1. Aitken Neuroscience Institute and Cornell University Medical College, New York, New York, U.S.A.
2. ^*Institute for Biomedical Engineering, Department of Medicine, University of California, California, U.S.A.
3. ^†Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, California, U.S.A.
4. ^‡Department of Neurosurgery, Klinikum Mannheim, Ruprecht-Karls University, Heidelberg, Germany.

Correspondence: Roger Härtl, Virchow-Klinikum, Neurochirurgisch-Neurologische Klinik, Abteilung Neurochirurgie, Augustenburger Platz 1,13353 Berlin, Germany.

Received 8 August 1995; Revised 28 December 1995; Accepted 5 March 1996.

Abstract

White blood cells (WBCs) play vital roles in host defense. Recently, increasing interest has been directed toward the question of whether WBCs, particularly polymorphonuclear leukocytes, could also act as mediators of secondary brain damage in the setting of focal and global cerebral ischemia with and without reperfusion. Considerable insight into the importance of WBC-mediated tissue injury has been gained from studies employing antileukocyte interventions in experimental cerebral ischemia. The purpose of this article is to survey the different approaches taken to interfere with WBC inflammatory function. Emphasis is laid on a discussion of the efficacy of these interventions, their effects and side effects on cerebral and systemic parameters, and the power of evidence they provide for identification of WBCs as important factors in cerebral ischemia. The role of WBCs has been investigated in a great variety of global and focal cerebral ischemia models with and without reperfusion, leading to sometimes contradictory results. In the light of currently available data, it seems likely that WBCs contribute to secondary brain damage in the scenario of experimental transient focal cerebral ischemia, if the insult is not too severe.