BRIEF COMMUNICATION Transcriptional status of HLA-G at the maternal À fetal interface in recurrent spontaneous abortion A. Abbas a, *, S. Javed b , S. Agrawal c a Department of Biochemistry, Era’s Lucknow Medical College and Hospital, Herdoi Road, Lucknow, India b Department of Biochemistry, Jamia Hamdarad University, New Delhi, India c Department of Medical Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India Received 11 November 2005; received in revised form 15 January 2006; accepted 17 January 2006 The nonclassic HLA-G antigen differs from classic class I genes by its unique promoter region, atypical splicing patterns, shortened cytoplasmic tail, min- imal genetic variation, and restricted tissue distri- bution. Tissue-specific expression of HLA-G at the maternal—fetal interface suggests the important role of HLA-G in maternal tolerance and pregnancy maintenance. The present study investigated the transcrip- tional status and relative expression levels of various HLA-G isoforms in the placentas of 17 women who had experienced recurrent spontane- ous abortion and 25 controls with no history of spontaneous abortion, all in the first trimester of pregnancy. The semiquantitative reverse transcrip- tase polymerase chain reaction (RT-PCR) method was used, followed by densitometric analysis. All participants gave informed consent and the study was approved by the local ethics committee. Cytotrophoblasts were isolated from the pla- centas following the method described by Loke and Burland 1988 [1]. Total RNA was then isolated from the cytotrophoblasts using Trizol reagent (Gibco Life Technologies) and purified according to the manu- facturer’s recommendations. The cDNA was synthe- sized using the Qiagen first-strand synthesis kit (Qiagen Inc.) and RT-PCR amplification was carried out. A 475-bp HLA class I-specific product was first amplified by RT-PCR, and HLA-A and HLA-G expres- sion was studied by the dot blot method [2]. Only HLA-A-negative samples were used for analysis of HLA-G transcriptional expression, with specific primers for different HLA-G transcripts, as recom- 0020-7292/$ - see front matter D 2006 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijgo.2006.01.019 * Corresponding author. Tel.: +91 522 2248123x249, +91 933 6586576. E-mail address: ata _ abbas@rediffmail.com (A. Abbas). KEYWORDS Cytotrophoblast cell; HLA-G isoform; Recurrent spontaneous abortion International Journal of Gynecology and Obstetrics (2006) 93, 148 — 149 www.elsevier.com/locate/ijgo