Microarray analysis of tonsils in immunoglobulin A nephropathy patients.
BACKGROUND
Recently, combination of tonsillectomy and steroid pulse therapy was reported to be effective as the treatment of the immunoglobulin A nephropathy (IgAN). However, the gene expression difference between the tonsils in patients with IgAN and those in control patients is not established.


METHODS
We performed tonsillectomy combined with steroid pulse as a treatment to IgAN, analyzed the gene expression in the tonsils (N=23) using microarray, compared with those with patients suffering from chronic tonsillitis (N=22). From some candidate genes related with IgAN, we confirmed the apolipoprotein B messenger RNA-editing enzyme catalytic polypeptides 2 (APOBEC2) gene expression in the tonsil and we also analyzed its expression levels and clinical features.


RESULTS
Up-regulated genes seem to be categorized into two groups. One group belongs to the muscle related genes which might be caused by structural differences. The other group includes the immune system-related genes, such as APOBEC2, CALB2, DUSP27, and CXCL11. APOBEC2 was positively stained in the epithelium and the peripheral region of the germinal center in both tonsils. APOBEC2 expression level was negatively related with serum igg level, but did not correlate with clinical course after tonsillectomy.


CONCLUSIONS
We confirmed gene expression differences related with immune system and muscle structure. The APOBEC2 was confirmed to be elevated in the tonsils with IgAN patients, and the gene expression level was negatively related with serum igg level in overall patients. These results might be helpful to reveal the mechanism of IgAN.
Department of Geriatric Medicine and Nephrology, Osaka University, Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
Kenichiro
K
Iio
Yasuyuki
Y
Nagasawa
Hirotsugu
H
Iwatani
Ryohei
R
Yamamoto
Arata
A
Horii
Daisuke
D
Okuzaki
Yoshiyuki
Y
Furumatsu
Hidenori
H
Inohara
Hiroshi
H
Nojima
Enyu
E
Imai
Yoshitaka
Y
Isaka
Hiromi
H
Rakugi
D000071478:APOBEC Deaminases; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage; D000328:Adult; D003564:Cytidine Deaminase / Q000235:genetics*; D015536:Down-Regulation; D005260:Female; D020869:Gene Expression Profiling; D005922:Glomerulonephritis, IGA / Q000235:genetics* / Q000276:immunology / Q000628:therapy; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D014066:Palatine Tonsil / Q000276:immunology* / Q000473:pathology; D020551:Pulse Therapy, Drug; D014068:Tonsillectomy; D014069:Tonsillitis / Q000235:genetics / Q000276:immunology / Q000601:surgery; D015854:Up-Regulation; D055815:Young Adult
D000305:Adrenal Cortex Hormones; D007074:Immunoglobulin G; D009124:Muscle Proteins; D000071478:APOBEC Deaminases; C120388:APOBEC2 protein, human; D003564:Cytidine Deaminase