Prevalence of Helicobacter pylori in HIV-infected, HAART-naïve Ugandan children: a hospital-based survey

<p>Abstract</p> <p>Background</p> <p>The aim of this survey was to determine the prevalence of and factors associated with <it>Helicobacter pylori </it>(<it>H. pylori</it>) colonization in HIV-infected, highly active antiretroviral therapy-naïve Ugandan children aged 0-12 years.</p> <p>Methods</p> <p>In a hospital-based survey, 236 HIV-infected children were tested for <it>H. pylori </it>colonization using a faecal antigen test. A standardized interview with socio-demographic information and medical history was used to assess risk factors. A cluster of differentiation 4 (CD4) cell percentage was prevalent in most children.</p> <p>Results</p> <p>The overall prevalence of <it>H. pylori </it>in the HIV-infected children was 22.5%. Age-specific prevalence was as follows: up to one year, 14.7%; 1-3 years, 30.9%; and 3-12 years, 20.7%. HIV-infected children who were more seriously affected by their disease (low CD4 cell percentage or WHO clinical stage II-IV) were less likely to be colonized with <it>H. pylori</it>. There was a trend for a lower prevalence of <it>H. pylori </it>in children who had taken antibiotics for the preceding two weeks (21.6%) than in those who had not taken antibiotics (35.7%). There was no statistically significant difference in prevalence by gender, housing, congested living, education of the female caretaker, drinking water or toilet facilities.</p> <p>Conclusions</p> <p>HIV-infected, HAART-naïve Ugandan children had a lower prevalence of <it>H. pylori </it>colonization compared with apparently healthy Ugandan children (44.3%). Children with a low CD4 cell percentage and an advanced clinical stage of HIV had an even lower risk of <it>H. pylori </it>colonization. Treatment with antibiotics due to co-morbidity with infectious diseases is a possible explanation for the relatively low prevalence.</p

Faecal calprotectin concentrations in apparently healthy children aged 0-12 years in urban Kampala, Uganda: a community-based survey

<p>Abstract</p> <p>Background</p> <p>Calprotectin is a calcium and zinc binding protein, abundant in neutrophils and is extremely stable in faeces. Faecal calprotectin is used as a non-specific marker for gastrointestinal inflammation. It has a good diagnostic precision to distinguish between irritable bowel syndrome and inflammatory bowel disease. Studies have established normal concentrations in healthy children; all these studies have been performed in high-income countries. The objective of this study was to determine the concentration of faecal calprotectin in apparently healthy children aged 0-12 years in urban Kampala, Uganda.</p> <p>Method</p> <p>We tested 302 apparently healthy children aged, age 0-12 years (162 female, 140 male) in urban Kampala, Uganda. The children were recruited consecutively by door-to-door visits. Faecal calprotectin was analyzed using a quantitative enzyme-linked immunosorbent assay. Faeces were also tested for <it>Helicobacter pylori (H. pylori) </it>antigen, for growth of enteropathogens and microscopy was performed to assess protozoa and helminths. A short standardized interview with socio-demographic information and medical history was obtained to assess health status of the children.</p> <p>Results</p> <p>In the different age groups the median faecal calprotectin concentrations were 249 mg/kg in 0 < 1 year (n = 54), 75 mg/kg in 1 < 4 years (n = 89) and 28 mg/kg in 4 < 12 years (n = 159). There was no significant difference in faecal calprotectin concentrations and education of female caretaker, wealth index, gender, habits of using mosquito nets, being colonized with <it>H. pylori </it>or having other pathogens in the stool.</p> <p>Conclusion</p> <p>Concentrations of faecal calprotectin among healthy children, living in urban Ugandan, a low-income country, are comparable to those in healthy children living in high-income countries. In children older than 4 years, the faecal calprotectin concentration is low. In healthy infants faecal calprotectin is high. The suggested cut-off concentrations in the literature can be used in apparently healthy Ugandan children. This finding also shows that healthy children living under poor circumstances do not have a constant inflammation in the gut. We see an opportunity to use this relatively inexpensive test for further understanding and investigations of gut inflammation in children living in low-income countries.</p

Regulation of ion transport in the gastrointestinal tract : aspects of early development

Ion transport in the gastrointestinal tract is vital for cellular homeostasis and to ensure growth during ontogeny. We have therefore investigated the regulation and maturation of sodium, potassium and hydrogen transport in the gastrointestinal tract. Net jejunal sodium absorption is significantly higher in young as compared to adult rats. During high salt intake, net sodium absorption decreases in young but not in adult rats. When dopamine production was inhibited we did not observe decreased sodium absorption in young rats on high salt diet. The reduced sodium absorption during high salt intake in young rats requires endogenous dopamine action. Net colonic potassium absorption in young rats is five times higher than in adult ones. The majority of colonic net potassium absorption occurs in the distal part of the colon. Using different approaches this study shows that apically located transporters which reabsorb potassium are upregulated in the infant rat while secreting basolateral transporters are upregulated in adult rats. Infant rat H+, K+- ATPase and ouabainsensitive sodium independent ATPase were higher but Na+, K+-ATPase was lower than in the adult rat. Angiotensin II induces potassium secretion in rat distal colon. This effect is mediated through both receptors (AT1, and AT2) and by at least three different pathways (Na+, K+, 2CIcotransporter, the apical barium-sensitive potassium channels and the Na+, K+-ATPase). Rat gastric H+, K+- ATPase matures postnatally. The expression of H+, K+-ATPase increases from day 10. Gastric H+, K+- ATPase increased 2.5-fold when 10-day-old rats were treated with a single dose of glucocorticoids. A study of human gastric H+, K+- ATPase enzyme was performed on biopsies from neonates. The amount of H+, K- ATPase increases in relation to gestational and postnatal age. Boys have a significantly higher amount than girls. This is the first study on a large number of infants showing that gastric H+, K+- ATPase is present before term birth and that it increases during development. Conclusion: In summary, these studies of ion transport in the gastrointestinal tract show new mechanisms that ensure proper regulation of sodium, potassium and hydrogen transport during development. We have found that glucorticoids and dopamine have specific actions on ion transport during early development. In addition we have found that angiotensin II regulates colonic potassium transport in a complex manner

Antibodies Against Deamidated Gliadin Peptides and Tissue Transglutaminase for Diagnosis of Pediatric Celiac Disease - Diagnostic Performance and Cost in Clinical Practice.

