Salivary Inflammatory Markers (Interleukin -1β, Interleukin -6, C- Reactive Protein) in Tension Type Headache and Migraine

Sixty subjects of both genders, aged from 18 to 60 years old, with primary headaches TTH and migraine, according to the International Classification of Headache Disorders, 3rd edition (beta version), were enrolled from the outpatient headache clinic of University Hospital of Athens between January to March 2016. 30 healthy control subjects aged matched were recruited mainly from hospital staff and patients' relatives.

Initially, the participants completed the Hamilton Anxiety (HAM-A), Scale Beck Depression Inventory (BDI). All patients had to keep a headache diary during the four-week run-in period. All headache suffers were instructed to collected salivary headache-free baseline samples at the time of study screening when they had been free of headache for at least 48 hours (time point A). All headache suffers collected additional samples during moderate/severe headache (time point B), and at self-defined resolution phase 24 hours of their headache attack (time point C). Healthy control subjects were instructed to collected samples at the time of study screening (time point D). Every week, until four weeks and one month after the end of the study, participants were contacted, in order to ensure the compliance and the appropriate use of the technique. One year later longitudinal data would also be obtain.

Saliva Sample Collection Detailed instructions for the correct collection of saliva samples were given to all participants. Such instructions include avoiding eating a major meal and teeth brushing 60 minutes prior to sample collection. Also consumption of high sugar and caffeine content foods as well as high acidity foods have to be excluded before saliva sample collection. Mouth rinse with water in order to remove any food residue and saliva sample collection at least 10 minutes after mouth rinse was recommended. Unstimulated whole saliva that pooled on the mouth floor were collected from patients and healthy volunteers in high quality polypropylene vials by the passive drool technique. Finally, all samples were stored in a plastic container at 2-4 ° C until analysis. Saliva was collected from the participants, at 8.00 a.m. in the morning in order to rule out any confounding factor caused by circadian rhythm.

Sample Analysis Morning samples were kept in the refrigerator at 4°C and at the end of the day were brought to the laboratory where they were centrifuged 3000 rpm at 4°C and the supernatant was aliquoted in to polypropylene Cryogenic vials. Vials were frozen in -80°C until analyzed. Saliva transferrin levels were measured by competitive immunoassay kits and Interleukin-6, Interleukin-1β and CRP levels were measured by sandwich ELISA kits. Transferrin levels were used as a screening tool for the presence of blood in saliva samples and samples with transferrin values greater than 1 mg/dl were considered as candidates for exclusion in other salivary assays. Cortisol assay has a sensitivity of < 0.007 μg/ml and an inter-assay coefficient of variation of < 11% while these characteristics are 0.07 pg/ml and 8 for Interleukin-6, 0.37 pg/ml and 7 for Interleukin-1β, 10 pg/ml and 11.2 for CRP as well as 0.08 mg/dl and 7.2 for transferrin respectively.