Characterization of the Fetal Blood Transcriptome and Proteome in Maternal Anti-Fetal Rejection: Evidence of a Distinct and Novel Type of Human Fetal Systemic Inflammatory Response

Authors

  • JoonHo Lee,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
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  • Roberto Romero,

    Corresponding author
    • Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
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  • Tinnakorn Chaiworapongsa,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
    2. Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
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  • Zhong Dong,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
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  • Adi L. Tarca,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
    2. Department of Computer Science, Wayne State University, Detroit, MI, USA
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  • Yi Xu,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
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  • Po Jen Chiang,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
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  • Juan Pedro Kusanovic,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
    2. Department of Obstetrics and Gynecology, Sótero del Río Hospital, Santiago, Chile
    3. Department of Obstetrics and Gynecology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
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  • Sonia S. Hassan,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
    2. Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
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  • Lami Yeo,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
    2. Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
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  • Bo Hyun Yoon,

    1. Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea
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  • Nandor Gabor Than,

    1. Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
    2. Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
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  • Chong Jai Kim

    Corresponding author
    1. Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
    • Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, Detroit, MI, USA
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Correspondence

Roberto Romero, MD, DMedSci, Perinatology Research Branch, NICHD/NIH/DHHS, Hutzel Women's Hospital, 3990 John R St., Detroit, MI 48201, USA. E-mail: romeror@mail.nih.gov;

Chong Jai Kim, MD, PhD, Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea. E-mail: ckim@amc.seoul.kr

Abstract

Background

The human fetus is able to mount a systemic inflammatory response when exposed to microorganisms. This stereotypic response has been termed the ‘fetal inflammatory response syndrome’ (FIRS), defined as an elevation of fetal plasma interleukin-6 (IL-6). FIRS is frequently observed in patients whose preterm deliveries are associated with intra-amniotic infection, acute inflammatory lesions of the placenta, and a high rate of neonatal morbidity. Recently, a novel form of fetal systemic inflammation, characterized by an elevation of fetal plasma CXCL10, has been identified in patients with placental lesions consistent with ‘maternal anti-fetal rejection’. These lesions include chronic chorioamnionitis, plasma cell deciduitis, and villitis of unknown etiology. In addition, positivity for human leukocyte antigen (HLA) panel-reactive antibodies (PRA) in maternal sera can also be used to increase the index of suspicion for maternal anti-fetal rejection. The purpose of this study was to determine (i) the frequency of pathologic lesions consistent with maternal anti-fetal rejection in term and spontaneous preterm births; (ii) the fetal serum concentration of CXCL10 in patients with and without evidence of maternal anti-fetal rejection; and (iii) the fetal blood transcriptome and proteome in cases with a fetal inflammatory response associated with maternal anti-fetal rejection.

Method of study

Maternal and fetal sera were obtained from normal term (= 150) and spontaneous preterm births (= 150). A fetal inflammatory response associated with maternal anti-fetal rejection was diagnosed when the patients met two or more of the following criteria: (i) presence of chronic placental inflammation; (ii) ≥80% of maternal HLA class I PRA positivity; and (iii) fetal serum CXCL10 concentration >75th percentile. Maternal HLA PRA was analyzed by flow cytometry. The concentrations of fetal CXCL10 and IL-6 were determined by ELISA. Transcriptome analysis was undertaken after the extraction of total RNA from white blood cells with a whole-genome DASL assay. Proteomic analysis of fetal serum was conducted by two-dimensional difference gel electrophoresis. Differential gene expression was considered significant when there was a P < 0.01 and a fold-change >1.5.

Results

(i) The frequency of placental lesions consistent with maternal anti-fetal rejection was higher in patients with preterm deliveries than in those with term deliveries (56% versus 32%; < 0.001); (ii) patients with spontaneous preterm births had a higher rate of maternal HLA PRA class I positivity than those who delivered at term (50% versus 32%; = 0.002); (iii) fetuses born to mothers with positive maternal HLA PRA results had a higher median serum CXCL10 concentration than those with negative HLA PRA results (< 0.001); (iv) the median serum CXCL10 concentration (but not IL-6) was higher in fetuses with placental lesions associated with maternal anti-fetal rejection than those without such lesions (< 0.001); (v) a whole-genome DASL assay of fetal blood RNA demonstrated differential expression of 128 genes between fetuses with and without lesions associated with maternal anti-fetal rejection; and (vi) comparison of the fetal serum proteome demonstrated 20 proteins whose abundance differed between fetuses with and without lesions associated with maternal anti-fetal rejection.

Conclusion

We describe a systemic inflammatory response in human fetuses born to mothers with evidence of maternal anti-fetal rejection. The transcriptome and proteome of this novel type of fetal inflammatory response were different from that of FIRS type I (which is associated with acute infection/inflammation).

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