The possible involvement of intestine-derived IgA1: a case of IgA nephropathy associated with Crohn's disease.
A link between IgA nephropathy and Crohn's disease has recently been reported. Other researchers hypothesize that intestine-derived IgA complexes deposit in glomerular mesangial cells, eliciting IgA nephropathy. Intestinal mucosal plasma cells mainly secrete IgA2. Nevertheless, IgA1 deposition is strongly implicated as being the primary cause of IgA nephropathy.



A 46-year-old Japanese man developed IgA nephropathy 29 years ago, following tonsillectomy. As a result, a normal urinalysis was obtained. The patient previously suffered Crohn's disease followed by urinary occult blood and proteinuria six years ago. Exacerbation of IgA nephropathy was highly suspected. Therefore a renal biopsy was performed. A diagnosis of exacerbation of IgA nephropathy with mesangial cell proliferation and fibrotic cellular crescent was based upon the pathological findings. The patient exhibited a positive clinical course and eventually achieved a remission with immunosuppressive therapy including prednisolone treatment. Immunostaining for the detection of IgA subtypes was performed on both of his kidney and excised ileum. The results revealed IgA1 and IgA2 deposition by submucosal cells in intestine. Furthermore, IgA1 deposition of mesangial areas in the patient's kidney, indicated an association of IgA1 with the exacerbation of IgA nephropathy.



This case represents the possibility that the intestine-derived IgA1 can be the origin of galactose-deficient IgA which is known to cause IgA nephropathy exacerbation.
Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Tomohiro
T
Terasaka
Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan. hauchida@okayama-u.ac.jp.|Department of Chronic Kidney Disease and Cardiovascular Disease, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan. hauchida@okayama-u.ac.jp.
Haruhito A
HA
Uchida
Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Ryoko
R
Umebayashi
Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Keiko
K
Tsukamoto
Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Keiko
K
Tanaka
Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Masashi
M
Kitagawa
Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.|Department of Human Resource Development of Dialysis Therapy for Kidney Disease, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Hitoshi
H
Sugiyama
Department of Medicine Oncology, Okayama Rosai Hospital, 1-10-25 Chikkomidori-machi, Minami-ku, Okayama, 702-8055, Japan.
Hiroaki
H
Tanioka
Department of Nephrology, Rheumatology, Endocrinology and Metabolism, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
Jun
J
Wada
D003424:Crohn Disease / Q000150:complications / Q000378:metabolism*; D018450:Disease Progression; D005922:Glomerulonephritis, IGA / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007082:Ileum; D007070:Immunoglobulin A / Q000032:analysis*; D007413:Intestinal Mucosa / Q000737:chemistry*; D008297:Male; D050527:Mesangial Cells / Q000737:chemistry*; D008875:Middle Aged
D007070:Immunoglobulin A
Crohn’s disease; IgA nephropathy; IgA1; IgA2; Inflammatory bowel disease