Adrenoleukodystrophy. Electron microscopic findings

Adrenoleukodystrophy with disease of the eye and optic nerve

Adrenoleukodystrophy is an X-chromosome-linked recessive disease characterized by primary atrophy of the adrenal glands with or without Addison's disease and low plasma cortisol levels, and a degeneration of white matter of the central nervous system with blindness. In suspected cases of adrenoleukodystrophy an impaired rise in plasma cortisol levels after adrenocorticotrophin stimulation may be diagnostic. With the electron microscope, pathognomonic intracytoplasmic lamellar inclusions have been seen in adrenal cortical cells, peripheral nerve Schwann's cells, testicular interstitial cells, and in macrophages of the brain. Adrenoleukodystrophy appears to be a genetically determined lipid storage disease with an error in membrane sterol metabolism. A 10-year-old boy with adrenoleukodystrophy had visual loss, a prominent early symptom. The ocular abnormality consisted of a disproportionate loss of nerve fibers from the macular region. No intracytoplasmic lamellar inclusions were identified in cells representing macrophages within the optic nerve. They contained myelin debris suggestive of end-stage disease.

Clinical and biochemical expression of a unique mucopolysaccharidosis

A boy who presented with painful joints leading to contractures was found to have a mucopolysaccharidosis not previously described. He had severe dysostosis multiplex of the long bones but nearly normal intellectual development and no involvement of the cornea. Lysosomal storage vacuoles were noted in dermal endothelial cells; these were similar to those seen in the genetic mucopolysaccharidoses. Mucopolysacchariduria was not excessive in amount but it was distinctly abnormal in pattern and his excretion of dermatan sulfate resembled that found in the Hunter and Hurler syndromes. The activities of the lysosomal hydrolases in cultured fibroblasts were normal or increased. The degradation of accumulated 35S-mucopolysaccharide in fibroblasts in culture was typical of a mucopolysaccharidosis. His mother accumulated 35S-mucopolysaccharides in fibroblasts, suggesting an X-linked inheritance of the disorder.

Spastic paraplegia associated with Addison's disease: adult variant of adreno-leukodystrophy

Clinical and pathological features of an adult variant of adreno-leukodystrophy (ALD) are presented. A male with clinical and laboratory signs of Addison's disease (AD) developed at age 22 a slowly progressing paraplegia with slight sensory deficits in both legs and bladder and sphincter dysfunctions; he died at age 24 in an AD crisis. Autopsy revealed hyperplasia of lymphatic tissues, lymphocytic infiltrates in various organs including the CNS and adrenocortical atrophy with prominence of large ballooned, sometimes bizarre and occassionally striated cortical cells. CNS lesions consisted in incomplete demyelination of long tracts of brain stem and spinal cord with accentuation in the pyramical tracts; in these areas, perivascular cuffs of "epitheloid" histiocytic cells contained a strongly PAS-positive non-sudanophilic material. Electron microscopy demonstrated massive stroge of leaflet structures in perivascular histiocytes identical to the lamellar profiles previously described as specific for ALD. Some leaflets were found in close contact with compact lamellar arrays and with an electron-dense fingerprint material within astrocytes. In our case, the spastic paraplegia-AD syndrome which has been described previously in several clinical observations could be neuropathologically classified as an adult variant of ALD. Several differences to "classical" ALD occurring in young boys are stressed: the predominance of the endocrine disorder probably accounting for some of the perivascular lymphocyte infiltrates within the CNS; the absence of both clinical and pathological signs of diffuse cerebral involvement and the peculiar topistic pattern of CNS lesions and the very slow evolution of neurological signs paralleled by the absence of active sudanophilic demyelinating lesions. The possible mechanism of demyelination and the nature of the suggested metabolic defect in ALD are discussed. The ultrastructurally prominent leaflet structures may originate from myelin remnants, thus relating ALD to pathological storage of a myelin degradation product.