OBJECTIVES: To evaluate diagnostic performance and actual costs in clinical practice of IgG/IgA deamidated gliadin peptide antibodies (DGP) as a complement to IgA antibodies against tissue transglutaminase (tTG) for the diagnosis of pediatric celiac disease (CD). PATIENTS AND METHODS: All consecutive patients <18 years tested for tTG and/or DGP and who underwent duodenal biopsy because of suspected CD in Stockholm and Gothenburg, Sweden, 2008-2010 were included. Medical records were reviewed. RESULTS: Of 537 children who underwent duodenal biopsy, 278(52%) had CD. 71(13%) were <2 years and 13(4%) had IgA deficiency. Sensitivity and specificity for tTG was 94% and 86% respectively. Corresponding values for DGP was 91% and 26%. Positive predictive values (PPV) were 88% for tTG and 51% for DGP. There were 148 children who were tTG negative and DGP positive, of which only 5%(8/148) had villous atrophy. Among children <2 years with normal IgA, PPV was 96%(25/26) for tTG and 48%(24/50) for DGP. In 13 IgA deficient children 9 were DGP positive of which 4 had CD (PPV 44%). 8/278 cases of CD would possibly have been missed without DGP. The cost of adding DGP and consequently more biopsies to be able to detect 8 extra cases of CD was &OV0556;399,520 or &OV0556;49,940 per case. CONCLUSION: For diagnosing CD, tTG is superior to DGP, even in children <2 years. Combining tTG and DGP does not provide a better trade off between number of missed cases of CD, number of unnecessary duodenal biopsies and cost than tTG alone

Tissue transglutaminase autoantibodies in children with newly diagnosed type 1 diabetes are related to human leukocyte antigen but not to islet autoantibodies : A Swedish nationwide prospective population-based cohort study

OBJECTIVES: This study explored the association between tissue transglutaminase autoantibody (tTGA), high-risk human leucocyte antigen (HLA) genotypes and islet autoantibodies in children with newly diagnosed type 1 diabetes (T1D).PATIENTS AND METHODS: Dried blood spots and serum samples were taken at diagnosis from children <18 years of age participating in Better Diabetes Diagnosis (BDD), a Swedish nationwide prospective cohort study of children newly diagnosed with T1D. We analyzed tTGA, high-risk HLA DQ2 and DQ8 (DQX is neither DQ2 nor DQ8) and islet auto-antibodies (GADA, IA-2A, IAA, and three variants of Zinc transporter; ZnT8W, ZnT8R, and ZnT8QA).RESULTS: Out of 2705 children diagnosed with T1D, 85 (3.1%) had positive tTGA and 63 (2.3%) had borderline values. The prevalence of tTGA was higher in children with the HLA genotypes DQ2/2, DQ2/X or DQ2/8 compared to those with DQ8/8 or DQ8/X (p = .00001) and those with DQX/X (p ≤ .00001). No significant differences were found in relation to islet autoantibodies or age at diagnosis, but the presence of tTGA was more common in girls than in boys (p = .018).CONCLUSION: tTGA at T1D diagnosis (both positive and borderline values 5.4%) was higher in girls and in children homozygous for DQ2/2, followed by children heterozygous for DQ2. Only children with DQ2 and/or DQ8 had tTGA. HLA typing at the diagnosis of T1D can help to identify those without risk for CD

Helicobacter pylori in apparently healthy children aged 0-12 years in urban Kampala, Uganda: a community-based cross sectional survey

Background Helicobacter pylori is one of the most common causes of bacterial infection in human beings. Studies have showed a high prevalence of Helicobacter pylori among people in low-income countries and colonization early in life. A monoclonal antigen test, performed on faeces, HpSA®ImmunoCardSTAT, has a high sensitivity, specificity and accuracy and the faecal test can be performed in all ages, also in resource-limited settings. The main objective of this study was to determine the prevalence and factors associated with Helicobacter pylori colonization in apparently healthy children aged 0-12 years in urban Kampala, Uganda. Method We tested 427 apparently healthy children, age 0-12 years (211 males, 216 females), in a cross sectional survey for Helicobacter pylori colonization using HpSA ®ImmunoCardSTAT. A short standardized interview with socio-demographic information and medical history was used to assess risk factors. Results The overall prevalence of Helicobacter pylori in the 427 children was 44.3% (189 out of 427). Early colonization was common, 28.7%, in children younger than 1 year of age. The age specific rates were 46.0% in children age 1- < 3 years, 51.7% in children age 3- < 6 years, 54.8% in children age 6- < 9 years and 40.0% in children age 9- < 12 years. There was a significant difference in prevalence by gender; female 38.5% versus male 49.8% and by type of housing; permanent house 38.5% versus semi-permanent house 48.6%. Congestive living and education level of the female caretaker showed a clear trend for a difference in prevalence. Factors independently associated with Helicobacter pylori colonization included: drugs taken last three months, using a pit latrine, sources of drinking water and wealth index. Conclusion The prevalence of Helicobacter pylori colonization among urban Ugandan children is high at an early age and increases with age. The impact of Helicobacter pylori colonization on children's health in Uganda needs to be further clarified