PLACERVILLE, California By Chia-Yi Hou Nov 15, 2022 — They found the genes after sequencing RNA found in the bloodstream.

A team of researchers finds that people with long term Lyme disease may have a pattern of immune response that might be detectable in a blood sample.

Lyme disease, which is caused by a species of bacteria transmitted by ticks, is difficult to diagnose. There isn’t a surefire sign to look for and two types of tests may be required. But the researchers suggest the pattern they found could help diagnose the disease more reliably in the future.

In a study published Tuesday in Cell Reports Medicine, researchers identified genes that may be associated with long term Lyme disease. Genes code for various things that the body needs to function, including an immune response to an infectious disease.

The team analyzed blood samples from 152 patients who had symptoms of Lyme disease post-treatment. They also looked at RNA sequencing data from 72 patients with acute Lyme disease and 44 people who were uninfected.

The differences in which RNA might be found in the blood are related to gene expression. As the body responds to a pathogen, that might change which genes get expressed, meaning the product a particular gene is coding for gets produced. How much of each gene product gets produced can depend on what the body is responding to.

In this case, the team identified 35 genes that were highly expressed in people with long term Lyme disease. This means that there were higher quantities of the RNA that these genes encode in the bodies of the patients.

The patterns were different between the post-treatment Lyme disease patients and the patients with acute Lyme disease, suggesting that it might be possible to distinguish between early and later stages of Lyme disease by analyzing RNA in blood samples.

The researchers think that these patterns in RNA levels could serve as a biomarker, or a signal in blood samples, that may help to diagnose Lyme disease.

“A diagnostic for Lyme disease may not be a panacea but could represent meaningful progress toward a more reliable diagnosis and, as a result, potentially better management of this disease,” says Avi Ma’ayan, who is a the Director of the Mount Sinai Center for Bioinformatics at Icahn Mount Sinai and the senior author on the paper, in a press release.