Lafora's disease. An ultrastructural and histochemical study

Lafora-like ground-glass inclusions in hepatocytes of pediatric patients: a report of two cases

We report 2 cases of ground-glass hepatocyte inclusions occurring in pediatric patients. Case 1 had alpha-thalassaemia major and was receiving iron chelation therapy, whereas case 2 had trisomy 21 with a history of bone marrow transplantation for acute myeloid leukemia. The liver sections in both cases showed eosinophilic, periodic acid-Schiff diastase-positive intracytoplasmic inclusions that were negative for hepatitis B surface antigen. Immunohistochemically the inclusions showed positive staining with KM279, a monoclonal antibody against polyglucosan derived from Lafora inclusions. On electron microscopy, in case 1, intracytoplasmic inclusions were composed of degenerate organelles, glycogen, and irregular fibrillar structures; in case 2, they were composed of vesicular structures containing granular material. Ultrastructural changes in both cases differed from classical Lafora inclusions and ruled out hepatitis B surface antigen, glycogenosis type IV, and fibrinogen storage disease. Genetic analysis of the Lafora's disease genes performed in case 2 revealed no mutations. The development of hepatocyte cytoplasmic inclusions in both our cases could be related to medication effects, because similar inclusions were reported in patients using cyanamide. Drug-induced inclusions, mimicking Lafora's disease, should be included in the differential diagnosis of hepatocyte ground-glass inclusions.

Lafora's disease: towards a clinical, pathologic, and molecular synthesis

Lafora's disease is one of five inherited progressive myoclonus epilepsy syndromes. It is an autosomal-recessive disorder with onset in late childhood or adolescence. Characteristic seizures include myoclonic and occipital lobe seizures with visual hallucinations, scotomata, and photoconvulsions. The course of the disease consists of worsening seizures and an inexorable decline in mental and other neurologic functions that result in dementia and death within 10 years of onset. Pathology reveals pathognomonic polyglucosan inclusions that are not seen in any other progressive myoclonus epilepsy. Lafora's disease is one of several neurologic conditions associated with brain polyglucosan bodies. Why Lafora's polyglucosan bodies alone are associated with epilepsy is unknown and is discussed in this article. Up to 80% of patients with Lafora's disease have mutations in the EPM2A gene. Although common mutations are rare, simple genetic tests to identify most mutations have been established. At least one other still-unknown gene causes Lafora's disease. The EPM2A gene codes for the protein laforin, which localizes at the plasma membrane and the rough endoplasmic reticulum and functions as a dual-specificity phosphatase. Work toward establishing the connection between laforin and Lafora's disease polyglucosans is underway, as are attempts to replace it into the central nervous system of patients with Lafora's disease.

Corpora-amylacea and the family of polyglucosan diseases

The history, characters, composition and topography of corpora amylacea (CA) in man and the analogous polyglucosan bodies (PGB) in other species are documented, noting particularly the wide variation in the numbers found with age and in neurological disease. Their origins from both neurons and glia and their probable migrations and ultimate fate are discussed. Their presence is also noted in other organs, particularly in the heart. The occurrence in isolated cases of occasional 'massive' usually focal accumulations of similar polyglucosan bodies in association with certain chronic neurological diseases is noted and the specific conditions Adult Polyglucosan body disease and type IV glycogenosis where they are found throughout the nervous system in great excess is discussed. The distinctive differences of CA from the PGB of Lafora body disease and Bielschowsky body disease are emphasised. When considering their functional roles, a parallel is briefly drawn on the one hand between normal CA and the bodies in the polyglucosan disorders and on the other with the lysosomal system and its associated storage diseases. It is suggested that these two systems are complementary ways by which large, metabolically active cells such as neurons, astrocytes, cardiac myocytes and probably many other cell types, dispose of the products of stressful metabolic events throughout life and the continuing underlying process of aging and degradation of long lived cellular proteins. Each debris disposal system must be regulated in its own way and must inevitably, a priori, be heir to metabolic defects that give rise in each to its own set of metabolic disorders.

Periodic acid-Schiff (PAS)-positive deposits in brain following kainic acid-induced seizures: relationships to fos induction, neuronal necrosis, reactive gliosis, and blood-brain barrier breakdown

Periodic acid-Schiff (PAS)-positive deposits have been demonstrated in the central nervous system (CNS) of patients suffering from a wide variety of neurodegenerative disorders including Alzheimer's disease, presenile dementia, Parkinson's disease, diabetes mellitus, myoclonic epilepsy, and cerebral palsy. The etiology of these deposits and their relationship to mechanisms of progressive neurodegeneration is unknown. In the present study, we demonstrate that the kainic acid model of limbic status epilepticus provides a useful system for the study of PAS-positive staining. The relationship between PAS-positive deposition, induction of fos-like immunoreactivity (FLI), neuronal necrosis, reactive gliosis, and blood-brain barrier breakdown following the kainic acid induction of status epilepticus was investigated. Epileptiform activity was elicited in rats by intraperitoneal administration of 10 mg/kg kainic acid and brains were examined 3, 5, 12, 24, 72, and 168 h after drug injection. Four distinct types of PAS-positive staining in rat brain were observed: type 1, extracellular matrix (ECM) or blood vessel associated-material; type 2, granular deposits; type 3, glial labelling; and type 4, neuronal labelling. Results demonstrated that the four types of PAS-positive staining were differentially associated with specific markers of neuropathology: (1) type 1 ECM staining and type 3 glia were preferentially localized to edematous tissue; (2) the majority of type 3 glia were identified as reactive astrocytes, while a minority of appeared to be proliferating microglia; (3) type 1 blood vessels labelled hemorrhaging vasculature; (4) early deposition of type 2 granules was predictive of subsequent cell loss; (5) chronic type 2 granular deposits and type 4 neuronal labelling not associated with cell death could be predicted by early changes in FLI; and (6) chronic deposition of all four forms of PAS-positive material was correlated with earlier, transient blood-brain barrier compromise. The results support the growing literature that local carbohydrate metabolism may be one of a constellation of parameters important to the development of progressive neurodegeneration.

