Morphology and distribution of cytoplasmic inclusions in adrenoleukodystrophy

Chronic Progressive Spastic Paraparesis: Think of Peroxisomal Disorders - A Case Report of X-Linked Adult Onset Adrenoleukodystrophy With an Update on The Latest Treatment Strategies

The etiology of chronic progressive myelopathy can be a challenging diagnostic dilemma, especially in the absence of a structural lesion of the neural axis or a conspicuous inflammatory process. The differential diagnosis can be pleomorphic. However, the emergence of signs of adrenal dysfunction, lack of a structural lesion of the spinal cord and the emergence of cerebral demyelination should raise the suspicion of X-linked adrenoleukodystrophy (ALD). The biochemical signature of elevated serum very long chain fatty acids and a pathogenic mutation of the ATP-binding cassette subfamily D1 (ABCD1) gene is pathognomic. We present an adult variant case that marched through the classic catena of clinical syndromes: subtle adrenal dysfunction, chronic progressive myelopathy and ultimately cerebral demyelination. We outline the biochemistry, clinical semiology, pathology and therapeutic challenges in this group of patients. The unfolding disease in children and young adults can be arrested with allogenic and more recently autologous hematopoetic bone marrow transplantation. The challenge of therapy in adult patients with chronic progressive myelopathy who develop cerebral demyelination remains a therapeutic dilemma. Our case highlights the nuances of managing this group of patients and alerts the clinician to early diagnosis prior to the emergence of cerebral demyelination.

Endocrine Dysfunction in X-Linked Adrenoleukodystrophy

X-linked adrenoleukodystrophy (X-ALD) is caused by mutations in the ABCD1 gene and leads to an elevation of very-long-chain fatty acids (VLCFA). The accumulation of the VLCFA and the associated oxidative stress can present with a spectrum of significant neurologic disease, adrenal insufficiency, and testicular dysfunction in males with ABCD1 gene mutations. Much of the published literature for X-ALD has focused on the associated devastating progressive neurologic conditions. The purpose of this review is to summarize the concerns for endocrine dysfunction associated with X-ALD and provide guidance for monitoring and management of adrenal insufficiency.

Effects of hematopoietic stem cell transplantation on acyl-CoA oxidase deficiency: a sibling comparison study

OBJECTIVE

Acyl-CoA oxidase (ACOX1) deficiency is a rare disorder of peroxisomal very-long chain fatty acid oxidation. No reports detailing attempted treatment, longitudinal imaging, or neuropathology exist. We describe the natural history of clinical symptoms and brain imaging in two siblings with ACOX1 deficiency, including the younger sibling's response to allogeneic unrelated donor hematopoietic stem cell transplantation (HSCT).

METHODS

We conducted retrospective chart review to obtain clinical history, neuro-imaging, and neuropathology data. ACOX1 genotyping were performed to confirm the disease. In vitro fibroblast and neural stem cell fatty acid oxidation assays were also performed.

RESULTS

Both patients experienced a fatal neurodegenerative course, with late-stage cerebellar and cerebral gray matter atrophy. Serial brain magnetic resonance imaging in the younger sibling indicated demyelination began in the medulla and progressed rostrally to include the white matter of the cerebellum, pons, midbrain, and eventually subcortical white matter. The successfully engrafted younger sibling had less brain inflammation, cortical atrophy, and neuronal loss on neuro-imaging and neuropathology compared to the untreated older sister. Fibroblasts and stem cells demonstrated deficient very long chain fatty acid oxidation.

INTERPRETATION

Although HSCT did not halt the course of ACOX1 deficiency, it reduced the extent of white matter inflammation in the brain. Demyelination continued because of ongoing neuronal loss, which may be due to inability of transplant to prevent progression of gray matter disease, adverse effects of chronic corticosteroid use to control graft-versus-host disease, or intervention occurring beyond a critical point for therapeutic efficacy.

Peroxisomal disorders: genotype, phenotype, major neuropathologic lesions, and pathogenesis

Neurological dysfunction is a prominent feature of most peroxisomal disorders. Enormous progress in defining their gene defects has been achieved. The genes and gene products, peroxins (PEX), in five of the complementation groups have been defined. These studies confirm that Zellweger syndrome (ZS), neonatal adrenoleukodystrophy (NALD), and infantile Refsum disease (IRD) are a disease continuum. The gene defect in adreno-leukodystrophy (ALD) / adrenomyeloneuropathy (AMN) involves an integral peroxisomal membrane protein. Neuropathologic lesions are of three major classes: (i) abnormalities in neuronal migration or differentiation, (ii) defects in the formation or maintenance of central white matter, and (iii) postdevelopmental neuronal degenerations. The central white matter lesions are those of: (i) inflammatory demyelination, (ii) non-inflammatory dysmyelination, and (iii) non-specific reductions in myelin volume or staining with or without reactive astrocytosis. The neuronal degenerations are of two major types: (i) the axonopathy of AMN involving ascending and descending tracts of the spinal cord, and (ii) cerebellar atrophy in rhizomelic chondrodysplasia punctata and probably IRD. We postulate that the abnormal fatty acids in peroxisomal disorders, particularly very long chain fatty acids and phytanic acid, are incorporated into cell membranes and perturb their microenvironments resulting in dysfunction, atrophy and death of vulnerable cells. The advent of mouse models for ZS and ALD is anticipated to provide even greater pathogenetic insights into the peroxisomal disorders.

