Analysis of leukotrienes in cerebrospinal fluid of a reference population and patients with inborn errors of metabolism: further evidence for a pathognomonic profile in LTC(4)-synthesis deficiency.

Cysteinyl leukotrienes (LTC(4), LTD(4), LTE(4)) are potent lipid mediators derived from arachidonate in the 5-lipoxygenase pathway. Recently, the first inborn error of leukotriene synthesis, LTC(4)-synthesis deficiency, has been identified in association with a fatal developmental syndrome. The absence of leukotrienes in cerebrospinal fluid was one of the most striking biochemical findings in this disorder. We analysed leukotrienes in cerebrospinal fluid of patients with a broad spectrum of other well-defined inborn errors of metabolism, including glutathione synthetase deficiency (n=2), Zellweger syndrome (n=3), mitochondrial disorders (n=8), fatty acid oxidation defects (n=7), organic acidurias (n=7), neurotransmitter defects (n=5) and patients with non-specific neurological symptoms, as a reference population (n=120). The concentrations of leukotrienes were not related to age. Representative percentiles were calculated as reference intervals of each leukotriene. In all patients with an inborn error of metabolism concentration of cysteinyl leukotrienes and LTB(4) did not differ from the reference group. Our results indicate that absence of cysteinyl leukotrienes (<5 pg/ml) in association with normal or increased LTB(4) (50.0-67.3 pg/ml) is pathognomonic for LTC(4)-synthesis deficiency. The unique profile of leukotrienes in cerebrospinal fluid in this new disorder is primarily related to the defect and represents a new diagnostic approach.

Temporal profiles of cerebrospinal fluid leukotrienes, brain edema and inflammatory response following experimental brain injury.

The post-traumatic changes of leukotrienes LTC4, LTD4, LTE4, and LTB4 in cerebrospinal fluid of rats from 10 min to 7 days were investigated after controlled cortical impact in relation to brain edema and cellular inflammatory response. LTC4 increased five-fold at 4 h, normalized at 24 h, and showed another four-fold increase at 7 days. The same pattern was observed for LTD4 and LTE4. LTB4 however, behaved differently: concentrations were lower and levels peaked two-fold at 24 h. Edema in the injured hemisphere increased continuously up to 24 h without change contralaterally. Leukocyte infiltration, macrophage presence and microglia activation were most prominent at 24 h, 7 days and 24 h respectively. Leukotriene changes in CSF seem to reflect those in the affected tissue, with a time delay and in lower concentrations, and were not linearly correlated to brain edema. The initially high leukotriene levels are rather likely to contribute to the cytotoxic edema than to enhance a vasogenic edema component. The profile of LTB4 was parallel to the time course of leukocyte infiltration, indicating initiation of infiltration as well as prolonged production by leukocytes themselves. The second leukotriene peak at 7 days is likely to follow a different pathway and might be related to a production in macrophages or activated glia.

Leukotrienes in patients with clinically active multiple sclerosis.

OBJECTIVES: The role of leukotrienes (LTs) in the pathophysiology of multiple sclerosis (MS) has been controversially discussed in the past. Studies of LTs in the cerebrospinal fluid (CSF) revealed different results mainly because of analytical difficulties. MATERIAL AND METHODS: In the present study we used highly sensitive and specific analytical methods for measuring LTs in the CSF as well as in urine samples from 20 patients with active MS and 20 control patients with noninflammatory neurological disorders. RESULTS: LTB4 concentrations in CSF were almost twice as high in MS patients compared with controls (P < 0.001). CSF concentrations of the cysteinyl-LTs (LTC4, LTD4 and LTE4) as well as urinary LTE4 showed no significant differences compared with controls (P > 0.05). In addition, there was no significant association between CSF pleocytosis, clinical severity or time of disease onset. CONCLUSIONS: The increased concentration of LTB4 in the CSF of MS patients may indicate a biological importance for this mediator in MS.

Levels of immunoreactive cysteinyl-leukotrienes in CSF after subarachnoid haemorrhage correlate with blood flow-velocity in TCD.

Lipid peroxidation and enhanced arachidonic acid metabolism is activated after blood-brain cell contact. Previous studies have indicated that cysteinyl-leukotrienes (cys-LT) have the capacity to constrict arterial vessels in vivo and in vitro suggesting their involvement in the pathogenesis of cerebral vasospasm. The purpose of this study was to measure the amount of cyst-LT in the cerebro-spinal fluid (CSF) in correlation with transcranial Doppler findings (TCD) in patients with aneurysmal subarachnoid haemorrhage (SAH). In all patients early surgery was performed. In the first cisternal CSF-sample which was already collected intra-operatively an initial peak of cys-LT was detected, followed by decreasing amounts of cys-LT during the next 5 days. The CSF-levels of immunoreactive cys-LT were significantly higher in those patients who showed signs of vasospasm on transcranial Doppler sonography (TCD) (p < 0.001). Normalization of TCD values was accompanied by decreasing levels of CSF-cys-LT. We found a significant correlation between the amounts of immunoreactive cys-LT in cerebrospinal fluid and cerebral vasospasm measured by TCD.