Neurophysiologic follow-up of long-term dietary treatment in adult-onset adrenoleukodystrophy

Effect of Lorenzo's Oil on Hepatic Gene Expression and the Serum Fatty Acid Level in abcd1-Deficient Mice

Lorenzo's oil is known to decrease the saturated very long chain fatty acid (VLCFA) level in the plasma and skin fibroblasts of X-linked adrenoleukodystrophy (ALD) patients. However, the involvement of Lorenzo's oil in in vivo fatty acid metabolism has not been well elucidated. To investigate the effect of Lorenzo's oil on fatty acid metabolism, we analyzed the hepatic gene expression together with the serum fatty acid level in Lorenzo's oil-treated wild-type and abcd1-deficient mice. The change in the serum fatty acid level in Lorenzo's oil-treated abcd1-defcient mice was quite similar to that in the plasma fatty acid level in ALD patients supplemented with Lorenzo's oil. In addition, we found that the hepatic gene expression of two peroxisomal enzymes, Dbp and Scp2, and three microsomal enzymes, Elovl1, 2, and 3, were significantly stimulated by Lorenzo's oil. Our findings indicate that Lorenzo's oil activates hepatic peroxisomal fatty acid β-oxidation at the transcriptional level. In contrast, the transcriptional stimulation of Elovl1, 2, and 3 by Lorenzo's oil does not cause changes in the serum fatty acid level. It seems likely that the inhibition of these elongation activities by Lorenzo's oil results in a decrease in saturated VLCFA. Thus, these results not only contribute to a clarification of the mechanism by which the saturated VLCFA level is reduced in the serum of ALD patients by Lorenzo's oil-treatment, but also suggest the development of a new therapeutic approach to peroxisomal β-oxidation enzyme deficiency, especially mild phenotype of DBP deficiency.

A mixture of oleic, erucic and conjugated linoleic acids modulates cerebrospinal fluid inflammatory markers and improve somatosensorial evoked potential in X-linked adrenoleukodystrophy female carriers

X-linked adrenoleukodystrophy is a rare inherited demyelinating disorder characterized by an abnormal accumulation of very long chain fatty acids, mainly hexacosanoic acid (26:0), due to a mutation of the gene encoding for a peroxisomal membrane protein. The only available, and partially effective, therapeutic treatment consists of dietary intake of a 4:1 mixture of triolein and trierucin, called Lorenzo's oil (LO), targeted to inhibit the elongation of docosanoic acid (22:0) to 26:0. In this study we tested whether, besides inhibiting elongation, an enhancement of peroxisomal beta oxidation induced by conjugated linoleic acid (CLA), will improve somatosensory evoked potentials and modify inflammatory markers in adrenoleukodystrophy females carriers. We enrolled five heterozygous women. They received a mixture of LO (40 g/day) with CLA (5 g/day) for 2 months. The therapeutic efficacy was evaluated by the means of plasma levels of 26:0, 26:0/22:0 ratio, modification of cerebrospinal fluid (CSF) inflammatory markers and somatosensory evoked potentials. Changes of fatty acid profile, and in particular CLA incorporation, were also evaluated in CSF and plasma. The results showed that CLA promptly passes the blood brain barrier and the mixture was able to lower both 26:0 and 26:0/22:0 ratio in plasma. The mixture improved somatosensory evoked potentials, which were previously found unchanged or worsened with dietary LO alone, and reduced IL-6 levels in CSF in three out of five patients. Our data suggest that the synergic activity of CLA and LO, by enhancing peroxisomal beta-oxidation and preventing 26:0 formation, improves the somatosensory evoked potentials and reduces neuroinflammation.

Hexacosanoic and docosanoic acids plasma levels in patients with cerebral childhood and asymptomatic X-linked adrenoleukodystrophy: Lorenzo's oil effect

X-linked adrenoleukodystrophy (X-ALD) is an inherited disorder of peroxisomal metabolism, biochemically characterized by deficient beta-oxidation of saturated very long chain fatty acids (VLCFA). The consequent accumulation of these fatty acids in different tissues and in biological fluids is associated with a progressive central and peripheral demyelination, as well as with adrenocortical insufficiency and hypogonadism. Seven variants of this disease have been described, cerebral childhood being the most frequent. The recommended therapy consists of the use of the glyceroltrioleate/glyceroltrierucate mixture known as Lorenzo's Oil (LO), combined with a VLCFA-poor diet, but only in asymptomatic patients will this treatment prevent the progression of the symptomatology. In the present study we evaluated the biochemical course of patients with cerebral childhood (CCER) and asymptomatic clinical forms of X-ALD treated with LO associated with a VLCFA-restricted diet. We observed that hexacosanoic acid plasma concentrations and hexacosanoic/docosanoic ratio were significantly reduced in CCER patients during treatment when compared with diagnosis. Hexacosanoic acid plasma level was significantly reduced when compared with that at diagnosis and achieved the normal levels only in asymptomatic patients under LO treatment. In asymptomatic patients the magnitude of hexacosanoic acid decrease was higher than that of the CCER patients. These results show the good biochemical response of LO treatment in asymptomatic X-ALD patients. It is possible to suppose that this could be correlated with the prevention of the appearance of neurological signals in this group of patients treated with LO.

