Revision of Cytomegalovirus Immunoglobulin M Antibody Titer Cutoff in a Maternal Antibody Screening Program in Japan: A Cohort Comparison Involving a Total of 32,000 Pregnant Women
Asa Kitamura,
Kuniaki Toriyabe,
Miki Hagimoto-Akasaka,
Kyoko Hamasaki-Shimada,
Makoto Ikejiri,
Toshio Minematsu,
Shigeru Suga,
Eiji Kondo,
Masamichi Kihira,
Fumihiro Morikawa,
Tomoaki Ikeda
Affiliations
Asa Kitamura
Department of Obstetrics and Gynecology, Mie University Graduate School of Medicine, Tsu 514-8507, Japan
Kuniaki Toriyabe
Department of Obstetrics and Gynecology, Mie University Graduate School of Medicine, Tsu 514-8507, Japan
Miki Hagimoto-Akasaka
Department of Obstetrics and Gynecology, Mie University Graduate School of Medicine, Tsu 514-8507, Japan
Kyoko Hamasaki-Shimada
Department of Obstetrics and Gynecology, Kurashiki Medical Center, Okayama 710-8522, Japan
Makoto Ikejiri
Clinical Laboratory, Mie University Hospital, Tsu 514-8507, Japan
Toshio Minematsu
Research Center for Disease Control, Aisenkai Nichinan Hospital, Miyazaki 887-0034, Japan
Shigeru Suga
Institute for Clinical Research, National Hospital Organization Mie National Hospital, Tsu 514-8507, Japan
Eiji Kondo
Department of Obstetrics and Gynecology, Mie University Graduate School of Medicine, Tsu 514-8507, Japan
Masamichi Kihira
Mie Association of Obstetricians and Gynecologists, Tsu 514-8507, Japan
Fumihiro Morikawa
Mie Association of Obstetricians and Gynecologists, Tsu 514-8507, Japan
Tomoaki Ikeda
Department of Obstetrics and Gynecology, Mie University Graduate School of Medicine, Tsu 514-8507, Japan
Cytomegalovirus (CMV) is associated with congenital infections. We aimed to validate the revised CMV immunoglobulin (Ig) M titer cutoff for IgG avidity measurements as a reflex test in maternal screening to identify women with primary CMV infection and newborn congenital cytomegalovirus (cCMV). We screened maternal CMV antibodies (the Denka assay) in Japan, from 2017 to 2019, using a revised IgM cutoff (≥4.00 index). Participants were tested for IgG and IgM antibodies, and for IgG avidity if IgM levels exceeded the cutoff. We compared these with corresponding results from 2013 to 2017 based on the original cutoff (≥1.21) and recalculated using the revised cutoff. Newborn urine CMV DNA tests were performed for women with low avidity (≤35.0%). Among 12,832 women screened in 2017–2019, 127 (1.0%) had IgM above the revised cutoff. Thirty-five exhibited low avidity, and seven infants developed cCMV. Of 19,435 women screened in 2013–2017, 184 (1.0%) had IgM above the revised cutoff, 67 had low avidity, and 1 had cCMV. The 2017–2019 results were not significantly different from the 2013–2017 results. The revised IgM cutoff improves maternal screening in identifying primary infection and newborn cCMV; however, further study related to other assays than Denka is required.
