Reactive astrocytes and macrophages in the brain stem of SIDS victims? Eleven age- and sex-matched SIDS and control cases.

The investigation was carried out on 11 sudden infant death (SIDS) cases which were compared with age- and sex-matched controls. Six brain nuclei were selected for evaluation. Using immunohistochemical methods, macrophages were selectively demonstrated by detection of lysozyme; reactive astrocytes, by detection of intracytoplasmic albumin (marker of prior impairment of blood-brain barrier function) or GFAP. No lysozyme-positive cells were demonstrable in the brain stem of any of the examined cases. Although a greater number of reactive, GFAP-expressing astrocytes were found in the SIDS cases, 3 of the 11 SIDS cases (compared to 5 controls) had no reactive astrocytes in any of examined brain nuclei. Reactive astrocytes, however, were identified in more than half the controls. Sections treated with anti-albumin serum were evaluated quantitatively. Total number of non-neuronal cells, relative proportion of astrocytes, and proportion of albumin-positive astrocytes were determined. Paired brain nuclei were counted on both sides of the brain stem. The number of non-neuronal cells, astrocytes, and albumin-positive astrocytes in the SIDS cases did not differ significantly from those in the controls. No statistically relevant difference was established between the right and left parts of the brain stem. The findings were discussed in light of the literature.