1785. Pro-inflammatory Cytokines Correlate with Hospitalization, as well as Gastrointestinal and Systemic Symptoms, in Influenza-like Illness
Session: Poster Abstract Session: Viral Infections; Pathogenesis and Epidemiology
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
Background: Serum biomarkers indicative of inflammatory state may predict severity and outcome of acute respiratory infection. We evaluated the association between serum cytokine concentrations and markers of disease severity and hospitalization status among healthy adults with influenza-like illness (ILI).

Methods: The Acute Respiratory Infection Consortium (ARIC) is a collaborative, multi-site research network for studying ILI etiology and severity at five military medical centers in the United States. Individuals presenting within 72 hours of ILI onset were prospectively enrolled in an observational cohort study. Viral etiologies were determined by nucleic acid amplification testing of nasopharyngeal specimens. Cytokine levels were measured in serum collected at time of presentation in 36 adults enrolled between 2009 and 2013 (16 influenza, 13 rhinovirus, and 7 undetermined etiology). Vital signs, self-reported symptom severity on a four-point scale and hospitalization status were ascertained. A composite score was calculated for systemic symptoms. Median cytokine concentrations were compared by Mann-Whitney U test.

Results: Neither baseline cytokine concentrations nor symptom scores differed based on etiology of illness. Patients hospitalized with ILI due to influenza or rhinovirus had higher levels of IL-8 at presentation compared with non-hospitalized (p=0.004). In contrast, IL-17 concentrations were lower among hospitalized versus non-hospitalized (p=0.05). Among subjects reporting lower respiratory tract symptoms (shortness of breath or chest pain), IL-6 (p=0.16) and IL-8 (p=0.17) concentrations did not differ by severity. However, median concentrations of IL-6 (p=0.003) and IL-8 (p=0.07) were higher among those reporting any gastrointestinal symptoms. In addition, median IL-6 concentration correlated with higher composite symptom scores (p=0.02).

Conclusion: In a healthy adult cohort without underlying risk factors for severe complications, baseline IL-8 levels discriminated between hospitalized and non-hospitalized subjects. In addition, IL-6 and IL-8 levels correlated with overall symptom severity and GI symptoms. The potential utility of these biomarkers as discriminators for ILI severity and prognosis warrants further study.

John Arnold, MD1, Mary Fairchok, MD2, Christina Schofield, MD FACP3, Patrick Danaher, MD4, Karl Kronmann, MD, MPH5, Michael Rajnik, MD6, Erin McDonough, BS7, Christopher Myers, PhD7, Peifang Sun, PhD8, Nicholas Martin, PhD8, Tadeusz J. Kochel, PhD8, Deepika Mor, MS9, Michelande Ridore, BA10, Mark Kortepeter, MD, MPH2,11, Timothy Burgess, MD, MPH6 and Eugene Millar, PhD12, (1)Department of Pediatrics, Naval Medical Center San Diego, San Diego, CA, (2)Infectious Disease Clinical Research Program, Tacoma, WA, (3)Madigan Army Medical Center, Tacoma, WA, (4)San Antonio Military Health System, Fort Sam Houston, TX, (5)Naval Medical Center Portsmouth, Portsmouth, VA, (6)Walter Reed National Military Medical Center, Bethesda, MD, (7)Naval Health Research Center, San Diego, CA, (8)Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, (9)Data Coordination Center, Infectious Disease Clinical Research Program, Rockville, MD, (10)Infectious Disease Clinical Research Program, Uniformed Services University of the Health Sciences, Rockville, MD, (11)Infectious Disease Clinical Research Program (IDCRP), Uniformed Services University of the Health Sciences, Rockville, MD, (12)Infectious Disease Clinical Research Program (IDCRP), Uniformed Services University of the Health Sciences (USU), Rockville, MD

Disclosures:

J. Arnold, None

M. Fairchok, None

C. Schofield, None

P. Danaher, None

K. Kronmann, None

M. Rajnik, None

E. McDonough, None

C. Myers, None

P. Sun, None

N. Martin, None

T. J. Kochel, None

D. Mor, None

M. Ridore, None

M. Kortepeter, None

T. Burgess, None

E. Millar, None

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