Adrénoleucodystrophie liée à l'X☆☆Cet article est publié en partenariat avec Orphanet et disponible sur le site www.orpha.net. © 2007 Orphanet. Publié par Elsevier Masson SAS. Tous droits réservés

X-linked adrenoleukodystrophy (ALD) is a severe neurodegenerative disorder. ALD is characterized by progressive demyelination within the central and peripheral nervous system, adrenal insufficiency (Addison's disease) and accumulation of very-long-chain fatty acids (VLCFA) in plasma, fibroblasts and tissues. The overall incidence of ALD is 1:17,000 including hemizygotes and heterozygotes who are frequently symptomatic. There are two main ALD phenotypes: 1) a cerebral demyelinating form which affects boys between 5-12 years, but also 35% of adult males; 2) a form that mainly involves the spinal cord (adrenomyeloneuropathy, AMN) in adult males between 20-50 years and 50% of heterozygous women after the age of 40 years. AMN presents with progressive spastic paraparesis. Addison's disease may be the first symptom of ALD in boys and adult males. These patients are at risk to develop cerebral ALD or AMN for life. ALD results from mutations in the ABCD1 gene without correlation between genotype and phenotype. The diagnosis of ALD relies upon the measurement of plasma VLCFA levels that allows the identification of 100% affected males and of 80-95% heterozygous women. Because of these false-negative, it is therefore mandatory to search for a mutation in the ABCD1 gene in all women at risk to be heterozygous for ALD. The ABCD1 gene encodes a peroxisomal transmembrane protein (ALD protein) with the structure of an half ATP-binding cassette transporter. It is possible that ALD protein imports VLCFA or VLCFA-CoA into peroxisomes in which they are degraded by a peroxisomal beta-oxidation system. Elongation of VLCFAs is enhanced in fibroblasts from ALD patients and likely contributes to the load of VLCFA in tissues. The underlying mechanisms that lead to cerebral demyelination, axonal degeneration in spinal cord and adrenal insufficiency are unknown. The "toxic" role of VLCFA accumulation remains to be demonstrated. The mechanisms that lead to the inflammatory reaction in cerebral ALD might involve abnormal acylation of gangliosides and phospholipids by VLCFA that would result in immune reaction of brain macrophages and astrocytes bearing CD1 molecules that recognize lipid antigens. De novo mutation of ABCD1 occurs in less than 8% of ALD patients. The genetic counseling aims to identify: 1) women who are at risk to be heterozygous; 2) neurologically asymptomatic boys. It is only at this stage that allogeneic bone marrow transplantation has clinical benefit; 3) ALD patients who have Addison's disease that can lead to sudden death. Prenatal diagnosis (chorionic villus samples, cultured amniotic fluid cells) relies upon DNA based mutation detection techniques, expression of ALD protein and measurement of VLCFA levels. Allogeneic bone marrow transplantation is the only treatment that provides a permanent cure when the procedure is performed at an early stage of cerebral demyelination, i.e when the patients are asymptomatic despite abnormal brain MRI. Treatment of Addison's disease is mandatory but does not modify the course of neurological symptoms. Dietary therapy failed to halt the neurologic progression in cerebral ALD and AMN. It might have a partial preventive effect in boys treated before 6 years of age.

The effect of Lorenzo's oil on oxidative stress in X-linked adrenoleukodystrophy

X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal disorder biochemically characterized by the accumulation of very long chain fatty acids (VLCFA), particularly hexacosanoic acid (C(26:0)) and tetracosanoic acid (C(24:0)), in tissues and biological fluids. Although patients affected by this disorder predominantly present central and peripheral demyelination as well as adrenal insufficiency, the mechanisms underlying the brain damage in X-ALD are poorly known. The current treatment of X-ALD with glyceroltrioleate (C(18:1))/glyceroltrierucate (C(22:1)) (Lorenzo's oil, LO) combined with a VLCFA-poor diet normalizes VLCFA concentrations, but the neurological symptoms persist or even progress in symptomatic patients. Considering that free radical generation is involved in various neurodegenerative disorders and that in a previous study we showed evidence that oxidative stress is probably involved in the pathophysiology of X-ALD symptomatic patients, in the present study we evaluated various oxidative stress parameters, namely thiobarbituric acid reactive species (TBA-RS) and total antioxidant reactivity (TAR) in plasma, as well as the activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in erythrocytes from symptomatic and asymptomatic X-ALD patients and verified whether LO treatment and a VLCFA restricted diet could change these parameters. We observed a significant increase of plasma TBA-RS in symptomatic and asymptomatic X-ALD patients, reflecting induction of lipid peroxidation even before the disease was manifested. In addition, LO treatment did not alter this profile. Furthermore, plasma TAR measurement of X-ALD patients was not different from that of controls. Similarly, the antioxidant enzyme activities CAT, SOD and GPx were not altered in erythrocyte from X-ALD patients as compared to controls. We also examined the in vitro effects of hexacosanoic acid (C(26:0)) and tetracosanoic acid (C(24:0)) alone or combined with oleic (C(18:1))/erucic (C(22:1)) acids on various oxidative stress parameters in cerebral cortex of young rats, namely chemiluminescence, TBA-RS, TAR, CAT, SOD and GPx in order to investigate whether those fatty acids were able to induce oxidative stress. We found that there was a significant increase of TBARS and of chemiluminescence in rat cerebral cortex exposed to C(26:0)/C(24:0), and that the addition of C(18:1)and C(22:1) to the assays did not prevent this effect. Furthermore, TAR measurement was not altered by C(26:0) and C(24:0) acids in rat cerebral cortex. Taken together, our results indicate that lipid peroxidation occurs in X-ALD and that LO treatment does not attenuate or prevent free radical generation in these patients. Therefore, it may be presumed that antioxidants should be considered as an adjuvant therapy for X-ALD patients.

