NDT Advance Access published online on March 30, 2009
Nephrology Dialysis Transplantation, doi:10.1093/ndt/gfp133
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Gluten sensitivity in patients with IgA nephropathy
1 Section of Nephrology, Department of Medical Sciences, Uppsala University Hospital, Uppsala, Sweden 2 Smerud Medical Research International AS, Oslo, Norway 3 Section of Rheumatology 4 Section of Clinical Chemistry 5 Section of Gastroenterology, Department of Medical Sciences, Uppsala University Hospital, Uppsala, Sweden
Correspondence and offprint requests to: Hilde Kloster Smerud; E-mail: hilde.kloster.smerud{at}smerud.com
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Abstract |
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Background. Coeliac disease is more frequent in IgA nephropathy (IgAN) patients compared to the healthy population. Several hypotheses postulate that food antigens like gluten may be involved in the onset of IgAN.
Methods. In this study, we used a recently developed mucosal patch technique to evaluate the rectal mucosal inflammatory reaction to gluten in patients with IgAN (n = 27) compared to healthy subjects (n = 18). The rectal mucosal production of nitric oxide (NO) and release of myeloperoxidase (MPO) and eosinophil cationic protein (ECP) were measured. Serum samples were analysed for IgA and IgG antigliadin antibodies (AGA), IgA antibodies against tissue transglutaminase and IgA endomysium antibodies.
Results. Gluten reactivity, defined as increase in MPO and/or NO after gluten exposure, was observed in 8 of 27 IgAN patients. The prevalence of HLA-DQ2 and DQ8 was not increased among gluten-sensitive patients, and the total prevalence among IgAN patients was the same as for the normal population. An elevated serum IgA AGA response was seen in 9 of 27 IgAN patients. The increase in IgA AGA did not correlate with the gluten sensitivity as measured by NO and/or MPO. A specific serum IgG AGA response was seen in one patient only. Antibodies against tissue transglutaminase and endomysium were not observed.
Conclusion. It is concluded that approximately one-third of our IgAN patients have a rectal mucosal sensitivity to gluten, but without signs of coeliac disease, and we hypothesize that such sub-clinical inflammation to gluten might be involved in the pathogenesis of IgAN in a subgroup of patients.
Keywords: food antigens; gluten sensitivity; IgA nephropathy; myeloperoxidase; nitric oxide
6 Present address: Department of Internal Medicine, Nyköping Hospital, Nyköping, Sweden.
7 Present address: Department of Internal Medicine, University Hospital of Akureyri, Akureyri, Iceland.
Received for publication: 2. 7.08
Accepted in revised form: 5. 3.09