A new study looked at whether a blood test could help predict how well infants with a rare seizure disorder called infantile epileptic spasms syndrome (IESS) respond to the steroid prednisone. Researchers measured levels of several immune-related proteins in the blood of 66 infants with IESS and 53 healthy infants of the same age.
They found that before treatment, infants with IESS had higher levels of several proteins, including HMGB1, TLR4, and certain interleukins, compared to healthy controls. After treatment with prednisone, these levels dropped significantly. Importantly, a greater decrease in HMGB1 from before to after treatment was linked to a better short-term response to prednisone.
The study also identified that the cause of the spasms and the presence of focal seizures were risk factors for prednisone not working well in the short term. Over the long term (at least 18 months), the underlying cause of the spasms was linked to ongoing seizures and poor development, while early control of spasms and long-term seizure freedom were linked to better development.
This is an early, observational study, so it does not prove that HMGB1 directly causes treatment response. The main limitation is that the cause of IESS is still not fully understood. While HMGB1 monitoring might help guide short-term treatment decisions, it did not predict long-term outcomes. Families should discuss any treatment changes with their child's neurologist.