In this thoroughly revised and updated second edition, a panel of distinguished clinical researchers from around the world takes stock of the wealth of new knowledge about the human spleen and applies it to the pathology and treatment of splenic diseases. This much enriched understanding encompasses the spleen's complex role in immunological defense, the recently defined function of particulate filtration by the spleen, and the structural basis for the functions of the spleen, most particularly the microvasculature around which it is organized. Among the diseases and disorders of the spleen considered in detail are splenomegaly, the consequences and management of hyper- and hyposplenism, and "dilutional anemia." Recent advances in splenic surgery are also reviewed, especially those techniques intended to preserve at least partial function while removing the greater part of the organ.

5 Function of Splenic Compartments . . . . . . . . . . . . . . . 45 5. 1 Splenic White Pulp Compartments during Primary T Cell-Dependent Antibody Responses against Protein Antigens . . . . . . . . . . . . . . . . . . . . . . . . . 46 5. 1. 1 Priming of CD4+ Helper T Cells by Dendritic Cells in the PALS . . . . . . . . . . . . . . . . . . . . 46 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 5. 1. 1. 1 5. 1. 2 Interaction of Primed CD4+ T Cells with Antigen-Specific B Cells in the PALS and Formation of Extrafollicular Foci . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 5. 1. 2. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 5. 1. 3 Formation of Germinal Centres . . . . . . . . . . . . . . . . . . . 50 5. 1. 3. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 5. 1. 4 Localisation of Memory B Cells in the Marginal Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 5. 1. 4. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 5. 2 Function of the Marginal Zone during Primary Antibody Responses against T Cell-Independent Type 2 Antigens . . . . . . . . 57 5. 2. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Function of the Red Pulp . . . . . . . . . . . . . . . . . . . . . . . . . 59 5. 3 5. 3. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 5. 4 Role of the Spleen in CD8+ Cytotoxic T Cell Responses . . . . . . . . . . . . . . . 61 5. 4. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 The Spleen, Natural Killer Cells 5. 5 and Gamma/Delta T Cells . . . . . . . . . . . . . . . . . . . . . . . . 62 5. 5. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 6 Recirculation of Lymphocytes Through the Spleen . . 65 6. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 7 The Role of Cytokines and Chemokines in the Development of Splenic Compartments . . . . . . 69 7. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 8 Unsolved Problems of Human Splenic Structure and Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 VI 8. 1 Arterial Blood Supply to the Splenic Follicles and to the Perifollicular Zone. . . . . . . . . . . . . . . . . 73 . . . . 8. 1. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 8.

The International Life Sciences Institute (ILSI) was estab lished in 1978 to stimulate and support scientific research and educational programs related to nutrition, toxicology, and food safety, and to encourage cooperation in these programs among scientists in universities, industry, and government agencies to assist in the resolution of health and safety issues. To supplement and enhance these efforts, ILSI has made a major commitment to supporting programs to harmon ize toxicologic testing, to advance a more uniform inter pretation of bioassay results worldwide, to promote a common understanding of lesion classifications, and to encourage wide discussion of these topics among scien tists. The Monographs on the Pathology of Laboratory Ani mals are designed to facilitate communication among those involved in the safety testing of foods, drugs, and chemicals. The complete set will cover all organ systems and is intended for use by pathologists, toxicologists, and others concerned with evaluating toxicity and carcinogen icity studies. The international nature of the project - as reflected in the composition of the editorial board and the diversity of the authors and editors - strengthens our ex pectations that understanding and cooperation will be im proved worldwide through the series. Alex Malaspina President International Life Sciences Institute Preface This book, on the hemopoietic system, is the eighth volume of a set prepared under the sponsorship of the International Life Sciences In stitute (ILSI).