%), and 30-39 yr (20.0%) groups in 2004-2005 had significant higher IgA seropositivity rate compared to the other three collection periods. These observations suggest that in the western region of Gyeongnam Province since the late 1990s, rotavirus reinfection has occurred more frequently than previously, with all ages being at risk.

The Optimal Time for Initiating Probiotics for Preterm and Very-Low-Birth-Weight Infants: A 10-Year Experience in a Single Neonatal Intensive Care Unit.

Purpose: The starting time for probiotic supplementation in preterm infants after birth varies widely. This study aimed to investigate the optimal time for initiating probiotics to reduce adverse outcomes in preterm or very low birth weight (VLBW) infants. Methods: Medical records of preterm infants born at a gestational age (GA) of <32 weeks or VLBW infants in 2011-2020 were reviewed respectively. The infants who received Saccharomyces boulardii probiotics within 7 days of birth were grouped into an early introduction (EI) group, and those who received supplemented probiotics after 7 days of birth were part of the late introduction (LI) group. Clinical characteristics were compared between the two groups and analyzed statistically. Results: A total of 370 infants were included. The mean GA (29.1 weeks vs. 31.2 weeks, p<0.001) and birth weight (1,235.9 g vs. 1491.4 g, p<0.001) were lower in the LI group (n=223) than in the EI group. The multivariate analysis indicated that factors affecting the LI of probiotics were GA at birth (odds ratio [OR], 1.52; p<0.001) and the enteral nutrition start day (OR, 1.47; p<0.001). The late probiotic introduction was associated with a risk of late-onset sepsis (OR, 2.85; p=0.020), delayed full enteral nutrition (OR, 5.44; p<0.001), and extrauterine growth restriction (OR, 1.67; p=0.033) on multivariate analyses after adjusting for GA. Conclusion: Early supplementation of probiotics within a week after birth may reduce adverse outcomes among preterm or VLBW infants.

Difference in macrophage migration inhibitory factor between preterm and term newborns and associating clinical factors: Preliminary study.

This study aimed to investigate the macrophage migration inhibitory factor (MIF) and associated clinical factors in neonates. Clinical information and blood samples were obtained from 77 neonates. Clinical details were reviewed from medical records, and MIF was measured by enzyme-linked immunosorbent assay using blood samples acquired within a week after birth. Statistical analyses were performed between plasma MIF concentration and clinical factors. Among the 77 newborn infants, 25 were born at <34 weeks of gestation (preterm), 25 at 34 to 37 weeks (late preterm), and 27 at term gestation. The mean MIF was 9849.5 ± 7187.8 pg/mL in preterm, 5718.7 ± 4596.4 in late preterm, and 5361.1 ± 3895.7 in term infants (P = .016). Among 25 preterm infants born at <34 weeks of gestation, MIF was significantly higher in infants with necrotizing enterocolitis (NEC, 19,478.6 ± 8162.4 pg/mL, n = 5) than that in infants without NEC (feeding intolerance 7173.7 ± 4203.0 pg/mL, n = 12 and others 7844.9 ± 5311.2 pg/mL, n = 8, P = .020). Elevated plasma MIF levels in the transitional period were significantly associated with preterm birth before 34 weeks of gestation and the development of NEC.

Antigenic Determinant of Helicobacter pylori FlaA for Developing Serological Diagnostic Methods in Children.

The early diagnosis of Helicobacter pylori infection is important for gastric cancer prevention and treatment. Although endoscopic biopsy is widely used for H. pylori diagnosis, an accurate biopsy cannot be performed until a lesion becomes clear, especially in pediatric patients. Therefore, it is necessary to develop convenient and accurate methods for early diagnosis. FlaA, an essential factor for H. pylori survival, shows high antigenicity and can be used as a diagnostic marker. We attempted to identify effective antigens containing epitopes of high diagnostic value in FlaA. Full-sized FlaA was divided into several fragments and cloned, and its antigenicity was investigated using Western blotting. The FlaA fragment of 1345-1395 bp had strong immunogenicity. ELISA was performed with serum samples from children by using the 1345-1395 bp recombinant antigen fragment. IgG reactivity showed 90.0% sensitivity and 90.5% specificity, and IgM reactivity showed 100% sensitivity and specificity. The FlaA fragment of 1345-1395 bp discovered in the present study has antigenicity and is of high value as a candidate antigen for serological diagnosis. The FlaA 1345-1395 bp epitope can be used as a diagnostic marker for H. pylori infection, thereby controlling various gastric diseases such as gastric cancer and peptic ulcers caused by H. pylori.

A20 suppresses inflammatory responses and bone destruction in human fibroblast-like synoviocytes and in mice with collagen-induced arthritis.

