Increased Proinflammatory Responses of Monocytes and Plasmacytoid Dendritic Cells to Influenza A Virus Infection During Pregnancy.

Pregnancy-induced alterations in immunity may contribute to the increased morbidity associated with influenza A virus infection during pregnancy. We characterized the immune response of monocytes and plasmacytoid dendritic cells (pDCs) to influenza A virus infection in 21 pregnant and 21 nonpregnant women. In pregnant women, monocytes and pDCs exhibit an exaggerated proinflammatory immune response to 2 strains of influenza A virus, compared with nonpregnant women, characterized by increased expression of major histocompatibility complex class II (approximately 2.0-fold), CD69 (approximately 2.2-fold), interferon γ-induced protein 10 (approximately 2.0-fold), and macrophage inflammatory protein 1β (approximately 1.5-fold). This enhanced innate inflammatory response during pregnancy could contribute to pulmonary inflammation following influenza A virus infection.