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The distribution of inclusions in adult-onset type intranuclear inclusion body disease (INIBD) has not been fully described. We analyzed the clinical and pathological changes of three autopsy cases of adult type INIBD and provide a detailed description of the distribution of inclusions in nervous system and visceral organs. Although patients showed cognitive decline and autonomic dysfunction, there were no specific symptoms related to general organs. The neuropathological changes responsible for cognitive decline and autonomic dysfunction were considered to be white matter changes in the cerebral hemispheres and inclusions in the autonomic nervous system, e.g., in the sympathetic ganglia and myenteric plexus. Alterations of spongiosis with both myelin and axon loss in the cerebral white matter seemed to be related to dysfunction of astrocytes with intranuclear inclusions. In visceral organs, the inclusions were much more widely distributed than previously appreciated and included renal mesangial cells, adrenal sustentacular cells, fibrocytes, Kupffer cells, pancreatic centroacinar and ductal epithelial cells. Since skeletal muscle cells, Schwann cells and smooth muscle cells were also inclusion positive, we propose that biopsy of muscle, peripheral nerve or rectum may prove useful for the clinical diagnosis of INIBD.

Neuronal intranuclear inclusion disease, a progressive ataxia that may be familial or sporadic, is characterized by numerous neuronal intranuclear inclusion bodies similar to those found in polyglutamine repeat diseases. Previously, we found that the intranuclear inclusion bodies are intensely immunopositive for SUMO-1, a protein which covalently conjugates to other proteins in a similar way to ubiquitin. To identify the SUMO-1-associated proteins in the inclusion bodies, we isolated intranuclear inclusion bodies from fresh, frozen brain tissue of a case with familial neuronal intranuclear inclusion disease and solubilized the proteins. SUMO-1-associated inclusion body proteins were then immunocaptured using an anti-SUMO-1 antibody. The proteins, NSF, dynamin-1 and Unc-18-1 (rbSEC1), involved in membrane trafficking of proteins, and the chaperone HSP90, were identified following anti-SUMO-1-immunocapture by using tandem mass spectrometry and database searching. Immunohistochemistry of brain sections and crude brain homogenates of three cases of familial neuronal intranuclear inclusion disease confirmed the presence of these proteins in intranuclear inclusions.

Ferritinopathy (neuroferritinopathy) has recently been identified as an autosomal dominant, multisystem disease, mainly affecting the central nervous system. It is caused by mutations in exon 4 of the ferritin light chain gene on chromosome 19. Its fine structural hallmarks are granular nuclear inclusions in neurons, oligodendroglial and microglial cells with similar extracellular derivatives in the central nervous system, muscle, peripheral nerve, and skin. These pathognostic structures have previously been described in perivascular cells of muscle and nerve biopsy specimens in a case with an obviously identical disease, formerly described as 'granular nuclear inclusion body disease'. The nuclear inclusions, at the light microscopic level, are iron positive following histochemical iron reactions and immunoreactive for ferritin antibodies. At the electron microscopic level, in contrast to filamentous nuclear inclusions in 'neuronal intranuclear hyaline inclusion disease', dominant spinocerebellar atrophies and other trinucleotide repeat diseases, they are basically composed of granules measuring 5-15 nm. A moderate peak of iron detectable by energy dispersive microanalysis of the granular nuclear inclusions in ferritinopathy may also be significant. It is emphasized that ferritinopathy or 'granular nuclear inclusion body disease' can be diagnosed by a simple muscle or nerve biopsy without brain biopsy, autopsy, or molecular genetic testing of the considerable number of neurodegenerative diseases with possibly similar symptomatology.

Mutations in the skeletal muscle alpha-actin gene ( ACTA1) are associated by and large with three muscle diseases (1) congenital actin myopathy, (2) nemaline myopathy, and (3) intranuclear rod myopathy. More than 70 mutations have now been identified. The majority of ACTA1 mutations are dominant, a small number are recessive and most isolated cases with no previous family history have de novo dominant mutations. The present case, a boy of healthy Turkish parents, had a severe form of the disease of the latter type due to a heterozygous, presumably de novo mutation of the ACTA1 gene in exon 4 (Asp154Asn), with lack of spontaneous movements at birth requiring immediate mechanical ventilation. He died at the age of 9 weeks due to respiratory failure, secondary pneumonia, and chylothorax. The biopsy specimen of the femoral muscle was characterized by pleomorphic alterations with numerous muscle fibers showing accumulation of actin filaments, but, in addition, both nemaline bodies and intranuclear rod bodies. This was also seen in several other muscles investigated at autopsy. No developmental abnormalities of the central nervous system, and no loss of spinal motor neurons were detected despite atrophy or hypotrophy of a considerable number of muscle fibers. The peripheral nervous system, which has not been studied before in patients with ACTA1 mutations, showed no loss of motor or sensory myelinated fibers and no loss of sensory neurons in spinal ganglia.

A 46-year-old patient developed amyotrophic lateral sclerosis (ALS) characterized by rapid progression. She needed respiratory assistance after a course of 9 months. She died 4.5 years after onset. Autopsy showed dramatic atrophy of the spinal cord, sparing only the posterior tracts, associated with neuronal loss and astrogliosis in various areas including the anterior horns, motor cortex, striatum, thalamus, and substantia nigra. Ubiquitin immunohistochemistry showed rare skein-like inclusions in the surviving spinal and medullary motor neurons. Eosinophilic inclusions were found in the nuclei of pyramidal neurons in the hippocampus. These inclusions were immunoreactive to antibodies against ubiquitin, promyelocytic leukemia gene product, proteasome, and ataxin-3. They were not immunoreactive to antibodies against tau, cystatin C, neurofilament, alpha-synuclein, SOD-1, and polyglutamine (1C2), and were not stained by ethidium bromide. Similar inclusions were found in the motor cortex. The immunoreactivity of the inclusions was similar to that encountered in diseases associated with CAG repeats, except for the negativity of the immunolabelling with 1C2. At the ultrastructural level, the nuclear inclusions were made of straight filaments (10-12 nm in diameter) arranged at random, reminiscent of the polyglutamine intranuclear hyaline inclusions.