At War Within - The Double-Edged Sword of Immunity - W. Clark (Oxford, 1995) WW

289 Pages·1995·13.44 MB·English

At War Within

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At War Within

The Double-Edged Sword of Immunity

William R. Clark

New York Oxford
Oxford University Press
1995

Oxford University Press

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Copyright © 1995 by Oxford University Press, Inc.

Published by Oxford University Press, Inc.,
198 Madison Avenue, New York, New York 10016

Oxford is a registered trademark of Oxford University Press

All rights reserved. No part of this publication may be reproduced,
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Library of Congress Cataloging-in-Publication Data
Clark, William R., 1958-
At War Within : the double-edged sword
of immunity / William R. Clark.
p. cm.
Includes bibliographical references and index.
ISBN 0-19-509286-4 (acid-free paper)
1, Immune system—Popular works.
2. Immunologic diseases—
Popular works.
I. Title.
QR181.7.C624
1995
616.07'9—dc20 94-45134

3 5 7 9 8 6 4

Printed in the United States of America
on acid-free paper

Contents

Introduction
ix

1 Overture to a Science Unborn: Smallpox and the
Origins of Immunology
3
Vaccination: The End of a Plague 19
Beyond Vaccination: Pasteur, Koch, and the Germ Theory of
Disease
26

2 The Anatomy of an Immune Response 35
A Gift of Life
35
The Antibody Response 39
T Cells: The Second Arm of the Immune Response 41
The Lymphatic System 44
The Bone Marrow and the Thymus 51

3 Living in the Bubble: Primary Immune Deficiency
Diseases 57
A Light Goes On
60

v

Going Naked in the World: SCID 66
Gene Therapy: The New Hope 73

4 Hypersensitivity and Allergy 81
The Discovery of Hypersensitivity 81

Allergy in Humans: The Tip of the Iceberg
87

Specific Forms of Human Allergy 91

A Dream Gone Wrong: Immune Complex Diseases
100
Why Hypersensitivity? 104

5 Horror Autotoxicus: The Immunology of
Self-Destruction 707
Tuberculosis and DTH Reactions
108
Tuberculosis as an Autoaggressive Disease
111
Viral Hepatitis
114
Immunological Tolerance 117
Autoimmune Disease in Humans
121
Autoimmune Hepatitis 124
Systemic Lupus Erythematosus 126
Myasthenia Gravis
127
Why Are We So Self-Destructive? 130

6 When the Wall Comes Tumbling Down: AIDS 735
AIDS as a Clinical Problem
139
Opportunistic Infections 142
AIDS-Associated Cancers
145
AIDS-Associated Neurological Disorders
147
AIDS as a Problem in Virology 149
The Immunology of AIDS
154

vi Contents

Preventing and Treating AIDS 158
What Lies Ahead? 163

A Solution to the Dormancy Problem
164

A Vaccine
165

Drugs
167
Gene Therapy 168
"The Worst Possible Nightmare"
170

7 Organ Transplantation: Exploring the Boundary
Between Technology and Ethics 175
The Immunological Basis of Organ Transplantation
I80

From Pastime to Prime Time: The Advent of Imrnuno-

suppressive Drugs
185
The Ethics of Organ Procurement: A Modern Moral
Dilemma
192

Living Donors
194

Cadaver Donors
199

Alternatives to Human Organ Transplantation
204
Xenotransplantation
205

Modern Moral Dilemmas: Part II 210
Molecular Biology to the Rescue (Again!) 214

Artificial Organs
216

8 Minding the Immune System's Business:
The Dialogue Between the Brain and the
Immune System 227
The Mind and Disease 221
Lines of Communication
231
Talking It Out
239

Contents vii

Appendix
Diversity, Tolerance, and Memory: The Politically
Correct Immune System 243

Bibliography
267
Index 277

viii Contents

Introduction

Most of us are aware that the immune system is designed to
protect us from the thousands upon thousands of predatory mi-
croorganisms that can invade and seriously damage virtually ev-
ery part of the body. Millions of years of evolution have honed it
to do just that, in animals and in humans. Our immune systems
are finely tuned, highly integrated defense complexes that re-
lentlessly track, identify, and destroy a wide range of would-be
body crashers. Once the immune system has an unwanted foreign
invader in its sights, it can bring a formidable array of chemical
and cellular weapons to bear on its elimination. This is the side of
the immune system of which most of us are aware—the nurturing
and protective side.
The immune system can and does provide a powerful defense
against potential pathogens, but what is perhaps less obvious is
that it is also capable of bringing too much power to bear during
the course of clearing away foreign invaders. Like an army lashing
out blindly against an unseen and unmeasured enemy, the im-
mune system is capable of using excessive deadly force in the
wrong time or place—and it is capable of overkill. And as almost
always happens in such situations, the most devastating damage
of all may be done to innocent bystanders. The result could be
nothing more than a mildly annoying allergy. But it can be more
deadly. People may die from hepatitis, not because the virus

IX