Neuropediatrics 2006; 37 - TP28
DOI: 10.1055/s-2006-945621

IMMUNOHISTOCHEMICAL ANALYSIS OF BILIRUBIN ENCEPHALOPATHY

Y Hachiya 1, M Hayashi 1, N Tanuma 1, A Uchiyama 1
  • 1Department of Pediatrics, Fuchu Metropolitan Medical Center for SMID, Fuchu-Shi, Tokyo, Japan

Objectives: Bilirubin encephalopathy (BE) results from severe and untreated neonatal jaundice. The globus pallidus, subthalamic nucleus and Ammon's horn are commoly affected. Pathophysiology of BE itself and selectivity of brain lesions remains elusive. To explore neurodegenerative mechanisms in BE, we immunohistochemically examined expressions of functional markers such as neurotransmitters, and deposition of oxidative products in the basal ganglia.

Methods: Subjects consisted of 12 BE cases and 11 aged-matched controls, which were divided into three groups. Subjects in groups I, II and III died during the neonatal period, in the first decade and after the age of 10 years, respectively. And three neonatal cases in group I suffered from acute form of BE, kernicterus, while the other nine cases in groups II and III suffered from chronic postkernicteric form of BE. Serial sections of the basal ganglia and thalamus were treated with antibodies to tyrosine hydroxylase (TH), neuropeptides, calcium-binding proteins and oxidative products to proteins, lipids and nucleosides.

Results: TH expression was altered in the globus pallidus in some BE cases, while neonatal cases of acute form of BE demonstrated disturbed TH expression with increased mottled pattern in the putamen. Methionine-enkephalin expression was disturbed in the external segment of globus pallidus in most of the BE cases, whereas immunoreactivity for substance P was altered in both the internal and external segments in cases of chronic postkernicteric form of BE. Parvalbumin immunoreactive interneurons were reduced in the globus pallidus in neonatal cases of acute form of BE. Immunoreactivity for 8-hydroxy-2'-deoxyguanosine and/or 8- hydroxyguanosine, markers for oxidative damages to DNA and RNA, respectively, were increased in the putamen and thalamus in the BE cases.

Conclusion: These findings indicated that the putamen and the external segment of globus pallidus were impaired in BE. Oxidative nucleoside damage may also be involved in neurodegeneration in BE.