Antigen-driven T cell-macrophage interactions mediate the interface between innate and adaptive immunity in histidyl-tRNA synthetase-induced myositis

Introduction

Previous work in humans has demonstrated that both innate and adaptive immune signaling pathways contribute to the pathogenesis of idiopathic inflammatory myopathy (IIM), a systemic autoimmune disease targeting muscle as well as extra-muscular organs. To better define interactive signaling networks in IIM, we characterized the cellular phenotype and transcriptomic profiles of muscle-infiltrating cells in our established murine model of histidyl-tRNA synthetase (HRS)-induced myositis.

Methods

Myositis was induced in wild type (WT) and various congenic/mutant strains of C57BL/6 mice through intramuscular immunization with recombinant HRS. Histopathological, immunohistochemical, flow cytometric, and transcriptomic assessments were used to characterize the functional relationship between muscle-infiltrating cell populations in these strains lacking different components of innate and/or adaptive immune signaling.

Results

RAG1 KO mice developed markedly reduced muscle inflammation relative to WT mice, demonstrating a key requirement for T cells in driving HRS-induced myositis. While the reduction of mononuclear cell infiltrates in CD4-Cre.MyD88fl/fl conditional knockout mice and OT-II TCR transgenic mice highlighted roles for both innate and TCR-mediated/adaptive immune signaling in T cells, diminished inflammation in Lyz2-Cre.MyD88fl/fl conditional knockout mice underscored the importance of macrophage/myeloid cell populations in supporting T cell infiltration. Single cell RNA sequencing-based clustering of muscle-infiltrating subpopulations and associated pathway analyses showed that perturbations of T cell signaling/function alter the distribution and phenotype of macrophages, fibroblasts, and other non-lymphoid cell populations contributing to HRS-induced myositis.

Discussion

Overall, HRS-induced myositis reflects the complex interplay between multiple cell types that collectively drive a TH1-predominant, pro-inflammatory tissue phenotype requiring antigen-mediated activation of both MyD88- and TCR-dependent T cell signaling pathways.

Aromatase-Inhibitor-Induced Musculoskeletal Inflammation Is Observed Independent of Oophorectomy in a Novel Mouse Model

Aromatase Inhibitors (AIs) block estrogen production and improve survival in patients with hormone-receptor-positive breast cancer. However, half of patients develop aromatase-inhibitor-induced arthralgia (AIIA), which is characterized by inflammation of the joints and the surrounding musculoskeletal tissue. To create a platform for future interventional strategies, our objective was to characterize a novel animal model of AIIA. Female BALB/C-Tg(NFκB-RE-luc)-Xen mice, which have a firefly luciferase NFκB reporter gene, were oophorectomized and treated with an AI (letrozole). Bioluminescent imaging showed significantly enhanced NFκB activation with AI treatment in the hind limbs. Moreover, an analysis of the knee joints and legs via MRI showed enhanced signal detection in the joint space and the surrounding tissue. Surprisingly, the responses observed with AI treatment were independent of oophorectomy, indicating that inflammation is not mediated by physiological estrogen levels. Histopathological and pro-inflammatory cytokine analyses further demonstrated the same trend, as tenosynovitis and musculoskeletal infiltrates were detected in all mice receiving AI, and serum cytokines were significantly upregulated. Human PBMCs treated with letrozole/estrogen combinations did not demonstrate an AI-specific gene expression pattern, suggesting AIIA-mediated pathogenesis through other cell types. Collectively, these data identify an AI-induced stimulation of disease pathology and suggest that AIIA pathogenesis may not be mediated by estrogen deficiency, as previously hypothesized.

Analysis of the bone fracture targeting properties of osteotropic ligands

PURPOSE

Although more than 18,000,000 fractures occur each year in the US, methods to promote fracture healing still rely primarily on fracture stabilization, with use of bone anabolic agents to accelerate fracture repair limited to rare occasions when the agent can be applied to the fracture surface. Because management of broken bones could be improved if bone anabolic agents could be continuously applied to a fracture over the entire course of the healing process, we undertook to identify strategies that would allow selective concentration of bone anabolic agents on a fracture surface following systemic administration. Moreover, because hydroxyapatite is uniquely exposed on a broken bone, we searched for molecules that would bind with high affinity and specificity for hydroxyapatite. We envisioned that by conjugating such osteotropic ligands to a bone anabolic agent, we could acquire the ability to continuously stimulate fracture healing.

RESULTS

Although bisphosphonates and tetracyclines were capable of localizing small amounts of peptidic payloads to fracture surfaces 2-fold over healthy bone, their specificities and capacities for drug delivery were significantly inferior to subsequent other ligands, and were therefore considered no further. In contrast, short oligopeptides of acidic amino acids were found to localize a peptide payload to a bone fracture 91.9 times more than the control untargeted peptide payload. Furthermore acidic oligopeptides were observed to be capable of targeting all classes of peptides, including hydrophobic, neutral, cationic, anionic, short oligopeptides, and long polypeptides. We further found that highly specific bone fracture targeting of multiple peptidic cargoes can be achieved by subcutaneous injection of the construct.