Liver and chorion cytochemistry

Microscopic visualization of peroxisomes in chorionic villus cytotrophoblast and in biopsy and autopsy samples of liver and kidney, the presence of enlarged liver macrophages containing lipid droplets insoluble in acetone and n-hexane as well as polarizing inclusions formed by stacks of trilamellar sheets are of diagnostic value in peroxisomal disorders. Methods are presented for evaluating these structures by light microscopy; trilamellar inclusions are only detected by electron microscopy. Macrophage features are preserved in archival paraffin blocks. In adrenal cortex, insoluble lipid, polarizing inclusions and trilamellar structures should be looked for. The stains are easily reproducible, and all reagents are commercially available.

Neonatal seizures and severe hypotonia in a male infant suffering from a defect in peroxisomal beta-oxidation

In this paper, we describe a baby male born to healthy non-consanguineous parents presenting at birth with hypotonia and seizures. Additional salient clinical features included the development of glaucoma, the absence of significant facial dysmorphism and the absence of liver enlargement or renal cysts. The patient died at the age of 3 months. At autopsy, liver fibrosis and kidney glomerulosclerosis were noted. Neuropathological findings included pachygyria of the olivary nuclei and cerebellar neuronal heterotopias. There was no evidence for a demyelinating process. Biochemically, the patient was found to have elevated plasma levels of very-long-chain fatty acids (VLCFA) and abnormal bile acid intermediates, whereas other indicators of peroxisomal function (plasmalogen biosynthesis and plasma pipecolic acid) were normal. Catalase staining of a liver biopsy specimen revealed peroxisomes to be present in normal numbers, although some were abnormally large. Trilamellar inclusions typical of a peroxisomal fatty acid oxidation defect were present in macrophages. Indeed, beta-oxidation of the very-long-chain fatty acid hexacosanoic acid (C26:0) was found to be strongly deficient. Fatty acyl-CoA oxidase activity in the patient's liver was normal, however. Furthermore immunocytochemical studies using antibodies against acyl-CoA oxidase, bifunctional protein and peroxisomal thiolase, revealed the normal localization of all three enzyme proteins within the peroxisomes. We suggest that our patient has a selective peroxisomal beta-oxidation defect, a recently identified heterogeneous group of early-onset peroxisomal disorders distinct from the Zellweger syndrome and other generalized peroxisomal disorders.

Peroxisomal localization of the immunoreactive beta-oxidation enzymes in a neonate with a beta-oxidation defect. Pathological observations in liver, adrenal cortex and kidney

A boy born to healthy, unrelated parents, presented at birth with hypotonia and seizures. Very long chain fatty acids in the plasma were strongly elevated; bile acid intermediates and plasmalogen biosynthesis were normal. Acyl-CoA oxidase activity was normal. The patient died at the age of 3 months. The cerebellum and medulla oblongata showed neuronal migration defects. The specific biochemical basis for the impaired peroxisomal beta-oxidation has not been found. The three immunoreactive peroxisomal beta-oxidation enzymes and catalase were localized in the hepatocellular peroxisomes. Aberrant features of the peroxisomes included: a subpopulation of organelles larger than 1 micron, an amorphous nucleoid in many organelles, and invaginations of the peroxisomal membrane into the matrix. Peroxisomes in the proximal renal tubules also contained the three immunoreactive beta-oxidation enzymes. Regularly spaced trilamellar inclusions were seen in hepatic macrophages; they were much more abundant in adrenocortical macrophages. The inclusions were birefringent and resistant to acetone extraction. Distinct hepatic fibrosis had developed over a period of 2.5 months. We speculate that the impaired beta-oxidation is due to a defect at the level of the peroxisomal carnitine octanoyl or -acetyl transferase, responsible for the export of beta-oxidation products.

