Increased expression of perforin, granzyme B, and C5b-9 in villitis of unknown etiology.
BACKGROUND
Villitis of unknown etiology (VUE) is associated with fetal growth restriction. However, the underlying mechanisms of villous injury in placentas with VUE are still largely unknown. We aimed to verify whether apoptosis-related factors are increased in VUE placentas. Furthermore, we determined apoptosis of villous cells.


METHODS
Six placentas with VUE and 3 control placentas were stained using immunohistochemistry with antibodies for CD3, CD4, CD8, CD68, CD163, perforin, granzyme B, granzyme K, and C5b-9. TUNEL assay analysis was also performed with these placentas. The percentage of cells that stained positive, CD163/CD68 ratio, percentage of C5b-9 positive area, and apoptosis index were quantified and compared between the inflammatory lesions of the VUE placentas, non-VUE inflammatory lesions of the VUE placentas, and control placentas.


RESULTS
The percentages of CD3, CD4, CD8 CD68, CD163, perforin, and granzyme B positive cells were significantly higher in the inflammatory lesions of the VUE placentas (p < 0.05). The intravillous CD163/CD68 ratio was higher in the inflammatory lesions compared with the non-inflammatory lesion of the VUE placentas (p < 0.05). The percentage of granzyme K-positive cells was not significantly different between the groups. C5b-9 deposition was higher in the inflammatory lesions of the VUE placentas (p < 0.05). TUNEL-positive cells were significantly higher in the inflammatory lesions of the VUE placentas (p < 0.05).


CONCLUSIONS
To the best of our knowledge, this is the first report to assess villous injury, especially from a viewpoint of villous apoptosis in VUE placentas. An activated perforin/granzyme pathway and C5b-9 are suggested as possible mechanisms of apoptosis.
Department of Obstetrics and Gynecology, The Jikei University School of Medicine, 3-25-8, Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan; Department of Pathology, National Center for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535, Japan; Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535, Japan.
Y
Y
Ito
Department of Pathology, National Center for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535, Japan. Electronic address: matsuoka-k@ncchd.go.jp.
K
K
Matsuoka
Department of Pathology, National Center for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535, Japan; Department of Obstetrics and Gynecology, St. Marianna University School of Medicine, 2-16-1, Sugao, Miyamae-ku, Kawasaki, Kanagawa 216-8511, Japan.
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T
Uesato
Department of Maternal-Fetal and Neonatal Medicine, National Center for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535, Japan.
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H
Sago
Department of Obstetrics and Gynecology, The Jikei University School of Medicine, 3-25-8, Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
A
A
Okamoto
Department of Pathology, National Center for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535, Japan.
A
A
Nakazawa
Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535, Japan.
K
K
Hata
D000328:Adult; D017209:Apoptosis; D016022:Case-Control Studies; D015938:Complement Membrane Attack Complex / Q000378:metabolism*; D005260:Female; D053804:Granzymes / Q000378:metabolism*; D006801:Humans; D020287:In Situ Nick-End Labeling; D054353:Perforin / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism* / Q000473:pathology; D010922:Placenta Diseases / Q000378:metabolism* / Q000473:pathology; D011247:Pregnancy
D015938:Complement Membrane Attack Complex; D054353:Perforin; D053804:Granzymes
Apoptosis; Fetal growth restriction; Placental inflammation; Placental villi; T lymphocytes