Bunina bodies in amyotrophic lateral sclerosis on Guam: a histochemical, immunohistochemical and ultrastructural investigation

An investigation of Bunina bodies is important when studying the pathoetiol ogy and pathomechanisms involved in amyotrophic lateral sclerosis (ALS). It may serve as a clue essential for the study of the pathogenesis of Guamani an amyotrophic lateral sclerosis (ALS-G), and it may provide a means of ans wering the question of whether ALS-G is the same disease as classical ALS o r a different entity. In ALS-G, however, no precise histochemical, immunohi stochemical, or detailed ultrastructural examination has been published to date. To elucidate the pathological differences/similarities of Bunina bodi es between classical ALS and ALS-G, we performed histochemical, immunohisto chemical, topographic and ultrastructural examinations. Histochemically, he matoxylin and eosin, Masson's trichrome, methylgreen-pyronin, phosphotungst ic acid-hematoxylin, Kluver-Barrera, Bodian and periodic acid-Schiff staini ng were utilized. Immunohistochemical examination was performed using antib odies for cystatin C, ubiquitin, Tau-2, Cu/Zn superoxide dismutase, phospho rylated neurofilament and glial fibrillary acidic protein. Histochemical fi ndings were consistent with those previously described for classical ALS. T he immunohistochemical study showed that in ALS-G Bunina bodies were intens ely labeled by an anti-cystatin C antibody. Topographic examination demonst rated that Bunina bodies were distributed in the spinal anterior horns and Clarke's column in the spinal cord. Ultrastructurally, Bunina bodies were c omposed of electron-dense amorphous/granular material accompanied by vesicu lar structures and neurofilaments. The results of the present study have re vealed that the pathological features of Bunina bodies in ALS-G are identic al to those seen in classical ALS. These findings strongly suggest that a s imilar degenerative process occurs in the spinal anterior hem cells in both ALS-G and classical ALS.