Studio dell'attivazione piastrinica nell'emicrania in età evolutiva

Although the evidence now available now suggests that migraine is associated with increased platelet activity, a specific role of platelets in migraine pathogenesis is still a cotroversial question. Plasma levels of beta-thromboglobulin (BTG) and platelet factor 4 (PF4), two specific proteis released by α-granules, as well as thromboxane B2 (TxB2), a stable metabolite of thromboxane A2 derived from arachidonic acid pathway which is a potent vasoconstrictor and an aggregating factor, are considered usefull indices of platelet activation in vitro. Elevated plasma concentrations of BTG and PF4 have been reported in adults during migraine attacks. With respect to the higher BTG and PF4 plasma levels observed during headache-free periods in classic migraine, only BTG values were significantly different in the common type in comparison with the control group. Although no changes were observed in the plasma levels of the TxB2 between attacks in migranious adults and children, evidences are now available showing that plasma TxB2 levels is lowered in adult migraine patients during headahce free period and platelet TxA2 formation is decreased in migranious children and in adults with classic form. Contradictory results therefore have been reported for the pediatric age. The aim of this study was to investigate the occurrence of platelet activation in headahce-free periods, in a selected group of migrainous children by means of radioimmunoassay at BTG, PF4 and TxB2: twenty five patients, 15 males and 10 females, ranging from 8 to 15 years of age (mean ± SD = 11.9 ± 1.9 years), were examined twenty-three with the common migraine headache and two with the classic form. There were 16 controls, the age range and sex ratio being similar to the migraine group. The mean levels of BTG and TxB2 of migraine patients during headahce free periods did not differ significantly from those of controls; also the platelet count was similar in both groups (Table 2). Between headache free periods, unlike in adult patients, our findings in migrainous children do not indicate platelets undergoing the release reactions. It suggests that hereditary or acquired events, later in the growth span, could modify the complex equilibrium between inhibiting snd stimulatory processes of platelet activation.