title: Titers of antibody to common pathogens: relation to food-based interventions in rural Kenyan schoolchildren.
abstract: BACKGROUND
  Undernutrition is widely perceived to affect the development of an effective immune system.
  
  
  OBJECTIVE
  We used a mini-analysis system to quantitate antibody titers and evaluate the sera of 200 Kenyan schoolchildren for antibodies to Helicobacter pylori [isotypes of immunoglobulins A (IgA), G (IgG), and M (IgM)], hepatitis A virus, rotavirus, tetanus toxoid (IgG), and a panel of recombinant malarial antigens (MSP1(19), MSP2, Ag512, MSP4, and MSP5).
  
  
  METHODS
  Children participated in a school-based feeding intervention with meat, milk, or nonanimal-source foods or in a nonintervention control group. Microvolumes (200 mL) of sera were analyzed at baseline and after 1 y.
  
  
  RESULTS
  Nearly all children had elevated titers of antibody to H. pylori, hepatitis A virus, rotavirus, and malaria at the outset, despite a high prevalence of apparent biochemical micronutrient deficiencies and stunting, but many had titers of tetanus toxoid IgG antibodies below the protective concentration. Children with low hemoglobin had a greater proportion of elevated H. pylori IgM antibody titers at baseline, which suggests that current infection with H. pylori may be associated with anemia. Compared with the control subjects, only the group eating meat had a significant increase in H. pylori IgM antibodies during the intervention (P = 0.019). No other group comparisons with the control subjects were statistically significant. The additional finding that the sera of some children showed inadequate tetanus-protective antibodies, despite immunization, suggests that the vaccination program was suboptimal.
  
  
  CONCLUSIONS
  A large battery of immune assays can be performed on microvolumes of sera. Furthermore, despite evidence of malnutrition, children do develop significant antibody-mediated responses to common pathogens.
authors.affiliation: Department of Nutrition, University of California, Davis 95616, USA.
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Siekmann
authors.forename: Lindsay H
authors.initials: LH
authors.lastname: Allen
authors.forename: Mitchell R
authors.initials: MR
authors.lastname: Watnik
authors.forename: Penelope
authors.initials: P
authors.lastname: Nestel
authors.forename: Charlotte G
authors.initials: CG
authors.lastname: Neumann
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Shoenfeld
authors.forename: James B
authors.initials: JB
authors.lastname: Peter
authors.forename: Meeta
authors.initials: M
authors.lastname: Patnik
authors.forename: Aftab A
authors.initials: AA
authors.lastname: Ansari
authors.forename: Ross L
authors.initials: RL
authors.lastname: Coppel
authors.forename: M Eric
authors.initials: ME
authors.lastname: Gershwin
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D000914:Antibodies, Viral / Q000096:biosynthesis*; D016022:Case-Control Studies; D002648:Child; D015362:Child Nutrition Disorders / Q000178:diet therapy / Q000276:immunology*; D002675:Child, Preschool; D004032:Diet; D005260:Female; D005293:Ferritins / Q000097:blood; D016480:Helicobacter pylori / Q000276:immunology* / Q000472:pathogenicity; D006801:Humans; D007630:Kenya; D008297:Male; D009752:Nutritional Status; D012424:Rural Population
chemical_list: D000907:Antibodies, Bacterial; D000914:Antibodies, Viral; D005293:Ferritins