CONCLUSIONS

Using similar constructs, we anticipate that healing of bone fractures in humans that have relied on immobilization alone can be greately enhanced by continuous stimulation of bone growth using systemic administration of fracture-targeted bone anabolic agents.

Pathological manifestation of autoimmune myocarditis is detected prior to glomerulonephritis in a murine model of lupus nephritis

OBJECTIVE

Since enhanced cardiac magnetic resonance imaging (cMRI) signals have been associated with lupus disease activity in humans prior to renal failure and novel, cardiac-focused therapeutic strategies could be investigated with an associated animal model, autoimmune myocarditis was characterized in murine lupus nephritis (NZM2410).

METHODS

Weekly blood urea nitrogen (BUN) levels and weights were recorded. Cardiac function was assessed by echocardiogram. Myocardial edema was measured with quantitative T2 cMRI mapping. Endpoint serum and cardiac tissue were collected for histopathological analysis and cytokine measurements.

RESULTS

Despite showing no signs of significant renal disease, mice displayed evidence of myocarditis and fibrosis histologically at 30-35 weeks. Moreover, T2 cMRI mapping displayed robust signals and analysis of sagittal heart sections showed significant myocardium thickening. Cytokine expression levels of IL-2, IL-10, TNF-α, CXCL1, and IL-6 were significantly enhanced in serum. Echocardiograms demonstrated significantly increased ventricular diameters and reduced ejection fractions, while immunohistochemical staining identified CD4+ and CD8+ T cells, and IL-17 in cardiac infiltrates. Human lupus cardiac tissue showed similar histopathology with enhanced infiltrates by H&E, fibrosis, and CD4+ detection.

CONCLUSIONS

Histopathology, functional abnormalities, and enhanced cMRI signals indicative of myocarditis are detected in NZM2410 mice without glomerulonephritis, which supports the primary pathological role of autoimmune-mediated, cardiac-targeted inflammation in lupus.

Physical activity prevents acute inflammation in a gout model by downregulation of TLR2 on circulating neutrophils as well as inhibition of serum CXCL1 and is associated with decreased pain and inflammation in gout patients

Objectives

Gout is the most prevalent inflammatory arthritis. To study the effects of regular physical activity and exercise intensity on inflammation and clinical outcome, we examined inflammatory pathogenesis in an acute model of murine gout and analyzed human gout patient clinical data as a function of physical activity.

Methods

NF-κB-luciferase reporter mice were organized into four groups and exercised at 0 m/min (non-exercise), 8 m/min (low-intensity), 11 m/min (moderate-intensity), and 15 m/min (high-intensity) for two weeks. Mice subsequently received intra-articular monosodium urate (MSU) crystal injections (0.5mg) and the inflammatory response was analyzed 15 hours later. Ankle swelling, NF-κB activity, histopathology, and tissue infiltration by macrophages and neutrophils were measured. Toll-like receptor (TLR)2 was quantified on peripheral monocytes/neutrophils by flow cytometry and both cytokines and chemokines were measured in serum or synovial aspirates. Clinical data and questionnaires accessing overall physical activity levels were collected from gout patients.

Results

Injection of MSU crystals produced a robust inflammatory response with increased ankle swelling, NF-κB activity, and synovial infiltration by macrophages and neutrophils. These effects were partially mitigated by low and moderate-intensity exercise. Furthermore, IL-1β was decreased at the site of MSU crystal injection, TLR2 expression on peripheral neutrophils was downregulated, and expression of CXCL1 in serum was suppressed with low and moderate-intensity exercise. Conversely, the high-intensity exercise group closely resembled the non-exercised control group by nearly all metrics of inflammation measured in this study. Physically active gout patients had significantly less flares/yr, decreased C-reactive protein (CRP) levels, and lower pain scores relative to physically inactive patients.

Conclusions

Regular, moderate physical activity can produce a quantifiable anti-inflammatory effect capable of partially mitigating the pathologic response induced by intra-articular MSU crystals by downregulating TLR2 expression on circulating neutrophils and suppressing systemic CXCL1. Low and moderate-intensity exercise produces this anti-inflammatory effect to varying degrees, while high-intensity exercise provides no significant difference in inflammation compared to non-exercising controls. Consistent with the animal model, gout patients with higher levels of physical activity have more favorable prognostic data. Collectively, these data suggest the need for further research and may be the foundation to a future paradigm-shift in conventional exercise recommendations provided by Rheumatologists to gout patients.

