Celiac disease or positive tissue transglutaminase antibodies in patients undergoing renal biopsies.

BACKGROUND: An association between celiac disease and renal diseases has been suggested, but the results are controversial.

AIMS: To investigate the prevalence of celiac disease autoimmunity among individuals undergoing renal biopsies and to evaluate whether co-existent celiac autoimmunity influences the clinical outcome of the renal disease.

METHODS: The prevalence of celiac autoimmunity (previous diagnosis of celiac disease or positive tissue transglutaminase antibodies) was determined in 827 consecutive patients undergoing kidney biopsies due to clinical indications. Up to 15 years' follow-up data on kidney function and co-morbidities were obtained.

RESULTS: Celiac autoimmunity was found in 45 (5.4%) patients. Among the IgA nephropathy patients, 8.2% of had celiac autoimmunity. At the time of kidney biopsy and after a median follow-up of 5 to 6 years, renal function measured by estimated glomerular filtration rate (eGFR) was inferior in IgA nephropathy patients with celiac autoimmunity compared to those without it (P=0.048 and P=0.022, respectively).

CONCLUSION: The prevalence of celiac autoimmunity seems to be high in patients undergoing renal biopsies, especially in patients with IgA nephropathy. Such autoimmunity may be associated with worse renal function in IgA nephropathy. Hence the co-existence of celiac disease should be taken into consideration when treating patients with renal diseases.