Histamine release from leucocytes during migraine attack

Prevalence of migraine headaches in patients with allergic rhinitis

BACKGROUND

Histamine has been implicated in the pathogenesis of migraine headaches. Because allergic rhinitis (AR) is a histamine-driven syndrome and the nasal passage is in close proximity to the central nervous system, we hypothesize that AR may trigger migraine headaches.

OBJECTIVE

To determine the prevalence of migraine headaches in patients with and without AR.

METHODS

Allergic rhinitis was diagnosed based on skin or radioallergosorbent test results, clinical history, and physical examination findings. The diagnosis of migraine headache was made if patients fulfilled the International Headache Society criteria. Surveys were obtained from hospital-based allergy, pediatric, and internal medicine clinics, all serving the same inner-city population.

RESULTS

A total of 294 surveys were completed. Of 76 patients in the AR group, 26 (34%) had headaches meeting the International Headache Society criteria for migraines, and of the 57 patients in the non-AR group, only 2 (4%) had headaches that met the criteria. A Fisher exact test showed P = 8.2 x 10(-6). The odds ratio was 14.3, which signifies that the odds of having migraine headaches is 14.3 times higher in the AR group than in the non-AR group.

CONCLUSIONS

There is a high prevalence of migraine headaches in patients with AR compared with those without AR. We propose that histamine plays a key role in triggering migraines by means of vasodilation and inflammation in the pathogenesis of migraine headaches.

The role of mast cells in migraine pathophysiology

Mast cells are critical players in allergic reactions, but they have also been shown to be important in immunity and recently also in inflammatory diseases, especially asthma. Migraines are episodic, typically unilateral, throbbing headaches that occur more frequently in patients with allergy and asthma implying involvement of meningeal and/or brain mast cells. These mast cells are located perivascularly, in close association with neurons especially in the dura, where they can be activated following trigeminal nerve, as well as cervical or sphenopalatine ganglion stimulation. Neuropeptides such as calcitonin gene-related peptide (CGRP), hemokinin A, neurotensin (NT), pituitary adenylate cyclase activating peptide (PACAP), and substance P (SP) activate mast cells leading to secretion of vasoactive, pro-inflammatory, and neurosensitizing mediators, thereby contributing to migraine pathogenesis. Brain mast cells can also secrete pro-inflammatory and vasodilatory molecules such as interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF), selectively in response to corticotropin-releasing hormone (CRH), a mediator of stress which is known to precipitate or exacerbate migraines. A better understanding of brain mast cell activation in migraines would be useful and could lead to several points of prophylactic intervention.

Migraine and function of the immune system: a meta-analysis of clinical literature published between 1966 and 1999

Mechanisms underlying migraine precipitation are largely unknown. A role of the immune system in migraine precipitation is a matter of debate because of the association of atopic disorders and migraine. Recently, it was demonstrated that migraineurs benefit from eradication of a Helicobacter pylori infection, which substantiates a possible role for (sub-clinical) infections in precipitation of migraine. Since 1966, about 45 clinical investigations have reported on alterations of immune function in migraine patients, which we present in this review. Changes of serum levels of complement and immunoglobulins, histamine, cytokines and immune cells were found in some of these studies but in most cases not corroborated by others. Migraineurs suffering from comorbid atopic disorders show elevated plasma IgE levels but not patients without a type I hypersensitivity. Histamine plasma levels are chronically elevated in migraineurs, and interictally decreased lymphocyte phagocytotic function and increased plasma tumor necrosis factor alpha (TNFalpha) levels were found, and may be related to increased infection susceptibility. The cause of this increased susceptibility is unclear but most likely is a result of chronic stress, a well-known suppressor of the immune system. Stress relief enhances immune activity and triggers a burst of circulating vasoactive compounds that function as mediators of inflammation and potential precipitators of a migraine attack in vulnerable subjects. In conclusion, in the clinical literature of the past decades, there is no clear-cut evidence of an immune dysfunction in migraineurs, but we cannot totally exclude the possibility of an altered immune function in migraineurs. Discrepancies in the literature most likely are caused by the divergent patterns of sample collection relative to the time of the attack. We propose stringent definition of sample collection times for future studies of immune function in migraine patients.

Glucosamine for migraine prophylaxis?

Following a fortuitous observation that migraine headaches ceased in a patient receiving glucosamine therapy for osteoarthritis, a further ten patients with migraine or migraine-like vascular headaches, refractory to established preventive or abortive therapies, have been treated with daily oral glucosamine. After a lag of 4-6 weeks, a substantial reduction in headache frequency and/or intensity has been noted; in some cases, the benefit appears to be dose-dependent. Since glucosamine can be a rate-limiting precursor for mucopolysaccharide synthesis, it is germane to note previous reports that heparin and pentosan polysulfate may have migraine-preventive activity. There is reason to suspect that mast cells are central mediators of the neurogenic inflammation associated with migraine and cluster headaches. The heparin produced by mast cells may function to provide feedback down-regulation of mast cell activation, and exerts a range of other anti-inflammatory effects. We postulate that supplemental glucosamine can boost mast cell heparin synthesis - perhaps correcting a functional heparin deficiency - thereby preventing or ameliorating the neurogenic inflammation that mediates pain in vascular headache. Whether or not this idea has validity, a controlled study of glucosamine for migraine prophylaxis appears to be warranted.

[Histamine-release and migraine]

Some studies suggested a role for histamine in the pathogenesis of the migraine. So we decided to investigate the histamine-release in two groups of patients: 8 common migraine patients, 8 healthy subjects. Plasma from either controls or migraineurs were mixed with the same control whole blood and histamine release was measured using a radio-enzymatic assay. Migraine plasma induced an histamine release significantly more important than control plasma (p less than 0.01). The nature of an "histamine releasing factor" in the plasma of migraine patient is discussed. This work is an argument for a possible immuno-allergic process in migraine.

Whole blood and plasma histamine in common migraine

Whole blood and plasma histamine levels were measured in 27 non-medicated patients with common migraine. In nine cases blood was drawn 1-2 h after the onset of a migraine attack. The whole blood histamine levels of migraineurs and controls did not differ significantly. In contrast, histamine levels were significantly increased in plasma from patients both during and between migraine attacks, as compared with controls (p less than 0.001). Finally, plasma taken from migraine patients induced a significantly greater release of histamine from control whole blood than did plasma taken from control subjects (p less than 0.01).