A Randomized Placebo Controlled Trial of Ibuprofen for Respiratory Syncytial Virus Infection in a Bovine Model

Abstract

BackgroundRespiratory syncytial virus (RSV) is the most common cause of bronchiolitis and hospital admission in infants. An analogous disease occurs in cattle and costs US agriculture a billion dollars a year. RSV causes much of its morbidity indirectly via adverse effects of the host response to the virus. RSV is accompanied by elevated prostaglandin E2 (PGE2) which is followed by neutrophil led inflammation in the lung. Ibuprofen is a prototypical non-steroidal anti-inflammatory drug that decreases PGE2 levels by inhibiting cyclooxygenase.HypothesesWe hypothesized that treatment of RSV with ibuprofen would decrease PGE2 levels, modulate the immune response, decrease clinical illness, and decrease the histopathological lung changes in a bovine model of RSV. We further hypothesized that viral replication would be unaffected.MethodsWe performed a randomized placebo controlled trial of ibuprofen in 16 outbred Holstein calves that we infected with RSV. We measured clinical scores, cyclooxygenase, lipoxygenase and endocannabinoid products in plasma and mediastinal lymph nodes and interleukin (Il)-4, Il-13, Il-17 and interferon-γ in mediastinal lymph nodes. RSV shedding was measured daily and nasal Il-6, Il-8 and Il-17 every other day. The calves were necropsied on Day 10 post inoculation and histology performed.ResultsOne calf in the ibuprofen group required euthanasia on Day 8 of infection for respiratory distress. Clinical scores (p<0.01) and weight gain (p = 0.08) seemed better in the ibuprofen group. Ibuprofen decreased cyclooxygenase, lipoxygenase, and cytochrome P450 products, and increased monoacylglycerols in lung lymph nodes. Ibuprofen modulated the immune response as measured by narrowed range of observed Il-13, Il-17 and IFN-γ gene expression in mediastinal lymph nodes. Lung histology was not different between groups, and viral shedding was increased in calves randomized to ibuprofen.ConclusionsIbuprofen decreased PGE2, modulated the immune response, and improved clinical outcomes. However lung histopathology was not affected and viral shedding was increased.

A randomized controlled trial of a combination of antiviral and nonsteroidal anti-inflammatory treatment in a bovine model of respiratory syncytial virus infection

“…[45,46] Steroids and NSAIDs increase viral shedding but have either null or beneficial effects on various clinical outcomes such as mortality, need for hospitalization, respiratory distress, and subsequent recurrent wheezing. [22,30,[47][48][49] We observed that NSAIDs and FPI when started on day 5 as monotherapy had almost identical clinical scores despite diverging viral loads, +174, (95% CI -303, +651) in ibuprofen monotherapy started on day 5 group) and -146, (95% CI -631, +340) in FPI monotherapy started on day 5 group.…”

“…This was useful only as proof of concept because infected but asymptomatic patients (human or bovine) will not often be diagnosable. [22] We have advanced current knowledge (1) by determining that initiation of treatment up to five days after inoculation is beneficial and (2) by demonstrating that dual therapy of an NSAID with an FPI should be used.…”

“…The animals were randomized to one of six treatment arms with varying start times for first dose of ibuprofen, FPI or both. Since previous studies had demonstrated efficacy of each drug singly administered beginning on the day following experimental bovine RSV infection and beginning on day 3 after infection for FPI, [22,27] we did not include drug initiation on day 1 for either drug or a day 3 start for FPI. Ibuprofen was administered at 10 mg/kg three times daily and 600mg (regardless of weight) of FPI was given in a total volume of 30 ml by oral dose syringe once daily in the morning.…”

“…Total RNA was extracted from the cell lysate using the RNeasy Mini Kit (Qiagen, Hilden, Germany), according to the manufacturer's directions as described elsewhere. [22] Extracted RNA was stored at -80˚C until used for further procedures. 10 μl of viral RNA from each sample was used for reverse transcription.…”

“…[21] We have previously shown improved clinical score but also increased viral shedding in bovine calves when ibuprofen rather than placebo was initiated on the day following experimental bovine RSV infection. [22] GS-561937 FPI initiated on the day following inoculation both improved clinical scores and decreased viral shedding; a smaller benefit was seen when this FPI was started three days after infection. [16] This earlier work demonstrates the these drugs' potential but is of limited practical value because clinical symptoms of RSV typically appear three to five days after inoculation.…”