Research on the so-called "long COVID" showed abnormalities that may explain shortness of breath even several years after infection. There is a possibility that the virus can cause microscopic lung damage that cannot be detected by basic tests.
The results of a 36-patient study indicate the possibility that COVID-19 may cause microscopic lung damage that is not detected by routine testing.
Dyspnoea is a symptom that occurs in most patients with long-term COVID-19, but it is unclear if it is related to other factors such as fatigue.
According to Dr. Emily Fraser, consultant at Oxford University Hospitals and co-author of the study, the latest findings are the first evidence that the virus can cause some persistent abnormalities in the lung microstructure or vascular system of the lungs.
More research is needed to clarify the clinical relevance of the findings, including how the apparent abnormalities relate to dyspnea.
The latest study, which aims to recruit 400 participants, uses a specialized MRI imaging technique in which patients breathe xenon while lying in a scanner. The gas can be tracked as it travels from the lungs into the bloodstream, giving you information about how the lungs are functioning. This contrasts with CT scans which only show the structure of the lungs.
Three groups were compared: patients diagnosed with long COVID who had good CT scans; people who had been hospitalized with COVID more than three months previously and did not experience symptoms of long-term COVID, and a he althy control group.
Preliminary results show that patients with long COVID have "significantly impaired gas transfer" from the lungs to the bloodstream, even when baseline research is normal. Similar abnormalities were found in COVID patients who were hospitalized due to the severe course of the disease.
Experts emphasize that these findings do not undermine the importance of rehabilitation programs and that rehabilitation strategies are really helpful.