Masatoki Kaneko1, Masanao Ohhashi2, Toshio Minematsu3, Junsuke Muraoka2, Kazumi Kusumoto2, Hiroshi Sameshima2. 1. Department of Obstetrics and Gynecology, Faculty of Medicine, University of Miyazaki, Japan; Graduate School of Nursing Science, Faculty of Medicine, University of Miyazaki, Japan. Electronic address: mkaneko@med.miyazaki-u.ac.jp. 2. Department of Obstetrics and Gynecology, Faculty of Medicine, University of Miyazaki, Japan. 3. Aisenkai Nichinan Hospital, Miyazaki, Japan.
Abstract
BACKGROUND: The immunoglobulin (Ig) G avidity index (AI) is useful to detect primary cytomegalovirus (CMV) infection. However, because IgG matures with time, this index is not useful to detect a primary infection, unless measured at an appropriate time. OBJECTIVES: We aimed to clarify the difference between using IgG AI and IgM positivity according to the stage of pregnancy to identify congenital CMV infection risk. STUDY DESIGN: We collected the serum samples from 1115 pregnant women who underwent maternal screening for primary infection (n = 956) and were referred to our hospital because of CMV IgM positivity (n = 155) or had abnormal fetal ultrasonography findings (n = 4). The same sera samples were used to measure CMV IgM, IgG, and IgG AI. An IgG AI of <35% was defined as low. Neonatal urine collected within 5 days after birth was examined by polymerase chain reaction to confirm congenital infection. RESULTS: Fourteen mothers gave birth to infected neonates. The sensitivity, specificity, and negative predictive values of the low IgG AI group with IgM-positive samples to discriminate between women with congenital infection at ≤14 weeks of gestation were 83.3, 83.8, and 99.1, respectively, which were higher than those of other subjects. Uni- and multivariate analyses revealed that IgM positivity and low IgG AI were independent variables associated with congenital infection at any stage of pregnancy, except low IgG AI at ≥15 weeks of gestation. CONCLUSION: Low IgG AI with IgM positivity at ≤14 weeks of gestation was a good indicator of congenital infection, which should prove useful in obstetric practice.
BACKGROUND: The immunoglobulin (Ig) G avidity index (AI) is useful to detect primary cytomegalovirus (CMV) infection. However, because IgG matures with time, this index is not useful to detect a primary infection, unless measured at an appropriate time. OBJECTIVES: We aimed to clarify the difference between using IgG AI and IgM positivity according to the stage of pregnancy to identify congenital CMV infection risk. STUDY DESIGN: We collected the serum samples from 1115 pregnant women who underwent maternal screening for primary infection (n = 956) and were referred to our hospital because of CMV IgM positivity (n = 155) or had abnormal fetal ultrasonography findings (n = 4). The same sera samples were used to measure CMV IgM, IgG, and IgG AI. An IgG AI of <35% was defined as low. Neonatal urine collected within 5 days after birth was examined by polymerase chain reaction to confirm congenital infection. RESULTS: Fourteen mothers gave birth to infected neonates. The sensitivity, specificity, and negative predictive values of the low IgG AI group with IgM-positive samples to discriminate between women with congenital infection at ≤14 weeks of gestation were 83.3, 83.8, and 99.1, respectively, which were higher than those of other subjects. Uni- and multivariate analyses revealed that IgM positivity and low IgG AI were independent variables associated with congenital infection at any stage of pregnancy, except low IgG AI at ≥15 weeks of gestation. CONCLUSION: Low IgG AI with IgM positivity at ≤14 weeks of gestation was a good indicator of congenital infection, which should prove useful in obstetric practice.
Authors: Bettie Voordouw; Barry Rockx; Thomas Jaenisch; Pieter Fraaij; Philippe Mayaud; Ann Vossen; Marion Koopmans Journal: Clin Microbiol Rev Date: 2019-12-11 Impact factor: 26.132