Pregnant women infected with the pandemic influenza A(H1N1)pdm09 virus show a different cytokine and chemokine response related to disease severity.

N. PERIOLO; M. RUSSO; M. AVARO; E. BENEDETTI; A. PONTORIERO; A. CAMPOS ; A. CZECH ; L. MARTÍNEZ PERALTA; E. BAUMEISTER.

Ciudad del Cabo

Congreso; Options for the Control of Influenza.; 2013

International Society for Influenza and other Respiratory Virus Diseases

Background: The innate immune system is the first line of defense against viruses inducing expression of cytokines and chemokines. During pregnancy, immunologic and hormonal alterations place women at increased risk for certain infections and associated complications. Pregnant women represent a disproportionately higher percentage of severe cases of influenza with an increased risk ranging from 4- to 10-fold higher than the general population. Increased morbidity and mortality in pregnant women was reported based on data from seasonal influenza. The impact of pregnancy on the immune response is not well known. Although 2009 (H1N1pdm) infection resulted in increased disease severity in pregnant women, the precise mechanisms responsible for this risk are not yet defined. In the present study we investigated the host cytokine profiles in (H1N1pdm) infection related to disease severity in pregnant women. Materials and methods: This study included 41 pregnant women with confirmed (H1N1 pdm) infection during the 2009 pandemics: 12 died as a consequence of the infection (ID), and 29 survived the infection (IS) Samples of 17 not infected pregnant women were included as controls (NI). Respiratory samples, tracheal aspirates (TA), as well as nasopharyngeal (NP) secretions were obtained from hospitals participating in the National Surveillance Network and kept at -80°C. 2009 (H1N1pdm) infection was confirmed by real time-RT-PCR using the CDC protocol. Total RNA from cells was extracted using kit QIAamp® Viral RNA Mini kit QIAGEN?. cDNA was synthesized with Oligo-dT primers and Superscript III reverse transcriptase (Invitrogen) and quantified by real-time quantitative PCR analysis. The gene expression profile for cytokines (IFN-β, TNF-α, IL-6, IL-12, TGF-β, IL-17) and chemokines (IL-8, RANTES, MCP-1) and viral matrix gene were quantified and normalized using the house-keeping gene product β-actin mRNA. We used in a SYBR green PCR MASTER MIX based (Applied Biosystems). The influenza matrix (M) gene copy number was measure by quantitative PCR as a measure of viral replication in each sample. For statistical analysis GraphPad Prism was used performing a test of ANOVA. This study was approved by the Independent Ethics Committee, School of Medicine, University of Buenos Aires. Results: IL-6 mRNA expression in ID were significantly higher than in IS and NI (5.424 ± 0.9513 vs. 1.370 ± 0.4333, p< 0. 01 and 1.578 ± 0.3566, p< 0.001, expressed as mRNA copies IL-6 /mRNA β- actin, respectively), while both ID and IS showed increased expression of TNF-α and IL-8. On the other hand, TGF-β mRNA was lower in both groups with influenza infection than in NI. The levels of expression of RANTES, MCP1 and IL-12 were not significantly different between all groups. Interestingly, the expression of INF-β in ID was significantly lower than in the other two groups (0.6000 ± 0.08528 vs. 1.275 ± 0.1058, P