VALUE OF NERVE BIOPSY IN THE DIAGNOSIS AND FOLLOW-UP OF LEPROSY - THEROLE OF VASCULAR-LESIONS AND USEFULNESS OF NERVE STUDIES IN THE DETECTION OF PERSISTENT BACILLI

Nerve biopsy specimens from 53 patients with leprosy and neuropathy we re taken from the sural, the dorsal branch of the ulnar, or the superf icial radial nerves and processed for light and electron microscopy. T here was inflammation in 40 cases (75%), 7 with a granulomatous reacti on, various stages of fibrosis in 35 (66%), and endoneurial vascular n eoformation in 7. In two cases, small focal infarcts were associated w ith marked endoneurial inflammation compressing the vessels, in additi on to endoneurial lymphocytic vasculitis. Most had an axonal neuropath y of varying degree, some with total fibre loss, others with predomina nt small myelinated and unmyelinated fibre loss. Signs of demyelinatio n and remyelination were the main findings in 9 cases (17%). Bacilli w ere present in endothelial, perineurial, Schwann cells and in macropha ges. On two occasions, they lost their alcohol acid resistance, were s uspected in semithin sections, and confirmed ultrastructurally. The bi opsy was decisive for the diagnosis of leprosy in 15 cases (28%), most without skin lesions. We evaluated the effectiveness of the treatment in 20 (37.7%), 12 without and 8 with bacilli, despite negativity in t he skin. The diagnosis of leprosy based on skin lesions was confirmed with the nerve biopsy in 9 cases, 6 had an inflammatory neuropathy sug gestive of leprosy in the absence of bacilli, and 3 had nonspecific ch anges in the sural nerve since the neuropathy was in the upper limbs. We conclude that nerve biopsy is indicated for the diagnosis of lepros y in cases without clinically visible skin lesions and To evaluate the effectiveness of the treatment. In these cases the ultrastructural st udies are important for recognition of the bacilli. Vascular lesions m ay play an important role in the progression of the nerve damage,inclu ding the occurrence of focal nerve infarcts which, to our knowledge, h ave not been previously reported in association with leprosy.