Minimizing Treatment Risks

Other scientists are looking at markers in the blood of individuals that can predict risk for medication side effects. One of the mostly widely studied drugs in this regard – as well as one of the most successful and widely used drugs for juvenile arthritis – is methotrexate. For some children, as well as adults, adverse effects make it necessary to stop the drug.

The reason, researchers have found, may be genetic mutations that interfere with the ability to metabolize the B vitamin folate.

Researchers are looking for other genetic variations which would better predict who would be most likely to suffer side effects and thus might not be appropriate candidates for methotrexate therapy.

Knowing When to Say When

Once doctors find the right treatment for a child, the next questions are: How do we know when arthritis is under control?  How long must the child take the medication? Will stopping medication cause the disease to flare?

In research supported by the Arthritis Foundation and led by James N. Jarvis, MD, at the Oklahoma University Health Services Center, researchers used genetic profiling to look for evidence of JIA remission. They found underlying abnormalities in gene expression are still present, even if such abnormalities are not reflected in standard clinical measures such as the sed rate, the C-reactive protein (CRP) level or white blood cell count. Rather than a resolution of the underlying inflammatory process, they say remission is more likely to be the result of a balance between pro-inflammatory and anti-inflammatory mechanisms, and a disruption of that balance can cause disease to flare. Further research is needed to determine the factors that disrupt the balance and to determine when and if children can discontinue or taper medication without experiencing a disease flare.

What’s Next?

The ability to design treatment plans to achieve the best outcomes for children with arthritis is one of the top goals for the Arthritis Foundation’s research program.

As a part of this goal, the Foundation has long advocated the establishment of a pediatric rheumatology registry, which Dr. Vehe says would be a crucial step toward personalized medicine.

“While a better understanding of the different types of JIA is already helping doctors select the most effective treatment by disease type, a database of tissues samples, medication histories, side effect histories and efficacy data would enable research that would help us to develop new ways to select appropriate treatments for each individual child with JIA,” says Dr. Vehe.

In the meantime, researchers are already making strides in developing new therapies and better classifying the forms of juvenile arthritis and factors that affect treatment response – either good or bad – so that, one day, a sample of blood may be all it takes to get each child the most effective treatment with the least risk of unwanted side effects.