A preliminary survey of anthropogenic gadolinium in water and sediment of a constructed wetland

Gadolinium (Gd) is a rare earth element used in magnetic resonance imaging (MRI) contrast agents that has recently been identified as an emerging contaminant of concern due to its possible toxic effects and accumulation in the environment. The objectives of this preliminary study were to determine the occurrence and fate of Gd in surface water and sediment of a constructed wetland that receives effluent from a wastewater treatment plant. The rate of anthropogenic Gd entering the wetland was determined to be approximately 25 g Gd day^-1, with surface water concentrations in the parts per trillion. Anthropogenic Gd concentrations in surface waters decreased as a function of distance from the inlet site to near the outfall, and were three orders of magnitude higher in sediment than in surface water suggesting that the wetland was providing a sink for Gd possibly through plant uptake and incorporation in organic biomass. An anthropogenic Gd anomaly was observed with an average Gd_Ant/Gd_Geo ratio of 5.34. Sediment with higher total organic carbon (TOC) tended to be higher in anthropogenic Gd, suggesting that Gd sequestration may occur through uptake by plants and/or through flocculation and deposition of natural organic matter.

CD38 Is Robustly Induced in Human Macrophages and Monocytes in Inflammatory Conditions

Macrophages and their monocyte precursors mediate innate immune responses and can promote a spectrum of phenotypes from pro-inflammatory to pro-resolving. Currently, there are few markers that allow for robust dissection of macrophage phenotype. We recently identified CD38 as a marker of inflammatory macrophages in murine in vitro and in vivo models. However, it is unknown whether CD38 plays a similar marker and/or functional role in human macrophages and inflammatory diseases. Here, we establish that CD38 transcript and protein are robustly induced in human macrophages exposed to LPS (±IFN-γ) inflammatory stimuli, but not with the alternative stimulus, IL-4. Pharmacologic and/or genetic CD38 loss-of-function significantly reduced the secretion of inflammatory cytokines IL-6 and IL-12p40 and glycolytic activity in human primary macrophages. Finally, monocyte analyses in systemic lupus erythematosus patients revealed that, while all monocytes express CD38, high CD38 expression in the non-classical monocyte subpopulation is associated with disease. These data are consistent with an inflammatory marker role for CD38 in human macrophages and monocytes.

Enhancer variants reveal a conserved transcription factor network governed by PU.1 during osteoclast differentiation

Genome-wide association studies (GWASs) have been instrumental in understanding complex phenotypic traits. However, they have rarely been used to understand lineage-specific pathways and functions that contribute to the trait. In this study, by integrating lineage-specific enhancers from mesenchymal and myeloid compartments with bone mineral density loci, we were able to segregate osteoblast- and osteoclast (OC)-specific functions. Specifically, in OCs, a PU.1-dependent transcription factor (TF) network was revealed. Deletion of PU.1 in OCs in mice resulted in severe osteopetrosis. Functional genomic analysis indicated PU.1 and MITF orchestrated a TF network essential for OC differentiation. Several of these TFs were regulated by cooperative binding of PU.1 with BRD4 to form superenhancers. Further, PU.1 is essential for conformational changes in the superenhancer region of Nfatc1. In summary, our study demonstrates that combining GWASs with genome-wide binding studies and model organisms could decipher lineage-specific pathways contributing to complex disease states.

Genetic variation in non-coding regions of DNA could raise osteoporosis risk by affecting osteoclast differentiation. Osteoporosis occurs when the normal process of bone remodeling by osteoblasts and osteoclasts falls out of balance. Genome-wide association studies (GWAS) have identified numerous single nucleotide polymorphisms (SNPs) associated with osteoporosis, but how these affect specific cell types was unclear. Sudarshana Sharma and Michael Ostrowski at the Medical University of South Carolina and colleagues wondered if variations in non-coding ‘enhancer’ regions of DNA, might shed light on the molecular underpinnings of osteoporosis. So, they overlaid SNPs associated with reduced bone mineral density onto enhancers in mesenchymal and myeloid cells—the precursors of osteoblasts and osteoclasts—identifying a transcription factor network in myeloid cells that drives the differentiation of osteoclasts. When this was disrupted in mice, severe defects in osteoclast differentiation and function resulted.

Therapeutic Development of Mesenchymal Stem Cells or Their Extracellular Vesicles to Inhibit Autoimmune-Mediated Inflammatory Processes in Systemic Lupus Erythematosus

