Chapter Immunopathology Atul K. Bhan, Robert B. Colvin, and Harold F. Dvorak he application of immunology to clini- and when, beginning in the 1980s, the unit rap- Tcal medicine and the development of immu- idly implemented diagnostic immunohistochem- nopathology as a specialized fi eld stem largely from istry into the routine diagnostic service; and (3) the pioneering work of the great immunologist/ from 1991 to the present, when the unit contin- pathologist Paul Ehrlich, who received the 1908 ued to develop new immunological diagnostic Noble Prize for his work on immune responses in tests and conduct basic research. infection (1). Th e introduction of immunofl uo- rescence techniques by Dr. Albert Coons in the Early Years: Before 1940s set the stage for establishment of immu- Th e earliest manifestations of the then-nascent nohistochemical techniques and development of fi eld of immunopathology at MGH were the fl ow cytometric analysis of cells. Dr. Coons, who studies of Dr. Louis Dienes, a bacteriologist who had been trained in internal medicine at the Mas- was recruited to the Pathology department in 1930 sachusetts General Hospital (MGH), performed (see fi gure 21.3; chapters 5 and 21). He showed that most of his work at Harvard Medical School simple proteins (ovalbumin) could elicit a “tuber- (HMS), initially in the Department of Microbi- culin reaction” in the skin if the animal (guinea ology and Immunology and later in the Pathology pig) had previously been sensitized by inoculation Department. Over the years, immunopathology of the protein into a tuberculous lesion (2). At the has applied the knowledge obtained from basic time only products of organisms were thought to immunology research to achieve a better under- trigger this type of response, termed a delayed- standing of disease pathogenesis, develop sophis- type hypersensitivity reaction and later shown ticated tests for accurate clinical diagnosis, and to be a T cell mediated reaction. With Dr. Tracy implement new therapeutic strategies. Mallory (chapter 6) in 1932 he characterized the Th e history of immunopathology at MGH morphology of the lesions and contrasted them will be described for three periods: (1) before with antibody-mediated reactions (Arthus reac- 1975, when immunopathology concepts were tion). Tuberculin sensitivity could also be pro- being developed and when the Immunopathol- duced by sensitization with protein alone (no ogy Laboratory was established; (2) from 1975 tuberculous infection), although it was milder to 1991, when the Immunopathology Unit was (Jones-Mote reaction). Also with Dr. Mallory, in formed and fl ourished under the leadership of 1937, he showed that tuberculin hypersensitivity Dr. Robert T. McCluskey (chapter 14) to become developed simultaneously with the mononuclear the dominant research unit in MGH Pathology, infi ltrate surrounding tuberculous lesions. 333 pathology_chap23.indd 333 8/16/11 10:25 AM Keen Minds to Explore the Dark Continents of Disease Starting in 1951, Dr. Byron Waksman (fi gure 23.1), a neurologist at MGH, showed that anal- ogous delayed immune reactions to autologous proteins (myelin) could produce a rapid-onset form of disseminated encephalomyelitis in rab- bits that had been immunized with rabbit spinal cord, characterized by a perivenous infi ltration of “round” cells and neuronal demyelination, which had pathologic similarities to multiple sclerosis (3). Dr. Waksman devoted most of his career to an understanding of the pathogenesis of delayed hypersensitivity as it occurred, not only in the brain, but also in joints (a model of rheuma- toid arthritis) and skin of animals of several spe- cies. His laboratory was on Warren 3, above the Pathology department, and he attracted several outstanding pathologists into the fi eld of immu- nopathology (chapter 17). One of those attracted was an HMS student, Harold F. (“Hal”) Dvorak, who was impressed by Dr. Waksman’s lectures and delighted to accept his joint off er, with Dr. Benjamin Castleman Figure 23.1 Byron Waksman (chapter 8), to take a post-sophomore pathology fellowship in 1959–1960, splitting time between attracted to the group on Warren 3, in his case by diagnostic pathology and research. Dr. Dvorak, Dr. Arnason’s lectures, and he spent the summer who worked on cell transfer studies and devel- of 1966, after his second year at HMS, studying opment of in vitro immune assays, considered the antigens of the hippocampus in the labora- the fellowship one of the most formative parts tory directly above Dr. Castleman’s offi ce. of his life. Dr. Waksman had a coterie of inter- Recognizing the increasing importance of national postdoctoral fellows in his lab at that immunology in the understanding and treat- time, including Branislov Jankovich (Yugo- ment of many diseases, Dr. Castleman decided to slavia), Barry Arnason (Canada), and Timo form an Immunopathology Laboratory in 1959 Kosunen (Finland), all of whom were working under the direction of Dr. Martin