What is included in a respiratory panel?

Components of a Respiratory Panel

A respiratory panel typically includes multiplex PCR assays that test for influenza viruses, respiratory syncytial virus (RSV), and multiple other respiratory viruses and select bacterial pathogens, depending on the specific panel being used. 1

Common Components of Respiratory Panels

Respiratory panels use nucleic acid-based testing methodologies to detect multiple respiratory pathogens simultaneously. The most common components include:

Viral Pathogens

• Influenza A and B viruses 1
• Respiratory syncytial virus (RSV) 1
• Parainfluenza viruses (types 1-4) 1
• Human metapneumovirus 1
• Rhinovirus 1
• Adenovirus 1
• Coronaviruses (229E, OC43, HKU1, NL63) 1
• SARS-CoV-2 (added to newer panels since the COVID-19 pandemic) 1

Bacterial Pathogens (in some panels)

• Bordetella pertussis 1, 2
• Atypical bacterial pathogens (in select panels) 1

Testing Methodologies

Commercially available respiratory panels employ various nucleic acid amplification techniques including:

• Real-time RT-PCR 1
• Multiplex microarray competitive DNA hybridization 1
• Nested multiplex RT-PCR 1
• Isothermal nucleic acid amplification 1
• Loop-mediated isothermal DNA amplification 1
• RT-PCR followed by microarray hybridization 1

Specimen Types

The most common specimen types used for respiratory panels include:

• Nasopharyngeal swabs (most common) 1
• Nasal swabs 1
• Nasal aspirates 1
• Nasal washes 1
• Throat swabs 1
• Bronchoalveolar lavage (BAL) fluid (for select panels) 1

Types of Commercial Respiratory Panels

Commercial respiratory panels can be categorized into five main types:

1. Comprehensive multiplex PCR panels (>4 targets): Include influenza, non-influenza respiratory viruses, and select atypical bacterial pathogens

   • Examples: FilmArray Pneumonia Panel and FilmArray Respiratory Panel (BioFire Diagnostics), ePlex Respiratory Pathogen Panel (GenMark Diagnostics) 1, 3

2. Multiplex PCR panels for viruses only (>4 targets): Include influenza and non-influenza respiratory viruses

   • Example: eSensor Respiratory Viral Panel (GenMark Diagnostics) 1, 3

3. Limited multiplex PCR panels (3 targets): Typically include influenza A/B and RSV

   • Example: Xpert Flu/RSV XC (Cepheid) 1

4. Multiplex PCR panels for non-influenza viruses (2-3 targets)

   • Examples: Solana RSV + human metapneumovirus assay (Quidel), Panther Fusion Paraflu Assay (Hologic) 1

5. Single-target assays for specific non-influenza viruses

   • Example: Alere I RSV (Abbott Laboratories) 1

Clinical Applications

Respiratory panels are particularly useful in:

• Diagnosing community-acquired pneumonia (CAP) 4
• Evaluating febrile patients in intensive care units 1
• Managing immunocompromised patients at high risk for severe respiratory infections 1
• Pediatric respiratory infections 1, 2

Advantages of Multiplex Respiratory Panels

• Decreased turnaround time compared to traditional methods 1
• Improved detection of co-infections 1, 4
• Potential reduction in antibiotic use 1
• Better utilization of hospital isolation resources 1
• Enhanced epidemiological surveillance 1

Limitations and Considerations

• Upper respiratory tract testing may not be sufficiently sensitive for lower respiratory tract infections, particularly in critically ill and immunocompromised patients 1
• Detection of viral nucleic acid does not always correlate with active infection, particularly in immunocompromised hosts who may have prolonged viral shedding 1
• Different commercial panels have varying sensitivities and specificities for different pathogens 5, 3
• Cost considerations may influence panel selection and utilization 1