Increased levels of ceramide in the retina of a patient with Farber's disease.
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Biomedical subjects
Publications and source records attributed to A B Moser.
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Plasmalogen biosynthesis and phytanic acid oxidation activity were measured in cultured chorionic villus samples or amniocytes from four pregnancies at risk for the rhizomelic form of chondrodysplasia punctata (RCDP). Normal results were obtained in three of the samples and post-natal examination or fetal ultrasound studies confirmed that the fetuses were unaffected. Chorionic villus culture in one case demonstrated defective plasmalogen biosynthesis and lack of phytanic acid oxidation. Pregnancy was interrupted at 10 weeks. Immunoblot studies of post-mortem fetal tissues showed that peroxisomal 3-oxoacyl-coenzyme A thiolase was present in the unprocessed form, a finding we had previously demonstrated in RCDP. These results establish that RCDP can be identified prenatally.
Neonatal hypotonia, seizures beginning at 5 days, and severe retardation were noted in a girl with normal karyotype and biochemical evidence of impaired adrenal function. Postmortem examination at 14 months revealed malformative and destructive lesions of central gray and white matter, atrophy of adrenal cortex with striated adrenocortical cells, hepatic fibrosis, and PAS-positive macrophages in several organs. Pathologically and clinically, this patient most closely approximated neonatal adrenoleukodystrophy (ALD) and differed strikingly from X-linked childhood ALD. In contrast, biochemical changes resembled the abnormalities observed in X-linked ALD and differed from those in the neonatal form. The very-long-chain fatty acid accumulation characteristic of both disorders was demonstrated, but unlike neonatal ALD, the levels or metabolism of plasmalogens, pipecolic acid, phytanic acid, and bile acid intermediates were normal, and peroxisomes in a liver biopsy specimen were present in normal number and appeared enlarged. While the case resembles the recently reported entity of peroxisomal acyl-CoA oxidase deficiency, assignment to this category was excluded by immunoblot studies on postmortem liver, which revealed normal amounts of this enzyme. Correlation of clinical, morphologic, and biochemical data suggests that this case is an example of a so-far undescribed entity, and reinforces the concept that the phenotypic spectrum of peroxisomal disorders is wider than realized.
Encephalitis and polyneuritis occurring after rabies vaccination are believed to be immunologically mediated. We studied antibody responses to neural antigens in 36 patients with major neurologic complications, 25 with minor complications, and 39 with no complications after immunization with a brain-derived, Semple rabies vaccine. Patients with major complications had significantly elevated levels of antibody to brain white matter as compared with the other groups (P less than 0.001). Assays for antibody to selected central nervous system antigens showed that high levels of serum and cerebrospinal fluid antibody to myelin basic protein correlated with the presence of major neurologic complications (both central and peripheral nervous systems). The level of antibody to cerebroside correlated best with the number of injections of vaccine, but like antibody to myelin basic protein, the antibody to cerebroside was present in the cerebrospinal fluid of patients with major complications. Some patients with major complications also had antibodies directed to the gangliosides GD1b and GT1b. No antibodies to myelin-associated glycoprotein were detected in any of the samples. These data implicate myelin basic protein as an encephalitogen in these autoimmune diseases of the human nervous system, but suggest that immune responses to cerebroside and certain gangliosides may have an augmentative role in severe disease.
A new dietary regimen has been administered for periods ranging from 60 days to 1 1/2 years in 34 patients with various forms of X-linked adrenoleukodystrophy (ALD), as well as in 1 patient with neonatal ALD and 1 patient with infantile Refsum's disease. The diet combines the administration of a glyceryl trioleate oil (GTO) with the dietary restriction of very-long-chain fatty acids (VLFA), particularly hexacosanoic acid (C26:0). Reductions in the levels of plasma C26:0 and other VLFA were achieved in 25 of the 36 patients. Fifteen of these 25 patients were treated for more than 100 days. The mean reduction of the plasma C26:0 level was 53% (range, 22 to 73%) in these 15 patients. While the focus of the study was on biochemical variables, comparison of pre- and post-diet studies of peripheral nerve function showed improvement in 1 patient with adrenomyeloneuropathy (AMN) and 1 heterozygote. In contrast, 2 patients with ALD onset in childhood developed new neurological deficits while on therapy. We conclude that it is possible to lower plasma VLFA levels in ALD patients. A clinical trial is indicated to test whether this approach can alter the neurological progression in patients with AMN or in symptomatic heterozygotes, and to determine whether it can prevent the onset of neurological disability in asymptomatic persons who have the biochemical defect of ALD.