H. Flax (fi gure on aspects of cellular immunity. Dr. Kosunen 23.2), a protégé of Dr. Waksman. Th e concept of made use of the recently available isotope triti- immune mediated injury was extended to other ated thymidine to perform autoradiography and organs by Drs. Flax and Waksman in 1963 stud- demonstrated for the fi rst time that a substantial ies on adjuvant disease (an autoimmune arthri- fraction of cells accumulating in tuberculin-type tis) and in 1963–1966 studies on experimental reactions were actively dividing (4). Dr. Arnason allergic thyroiditis (5) with Drs. Stuart Sell and was one of the fi rst to demonstrate that neonatal James Billote; on allergic contact dermatitis with thymectomy severely compromised the immune Dr. James Caulfi eld; and on beryllium granu- system, so that rats were able to “tolerate” and lomatous hypersensitivity with Dr. Sidney Les- not reject grafts of foreign tissues. Dr. Robert B. kowitz in Medicine (6). As the early focus of the Colvin (chapter 25) was another HMS student laboratory was diagnostic renal biopsies, a close 334 pathology_chap23.indd 334 8/16/11 10:25 AM Immunopathology relationship developed between the Immunopa- basophil content, the reaction was called cuta- thology Laboratory and nephrologists as well as neous basophil hypersensitivity (CBH). Simi- the Renal Transplantation Unit. lar, basophil-rich reactions were found in other Dr. Vivian Pinn started working with Dr. Flax organs and tissues in response to an immune in 1967, when she joined MGH as a resident in challenge: for example, the eye in ocular hyper- Pathology (see fi gure 7.26). Dr. Pinn moved with sensitivity and human kidneys undergoing acute Dr. Flax to Tufts University Medical School in allograft rejection (8, 9). Dr. Dvorak remembers 1970, when Dr. Flax was made the Chairman of showing one-micron Epon slides to Dr. Castle- the Department of Pathology there. She remained man; he was impressed but asked for a hematoxy- involved in immunopathology of the kidney and lin and eosin (H&E) section of the same lesions subsequently became Professor and Chairman of and had no trouble detecting basophils! Pathology at Howard University College of Med- Th ese studies were extended to human cellular icine, the fi rst African American woman to chair immunity when Dr. Dvorak developed poison an academic pathology department. ivy on Martha’s Vineyard. He biopsied his rash Dr. Colvin, who at that time was a resident and found it was swarming with basophils. He in Pathology, worked on renal and transplant secured the help of Dr. Colvin and Dr. Martin pathology with Drs. Pinn and Flax and became C. Mihm Jr. of Dermatopathology (chapter 18) the resident expert in this area when they left to extend these studies to other contact allergens, for Tufts. Dr. Colvin was able to resuscitate an employing volunteers who were biopsied, includ- ancient Reichert fl uorescent microscope for ing the investigators. Dr. Ann Dvorak (Hal’s immunofl uorescence, which had to be done at night, since the room on Warren 1 had no shades on the windows. Dr. Dvorak had come back to MGH for an internship and residency in Pathology in 1963 and then, working with Dr. Flax, made impor- tant observations regarding immunological unre- sponsiveness induced by intravenous tolerizing antigen. After two years of research at NIH, Dr. Dvorak returned to the MGH in 1967 and began developing and directing immunopathology research. Dr. Dvorak used elegant one-micron Giemsa-stained Epon sections, prepared by his research assistant, Eleanor Manseau, to study the cellular details of delayed-hypersensitivity reac- tions by light microscopy (7). He was, therefore, for the fi rst time able to appreciate infi ltrating basophil leukocytes in tissues and their participa- tion in a type of delayed-hypersensitivity reaction (Jones-Mote reaction) induced by immunization with protein antigens in incomplete Freund’s adjuvant (which were probably what Drs. Dienes and Mallory had created by injecting ovalbumin without tubercle bacillus). Because of its high Figure 23.2 Martin Flax 335 pathology_chap23.indd 335 8/16/11 10:25 AM Keen Minds to Explore the Dark Continents of Disease wife), who had done a postdoctoral fellowship in research fellowship at Children’s Hospital, moved electron microscopy with Dr. Morris Karnovsky to MGH to pursue immunopathology research. at HMS and had helped demonstrate basophils as Th e Immunopathology Laboratory at that time an important feature of other cellular immunity was located on the fi rst fl oor of the Warren Build- in guinea pigs, also participated in the studies. ing. Dr. Elizabeth Hammond, who graduated Dr. Ann Dvorak showed through ultrastructural from the University of Utah School of Medicine studies the activation of microvascular endothe- in 1967, joined the lab fi rst as a research fellow lial cells and pericytes in the venules from which in 1972 and subsequently as a staff member in lymphocytes, basophils, and other infl ammatory 1974.