Since being discovered over half a century ago, mesenchymal stem cells (MSCs) have been investigated extensively to characterize their cellular and physiological influences. MSCs have been shown to possess immunosuppressive capacity through inhibiting lymphocyte activation/proliferation and proinflammatory cytokine secretion while simultaneously demonstrating limited allogenic reactivity, which subsequently led to the evaluation of therapeutic feasibility to treat inflammatory diseases. Although regulatory constraints have restricted MSC development pharmacologically, limited clinical studies have shown encouraging results using MSC infusions to treat systemic lupus erythematosus (SLE); but, more trials will have to be performed to conclusively determine the clinical efficacy of MSCs to treat SLE. Moreover, there are some data to suggest that MSCs possess tumorigenic potential and that the immunosuppressive influence can be dramatically affected by both donor variability and ex vivo expansion. Given that recent studies have found that the immunosuppressive effects of MSCs are a result, at least in part, to extracellular vesicle (EV) secretion, the use of MSC-derived EVs has been suggested as a cell-free therapeutic alternative. Despite the positive data observed using EVs isolated from human MSCs to suppress inflammatory responses in vitro and in inhibiting autoimmune disease pathogenesis in preclinical work, there are no studies to date examining EVs from MSCs to treat SLE in humans or animal models. Considering that EVs are not subject to the strict regulatory constraints of stem cell-based pharmacological development and are more readily standardized with regard to industrial-scale production and storage, this review outlines the anti-inflammatory biology of MSCs and the scientific evidence supporting the potential use of EVs derived from human MSCs to treat patients with SLE.

Daily Moderate Exercise Is Beneficial and Social Stress Is Detrimental to Disease Pathology in Murine Lupus Nephritis

Daily moderate exercise (DME) and stress management are underemphasized in the care of patients with lupus nephritis (LN) due to a poor comprehensive understanding of their potential roles in controlling the inflammatory response. To investigate these effects on murine LN, disease progression was monitored with either DME or social disruption stress (SDR) induction in NZM2410/J mice, which spontaneously develop severe, early-onset LN. SDR of previously established social hierarchies was performed daily for 6 days and DME consisted of treadmill walking (8.5 m/min for 45 min/day). SDR significantly enhanced kidney disease when compared to age-matched, randomly selected control counterparts, as measured by histopathological analysis of H&E staining and immunohistochemistry for complement component 3 (C3) and IgG complex deposition. Conversely, while 88% of non-exercised mice displayed significant renal damage by 43 weeks of age, this was reduced to 45% with exercise. DME also reduced histopathology in kidney tissue and significantly decreased deposits of C3 and IgG complexes. Further examination of renal infiltrates revealed a macrophage-mediated inflammatory response that was significantly induced with SDR and suppressed with DME, which also correlated with expression of inflammatory mediators. Specifically, SDR induced IL-6, TNF-α, IL-1β, and MCP-1, while DME suppressed IL-6, TNF-α, IL-10, CXCL1, and anti-dsDNA autoantibodies. These data demonstrate that psychological stressors and DME have significant, but opposing effects on the chronic inflammation associated with LN; thus identifying and characterizing stress reduction and a daily regimen of physical activity as potential adjunct therapies to complement pharmacological intervention in the management of autoimmune disorders, including LN.

Estrogen-regulated STAT1 activation promotes TLR8 expression to facilitate signaling via microRNA-21 in systemic lupus erythematosus

Recent studies implicate innate immunity to systemic lupus erythematosus (SLE) pathogenesis. Toll-like receptor (TLR)8 is estrogen-regulated and binds viral ssRNA to stimulate innate immune responses, but recent work indicates that microRNA (miR)-21 within extracellular vesicles (EVs) can also trigger this receptor. Our objective was to examine TLR8 expression/activation to better understand sex-biased responses involving TLR8 in SLE. Our data identify an estrogen response element that promotes STAT1 expression and demonstrate STAT1-dependent transcriptional activation of TLR8 with estrogen stimulation. In lieu of viral ssRNA activation, we explored EV-encapsulated miR-21 as an endogenous ligand and observed induction of both TLR8 and cytokine expression in vitro. Moreover, extracellular miR detection was found predominantly within EVs. Thus, just as a cytokine or chemokine, EV-encapsulated miR-21 can act as an inflammatory signaling molecule, or miRokine, by virtue of being an endogenous ligand of TLR8. Collectively, our data elucidates a novel innate inflammatory pathway in SLE.

Oral administration of nano-emulsion curcumin in mice suppresses inflammatory-induced NFκB signaling and macrophage migration

Despite the widespread use of curcumin for centuries in Eastern medicine as an anti-inflammatory agent, its molecular actions and therapeutic viability have only recently been explored. While curcumin does have potential therapeutic efficacy, both solubility and bioavailability must be improved before it can be more successfully translated to clinical care. We have previously reported a novel formulation of nano-emulsion curcumin (NEC) that achieves significantly greater plasma concentrations in mice after oral administration. Here, we confirm the immunosuppressive effects of NEC in vivo and further examine its molecular mechanisms to better understand therapeutic potential. Using transgenic mice harboring an NFκB-luciferase reporter gene, we demonstrate a novel application of this in vivo inflammatory model to test the efficacy of NEC administration by bioluminescent imaging and show that LPS-induced NFκB activity was suppressed with NEC compared to an equivalent amount of curcumin in aqueous suspension. Administration of NEC by oral gavage resulted in a reduction of blood monocytes, decreased levels of both TLR4 and RAGE expression, and inhibited secretion of MCP-1. Mechanistically, curcumin blocked LPS-induced phosphorylation of the p65 subunit of NFκB and IκBα in murine macrophages. In a mouse model of peritonitis, NEC significantly reduced macrophage recruitment, but not T-cell or B-cell levels. In addition, curcumin treatment of monocyte derived cell lines and primary human macrophages in vitro significantly inhibited cell migration. These data demonstrate that curcumin can suppress inflammation by inhibiting macrophage migration via NFκB and MCP-1 inhibition and establish that NEC is an effective therapeutic formulation to increase the bioavailability of curcumin in order to facilitate this response.

