Nikhil Prasad Fact checked by:Thailand Medical News Team Jul 13, 2026 49 minutes ago
Medical News: New Study Suggests Salivary Immune Proteins Could Help Explain COVID-19 Severity
Scientists from İnönü University Faculty of Medicine, Fethi Sekin City Hospital, and Fırat University Faculty of Medicine in Türkiye have uncovered intriguing evidence that naturally occurring immune proteins known as histatins behave differently during COVID-19 than previously expected. Their findings suggest these proteins could eventually become useful markers for understanding how the body responds to SARS-CoV-2 infection.
Researchers discover unexpected changes in immune-related histatin proteins that may offer new insights into how the
body responds to COVID-19
Histatins are small antimicrobial proteins mainly produced by the salivary glands. While they are best known for protecting the mouth from harmful microbes, researchers have increasingly recognized that they also help regulate inflammation and support the immune system. Until now, little was known about how these proteins change during COVID-19.
Study Compared Mild, Severe and Healthy Individuals
The researchers enrolled 90 participants divided equally into three groups: healthy volunteers, patients with mild COVID-19 without pneumonia, and patients with severe COVID-19 suffering from pneumonia. Blood samples were collected during the first week of illness, and levels of histatin-1, histatin-3 and histatin-5 were measured.
All patients with severe disease were receiving corticosteroid treatment when their blood samples were taken. Because of the study design, the researchers stressed that their findings show an association rather than proving that the medication caused the observed changes.
Surprising Drop Seen Only in Mild Cases
The biggest surprise came from histatin-3 and histatin-5. Patients with mild COVID-19 had significantly lower levels of both proteins than healthy individuals. Histatin-3 fell by roughly 38 percent, while histatin-5 dropped by about 30 percent. However, patients with severe COVID-19 did not experience an additional decline. Instead, their histatin levels were similar to those of healthy volunteers and noticeably higher than those found in patients with mild illness.
Histatin-1 showed no meaningful differences among the three groups.
This unexpected pattern suggests the body's immune response during severe disease may be far more complex than simply becoming progressively weaker as infection worsens.
Important Links with Inflammation
This
Medical News report highlights another important finding from the research. Histatin-3 was closely linked with several laboratory markers commonly associated with severe COVID-19.
Higher histatin-3 levels were associated with increased ferritin, a protein that often rises during intense inflammation, and with elevated D-dimer, a marker linked to abnormal blood clotting. Histatin-3 also showed an inverse relationship with albumin, meaning lower
albumin levels tended to accompany higher histatin-3 concentrations.
Interestingly, histatin-5 did not demonstrate similar relationships, suggesting histatin-3 may become the more useful biological marker for future studies.
Why Did Severe Patients Maintain Histatin Levels?
The researchers proposed several possible explanations. SARS-CoV-2 can directly infect the salivary glands, potentially reducing histatin production during mild disease when the virus mainly affects the upper airways. In severe disease, the infection shifts more toward the lungs, which may lessen damage to the salivary glands.
Another possibility is that corticosteroid treatment helped preserve histatin production by reducing inflammation or protecting gland tissue. However, because every severe patient had already begun steroid treatment before blood collection, the study cannot determine whether the medication was responsible.
More Research Still Needed
The investigators also found that survivors of severe COVID-19 tended to have higher histatin-3 and histatin-5 levels than those who died, although the number of survivors was too small to draw firm conclusions. Future studies involving larger patient groups and repeated blood sampling before and after treatment will be needed to determine whether histatins could become reliable biomarkers or even therapeutic targets.
Conclusion
The study reveals that COVID-19 alters important immune-related proteins in an unexpected way. Rather than declining steadily as illness becomes more severe, histatin-3 and histatin-5 were significantly reduced only in mild infections, while severe patients receiving corticosteroids maintained levels similar to healthy individuals. These findings point toward a complicated interaction between viral infection, inflammation, salivary gland function and medical treatment. Although much more research is required before these proteins can be used in routine care, histatin-3 in particular appears to hold promise as a potential indicator of immune activity and inflammatory responses during COVID-19.
The study findings were published in the peer reviewed Journal of Medical Virology.
https://www.ovid.com/journals/jomv/fulltext/10.1002/jmv.71009~serum-histatin-levels-in-covid-19-association-with-disease
For the latest COVID-19 news, keep on logging to Thailand
Medical News.
Read Also:
https://www.thailandmedical.news/articles/coronavirus
Share
Tweet
Share
