ORIGINAL ARTICLE: Maternal and Neonatal Interleukin-1 Receptor Antagonist Genotype and Pregnancy Outcome in a Population with a High Rate of Pre-term Birth

Authors

  • José Humberto Belmino Chaves,

    1. Universidade Estadual de Ciências da Saúde de Alagoas, Maceio, Brazil
    2. Department of Obstetric, Universidade Federal de Alagoas, Sao Paulo, Brazil
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  • Arthur Babayan,

    1. Division of Immunology and Infectious Diseases, Department of Obstetrics and Gynecology, Weill Medical College of Cornell University, New York, NY, USA
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  • Cledna De Melo Bezerra,

    1. Department of Obstetric, Universidade Federal de Alagoas, Sao Paulo, Brazil
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  • Iara M Linhares,

    1. Division of Immunology and Infectious Diseases, Department of Obstetrics and Gynecology, Weill Medical College of Cornell University, New York, NY, USA
    2. Department of Gynecology, Sao Paulo University Medical School and Hospital das Clinicas, Sao Paulo, Brazil
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  • Steven S Witkin

    1. Division of Immunology and Infectious Diseases, Department of Obstetrics and Gynecology, Weill Medical College of Cornell University, New York, NY, USA
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Steven S. Witkin, Department of Obstetrics and Gynecology, Weill Medical College of Cornell Univeristy, 525 East 68th Street, PO Box 35, New York, NY 10065, USA.
E-mail: switkin@med.cornell.edu

Abstract

Problem We evaluated associations between a length polymorphism in intron 2 of the gene coding for IL-1ra (gene symbol IL1RN) and pregnancy outcome in a population with a high rate of preterm birth.

Method of study Subjects were pregnant women in Maceio, Brazil and their newborns. DNA was tested for IL1RN genotypes and alleles by gene amplification using primer pairs that spanned the polymorphic region. Every subject completed a detailed questionnaire.

Results The frequency of allele 2 (IL1RN*2) carriage was elevated in mothers with a spontaneous preterm birth (SPTB) in the current pregnancy (P = 0.02) and also with a prior preterm delivery (P = .01). Both SPTB with intact membranes (P = 0.01) and SPTB preceded by pre-term pre-mature rupture of membranes (P = .03) were associated with IL1RN*2 carriage. A previous fetal demise was more than twice as prevalent in mothers positive for two copies of IL1RN*2.

Conclusion Maternal carriage of IL1RN*2 increases susceptibility to inflammation-triggered spontaneous pre-term birth.

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