Pictures of the immune system in action may give doctors an edge in treating autoimmune diseases and cancer.
Until now, there have been few options for imaging the immune system, which is dispersed throughout the body and does not show up readily with X-rays or other imaging methods.
To address this problem, Owen Witte and his colleagues at the University of California at Los Angeles, US, have developed a molecular tag that binds preferentially to immune-system cells to make them visible by positron emission tomography (PET).
When the researchers injected the tag, known as FAC, into mice, they found it gave an image of the animals' spleen, lymph nodes and other immune tissues. Mice whose immune systems had been challenged by a viral infection "lit up" more brightly than uninfected mice, as did mutant mice with autoimmune disorders.
If the same technique works in people, it should give doctors an easier way to monitor the progression of autoimmune diseases such as rheumatoid arthritis or lupus, and quickly gauge the effectiveness of treatments, says Witte.
It may also help in the early detection of cancer, which often involves inflammation at the tumour site. Moreover, because FAC is closely related to gemcitabine, a drug commonly used in chemotherapy for leukemia and some other cancers, oncologists may be able to use the uptake of FAC to predict which patients are likely to respond well to chemotherapy.
Journal reference: Nature Medicine (DOI: 10.1038/nm1724
Interesting! Really promising. Our immune system has been such a 'black box' that our specialists give us the blank stare and shoulder shrug in answer to most of our questions. If they can somehow see how patients' extracted immune cells respond to each drug it will save a lot of precious time (time erodes joints) and unnecessary side-effects, not to mention the cost of tipping ineffective drugs into the bin.