A chimeric human-mouse model of Sjögren's syndrome

Despite recent advances in the understanding of Sjögren's Syndrome (SjS), the pathogenic mechanisms remain elusive and an ideal model for early drug discovery is not yet available. To establish a humanized mouse model of SjS, peripheral blood mononuclear cells (PBMCs) from healthy volunteers or patients with SjS were transferred into immunodeficient NOD-scid IL-2rγ(null) mouse recipients to produce chimeric mice. While no difference was observed in the distribution of cells, chimeric mice transferred with PBMCs from SjS patients produced enhanced cytokine levels, most significantly IFN-γ and IL-10. Histological examination revealed enhanced inflammatory responses in the lacrimal and salivary glands of SjS chimeras, as measured by digital image analysis and blinded histopathological scoring. Infiltrates were primarily CD4+, with minimal detection of CD8+ T-cells and B-cells. These results demonstrate a novel chimeric mouse model of human SjS that provides a unique in vivo environment to test experimental therapeutics and investigate T-cell disease pathology.

Aberrant muscle antigen exposure in mice is sufficient to cause myositis in a Treg cell-deficient milieu

Objective

Myositis is associated with muscle-targeted inflammation and is observed in some Treg cell–deficient mouse models. Because an autoimmune pathogenesis has been strongly implicated, the aim of this study was to investigate the hypothesis that abnormal exposure to muscle antigens, as observed in muscle injury, can induce autoimmune-mediated myositis in susceptible hosts.

Methods

FoxP3 mutant (scurfy) mice were mated to synaptotagmin VII (Syt VII) mutant mice, which resulted in a new mouse strain that combines impaired membrane resealing with Treg cell deficiency. Lymphocyte preparations from double-mutant mice were adoptively transferred intraperitoneally, with or without purified Treg cells, into recombination-activating gene 1 (RAG-1)–null recipients. Lymph node cells from mice with the FoxP3 mutation were transferred into RAG-1–null mice either 1) intraperitoneally in conjunction with muscle homogenate or purified myosin protein or 2) intramuscularly with or without cotransfer of purified Treg cells.

Results

FoxP3-deficient mouse lymph node cells transferred in conjunction with myosin protein or muscle homogenate induced robust skeletal muscle inflammation. The infiltrates consisted predominantly of CD4+ and CD8+ T cells, a limited number of macrophages, and no B cells. Significant inflammation was also seen in similar experiments using lymph node cells from FoxP3/Syt VII double-mutant mice but was absent in experiments using adoptive transfer of FoxP3 mutant mouse cells alone. The cotransfer of Treg cells completely suppressed myositis.

Conclusion

These data, derived from a new, reproducible model, demonstrate the critical roles of Treg cell deficiency and aberrant muscle antigen exposure in the priming of autoreactive cells to induce myositis. This mouse system has multifaceted potential for examining the interplay in vivo between tissue injury and autoimmunity.

Novel estrogen target gene ZAS3 is overexpressed in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a prototypic, inflammatory autoimmune disease characterized by significant gender bias. Previous studies have established a role for hormones in SLE pathogenesis, including the sex hormone estrogen. Estrogen regulates gene expression by translocating estrogen receptors (ER) α and β into the nucleus where they induce transcription by binding to estrogen response elements (EREs) of target genes. The ZAS3 locus encodes a signaling and transcriptional molecule involved in regulating inflammatory responses. We show that ZAS3 is significantly up-regulated in SLE patients at both the protein and mRNA levels in peripheral blood mononuclear cells (PBMCs). Furthermore, estrogen stimulates the expression of ZAS3 in vitro in several leukocyte and breast cancer cell lines of both human and murine origin. In vivo estrogen treatment mediates induction of tissue specific ZAS3 expression in several lymphoid organs in mice. Estrogen stimulation also significantly up-regulates ZAS3 expression in primary PBMCs, while treatment with testosterone has no effect. Mechanistically, estrogen induces differential ERα binding to putative EREs within the ZAS3 gene and ERα knockdown with siRNA prevents estrogen induced ZAS3 up-regulation. In contrast, siRNA targeting IFNα has no effect. These data demonstrate that ZAS3 expression is directly regulated by estrogen and that ZAS3 is overexpressed in lupus. Since ZAS3 has been shown to regulate inflammatory pathways, its up-regulation by estrogen could play a critical role in female-biased autoimmune disorders.