Therapy of X-linked adrenoleukodystrophy

Current therapies for X-linked adrenoleukodystrophy (X-ALD) include replacement therapy with adrenal steroids, which is mandatory for all patients with impaired adrenal function but does not alter neurological progression significantly; dietary therapy with "Lorenzo's Oil," which appears to have a preventive effect in asymptomatic boys whose brain MRI is normal; and hematopoietic stem cell transplantation in patients in the early stage of the cerebral inflammatory phenotype. Application of these interventions requires careful assessment of the patients' phenotype, which often changes over time. Family screening provides important opportunities for disease prevention.

Long-term effect of bone marrow transplantation in adult-onset adrenoleukodystrophy

We report a long-term outcome of motor function in a patient with adult-onset adrenoleukodystrophy after bone marrow transplantation (BMT). Clinically motor function gradually improved and became almost normal in 2 years after BMT. Serial transcranial magnetic stimulation showed gradual improvement of central motor conduction until 1 year after BMT, and then it became stable. Central motor conduction time and motor threshold were useful for monitoring the central motor function in this patient.

Clinical and biochemical findings in 7 patients with X-linked adrenoleukodystrophy treated with Lorenzo's Oil

X-Linked adrenoleukodystrophy (X-ALD) is a hereditary disorder of the peroxisomal metabolism biochemically characterized by the accumulation of very long chain fatty acids (VLCFA) in tissues and biological fluids. The major accumulated acids are hexacosanoic acid (C26:0) and tetracosanoic acid (C24:0). The disorder is characterized clinically by central and peripheral demyelination and adrenal insufficiency closely related to the accumulation of fatty acids. The incidence of X-ALD is estimated to be 1:25,000 males. At least six phenotypes can be distinguished. The most common phenotypes are childhood cerebral ALD and adrenomyeloneuropathy (AMN). The recommended therapy consists of the use of the glyceroltrioleate/glyceroltrierucate (GTO/GTE) mixture, known as Lorenzo's Oil, combined with a VLCFA-poor diet. There are alternative treatments such as bone marrow transplantation and immunosuppression, as well as the use of lovastatin and sodium phenylacetate. In the present study we report the clinical and biochemical course of 7 male patients with X-ALD treated with Lorenzo's Oil and a VLCFA-restricted diet. Treatment produced 50% reduction in C26:0 and 42.8% reduction in the C26:0/C22:0 ratio. Most patients remained clinically well, although approximately 30% of them presented a rapid clinical deterioration. The results showed a poor biochemical-clinical correlation for treatment, indicating that new therapies for X-ALD are needed in order to obtain a better prognosis for patients.

Therapeutic plasma exchange in treatment of adrenoleukodystrophy

Adrenoleukodystrophy (ALD) is an X-linked disorder of metabolism of very long-chain fatty acids (VLCFA) with a frequency of up to 1:20,000 in males. VLCFA C 24:0 and C 26:0 accumulate in the cholesterol ester and ganglioside fraction in plasma and red cells. Symptoms of ALD are ataxia, loss of visual and auditory functions, and cerebral convulsions. Presently, no sure therapeutic approaches are established. Efforts were reported by dietary regimens with VLCFA-restriction and glycerol trioleate and glycerol trierucate intake. In the present trial, we report on a 58-year-old white male suffering from progressive ALD with spastic paraparesis. He has a positive family history back to the 18th century. In this patient, although maximum dietary therapy was applied over a period of 60 months, no normalization of VLCFA C24:0 and C26:0 was reached, and neurological disorders were progressive. As a result, therapeutic plasma exchange (TPE) was applied from 1990 to 1994. Then, for more selective adsorption of VLCFA, dextran-sulfate adsorption (Liposorber, Kaneka, Osaka, Japan) until 1996, and after that, immunoadsorption (Therasorb, Baxter, Munchen, Germany) were used. During these periods (total, 101 months), VLCFA C 24:0 and C 26:0 levels were reduced by 55% and 50% (p < 0.001). The patient experienced a significant improvement in performance and general well-being. No further progression of neuronal disorders was documented. This anecdotal data suggest a very beneficial effect of TPE in treatment of progressive ALD.