Abstract
A nephelometric immunoassay was developed to quantify immunoglobulin A (IgA) in children's stools. This method enables IgA in faecal protein extracts to be measured over a large range of concentrations (1.61–51.50 mg/L) with good accuracy (linear recovery in dilution‐overloading assay) and precision (within‐ and between‐run coefficients of variation (CVs) of 1–6%). An excellent recovery (105%) was obtained in stool samples overloaded by purified colostral IgA, demonstrating that the method used for faecal IgA extraction is adapted, not to induce significant IgA degradation, and probably allow a complete extraction of IgA. The amount of faecal IgA, as determined in stool samples from 125 children (6–24 months old), was an average of 14 mg per 100 g of stools (about 10% of the total protein stool content), with large individual variation (3–30 mg per 100 g of stools). No correlation was observed between faecal IgA amounts and the children's age or sex. Such an immunoassay could enable exhaustive noninvasive investigations of the maturation of the intestinal immune system, as well as accurate studies of the effect of oral dietary supplementation on IgA regulation. J. Clin. Lab. Anal. 18:195–199, 2004. © 2004 Wiley‐Liss, Inc.
Keywords: immunoglobulin A, stools, immunoassay
REFERENCES
- 1. Besredka A. 1919. De la vaccination contre les états typhoïdes par la voie buccale. Ann Inst Pasteur 33:882–903. [Google Scholar]
- 2. Davies A. 1922. An investigation into the serological properties of dysentery stools. Lancet ii:1009–1012. [Google Scholar]
- 3. Tomasi TB Jr, Tan EM, Solomon A, Prendergast RA. 1965. Characteristics of an immune system common to certain external secretions. Exp Med 121:101–124. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Jonard PP, Rambaud JC, Dive C, Vaerman JP, Galian A, Delacroix DL. 1984. Secretion of immunoglobulins and plasma proteins from the jejunal mucosa. Transport rate and origin of polymeric immunoglobulin A. J Clin Invest 74:525–535. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5. Brandtzaeg P. 1973. Two types of IgA immunocytes in man. Nat New Biol 243:142–143. [DOI] [PubMed] [Google Scholar]
- 6. Abraham SN, Beachey EH. 1985. Host defenses against adhesion of bacteria to mucosal surfaces In: Gallin JF, Fauci AS, editors. Advances in host defense mechanisms. New York: Raven Press; p 63–88. [Google Scholar]
- 7. Lamm ME. 1997. Interaction of antigens and antibodies at mucosal surfaces. Annu Rev Microbiol 51:311–340. [DOI] [PubMed] [Google Scholar]
- 8. Conley ME, Delacroix DL. 1987. Intravascular and mucosal immunoglobulin A: two separate but related systems of immune defense? Ann Intern Med 106:892–899. [DOI] [PubMed] [Google Scholar]
- 9. Bienenstock J, Befus D. 1984. Gut‐ and bronchus‐associated lymphoid tissue. Am J Anat 170:437–445. [DOI] [PubMed] [Google Scholar]
- 10. Meillet D, Raichvarg D, Tallet F, Savel J, Yonger J, Gobert JG. 1987. Measurement of total, monomeric and polymeric IgA in human faeces by electroimmunodiffusion. Clin Exp Immunol 69:142–147. [PMC free article] [PubMed] [Google Scholar]
- 11. Delacroix DL, Dive C, Rambaud JC, Vaerman JP. 1982. IgA subclasses in various secretions and in serum. Immunology 47:383–385. [PMC free article] [PubMed] [Google Scholar]
- 12. Kilian M, Russell MW. 1994. Function of mucosal immunoglobulins In: Ogra PL, Lamm ME, McGhee JR, Mestecky J, Strober W, Bienenstock J, editors. Handbook of mucosal immunology. New York: Academic Press Inc; p 127–137. [Google Scholar]
- 13. Haworth JC, Dilling L. 1966. Concentration of gA‐globulin in serum, saliva and nasopharyngeal secretions of infants and children. J Lab Clin Med 67:922–933. [PubMed] [Google Scholar]
- 14. Mellander L, Carlsson B, Hanson LA. 1984. Appearance of secretory IgM and IgA antibodies to Escherichia coli in saliva during early infancy and childhood. J Pediatr 104:564–568. [DOI] [PubMed] [Google Scholar]
- 15. El Kaissouni J, Béné MC, Thionnois S, Monin P, Vidailhet M, Faure G. 1998. Maturation of B cells in the lamina propria of human gut and bronchi in the first months of human life. Dev Immunol 5:153–159. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16. Cripps AW, Gleeson M. 1999. Ontogeny of mucosal immunity and aging In: Ogra PL, Lamm ME, Bienenstock J, Mestecky J, Strober W, McGhee JR, editors. Mucosal immunology. New York: Academic Press Inc; p 253–266. [Google Scholar]
- 17. Vaerman JP. 1984. Effector mechanisms of IgA. Ann Biol Clin 42:61–70. [PubMed] [Google Scholar]
- 18. Warny M, Vaerman JP, Avesani V, Delmée M. 1994. Human antibody response to clostridium difficile toxin A in relation to clinical course of infection. Infect Immun 62:384–389. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19. Lowry OH, Rosenbrough NJ, Farr AL, Randall RJ. 1951. Protein measurement with the folin phenol reagent. J Biol Chem 193:265–275. [PubMed] [Google Scholar]
- 20. Hodges M, Kingstone K, Brydon WG, Sallam J, Ferguson A. 1994. Use of whole‐gut lavage to measure intestinal immunity in healthy Sierra Leonean children. J Pediatr Gastroenterol Nutr 19:65–70. [DOI] [PubMed] [Google Scholar]
- 21. Haneberg B, Aarskag D. 1975. Human faecal immunoglobulins in healthy infants and children and some with diseases affecting the intestinal tract or the immune system. Clin Exp Immunol 22:210–222. [PMC free article] [PubMed] [Google Scholar]
- 22. Schoof E, John MR, Arndt B, et al. 1997. Solid phase competitive luminescence immunoassay for immunoglobulin A in faeces: development and clinical validation. Clin Chim Acta 261:1–17. [DOI] [PubMed] [Google Scholar]
- 23. Hodges M, Kingstone K, Brydon WG, Sallam J, Ferguson A. 1995. Use of gut lavage fluid to measure intestinal humoral immunity, GI bleeding and protein losses in Sierra Leonean children. Adv Exp Med Biol 371:813–815. [PubMed] [Google Scholar]
- 24. Arranz E, Ferguson A. 1993. Intestinal antibody pattern of coeliac disease: occurrence in patients with normal jejunal biopsy histology. Gastroenterology 104:1263–1272. [DOI] [PubMed] [Google Scholar]