Nasal and Bronchial Absorption Sampling in RSV Bronchiolitis

Validation of Nasal and Bronchial Absorption Sampling Methods for the Assessment of RSV Bronchiolitis in Babies and Children

This study will compare the novel methods of NS and BS with the standard technique of nasophayngeal aspiration (NPA) and routine ETT suction. We shall assess the samples for diagnosis of RSV, viral load and immune responses in the airways of babies with RSV infection. We shall also assess the genetics of babies included in this study, to see if they may be vulnerable to RSV infection.

In conjunction with a specialist medical device manufacturing company (Hunt Developments (Midhurst, West Sussex) we have produced novel nasosorption and bronchosorption kits that have CE marking. Both nasosorption and bronchosorption methods use synthetic absorptive matrix (SAM) strips: that look and feel like blotting paper, and will be placed onto the mucosal surface. These are comfortable to use and can be used at frequent intervals over extended periods of time. This non-invasive technique is ideal for infants and children, and it is possible to obtain neat mucosal lining fluid (MLF) even from normal healthy noses. The eluates contain cytokines and chemokines at high detectable levels on multiplex immunoassay.

We would like to use these SAMs to take MLF samples from the nasal and bronchial mucosal surfaces to see if these novel techniques can overcome the problems with current sampling methods. We plan to use these absorption techniques to measure RSV viral load. We also aim to look at the immune response in terms of the anti-viral interferon response (IFN-γ, IFN-λ, IFN-α2a, IP10, ITAC). In therapeutic studies in the future, it may be possible to document levels of drug (pharmacokinetics) in nasal MLF.

Group 1 and Group 2

Inclusion Criteria

• Infants aged 2 weeks-24 months
• Presentation to the Emergency Department with any upper respiratory tract infection (URTI) in the RSV season (Oct-March).

OR • Documented RSV infection, admitted to the paediatric wards at St Mary's Hospital.

Exclusion Criteria

• Any local or systemic factor that would influence the safety of nasal sampling.
• Bilateral indwelling nasal catheters or local nasal pathology preventing access for nasal sampling.
• Bleeding disorders.
• The baby is taking part in another interventional study.
• The parents or guardians not able to sign the informed consent from due to limited English or comprehension despite the use of independent interpreter services.
• Limited life expectancy of the baby,

Group 3

Inclusion criteria

• Hospitalised Infants admitted to the PICU at St. Mary's Hospital, aged 2 weeks-24 months with documented RSV infection (by rapid test and/or PCR).
• Infants of weight >2kg.
• On a conventional ventilator with an Endotracheal Tube (ETT) of >3.0mmm diameter

Exclusion criteria

• Any local or systemic factor that would influence the safety of nasal sampling.
• Bilateral nasal catheters or local nasal pathology preventing access for nasal sampling.
• The baby is taking part in another interventional study.
• Prematurity - corrected gestational age <36 weeks, weight <2kg
• Significant hypoxia or instability precluding ventilator disconnection
• ETT < 3mm internal diameter
• Transcutaneous oxygen saturation of <95% on 60% oxygen
• Risk of bleeding
• Pneumothorax
• Infants receiving oral corticosteroid therapy at any time in past month
• Parents or guardians not able to sign informed consent from due to limited English or understanding despite the use of independent interpreter services.
• Limited life expectancy or a decision to limit management,

Control Group 1 Inclusion criteria

• Babies, aged 2 weeks-24 months, attending routine outpatient appointments or undergoing elective surgical procedures.

Exclusion criteria

• Any respiratory symptoms
• All other exclusion are the same as Groups 1 and 2

Control Group 2

Inclusion criteria

• Infants aged 2 weeks-24 months.
• Infants ventilated on the PICU for any condition
• Confirmed RSV negative by PCR of respiratory tract samples

Exclusion Criteria

• All exclusions are the same as Group 3
• In addition - any concern about raised intracranial pressure