Diagnostic value of hepatocyte paraffin 1 antibody to discriminate hepatocellular carcinoma from metastatic carcinoma in fine-needle aspiration biopsies of the liver

BACKGROUND

Diagnosing liver tumors by fine-needle aspiration biopsy is safe and accurate. However, there are cases that prove diagnostically difficult. Traditionally, immunostains for alpha-fetoprotein and polyclonal carcinoembryonic antigen have been used to distinguish adenocarcinomas from hepatocellular carcinomas (HCCs). In poorly differentiated tumors, these immunostains have limitations in both sensitivity and specificity. An hepatocyte-specific immunostain has been described in the surgical pathology literature. To the authors' knowledge, this hepatocyte antibody has not been studied in liver fine-needle aspiration biopsies. The authors examined the Hepatocyte Paraffin 1 (HP1) antibody for its diagnostic utility in this cytologic setting.

METHODS

Cell-block material from 40 cases of HCC and 53 cases of metastatic adenocarcinoma were studied. Slides were stained for HP1 by the avidin-biotin complex method following antigen retrieval. The percentage of malignant cells that exhibited coarse granular staining in the cytoplasm was estimated for all cases of HCC, poorly differentiated HCC, and metastatic adenocarcinoma.

RESULTS

HP1 was expressed in 83% of all HCCs but in only 56% of poorly differentiated HCCs. Only 2 of 53 (4%) of metastatic tumors expressed HP1. The overall sensitivity of HP1 was 79% and its specificity was 96%.

CONCLUSION

HP1 was found to be a specific immunostain that may prove helpful in diagnosing all but the most undifferentiated liver tumors biopsied by fine-needle aspiration.

Differentiating large cell lymphoma from indolent small B-cell lymphoma in fine needle aspirates using p53, PCNA and transformed lymphocyte count

OBJECTIVE

To determine the usefulness of proliferating cell nuclear antigen (PCNA), p53 protein expression and transformed lymphocyte count (TLC) as adjunctive tests to differentiate indolent small B-cell lymphoma from large cell lymphoma in fine needle aspiration biopsies.

STUDY DESIGN

Aspirates of lymphoproliferative disorders from April 1993 to January 1997 were reviewed. The percentage of TLCs was determined on the Papanicolaou smear. The percentage and intensity of p53 and PCNA immunocytochemical staining was evaluated on cell block sections. These results were compared and correlated with the final diagnoses based on available morphology, flow cytometry and clinical history.

RESULTS

There were 40 cases of non-Hodgkin's lymphoma and 12 reactive lymph nodes. Adequate cell blocks were available on 16 large cell lymphomas, 7 grade 1-2 follicular center cell lymphomas, 6 mucosal associated lymphoid tissue lymphomas, 2 small lymphocytic lymphomas and 2 mantle cell lymphomas. Average TLC and p53 nuclear staining was highest in large cell lymphomas (57% TLC and 24% p53), followed by grades 1 and 2 follicular lymphomas (14% TLC and 15% p53) and lowest in other indolent lymphomas (< 10% TLC and < 1% p53). Average PCNA staining was highest in large cell lymphomas (46%) and lowest in small lymphocytic lymphomas (7%); however, TLC was the best parameter for differentiating large cell lymphoma from indolent small B-cell lymphoma.

CONCLUSION

TLC differentiated large cell lymphoma from indolent small B-cell lymphoma better than either p53 or PCNA alone or in combination. Significant overlap between categories limits usefulness of these immunocytochemical stains for differentiating these entities.

Diagnosis of lymphoma by fine-needle aspiration cytology using the revised European-American classification of lymphoid neoplasms

BACKGROUND

Recent changes in the classification of non-Hodgkin lymphoma (NHL) emphasize the diagnostic importance of cytomorphology, immunophenotyping, and molecular findings in addition to histology. These changes have allowed for a greater role of fine-needle aspiration cytology (FNA) in the diagnosis of NHL.

METHODS

A review of the English language literature regarding the use of FNA in the cytodiagnosis of lymphoma was performed. The revised European-American classification of lymphoid neoplasms (REAL) was reviewed in the context of its adaptability to the cytologic diagnosis of lymphoid neoplasms.

RESULTS

FNA is being used more frequently in the diagnosis, staging, and follow-up of lymphoma whenever supportive studies are readily available. Cytomorphologic, immunophenotypic, and molecular criteria as well as pitfalls in the diagnosis of lymphoma by FNA have been delineated. Information was compiled into tables to facilitate correlation of criteria with the proposed REAL system.

CONCLUSIONS

Many cases of NHL can be diagnosed and subclassified by FNA when there is adequate immunophenotypic information. Cancer (Cancer Cytopathol)

Preoperative chemotherapy of chemoradiotherapy for the treatment of adenocarcinoma of the pancreas and ampulla of Vater

Much has been written about preoperative strategies in the treatment of pancreatic adenocarcinoma, yet there has been very little comment concerning other periampullary malignancies. This review discusses current issues relevant to the further development of preoperative adjuvant treatment of pancreatic adenocarcinoma. A small series of patients with ampullary adenocarcinomas treated with preoperative adjuvant chemoradiotherapy is also described.

