Reduced Activity of the NK Cells from Patients with Cluster Headache and the “In Vitro” Response to β‐Interferon

Abstract

SYNOPSIS A quantitative increase of leukocyte Leu7+ subset (largely represented by cells with natural killer activity, NK) was observed in the peripheral blood mononuclear cells of patients during the active period of cluster headache (CH). These patients are susceptible to herpes virus infections. In order to ascertain whether or not the quantitative changes in Leu7+ leukocyte subset would correspond to changes of the NK function, the activity of NK cells was investigated in CH patients. Eighteen patients with the episodic form of CH were studied during cluster periods and in painless periods. The control group consisted of 11 healthy volunteers. The results show that the NK activity of CH patients is significantly lower in comparison to that of control values. This impairment appears to be independent of the cluster period. Since β‐IFN has been shown to increase “in vitro” NK cell activity, studies were performed to investigate if β‐IFN could restore the limited NK activity found in CH patients. For this purpose the “in vitro” effect of overnight incubation with β‐IFN (1000 I.U./ml) was assessed on NK cell activity in CH patients and in the control group. It was found that β‐IFN was more effective in increasing NK activity of effector cells collected from CH patients when compared with healthy controls.

Immunological Alterations in Cluster Headache During Remission and Cluster Period. Comparison with Low Back Pain Patients

“…We found a reduction in NK + lymphocytes in cluster headache patients during the remission phase. This might be linked to previously described functional abnormalities of this subset (6). We detected a similar reduction in the low back pain patients, however, which may indicate that a decrease in NK + cells can be brought about by a non-specific reaction to chronic stress (13).…”

“…Giacovazzo et al showed an increase in natural killer (NK + ) lymphocytes and monocytes during the cluster period (5). They also reported reduced NK activity in cluster headache patients both in the cluster period and in the remission (6), and suggested that b-interferon might have a restorative action on NK activity.…”

Lymphokine‐Activated Killer (LAK) Cell Phenomenon in Cluster Headache. “In Vitro” Activation by Recombinant Interleukin‐2

“…1,4 These data taken together suggest that some non T cytotoxic systems of CH patients are very susceptible to lymphokine activation, i.e. A significant difference between the active and inactive phase of the disease was noted.…”

“…1 This diminution is more pronounced in patients presenting clinical infections by herpes virus. The activity of these cells is reduced all year without relation to CH activity.…”

“…The activity of these cells is reduced all year without relation to CH activity. 1 In addition, b-IFN when administered "in vivo," restores the NK activity 4 in some CH patients. 2 b-Interferon (b-IFN) enhances the natural cytotoxicity of human lymphocytes.…”