Detection of maternal-fetal microchimerism in the inflammatory lesions of patients with Sjögren's syndrome.
BACKGROUND
A possible relation between maternal-fetal microchimerism and autoimmune diseases with some similarities to chronic graft versus host disease (cGVHD) has been reported.


OBJECTIVE
To investigate whether cells with male DNA exist in female patients with Sjögren's syndrome (SS) as SS has clinical features similar to those of cGVHD.


METHODS
DNA was extracted from 27 samples of peripheral blood mononuclear cells (PBMC), 42 biopsy samples of labial salivary glands (LSG), and nine samples of bronchoalveolar lavage fluid (BALF) cells from 56 female patients with SS. The presence of male DNA was determined by nested polymerase chain reaction (PCR) and by fluorescence in situ hybridisation (FISH).


RESULTS
Among 56 female patients with SS, 42 patients had at least one male child. Among those 42 patients, none of the 22 PBMC but 10/28 (36%) LSG samples tested positive by PCR for the Y chromosome-specific sequence (p=0.0013). The Y chromosome-specific sequence was not detected in the samples of LSG in 10 patients without SS. In the BALF samples 2/9 (22%) patients with SS tested positive by PCR. Cells containing the Y chromosome were shown to exist in all the LSG specimens from three female patients with SS by FISH.


CONCLUSIONS
Maternal-fetal microchimerism was shown for the first time to exist in the salivary glands and lungs of female patients with SS in this study. The presence of non-host cells in the inflammatory lesions but not in the peripheral blood suggests a possible role for maternal-fetal microchimerism in the pathogenesis of SS.
Kuroki
M
M
Department of Internal Medicine II, Miyazaki Medical College, Miyazaki, Japan.
Okayama
A
A
Nakamura
S
S
Sasaki
T
T
Murai
K
K
Shiba
R
R
Shinohara
M
M
Tsubouchi
H
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D001483:Base Sequence; D001706:Biopsy / Q000379:methods; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002648:Child; D002678:Chimera; D041322:Chromosomes, Human, Y; D004247:DNA / Q000032:analysis; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007963:Leukocytes, Mononuclear; D008297:Male; D008431:Maternal-Fetal Exchange; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012469:Salivary Glands / Q000276:immunology; D012859:Sjogren's Syndrome / Q000235:genetics / Q000473:pathology*
D004247:DNA