Rhinovirus is not detectable in peripheral lung tissue after asthma death

Viral infections are associated with both mild and severe exacerbations of asthma and may therefore be associated with asthma death. As such we hypothesized that it might be possible to detect rhinovirus (RV), the virus most frequently implicated in acute asthma, in lung tissue from patients who died from asthma.

We studied archival, wax-embedded lung tissue obtained postmortem from: (i) patients who died from asthma (n = 12), (ii) asthma patients with non-asthma-related death (n = 3), and (iii) non-asthmatic individuals who died from unrelated causes (n = 3). A validated reverse transcription-polymerase chain reaction (RT-PCR) assay was used to detect RV. To confirm RNA preservation, RT-PCR was used to detect expression of the constitutive gene adenine-phosphoribosyl-transferase (APRT). Sensitivity of the assay was assessed using wax-embedded RV-infected cells.

Sensitivity of RT-PCR for RV in wax-embedded sections was similar to previous studies (approximately 100 viral copies). Specimens used for study were predominantly of alveolar and small airway origin (< 2 mm). All tissues examined were negative for the presence of RV mRNA and positive for APRT mRNA.

RV infection of the lower airway may be an uncommon cause of fatal asthma. Alternatively, RV may not extend to peripheral airways and more proximal tissue sampling or PCR assays for other viruses may be required to determine an association between viral respiratory tract infection and fatal asthma.