Application of Immunohistochemical Techniques to Sural Nerve Biopsies

The Relationship between Quiescent Inflammatory Bowel Disease and Peripheral Polyneuropathy

BACKGROUND/AIMS

Inflammatory bowel disease is a chronic, recurrent disorder that involves multiple organ systems. Polyneuropathy is the most common neurological manifestation. The aim of the present study was to investigate the relationship between polyneuropathy and inflammatory bowel disease.

METHODS

The study included 40 patients with infl ammatory bowel disease (20 with ulcerative colitis and 20 with Crohn's disease) and 24 healthy controls. The patients had no clinical signs or symptoms of polyneuropathy. Nerve conduction studies were performed using an electroneuromyography apparatus.

RESULTS

Mean distal motor latencies, conduction velocities, and F wave minimum latencies of the right median nerve were signifi cantly abnormal in the patient group, compared to the healthy controls (p<0.05).

CONCLUSIONS

Some electrophysiological alterations were observed in chronic inflammatory bowel disease patients who showed no clinical signs. While investigating extra-intestinal manifestations in inflammatory bowel disease patients, nerve conduction studies must be performed to identify electrophysiological changes and subclinical peripheral polyneuropathy, which can subsequently develop.

An immunohistochemical marker for Wallerian degeneration of fibers in the central and peripheral nervous system

This work was prompted by the accidental observation that a newly developed, affinity purified polyclonal antibody against the C-terminus of the neuropeptide tyrosine (NPY) Y1-receptor protein decorates degenerating fibers in the central nervous system (CNS). This staining did not appear in control animals in which the antibody marked perikarya and dendrites at previously described locations [X. Zhang, L. Bao, Z.-Q. Xu, J. Kopp, U. Arvidsson, R. Elde, T. Hökfelt, Localization of neuropeptide Y Y1-receptors in the rat nervous system with special reference to somatic receptors on small dorsal root ganglion neurons, Proc. Natl. Acad. Sci. USA 91 (1994) 11738-11742]. Three models of experimental lesions were studied: sciatic nerve transection, spinal cord transection and parietal cortex thermocoagulation. In each model, animals were divided in groups (n=2) and processed for indirect immunofluorescence at different time intervals up to 28 days post-lesion (PL) (see below). All three experimental lesions produced a very intense immunolabeling of fibers in the projection pathways of the lesioned structures, strongly reminding of Wallerian degeneration (WD). In the sciatic nerve, the staining first appeared on day 1 PL, was strongly increased on day 3 PL, then declined after 7 days and had almost completely disappeared after 14 days. In the CNS, the staining appeared later and was first observed on day 3 PL and remained for a longer period, thus showing different time courses in the brain and spinal cord as compared to the sciatic nerve. The labeling was completely abolished, both in the CNS and in the sciatic nerve, by pre-incubation of the Y1-R antibody with the immunogenic peptide at a dilution of 10-6 M. The appearance of the staining and its time course strongly suggest that the process was related to degenerating axons. Although the protein actually detected remains to be determined, it is suggested that the staining ability of this antibody could be used as a positive marker of axonal degeneration following experimental or naturally occurring lesions of the nervous system.

[Intravenous therapy with methylprednisolone and cyclophosphamide in vasculitis of peripheral nervous system. Evaluation of 8 patients]

The peripheral nervous system is frequently involved in systemic vasculitis and it may be helpful in the disease diagnosis. We report on eight patients: seven women and one man; five white, two black and one yellow; age mean 55.9 years; four had polyarteritis nodosa, one had systemic lupus erythematosus, one had isolated peripheral nerve vasculitis and one had livedoid vasculitis. All of them received endovenous therapy with "pulse" of methylprednisolone (1 g/day/3 days) and cyclophosphamide (1 g/1 day). Five patients improved, two remained unchanged and one died. The neurological improvement occurred after the third or fourth pulse and in the patients who have had a shorter time of disease.

Epidemic neuropathy in Cuba: morphological characterization of peripheral nerve lesions in sural nerve biopsies

More than 50,000 patients were affected in Cuba during an epidemic outbreak of peripheral neuropathy from January 1992 until September 1993. The disease presented as either a retrobulbar optic neuropathy, a predominantly sensory peripheral neuropathy, a dorsolateral myeloneuropathy, or as mixed forms. The morphological findings in sural nerve biopsies from 34 patients with various forms of the disease are presented here. Frozen, paraffin and semi-thin sections were prepared for light and electron microscopy, immunohistochemistry and morphometric analysis. Every case presented morphological alterations ranging from mild axonal dystrophy (9 cases, or 27%) to moderate and severe axonal damage (25 cases, or 73%). In 6 cases (18%), axonal damage was accompanied by perineural fibrosis and vascular abnormalities. Axonal regeneration was noted in 8 cases (23%) and remyelination in 9 (26%). Morphometric analysis showed a predominant loss of myelinated fibers in 92% of the patients. Quantification of myelinated fiber loss in 11 patients revealed a remarkable decrease in large caliber fibers. Scarce mononuclear cells were observed in 17 cases. No virus-like elements were seen. The morphological features found in this study indicate that, regardless of the clinical presentation, peripheral nerve lesions of the epidemic neuropathy in Cuba correspond to an axonal neuropathy. These lesions are compatible with nutritional, toxic, or metabolic etiologies. An inflammatory etiology would be unusual with these lesions.