Dylan V. Miller

Bone Marrow–Derived Cardiomyocytes Are Present in Adult Human Heart A Study of Gender-Mismatched Bone Marrow Transplantation Patients

Background—Recent studies have identified cardiomyocytes of extracardiac origin in transplanted human hearts, but the exact origin of these myocyte progenitors is currently unknown. Methods and Results—Hearts of female subjects (n=4) who had undergone sex-mismatched bone marrow transplantation (BMT) were recovered at autopsy and analyzed for the presence of Y chromosome–positive cardiomyocytes. Four female gender-matched BMT subjects served as controls. Fluorescence in situ hybridization (FISH) for the Y chromosome was performed on paraffin-embedded sections to identify cells of bone marrow origin with concomitant immunofluorescent labeling for &agr;-sarcomeric actin to identify cardiomyocytes. A total of 160 000 cardiomyocyte nuclei were analyzed approximating 20 000 nuclei per patient. The mean percentage of Y chromosome–positive cardiomyocytes in patients with sex-mismatched BMT was 0.23±0.06%. Not a single Y chromosome–positive cardiomyocyte was identified in any of the control patients. Immunofluorescent costaining for laminin and chromosomal ploidy analysis with FISH showed no evidence of either pseudonuclei or cell fusion in any of the chimeric cardiac myocytes identified. Conclusions—These data establish for the first time human bone marrow as a source of extracardiac progenitor cells capable of de novo cardiomyocyte formation.

Primary central nervous system vasculitis: analysis of 101 patients

To analyze the clinical findings, response to therapy, outcome, and incidence of primary central nervous system vasculitis (PCNSV) in a large cohort from a single center

Smooth muscle cells in human coronary atherosclerosis can originate from cells administered at marrow transplantation

Atherosclerosis is the major cause of adult mortality in the developed world, and a significant contributor to atherosclerotic plaque progression involves smooth muscle cell recruitment to the intima of the vessel wall. Controversy currently exists on the exact origin of these recruited cells. Here we use sex-mismatched bone marrow transplant subjects to show that smooth muscle cells throughout the atherosclerotic vessel wall can derive from donor bone marrow. We demonstrate extensive recruitment of these cells in diseased compared with undiseased segments and exclude cell–cell fusion events as a cause for this enrichment. These data have broad implications for our understanding of the cellular components of human atherosclerotic plaque and provide a potentially novel target for future diagnostic and therapeutic strategies.

The 2013 International Society for Heart and Lung Transplantation Working Formulation for the standardization of nomenclature in the pathologic diagnosis of antibody-mediated rejection in heart transplantation

During the last 25 years, antibody-mediated rejection of the cardiac allograft has evolved from a relatively obscure concept to a recognized clinical complication in the management of heart transplant patients. Herein we report the consensus findings from a series of meetings held between 2010-2012 to develop a Working Formulation for the pathologic diagnosis, grading, and reporting of cardiac antibody-mediated rejection. The diagnostic criteria for its morphologic and immunopathologic components are enumerated, illustrated, and described in detail. Numerous challenges and unresolved clinical, immunologic, and pathologic questions remain to which a Working Formulation may facilitate answers.

The ISHLT working formulation for pathologic diagnosis of antibody-mediated rejection in heart transplantation: Evolution and current status (2005-2011)

From the Department of Pathology, Stanford University, Stanford, California; Universita of Padua Medical School, Padua, Italy; Royal Brompton and Harefield NHS Trust, London, United Kingdom; Hopital Europeen Georges Pompidou, Paris, France; David Geffen School of Medicine at the University of California-Los Angeles, Los Angeles, California; Intermountain Medical Center, Salt Lake City, Utah; Queen Elizabeth Hospital, Birmingham, United Kingdom; University of Utah, Salt Lake City, Utah; Cleveland Clinic, Cleveland, Ohio; Papworth Hospital, Papworth, United Kingdom; Brigham & Women’s Hospital, Boston, Massachusetts; Cedars Sinai Heart Institute, Los Angeles, California; University of Maryland School of Medicine, Baltimore, Maryland.

Surgical pathology of noninfectious ascending aortitis : A study of 45 cases with emphasis on an isolated variant

BackgroundAortitis is emerging as an important cause of ascending aortic aneurysm in the elderly. Its features have not been described in a surgical population. DesignRetrospective clinicopathologic review of 45 cases of active noninfectious aortitis among 513 consecutive ascending aortic resections (1985 to 1999). MethodsClinical data were collected from medical records. Histopathologic features were recorded during review of slides stained with hematoxylin-eosin and Verhoeff-van Gieson. Cases were categorized by predefined clinical criteria. Clinicopathologic features were compared among groups, with emphasis on unsuspected aortitis without systemic arteritis. ResultsThe 2 largest groups were isolated aortitis (47%) and giant cell arteritis (31%). Other aortitis groups included Takayasu (14%), rheumatoid (4%), and unclassified (4%). Patients with isolated aortitis and giant cell arteritis were generally women (80%; mean age 73 y). All 6 with Takayasu arteritis were women (mean age 26). Although giant cell arteritis and isolated aortitis were histologically indistinguishable, their clinical courses differed substantially. Among 21 patients with isolated aortitis (2 treated with corticosteroids), only 10% later developed aortic aneurysms. In contrast, of 14 patients with giant cell arteritis (11 treated with corticosteroids), 21% subsequently developed aneurysms (P=0.09). ConclusionsAortitis primarily affected women. Patients with isolated aortitis and giant cell arteritis were generally older than 50 years and, by definition, those with Takayasu arteritis were younger. In patients with isolated aortitis, outcomes were generally good, despite the absence of anti-inflammatory therapy. Accordingly, a conservative approach may be warranted for managing this subset of patients with aortitis.