Liver pathology and immunocytochemistry in congenital peroxisomal diseases: a review

Diagnostic and pathogenetic investigations of peroxisomal disorders should include the study of the macroscopic and microscopic pathology of the liver, in addition to careful clinical observations, skeletal X-ray and brain CT scan, assays of very long-chain fatty acids and bile acid intermediates, and selected enzyme activities. This review of the literature also contains novel observations about the following syndromes: cerebro-hepato-renal (Zellweger) syndrome, X-linked and neonatal adrenoleukodystrophies (ALD, NALD), NALD-like syndromes, infantile phytanic acid storage, classical Refsum disease, rhizomelic and other forms of chondrodysplasia punctata (XD, XR, AR), hyperpipecolic acidaemia, primary hyperoxaluria I, pseudo-Zellweger and Zellweger-like syndromes, and single enzyme deficiencies. Microscopic data include catalase staining and morphometry of peroxisomes, immunolocalization of beta-oxidation enzymes, detection of trilamellar, polarizing inclusions in PAS-positive macrophages, fibrosis and iron storage. Peroxisomal enlargement appears to be related to functional deficit in beta-oxidation disorders as well as in rhizomelic chondrodysplasia punctata. Because normal peroxisomal localization of active beta-oxidation enzymes can accompany a C26 beta-oxidation deficit, other mechanisms such as impaired transport of metabolites should be investigated. 'Ghost'-like organelles are shown in the liver of an infantile Refsum patient and in an NALD-like case; immuno-gold labelling of membrane proteins did not reveal ghosts in Zellweger livers.

Infantile phytanic acid storage disease, a disorder of peroxisome biogenesis: a case report

The infantile and classic forms of phytanic acid storage disease belong to the newly recognized group of peroxisomal disorders. In this paper we report the full clinical, morphological and biochemical results in a patient with infantile phytanic acid storage disease. The results indicate a generalized loss of peroxisomal functions due to a deficiency of peroxisomes as demonstrated in hepatocytes and cultured skin fibroblasts.

Adrenoleukodystrophy--early ultrastructural changes in the brain

A light and electron microscopic study was performed on the cerebral white matter in a case of adrenoleukodystrophy (ALD) with peculiar symptoms of olivopontocerebellar atrophy. The affected white matter on the light microscope had many macrophages containing characteristic membrane-bound linear inclusions. The unaffected white matter on the light microscope demonstrated the following ultrastructural changes: (1) slight but definite degeneration of myelin sheaths scattered among apparently normal myelinated axons; (2) oligodendroglia-like cells containing membrane-free intracytoplasmic inclusions; and (3) many swollen astrocytes containing the same membrane-bound linear inclusions as those in the macrophages within the affected white matter. The mechanism of demyelination in ALD is also discussed.

Hepatic peroxisomes in adrenoleukodystrophy and related syndromes: cytochemical and morphometric data

Peroxisomes were visualized by cytochemical staining for catalase or/and electron microscopy in liver biopsies of two boys with childhood adrenoleukodystrophy (ALD), and of two girls with autopsy confirmed neonatal adrenoleukodystrophy (NALD). In a third patient previously described as NALD, unusual organelles were seen which may be large abnormal microbodies. Enlarged peroxisomes (determined by morphometry) were also present in the livers of the other two NALD patients. In the ALD patient whose clinical disease was more severe, peroxisomes were larger than in the older ALD case. Catalase staining was diminished and markedly heterogeneous. Additional unusual features such as a separate population of tubular forms, contact with fat droplets, of tubular forms, contact with fat droplets, marginal plate and invaginations containing glycogen were seen in the neonatal cases. These data are compared to the enlarged or elongated peroxisomes and heterogeneous staining in the thiolase-deficient "pseudo-Zellweger" patient (Goldfischer et al. 1986) and in 2 siblings with acylCoA oxidase deficiency (Poll-Thé et al. 1986, 1988). Enlarged peroxisomes are a common feature in this group of patients with peroxisomal deficiency disorders, suggesting that increased size and lowered metabolic capacity are associated. Nevertheless a marked morphopathological heterogeneity of peroxisomes thus exists in syndromes described as NALD including previously published cases. Most likely this heterogeneity reflects different enzymatic deficiencies, as confirmed by the biochemical data available. Clinically similar syndromes cover divergent microscopical and enzymatic peroxisomal patterns, and naming of the disease should be adapted to reflect such data. Cytochemical studies are urged in every suspected patient.

Polarizing inclusions in some organs of children with congenital peroxisomal diseases (Zellweger's, Refsum's, chondrodysplasia punctata (rhizomelic form), X-linked adrenoleukodystrophy)

Polarizing material has been reported in the liver of children with infantile Refsum's disease (IRD) and was absent in two patients with the cerebro-hepato-renal syndrome of Zellweger (CHRS). We examined in polarized light 15 liver biopsy and autopsy samples from six other patients with the cerebro-hepato-renal syndrome of Zellweger, two with the rhizomelic form of chondrodysplasia punctata (rCDP) and two with X-linked adrenoleukodystrophy (ALD), all conditions with deficient peroxisomes. Two types of birefringent inclusions were found in CHRS only: the first is transparent in bright field, the second appears as brown granules or rods, similar to lipofuscins. As in IRD large PAS-positive macrophage-like cells contain the transparent type. Electron microscopical investigation of these cells shows trilaminar structures within membrane-bound organelles. The two types were also seen in kidney and brown adipose tissue, the first type in pancreas, the second type in adrenal gland; no such was observed in myocardium or in thyroid gland (CHRS). No birefringent inclusions were present in rCDP and ALD. The nature of the inclusions is still unclear. An accumulation of the transparent polarizing material with increasing age of the patients is most likely.

