The PET scan offers the possibility of detecting incipient inflammations in rheumatoid arthritis (RA) and axial spondyloarthritis (ax-SpA) at an earlier stage. This has been shown in research among patients by rheumatologist and researcher of AII Conny van der Laken. With the PET scan we can see inflammations that cannot yet be seen on the outside.
The early detection of inflammatory rheumatic diseases such as RA and Ax-SpA is important because it can prevent damage. The PET scan has already been used for some time to see if someone has a certain condition. Dr. Conny van der Laken is one of the first researchers to use the PET scan to diagnose incipient inflammatory rheumatism.
Detecting inflammatory cells early on
Her research shows that the PET scan offers the possibility of detecting at a very early stage certain inflammatory cells in the joints that are associated with rheumatoid arthritis. We did this in people who did not yet have RA, but did have antibodies in their blood. They were therefore at risk of developing RA. In one of our earlier studies we showed that with the PET scan we could detect joint inflammation in the hands up to a year earlier, well before someone was diagnosed with RA.
Looking beyond joints
In the meantime, her research has been expanded, partly due to support from ReumaNederland, and her research team is using the PET scan to look for early joint inflammations in the entire body. Because the PET scan is a 'photograph' of the entire body, we can also detect the inflammatory cells in the organs. This is important because, for example, inflammations can also occur in the arteries in people with RA. By detecting and treating them at an early stage, you can also prevent damage here.
Detecting the formation of bone
A second study by Conny van der Laken shows that the PET scan can also be used for the early detection of another form of inflammatory arthritis: Ax-SpA. Ax-SpA or axial spondyolartritis includes Bechterew's disease and psoriatic arthritis. Inflammation causes the formation of extra bone in people with Ax-SpA. The spinal deformities associated with Bechterew's disease are well known. With the PET scan, we can easily detect the formation of new bone. Again, if you can detect it early, you can start treating people with Ax-SpA sooner.
New: quickly determining whether a treatment is effective
In her latest research, Conny van der Laken and her team will use the PET scan to determine more quickly whether a treatment is effective. Dr Van der Laken: 'As rheumatologists we can now often only see after three or four months in the joints and in the blood whether the treatment is working in RA patients. With the PET scan, we hope to be able to see this after only four weeks. In Ax-SpA patients, we can see after only 12 weeks whether medication is inhibiting bone formation. On ordinary X-rays, this can only be seen after an average of two years. Our ultimate goal is to prevent people from having to continue taking medicines that do not work for them for an unnecessarily long time.
Participate in these studies?
The detection of inflammatory arthritis with the PET scan is still in the research phase. You too may be able to participate in one of the three studies conducted by Dr Conny van der Laken of the Amsterdam UMC, location VUmc. Her team of researchers is looking for participants with:
- doctor-diagnosed joint pain (no joint swelling yet) and the antibody anti-CCP/ACPA in the blood
- Axial spondyloarthritis (Bechterew's disease/arthritis psoriatica) with active disease
- RA starting treatment with TNF-alpha inhibitors or switching from TNF-alpha inhibitors