Utilization of fine-needle aspiration cytology and flow cytometry in the diagnosis and subclassification of primary and recurrent lymphoma

BACKGROUND

The primary diagnosis of non-Hodgkin's lymphoma/leukemia (NHL) by fine-needle aspiration (FNA) is controversial. The authors reviewed their experience with FNA and flow cytometry (FC) to determine the usefulness and limitations of these techniques in the diagnosis of NHL.

METHODS

Slides and reports from all lymph node and extranodal FNAs performed during the period July 1993 to January 1997 with a diagnosis of lymphoma or benign lymphoid process were reviewed. Clinical and biopsy follow-up data were recorded. Results were tabulated and the usefulness of cytology was analyzed.

RESULTS

There were 100 adequate aspirates from 87 patients. These included 72 cases of NHL, 58 (80%) of which were diagnosed by FNA and FC without the need for histologic sampling (69% of the primary lymphomas and 88% of the recurrent lymphomas). There were 22 aspirates suspicious for lymphoma, 12 equivocal results, and 7 benign diagnoses. Eighty-six percent of malignant FNAs (50 of 58) had flow cytometry (FC) as compared with only 15% (5 of 34) of the suspicious or equivocal FNAs.

CONCLUSIONS

FNA is a valuable method for diagnosing and subclassifying NHL, although immunophenotyping by FC is often an essential ancillary test. In our experience, correlating the FNA results with the FC results can eliminate the need for a more invasive surgical biopsy in many cases.

The value of transformed lymphocyte count in subclassification of non-Hodgkin's lymphoma by fine-needle aspiration

No established criteria exist for predicting lymphoma grade or transformation in cytologic material. We counted transformed lymphocytes in fine-needle aspiration (FNA) biopsy specimens to determine whether the percentage of these cells in the smear could predict the histologic grade, the biologic behavior, or both. The percentage of transformed lymphocytes out of total lymphoid cells was determined on Papanicolaou-stained smears. Afterward, a cytodiagnosis was based on clinical information available at the time of the FNA, cytomorphologic data, and flow cytometry data. Results were correlated with results of examination of the surgical biopsy specimen, clinical behavior of the lymphoma, or both. The percentage of transformed lymphocytes was 10% or less in all low-grade or indolent lymphomas. Aspirates with transformed lymphocyte counts of 20% or greater were aggressive lymphomas. We also report our experience in the diagnosis of non-Hodgkin's lymphoma by FNA using cytomorphologic examination and immunophenotyping by flow cytometry at a cancer referral hospital. This is a preliminary study, and larger series may help establish the ranges of transformed lymphocyte counts that correlate with the lymphoma subtype.

Zinc co-ordination in the DNA-binding domain of the yeast transcriptional activator PPR1

The structure of the native zinc form of the DNA binding domain in the yeast transcriptional activator PPR1 was investigated by extended X-ray absorption fine structure (EXAFS). By carrying out the EXAFS measurements at 11k we were able to demonstrate explicitly the proximity of the two zinc ions (Zn-Zn distance = 3.16 +/- 0.03 A) and the presence of bridging cysteine ligands. The results show that the six cysteine residues co-ordinate two zinc ions in a two-metal ion cluster. PPR1 is the first member of this class of protein for which such information has been obtained.

Interobserver variability of cervical smears with squamous-cell abnormalities: a Philadelphia study

The reproducibility of reporting squamous lesions by the Bethesda System (TBS) was evaluated by distributing 20 slides to be classified among 5 panelists considered experts in the field of cytopathology. Four cases were chosen for their classic morphology and the remainder were foreseen to produce possible discrepancies within one diagnostic category. For 7/20 (35%) cases there was unanimous agreement. Participants disagreed within one category of magnitude for seven (35%) cases. In six (30%) cases there was a range of more than one category disagreement. However, additional written comments modifying TBS diagnoses often diminished the clinical significance of these discrepancies. We conclude that despite the important role of TBS in standardization of Pap smear reports, a great degree of subjectivity exists in classifying squamous abnormalities without "classic" morphology. The lack of reproducibility should be taken into account in cytology proficiency testing.