Biopsy Findings in Primary Angiitis of the Central Nervous System

Primary angiitis of the central nervous system (PACNS) is a form of vasculitis restricted to the brain and spinal cord, with protean clinical manifestations and often slowly progressive course. Outcomes vary, ranging from spontaneous resolution to rapid decline and death. Diagnosis of PACNS is based on angiography and/or biopsy. We reviewed surgical biopsies from 46 patients (53 biopsies) with PACNS, including 25 men and 21 women (median age 46, range: 25 to 84 y) and correlated the findings with relevant clinical parameters. Biopsies (51 brain, 2 spinal) were diagnostic of vasculitis in 29 (63%) patients. Three morphologic patterns of vasculitis were observed: acute necrotizing (n=4, 14%); purely lymphocytic (n=8, 28%); and granulomatous (n=17, 58%), 8 associated with deposition of β-A4 amyloid. Biopsies not diagnostic of PACNS (n=17, 37%) showed nonspecific gliosis (53%), mild perivascular mononuclear inflammation (18%), and parenchymal ischemic damage/infarct (18%). All positive biopsies were among those directed to an imaging abnormality (targeted biopsies) and biopsies including leptomeninges were more often positive than those that did not. Thus, where possible, a targeted biopsy that includes leptomeninges is recommended to maximize diagnostic potential. No statistically significant differences in outcome were noted among the 3 histopathologic groups or when comparing biopsy positive versus biopsy negative PACNS groups. Overall the outcomes were relatively favorable, with only 14% mortality or severe morbidity at 1.14 years (mean) after biopsy.

Pathology of pulmonary antibody-mediated rejection: 2012 update from the Pathology Council of the ISHLT

Gerald Berry, MD, Margaret Burke, FRCPath, Claus Andersen, MD, DMSc, Annalisa Angelini, MD, Patrick Bruneval, MD, Fiorella Calbrese, MD, Michael C. Fishbein, MD, Martin Goddard, FRCS, MRCPa, Ornella Leone, MD, Joseph Maleszewski, MD, Charles Marboe, MD, Dylan Miller, MD, Desley Neil, FRCPath, Robert Padera, MD, PhD, Doris Rassi, MBBS, MRCP, Monica Revello, MD, PhD, Alexandra Rice, FRCPath, Susan Stewart, FRCPath, and Samuel A Yousem, MD

Primary CNS vasculitis with spinal cord involvement

Background: Primary CNS vasculitis (PCNSV) is an uncommon disease in which lesions are limited to the brain and spinal cord. Our objective was to evaluate the frequency, clinical features, and outcome of spinal cord involvement in PCNSV. Methods: We retrospectively identified 101 consecutive patients with PCNSV. Spinal cord involvement was documented for five. Clinical findings, laboratory studies, and outcomes of patients with spinal cord involvement were assessed and compared with those without spinal cord manifestations. Results: Spinal cord symptoms developed before cerebral symptoms in one patient, concurrently in two, and after cerebral symptoms in two. CNS biopsy specimens showed necrotizing vasculitis in three patients and granulomatous vasculitis in two. MRI of the spinal cord showed enhanced thoracic lesions in all five. Cerebral angiograms from four patients had normal findings. One patient had a fatal clinical course. The other four had relapses during follow-up but responded well to therapy and had favorable overall outcomes. At the last follow-up (median, 19 months after diagnosis), the four patients had recovered with slight or moderate residual disability. No significant differences in clinical and laboratory features were observed when comparing patients with or without spinal cord involvement. Cerebral angiograms with evidence of vasculitis were significantly more frequent for patients without spinal cord involvement (p = 0.002). Conclusion: Spinal cord involvement was documented in 5% of patients with primary CNS vasculitis. The thoracic cord was the predominantly affected site. Other than myelopathy, clinical characteristics were similar to those of the patients without spinal cord involvement. GLOSSARY: ATM = acute transverse myelitis; ESR = erythrocyte sedimentation rate; ND = no data; PCNSV = primary CNS vasculitis; WBC = white blood cells.

Dense deposit disease associated with monoclonal gammopathy of undetermined significance.

Dense deposit disease (DDD) is a rare glomerular disease that typically affects children, young adults, and much less commonly, older patients. The pathophysiologic process underlying DDD is uncontrolled activation of the alternative pathway (AP) of complement cascade, most frequently secondary to an autoantibody to C3 convertase called C3 nephritic factor, although mutations in factor H and autoantibodies to this protein can impair its function and also cause DDD. Since 1995, we have diagnosed DDD in 14 patients aged 49 years or older; 10 of these patients (71.4%) carry a concomitant diagnosis of monoclonal gammopathy of undetermined significance (MGUS). In 1 of these 10 patients, the index case described here, we evaluated the AP and showed low serum AP protein levels consistent with complement activity, heterozygosity for the H402 allele of factor H, and low levels of factor H autoantibodies, which can affect the ability of factor H to regulate AP activity. In aggregate, these findings suggest that in some adults with MGUS, DDD may develop as a result of autoantibodies to factor H (or other complement proteins) that on a permissive genetic background (the H402 allele of factor H) lead to dysregulation of the AP with subsequent glomerular damage. Thus, DDD in some older patients may be a distinct clinicopathologic entity that represents an uncommon complication of MGUS.