News in brief: ERS/ATS update standards for interpreting PFTs; Study offers clues on how COVID-19 causes persistent lung disease; 4D lung scanner installed at Sydney hospital

Thursday, 17 Mar 2022

ERS/ATS update standards for interpreting PFTs

Updated standards on how to interpret the results of pulmonary function tests have been released by the American Thoracic Society and European Respiratory Society.

The first update since 2005, the standards focus on the levels of uncertainty relating to test results and reference values, with a shift away from the historical approach of fixed adjustment factors for race, the authors say.

“As there are observed population differences in body proportions and lung function, in some contexts it may be relevant to interpret results for an individual relative to that of a similar ancestral grouping, whereas in others it may be more appropriate to compare to the whole population,” they said.

“Translation of these recommendations to clinical practice will require a paradigm shift whereby the idea of an absolute level of ideal lung function (i.e., the predicted value) is replaced in favour of a range of values that are observed in the majority of individuals without respiratory disease (i.e., z-scores or percentiles),” the authors say.

The new standards are published in the European Respiratory Journal.

Study offers clues on how COVID-19 causes persistent lung disease

COVID-19 can cause a sustained alteration of the airway immune landscape in patients with persistent lung disease, “with evidence of cell death and tissue repair linked to the ongoing activation of cytotoxic T cells,” according to research published in the journal Immunity.

The 38-patient study looked at the relationship between the immune system respiratory pathology after COVID-19 infection, by analysing the immune cell and proteomic composition of the airways and peripheral blood in previously hospitalised patients who showed lung abnormalities more than 3 months post discharge.

According to the authors, compared to healthy individuals the post-COVID-19 airways “showed substantial increases in activated CD8+ and CD4+ tissue-resident memory (Trm) cells, and an altered monocyte pool,” while “the airway proteome was also distinct from that observed in healthy individuals, with elevation in proteins associated with ongoing cell death, loss of barrier integrity and immune cell recruitment”.

Also of note, these airway abnormalities did not seem to alter the proteome or immune cells of the matched peripheral blood, and “the scale of these alterations was not linked to the initial severity of disease while in hospital and were heterogenous”.

“Our post-COVID-19 data support the concept that sustained activation of CD8 Trm cells in the airways long after recovery from acute disease contributes to the ongoing damage to the respiratory epithelium, resulting in airway disease,” the authors concluded.

The also suggested that “the involvement of the immune response in different aspects of ongoing respiratory disease post-COVID-19 suggests that…recovery could be accelerated using immunomodulatory treatments”.

4D lung scanner installed at Sydney hospital

A novel ‘4D’ lung scanner that was developed and built in Australia has been officially unveiled at the Prince of Wales Hospital, Sydney.

The XV Scanner uses an automated scanning process to produce detailed lung function and airflow information in real time and will be used for the diagnosis and monitoring of conditions such as COPD, cystic fibrosis and asthma.

According to manufacturer 4DMedical, the scanner uses lung ventilation analysis software that is the first and only modality that can dynamically quantify ventilation in four dimensions. The scanner also uses lower levels of radiation relative to other diagnostic methods and without the need for contrast agents.

The XV Scanner will be used by researchers and clinicians from the University of New South Wales (UNSW) and the Sydney Children’s Hospital, including eminent lung health expert Professor Adam Jaffe, who is currently the John Beveridge Professor of Paediatrics at UNSW.

Developed by global medical technology company 4DMedical, the XV Scanner was funded with $28 million from the government’s Medical Research Future Fund (MRFF).

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