726. Viral Genomic Load, Cytokine Profiles and Life-Threatening Respiratory Syncytial Virus Infection in Previously Healthy Infants.
Session: Poster Abstract Session: Respiratory Infections: Viral
Thursday, October 4, 2018
Room: S Poster Hall
Posters
  • Poster RSV IDweek2018 final.pdf (783.1 kB)
  • Background: Data are controversial regarding the role of viral load and the host immune response in the severity of Respiratory Syncytial Virus (RSV) infection. Objective: to analyze the relationship between viral load (VL) and host cytokine responses with RSV life-threatening disease (LTD).

    Methods: prospective cohort study including previously healthy infants <12 mo, hospitalized with a first RSV infection in 2017. Viral titers were assessed by qPCR and cytokine levels measured in nasopharyngeal aspirates obtained on admission. All patients with LTD were admitted to the intensive care unit.

    Results: 51 patients, median age 3 mo (IQR 2-4), 29(56.9%) male. Eight developed LTD (1.569 LTD cases/10.000 RSV-hospitalizations/year [CI95% 702-2.859]). Antibiotic prescription was significantly higher (42.9 vs. 87.5%, p<0.001) and length of hospitalization significantly prolonged (5.2 ±1.9 vs. 16.1 ±12.7 days, p<0.001) in infants with LTD. No differences were seen in the number of amplification cycles needed for a positive qPCR test (CT) nor in the viral titers of patients with LTD compared with those with better outcome (p=0.71), figure 1. VL was not a predictor of LTD (AUC=0.53), however no LTD was seen with ≤159.200copies/ml. CT/VL did not correlate with other outcomes (figure 2). IFN-y levels (Th1 response) were significantly lower in infants with LTD (p=0.034). We detected no differences in TNF-α (pro-inflammatory), IL-9, IL-13 (Th2), IL-10 or IL-17 (regulatory) levels from mildly/severely or extremely severe ill patients; lower IL-5 levels were seen in LTD (figure 3). VL correlated with TNF-α (p<0.001) and IL-10 (p<0.001) levels. After logistic regression analysis, socioeconomic, pregnancy and infant variables showed no association with bad outcomes; only frequent consumption of fruits and vegetables during pregnancy conferred protection (aOR 0.03; p<0.001).

    Conclusion:

    ·         RSV titers did not correlate with LTD. Lower levels of IFN-γ were associated with increased disease severity.

    ·         These findings could provide additional data for future RSV preventive and therapeutic strategies.

     

    Fausto Martin Ferolla, MD1, Ana Caratozzolo, PhD2, Analía Toledano, PhD1, Cecilia Anselmino, MD1, Carlos Mauricio Vergara Lobo, MD3, Maria Agustina Chiormi, MD4, Gabriela Visingardi, MD4, Patricia Ratto, MD5, Graciela Theiler, PhD6, Pablo Neira, MD7, Mónica Dastugue, MD8, Normando Mascardi, MD8, Maria Marta Contrini, MD9 and Eduardo Lopez, MD10, (1)Pediatric Infectious Disease, Hospital de Niños "Dr. Ricardo Gutiérrez", Buenos Aires, Argentina, (2)Pediatricinfectious Disease, Hospital de Niños "Dr. Ricardo Gutiérrez", Buenos Aires, Argentina, (3)Infectologia, Hospital de Niños "Ricardo Gutierrez", Universidad de Buenos Aires, Buenos aires, Argentina, (4)Kinesiology, Hospital de Niños "Dr. Ricardo Gutiérrez", Buenos Aires, Argentina, (5)Hospital de Niños "Dr. Ricardo Gutiérrez", Buenos Aires, Argentina, (6)Hospital de Clínicas "José de San Martín", Buenos Aires, Argentina, (7)Pediatric Intensive Care, Hospital de Niños "Dr. Ricardo Gutiérrez", Buenos Aires, Argentina, (8)Pediatrics, Hospital de Niños "Dr. Ricardo Gutiérrez", Buenos Aires, Argentina, (9)Hospital de Niños Ricardo Gutierez, Buenos Aires, Argentina, (10)Pediatric Infectious Disease, Hospital de Niños "Dr. Ricardo Gutierrez", Buenos Aires, Argentina

    Disclosures:

    F. M. Ferolla, None

    A. Caratozzolo, None

    A. Toledano, None

    C. Anselmino, None

    C. M. Vergara Lobo, None

    M. A. Chiormi, None

    G. Visingardi, None

    P. Ratto, None

    G. Theiler, None

    P. Neira, None

    M. Dastugue, None

    N. Mascardi, None

    M. M. Contrini, None

    E. Lopez, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 3rd with the exception of research findings presented at the IDWeek press conferences.