OBJECTIVE: Nuclear factor-kappaB (NF-kappaB) has been implicated as a therapeutic target for the treatment of rheumatoid arthritis (RA). The purpose of this study was to determine whether A20, a universal inhibitor of NF-kappaB, might have antiarthritic effects. METHODS: An adenovirus containing A20 complementary DNA (AdA20) was used to deliver A20 to human rheumatoid fibroblast-like synoviocytes (FLS) in vitro as well as to mice with collagen-induced arthritis (CIA) in vivo via intraarticular injection into the ankle joints bilaterally. RESULTS: In vitro experiments demonstrated that AdA20 suppressed NF-kappaB activation, chemokine production, and matrix metalloproteinase secretion induced by tumor necrosis factor alpha in FLS. Mice with CIA that were treated with AdA20 had a lower cumulative disease incidence and severity of arthritis, based on hind paw thickness, radiologic and histopathologic findings, and inflammatory cytokine levels, than did control virus-injected mice. The protective effects of AdA20 were mediated by the inhibition of the NF-kappaB signaling pathway. The severity of arthritis was also significantly decreased in the untreated front paws, indicating a beneficial systemic effect of local suppression of NF-kappaB. Surprisingly, mice treated with AdA20 after the onset of CIA had significantly decreased arthritis severity from the onset of clinical signs to the end of the study. CONCLUSION: These results suggest that using A20 to block the NF-kappaB pathway in rheumatoid joints reduces both the inflammatory response and the tissue destruction. The development of an immunoregulatory strategy based on A20 may therefore have therapeutic potential in the treatment of RA.

Vascular endothelial growth factor stimulates osteoblastic differentiation of cultured human periosteal-derived cells expressing vascular endothelial growth factor receptors.

Angiogenesis plays an important role in bone development and postnatal bone fracture repair. Vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptors (VEGFRs) are primarily involved in angiogenesis. This study investigated the expression of VEGF isoforms, VEGFR-1, and VEGFR-2 during the osteoblastic differentiation of cultured human periosteal-derived cells. In addition, the effect of exogenous VEGF on the osteoblastic differentiation of cultured human periosteal-derived cells was also examined. The expression of the VEGF isoforms (VEGF(121), VEGF(165), VEGF(189), and VEGF(206)), VEGFR-1, and VEGFR-2 was observed in the periosteal-derived cells. Administration of KRN633, a VEGFR-1 and VEGFR-2 inhibitor, decreased the alkaline phosphatase (ALP) activity during the osteoblastic differentiation of cultured human periosteal-derived cells. However, the administration of VEGFR2 Kinase Inhibitor IV, a VEGFR-2 inhibitor, did not affect the ALP activity. The addition of recombinant human VEGF(165) elevated the ALP activity and increased the calcium content in the periosteal-derived cells. Treating the periosteal-derived cells with recombinant human VEGF(165) resulted in an increase in Runx2 transactivation in the periosteal-derived cells. These results suggest that exogenous VEGF stimulates the osteoblastic differentiation of cultured human periosteal-derived cells and VEGF might act as an autocrine growth factor for the osteoblastic differentiation of cultured human periosteal-derived cells.

Dietary alpha lipoic acid supplementation prevents synovial inflammation and bone destruction in collagen-induced arthritic mice.

Rheumatoid arthritis (RA) is a chronic inflammatory disorder characterized by chronic inflammation and joint destruction. In this study, we investigated whether dietary supplementation with alpha lipoic acid (ALA) suppresses collagen-induced arthritis (CIA) in mice. Mice were randomly divided into three groups: (1) a control CIA group was fed a normal diet, (2) a CIA group was fed a 0.1% ALA diet (average ALA intake of 160 mg/kg/day), and (3) a CIA group was fed a 0.5% ALA diet (average ALA intake of 800 mg/kg/day). The ALA-fed mice showed a decreased incidence and severity of arthritis compared to the normal diet group. Radiographic findings revealed a dramatic decrease in bone destruction, and histological findings showed extensively suppressed pathological changes in the ALA-fed mice. The ALA-fed mice exhibited inhibited generation of tartrate resistant acid phosphatase (TRAP)-positive osteoclasts in vivo. Additionally, ALA-fed mice reduced production of various proinflammatory cytokines and the soluble receptor activator of NF-κB ligand (sRANKL) in the joint tissues and the sera. In conclusion, dietary supplementation with ALA attenuated inflammatory responses and bone destruction in CIA mice.

Changing prevalence of Helicobacter pylori infection in children and adolescents.

Helicobacter pylori infection has declined over recent decades. However, its prevalence remains high, and nearly 50% of the global population has been infected. In Korea, seroprevalence has steadily decreased in adults, but the status of H. pylori infection in children is unknown. The current status or trend of H. pylori infection in children is important because it can help estimate H. pylori-related diseases including gastric cancer in later life. In this review, the authors discuss the change in H. pylori infection rate among children and adolescents based on literature reviews and our research.

Changes in the Treatment Strategies for Helicobacter pylori Infection in Children and Adolescents in Korea.