Adrenoleukodystrophy: frequency of presentation as a psychiatric disorder

Adrenoleukodystrophy (ALD) is an inheritable clinical disorder in which very long chain fatty acids accumulate in several tissue types. ALD is underrepresented in the psychiatric literature, although the disorder may cause an organic brain syndrome, often misdiagnosed as another psychiatric problem. A survey of 109 reported cases of ALD revealed that 39% presented with some psychiatric sign or symptom, whereas 17% presented exclusively as a psychiatric problem. A computed axial tomogram (CAT) head scan is recommended to rule out ALD in psychiatric patients suspected of having organic brain disease, as a characteristic image may be found in ALD patients who have brain involvement.

Adrenoleukodystrophy in an adult female. A clinical, morphological, and neurochemical study

A 43-year-old female with adrenoleukodystrophy (ALD) is described, who developed spastic tetraparesis, suffered grand mal seizures, and became stuporous and demented during the last 5 years of her life. Computed tomography revealed symmetrical hypodense lesions in the peritrigonal regions. Adrenal insufficiency was not evident except for skin pigmentation. The ultrastructure of a rectal biopsy specimen showed inclusions with lamellae and interspersed clefts in macrophages of the submucosal layer. At autopsy, the adrenals were found to contain large foam cells filled with similar inclusions. The brain cortex and the spinal cord were histologically normal. However, cerebral white matter exhibited widespread demyelination which spared only the arcuate fibres. In regions of less severe demyelination scattered inflammatory cells were seen. On electron microscopy, aggregates of typical paired leaflets with distinct intermediate lines were demonstrated in perivascular macrophages. Histochemical study showed these cells to contain free as well as esterified cholesterol. Gas chromatographic analysis of very long chain fatty acids (VLFA) from the demyelinated cerebral white matter showed a marked increase of C26:0 fatty acid in cholesterol esters and above-normal values for C24:0 and C24:1 in gangliosides. It is suggested that the condition was a heterozygote form of X-linked ALD. Patients with neurodegenerative symptoms with or without adrenal insufficiency can easily be screened for X-linked ALD by VLFA analysis in blood or cultured fibroblasts.

Adrenoleukodystrophy in a mother and son

A 6 year old boy died from a degenerative brain disease which was clinically and pathologically typical of adrenoleukodystrophy. Shortly before his disease became manifest his 28 year old mother had presented with similar symptoms, and subsequently died. Her brain showed almost identical features including the presence of pathognomonic ultrastructural inclusions. The accumulation of very long chain fatty acids in cerebral white matter as well as high hexacosanoic to docosanoic acid (C26:22) ratios, substantiated the diagnosis in both cases. This is one of the few documented cases of adrenoleukodystrophy in an adult female, and is almost certainly an example of clinical manifestation of this X-linked inherited disease in a carrier.

Adrenoleukodystrophy: clinical, pathological and biochemical findings in two brothers with the onset of cerebral disease in adult life

Two brothers are described in whom adrenoleukodystrophy (ALD) presented as progressive cerebral degeneration in early adult life. Diagnosis during the life of one brother was based on cerebral biopsy appearances. At autopsy there was a leucodystrophy and an additional myelopathy in both cases. Biochemical studies carried out on the propositi and other family members revealed characteristic abnormalities of ALD in the propositi and two, as yet clinically unaffected, adult brothers, and abnormalities characteristic of the heterozygous state in their mother. Neither of the clinically affected brothers showed clinical features of hypoadrenalism and these cases emphasize the importance of considering the diagnosis of ALD in adult males with leucodystrophy even in the absence of overt adrenal insufficiency.

Adrenoleukodystrophy

Adrenoleukodystrophy (ALD) is an X-linked degenerative disease characterized by progressive demyelination and adrenal insufficiency. Several phenotypes are described. In post-mortem tissues there is an accumulation of saturated or mono-unsaturated very long chain fattyacids (VLCFA) in the cholesterol ester fraction of adrenal cortex and cerebral white matter. The accumulated fatty acids are unbranched with carbon chain length between 23 and 32 with most containing 25 or 26 carbons. Determination of VLCFA in readily accessible tissues such as skin fibroblasts and plasma allows for reliable detection of patients and carriers.