Fibrinogen inclusions in liver cells: a new type of ground-glass hepatocyte. Immune light and electron microscopic characterization

A new type of ground-glass hepatocyte is described. The appearance is due to pale, homogeneous, weakly eosinophilic inclusions filling a portion of or the entire hepatocytic cytoplasm. On haematoyxlin and eosin stained sections, these cells closely resemble ground-glass hepatocytes described in other conditions. However, they are negative on special stains for HBsAg and on PAS staining. Immunohistochemically, they reveal a selective and exclusive positivity for fibrinogen. On electron microscopy, the immunoreactive fibrinogen appears as amorphous, fluffy or granular material within dilated cisternae of the rough endoplasmic reticulum. This finding suggests intracellular storage possibly reflecting a defective intracellular transport of fibrinogen.

Transient ground glass hepatocellular change following a period of glue sniffing in a patient with underlying benign recurrent cholestatic jaundice

This report describes the liver biopsy findings in an obese adolescent male suffering from benign recurrent intrahepatic cholestatic jaundice who developed transient focal feathery swelling and ground glass hepatocellular change within several weeks of indulging in glue sniffing. Clinically the situation provided a rare opportunity to observe the nature and progress of morphological features by means of sequential liver biopsies taken for the investigation of the patient's underlying jaundice. The temporal relationship between the confessed period of glue sniffing and appearance of the hepatocellular abnormality provides, in our opinion, strong supportive evidence of a definite link between the two.

A type of adult polyglucosan body disease

Polyglucosan bodies in the nervous system and other viscera are the main findings at autopsy of a 64-year-old woman who had a chronic neurologic disorder of 20 years' duration. The clinical features included muscle weakness, sensory disturbances, neurogenic bladder, dementia, and cataracts. Light and electron microscopy of the nervous system showed numerous polyglucosan bodies in the processes of neurons and astrocytes but not in neuronal perikarya. A similar clinico-pathologic presentation has been described in six previous cases. It is suggested that this is a type of adult polyglucosan body disease which probably froms a variant of Lafora's disease.

Liver cell injury (bodies similar to Lafora's) in alcoholics treated with disulfiram (Antabuse)

Inclusions, structurally similar to Lafora's bodies, are described in the liver cells of three chronic alcoholic patients who stopped drinking after disulfiram treatment. The inclusions were strongly positive with PAS and methenamine silver stains. Shikata stain for HBsAg was negative. On electron microscopy the inclusions are not membrane-bound and contain glycogen beta-granules, secondary lysosomes containing lamellar structures, lipid droplets and filaments; the SER was almost completely lost. In the patient least affected, the cells bearing inclusions were predominantly periportal in location, as is usual in Lafora's disease. In the two other patients the change involved the whole lobule. The possibility of an induced carbohydrate metabolic disorder, which could be due to the disulfiram, a drug that interferes with the activity of several hepatic enzymes is discussed. The presence of appearances suggestive of SER breakdown could also be interpreted as a manifestation of 'disuse atrophy' due to alcohol withdrawal.

Urinary glycosaminoglycans in patients with progressive myoclonus epilepsy

Urinary GAGs analysis in Progressive Myoclonus Epilepsy (PME) showed an accumulation of uronic acid in the fraction eluted by 1 M NaCl and 3 M NaCl. As analogous changes were found in other myoclonic and epileptic patients receiving large doses of anticonvulsant drugs, these alterations in the GAG urinary pattern were not considered a primary disturbance of PME.

Corpora amylacea in the peripheral nerve axons

Deposits similar to corpora amylacea were observed by electron microscopy within myelinated axons in the peripheral nerves in a case of familial spastic paralysis. Ultrastructurally the deposits consisted of randomly interlacing short filaments which were closely related to glycogen granules present in the periphery of the deposits. A possible relationship between the filamentous structures and glycogen granules is discussed. The significance of this inclusion and of related bodies is also discussed.

[The so-called filaments in lafora-bodies, corpora amylacea and Bielschowsky-bodies. Fasciolar substructures in accumulated intraplasmatic material of cellular dysmetabolies (author's transl)]

Both the corpora amylacea and Lafora bodies have been described in the literature as filamentous structures. On electron microscopic examination they are often composed of ribbon-like fasciolar units. The ultrastructural appearance of these structures is discussed on the example of an amylopectin model. These fasciolar substructures are also encountered in Bielschowsky bodies and are then considered to be a sign of intracellular accumulation of dysmetabolic products. The histological and electron microscopical similarity of corpora amylacea, Lafora bodies and Bielschowsky bodies suggest that all these structures are an unspecific, nearly identical endproduct of various intracellular metabolic disturbances. The pathognomonic significance of these structures depends on their regional distribution: the common corpora amylacea occur predominantly in the astroglia, the Lafora bodies typical in the neurons and the Bielschowsky bodies are restricted to the neurons of the exterior pallidum.