The policies developed for the treatment of Helicobacter pylori infection in adults may not be the most suitable ones to treat children and adolescents. Methods used to treat children and adolescents in Europe and North America may not be appropriate for treating children and adolescents in Korea due to differences in epidemiological characteristics of H. pylori between regions. Moreover, the agreed standard guidelines for the treatment of H. pylori infection in children and adolescents in Korea have not been established yet. In this study, the optimal treatment strategy for H. pylori infection control in children and adolescents in Korea is discussed based on these guidelines, and recent progress on the use and misuse of antimicrobial agents is elaborated. Non-invasive as well as invasive diagnostic test and treatment strategy for H. pylori infection are not recommendable in children aged less than ten years or children with body weight under 35 kg, except in cases of clinically suspected or endoscopically identified peptic ulcers. The uncertainty, whether enough antimicrobial concentrations to eradicate H. pylori can be maintained when administered according to body weight-based dosing, and the costs and adverse effects outweighing the anticipated benefits of treatment make it difficult to decide to eradicate H. pylori in a positive non-invasive diagnostic test in this age group. However, adolescents over ten years of age or with a bodyweight of more than 35 kg can be managed aggressively as adults, because they can tolerate the adult doses of anti-H. pylori therapy. In adolescents, the prevention of future peptic ulcers and gastric cancers is expected after the eradication of H. pylori. Bismuth-based quadruple therapy (bismuth-proton pump inhibitor-amoxicillin/tetracycline-metronidazole) with maximal tolerable doses and optimal dose intervals of 14 days is recommended, because in Korea, the antibiotic susceptibility test for H. pylori is not performed at the initial diagnostic evaluation. If the first-line treatment fails, concomitant therapy plus bismuth can be attempted for 14 days as an empirical rescue therapy. Finally, the salvage therapy, if needed, must be administered after the H. pylori antibiotic susceptibility test.

NSP4 antibody levels in rotavirus gastroenteritis patients with seizures.

BACKGROUND: Rotavirus nonstructural protein 4 (NSP4) has been suggested as a pathogen of rotavirus-associated seizures. We investigated pre-existing serum antibodies against NSP4 and VP6 (the most highly immunogenic rotavirus protein) in patients with rotavirus gastroenteritis and its correlation with the occurrence of seizures. METHODS: With an enzyme-linked immunosorbent assay, IgG and IgA titers against NSP4 (genotype [A] and [B]) and VP6 were measured in acute-phase sera of 202 children aged 0.5-6.0 years with rotavirus gastroenteritis. The clinical characteristics and antibody levels were compared between patients with (seizure group) and without seizures (non-seizure group). RESULTS: The non-seizure and seizure groups comprised 173 and 29 patients, respectively. Age, sex, hospital stay, presence of fever, white blood cell counts, C-reactive protein, vaccine status, IgG/IgA titers for VP6, and IgA titers for both NSP4s did not differ between the groups. The seizure group showed a lower level of IgG against NSP4 [A] (184.5 vs. 163.0 U/mL; P = 0.03) and NSP4 [B] (269.0 vs. 196.0 U/mL; P = 0.02). Delayed sampling time from the onset of gastroenteritis symptoms (3 vs. 2 days; P = 0.02) and lower serum sodium level (133.4 vs. 136.3 mEq/L; P < 0.01) were observed in the seizure group. Even after adjusting these factors, anti-NSP4 [A] IgG (OR 2.56 per 100 U/mL increment; 95% CI, 1.20-5.26, P = 0.01) and anti-NSP4 [B] IgG (OR 1.51 per 100 U/mL-increment; 95% CI, 1.04-2.22, P = 0.03) were independently associated with protection against seizures. CONCLUSIONS: Serum anti-NSP4 IgG might protect rotavirus-associated seizures.

Characterizing antigenic determinants in Helicobacter pylori CagA capable of detecting serum antibodies in children.

Helicobacter pylori can persistently colonize the mucosa of the human stomach, resulting in gastric disorders. Endoscopic biopsy for rapid urease test and histopathologic examination are considered as the most accurate diagnostic methods for H. pylori infection. Serological methods are recommended for children because of invasiveness of the diagnosis mentioned above. Here, the cytotoxin-associated gene A protein (Cag A), as an immunodominant antigen, was subdivided to determine which regions harbor antigenicity for humans. CagA was divided into 17 overlapping fragments of ∼400 bp, which were used for the analysis of antigenic determinants. The partial proteins were subjected to immunoblot analysis using pooled serum samples from children with gastric symptoms. A partial recombinant CagA protein containing epitope regions (683-749 amino acids), which were identified in this study, was produced and used for the detection of anti-CagA antibodies and further investigated its serodiagnostic value for determination of H. pylori infection in children. The serum IgG reactivities from children with gastric symptoms were significantly three times more than that of serum samples from children with non-gastric symptoms (P < 0.005). Moreover, the serum IgG reactivities from children showing strong urease activity of gastric biopsies were significantly higher than those with moderate and weak urease activities (P < 0.05). Hence, the partial CagA is a candidate antigen for diagnosis of H. pylori infection.