The researchers measured blood levels of ADP, a protein hormone secreted from fat tissue and known to modulate several of the pain pathways implicated in migraine. The hormone is also implicated in sugar metabolism, insulin regulation, immunity and inflammation, as well as obesity, which is a risk factor for migraines.
Peterlin and her colleagues looked at total adiponectin levels and two subtypes or fragments of total ADP in circulation in the blood: low molecular weight (LMW)-adiponectin and high molecular weight (HMW)-adiponectin. LMW is comprised of small fragments of ADP and it is known to have anti-inflammatory properties, while HMW is made up of larger fragments of ADP and is known to have pro-inflammatory properties. Inflammatory pathways in blood vessels in the head are at work in migraine headache.
The researchers found that in all 20 participants when levels of LMW increased, the severity of pain decreased. When the ratio of HMW to LMW molecules increased, the pain severity increased.
"The blood tests could predict response to treatment," Peterlin says.
At onset of pain -- even before study drug was given the researchers could identify who would be a responder to treatment and who would not, as there was a greater ratio of HMW to LMW in those who would be responders as compared to those who were not.
After study treatment changes in adiponectin were also seen. Interestingly, in those patients who reported less pain after receiving study drug to treat the migraine whether they got the active migraine medication or a placebo researchers were able to see a decrease in total levels of ADP in the blood.
Peterlin says the findings indicate it may be possible to develop a treatment that would reduce levels of ADP or parts of adiponectin such as HMW or LMW adiponectin. She says should ADP prove to be a biomarker for migraine
|Contact: Stephanie Desmon|
Johns Hopkins Medicine