Neuropathological examination of three males with cerebro-hepato-renal (Zellweger) syndrome (CHRS) revealed selective neuronal lipidosis and neuroaxonal dystrophy of the dorsal nucleus of Clarke and lateral cuneate nucleus. This lipidotic alteration was visualized as perikaryal or axonal enlargements with cytoplasmic striations. With the light microscope, the striated material was birefringent and resistant to traditional lipid stains; ultrastructurally, it was composed of lipid clefts, lamellae and lamellar-lipid profiles; biochemically, the affected region contained large amounts of cholesterol esterified to very long-chain fatty acids, both saturated and monounsaturated. This metabolic lesion, though localized to specific sensory neurons, suggests that a more generalized defect in neuronal fatty acid metabolism may be operative in CHRS.
Neonatal adrenoleukodystrophy belongs to the newly recognized group of inherited diseases, the peroxisomal disorders. Based on the reported similarities between neonatal adrenoleukodystrophy and the cerebro-hepato-renal (Zellweger) syndrome, we have studied peroxisomal functions in cultured skin fibroblasts from 5 neonatal adrenoleukodystrophy patients. The results indicate that multiple peroxisomal enzyme activities are deficient in fibroblasts from neonatal adrenoleukodystrophy patients. Digitonin titration experiments revealed that peroxisomes are strongly deficient in these fibroblasts as found earlier in fibroblasts from Zellweger patients. These findings not only explain the generalized loss of peroxisomal functions in neonatal adrenoleukodystrophy, but also provide an explanation for the observed resemblance in clinical and biochemical abnormalities between neonatal adrenoleukodystrophy and Zellweger syndrome. The implications for the pre- and postnatal detection of this disease will be discussed.
Two women, heterozygous for X-linked adrenoleukodystrophy, contained striated adrenocortical cells without inflammation and central nervous system demyelinative lesions. Only one was symptomatic neurologically; neither exhibited hypoadrenalism. These findings further document the variability of adrenoleukodystrophy heterozygotes and provide evidence that the major pathologic differences between hemizygote and heterozygote are quantitative in nature.
Eight new cases of autopsy-confirmed or suspected neonatal adrenoleukodystrophy (NALD) are presented together with new biochemical data on very-long-chain fatty acids (VLCFA) and plasmalogens and a review of all previously published cases. The clinical, biochemical, and histopathologic abnormalities characteristic of this newly recognized form of adrenoleukodystrophy are analyzed in detail and compared to the principal characteristics of the similar disorder, the cerebrohepatorenal syndrome of Zellweger (ZS). Using strict pathologic criteria for the diagnosis of NALD, we find that, despite many clinical resemblances, NALD and the ZS are distinguishable on the basis of histology and peroxisomal biochemistry. Patients with NALD demonstrate adrenal atrophy, systemic infiltration by abnormal lipid-laden macrophages, and elevations of saturated VLCFA. In contrast, patients with ZS have chondrodysplasia, glomerulocystic disease of the kidney, central nervous system dysmyelination, and elevations of unsaturated as well as saturated VLCFA, but they lack adrenal atrophy. We conclude that NALD and the ZS probably represent at least two different genetic defects.
Cultured skin fibroblasts from six patients demonstrating clinical signs and biochemical characteristics of infantile phytanic acid storage disease (IPSD) were examined by electron microscopy, using cytochemical procedures for the demonstration of peroxisomal catalase activity. In four of the six fibroblast cell lines peroxisomes strongly reactive for catalase were present in numbers similar to those found in normal fibroblasts. Liver biopsy tissue from one of these patients showed no typical hepatic peroxisomes, but did show small, marginally reactive bodies. In two other IPSD fibroblast cell lines peroxisomes with appreciable cytochemical reactivity were rare or absent. It seems, therefore, that infantile phytanic acid storage disease is heterogeneous with respect to the presence of cytochemically recognizable peroxisomes, at least in the cases studied here. Furthermore, peroxisomes may be markedly affected in one cell type - liver - and yet not affected in another - skin fibroblasts - within a single individual.
[9,10-3H] palmitic (C16:0) and [1-14C] lignoceric (C24:0) acid dissolved in 10 microL of ethanol were injected subperineurially into the sciatic nerve of rats. Both C16:0 and C24:0 were incorporated into lipids, and in most lipid fractions C16:0 incorporation exceeded that of C24:0. Free ceramide and cholesterol ester were the only lipid moieties in which C24:0 incorporation was equal to or greater than that of C16:0. This finding is of particular interest since the very-long-chain fatty acid excess is by far the most striking in the cholesterol ester fraction in adrenoleukodystrophy. Furthermore, incorporation into cerebroside and sulfatide indicates that at least some of the injected fatty acids were metabolized in the Schwann cell. Subperineurial injections of either very-long-chain fatty acids or medium-chain fatty acids into rat sciatic nerve caused demyelination, and this morphological change does not occur following injection of pure solvent.
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Adrenoleukodystrophy is a disorder of long-chain fatty acid metabolism associated with adrenal cortical insufficiency and central nervous system demyelination. The central nervous system disease is unusual in that it is abrupt in onset and accompanied by a considerable infiltration of mononuclear inflammatory cells. To determine the nature of these inflammatory cells, immunocytochemical staining was carried out on the mononuclear cells in the brain and cerebrospinal fluid of patients with adrenoleukodystrophy. Monoclonal antibodies to T lymphocytes (T11), the helper/inducer (T4) and cytotoxic/suppressor (T8) subsets of T lymphocytes, B lymphocytes (B1), and monocyte/macrophages (M1 or esterase) were used. Mononuclear cells in the perivascular cuffs of autopsy material from 4 patients were, on average, 59% T cells, 34% T4 cells, 16% T8 cells, 24% B cells, and 11% monocyte/macrophages. Cerebrospinal fluid from 8 of 10 patients had increased IgG concentrations. Mononuclear cells in the cerebrospinal fluid of 6 patients with active disease were, on average, 61% T cells, 40% T4 cells, 16% T8 cells, 3% B cells, and 18% monocyte/macrophages. This distribution of cells is similar to that found in the central nervous system during a cellular immune response and suggests the possibility that one component of this disease is immunologically mediated.
Four fetuses with positive family histories for cerebrohepatorenal (Zellweger) syndrome (CHRS) underwent diagnostic amniocentesis or chorionic villus biopsy. Cultured amniocytes or fibroblasts from all of the fetuses displayed abnormal fatty acid ratios, and the parents elected therapeutic abortions. Dysmorphic features in one fetus consisted of micrognathia, proximal implantation of toes, and bilateral talipes equinovarus. Radiologic examination of the fetus confirmed the dysmorphic features and revealed foci of mineralization in the patellae. Biochemical analysis of three of the fetuses demonstrated markedly increased levels of very-long-chain fatty acids, both saturated and monounsaturated, in liver, kidney, adrenal, and brain. Pathologic findings consisted of premature mineralization of patellae; renal cystic tubular dilations; striated cells in adrenal fetal zone and testicular interstitium; dysplastic alterations of inferior olivary nuclei, dentate nuclei, and cerebral cortex; equivocal increases in portal fibrous tissue; and abnormal cytosomes in fetal zone adrenocortical cells, testicular and renal interstitial cells, and brain macrophages. Iron deposition, probably physiologic, was observed only in liver tissue. Distributions of immunoreactive catalase were identical in the fetuses with CHRS and age-matched control subjects. These findings document the accuracy of the prenatal diagnostic test and provide insights into the morphogenesis and pathogenesis of CHRS.
The oxidation of very long chain fatty acids and synthesis of ether glycerolipids (plasmalogens) occurs mainly in peroxisomes. Zellweger's cerebrohepatorenal syndrome (CHRS) is a rare, inherited metabolic disease characterized by an apparent absence of peroxisomes, an accumulation of very long chain fatty acids, and a decrease of plasmalogens in tissues and cultured fibroblasts from these patients. As peroxisomes are ubiquitous in mammalian cells, we examined normal and CHRS-cultured fibroblasts for their presence, using an electron microscopic histochemical procedure for the subcellular localization of catalase, a peroxisomal marker enzyme. Small (0.08-0.20 micron) round or slightly oval peroxisomes were seen in both normal and CHRS fibroblasts. The number of peroxisomes was analyzed morphometrically and found to be significantly reduced in all CHRS cell lines. These results are discussed in relation to the underlying defect in peroxisomal function and biogenesis in this disease.
Adrenoleukodystrophy (ALD) is an X-linked progressive neurological disorder characterized by the accumulation of saturated very-long-chain fatty acids (C24 to C30) in lipids, especially cholesterol esters of the brain white matter and adrenal cortex. In the present study we have investigated the localization of accumulated cholesterol esters in brain white matter. During isolation of purified myelin membrane from regions of active demyelination, significant enrichment in cholesterol ester was found in two fractions, mainly in a low-density floating fraction and to a lesser degree in the purified myelin preparation. The fatty acid composition of cholesterol esters from both the ALD floating and myelin fractions was enriched approximately 10-fold in saturated very-long-chain fatty acids (greater than or equal to C24) compared with control preparations.
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Amniocentesis was performed in two women heterozygous for adrenoleukodystrophy (ALD). One fetus was male, and the hexacosanoic acid (C26) level in the cultured amniotic cells was 0.808 microgram per mg of protein, compared to 0.104 +/- 0.069 (S.D.) in controls. Pregnancy was interrupted at 22 wk gestation. The fetal adrenal cortex showed the ultrastructural inclusions characteristic of ALD and C26 accounted for 35% of the fatty acids in the cholesterol esters extracted from this tissue, more than one thousand times control. The second amniocentesis was performed in a woman who was also heterozygous for an electrophoretic variant of glucose 6- phosphate dehydrogenase (G6PD), and a member of a kindred showing genetic linkage of loci for ALD and G6PD. The fetus was female and the C26 level in cultured amniotic cells was 0.577. Pregnancy was interrupted at 11 wk for reasons unrelated to ALD. Study of C26 level and G6PD type in cultured fetal tissues confirmed heterozygosity for ALD.