Three-dimensional volumetric ultrasound imaging of arterial pathology from two-dimensional intravascular ultrasound: an in vitro study

The objectives of this study were to evaluate: (1) the feasibility of generating three-dimensional (3-D) ultrasound (US) volumetric images of arterial segments from intravascular (IV) US images by retaining full range of gray levels; (2) the feasibility of volumetric quantitation of various arterial wall pathology from the 3-D volume US images of arterial segments. IVUS provides morphologic details of arterial wall diseases. This is seen as variation in gray levels. However, when a 3-D US image is generated currently, the full range of gray levels is not utilized. This limits optimal assessment of arterial wall pathology. Sequential cross-sectional IVUS images from 11 arterial segments consisting of various pathology were obtained in vitro by calibrated withdrawal of an IVUS catheter. These images were digitized by an 8 bit digitizer to retain full 256 gray levels of brightness. 3-D volume generation was carried out using "ANALYZE" software. After the IVUS imaging, arterial segments were sectioned transversely in a 0.3-0.4 mm cross section and stained with hematoxylin, eosin and elastin. Geometrical measurements and gross morphological changes of the arterial segments were noted and correlated with the corresponding section of the image from the three-dimensional volume. Arterial wall pathology, its extent and its effect on lumen geometry were easily appreciated in multiple tomographic sections of a 3-D volume image. Similarly, arterial wall pathology was easily quantitated from 3-D volume. The above assessments were only feasible by retaining full range of gray levels in the 3-D volume image. This study indicates that (1) it is feasible to generate a 3-D US volume image by retaining full range of gray levels from IVUS images, (2) retaining full range of gray levels allows optimal assessment of arterial wall pathology and its extent in 3-D volume, and (3) IVUS allows quantitation of arterial wall pathology, and thereby one can assess the effect of intervention.

Ischemic changes in fetal myocardium. An autopsy series

It has been assumed that fetal myocardial necrosis is an uncommon event that occurs only under unusual circumstances. We studied random heart sections on 76 fetal and perinatal autopsies from a 4-year period to determine the types and frequency of histologic abnormalities that occur in fetal myocardium. Vacuolar degeneration was extremely common (43% of stillbirths, 84% of live births) but a nonspecific finding. Ischemic changes, which are typically associated with coagulation necrosis, myofiber waviness, or contraction band necrosis, were seen in 21% of stillbirths and 32% of live births. In the majority of cases with histologic evidence of ischemic change, a combination of either contraction band necrosis, coagulation necrosis, and/or myofiber waviness was identified. Only rarely was any one of the abnormalities seen as an isolated feature. In only two autopsies were the ischemic changes identified in the initial autopsy report. We conclude that the histologic changes associated with ischemia that may represent myocardial necrosis are not uncommon and are frequently overlooked at autopsy.

Value of repeat cervical smears at the time of colposcopic biopsy

At our institution, gynecologists perform Pap smears not only as an initial screening procedure but also at the time of colposcopy and biopsy. We compared the results of initial Papanicolaou (Pap) smears with those taken at colposcopic biopsy to determine if repeating the Pap smear at the time of colposcopy contributed to patient management. We found that repeat colposcopic smears often agreed with the referral smears and biopsies. When there was disagreement, the colposcopic smear was more often a lower grade than the referral smear and correlated best with the biopsy. Both referral and colposcopic smears underestimated the severity of cervical lesions with the same frequency. We could document only 5/414 (1.2%) colposcopic smears that contributed to patient care.

Diagnostic value of electron microscopy on paraffin-embedded cytologic material

Transmission electron microscopy (TEM) is an important adjuvant to light microscopy, but is underutilized in cytopathology because of technical obstacles. One should attempt to obtain properly fixed material for TEM whenever possible. If that is not available, TEM on the cell block requires no preplanning or additional needle passes, and avoids problems of inadequate tissue for diagnosis. However, cell blocks are often not examined because of the perception that their poor ultrastructural preservation precludes their utility. We describe our experience in performing TEM on cell blocks from 15 cytologic specimens. In 13 of 15 cases, the cell block material was adequate for ultrastructural evaluation, and it clarified or extended the diagnosis in seven of these cases. TEM is a useful adjuvant technique to cytodiagnosis and can be successfully performed on cell blocks when gluteraldehyde-fixed material is not available.

An implementation plan for autopsy quality control and quality assurance

The few guidelines that exist for performing autopsy quality assurance are vague. Much has been written about the use of the autopsy to monitor clinical services, but not how to monitor the quality of the autopsy and autopsy reports. We present the comprehensive quality assurance program that has been developed and implemented at Hahnemann University Hospital, Philadelphia, Pa, for the past 2 years; this program has encompassed quality control of our diagnostic work. Key features have included in-depth peer review of completed reports, documentation of review at conferences, and careful monitoring of turnaround time. We have found that integrating quality assurance into departmental conferences is a useful supplement to in-depth peer review of randomly chosen autopsies. Our approach to quality assurance may serve as a model for other pathology departments, particularly those with pathology residency training programs.

Respiratory cytology: a review of non-neoplastic mimics of malignancy

Respiratory cytology has its share of pitfalls. Some, such as vegetable cell contaminants, pose problems for only inexperienced observers, while others, such as reactive bronchoalveolar cells from pneumonia, can lead even experienced cytopathologists to make a misdiagnosis of malignancy. This review illustrates and analyzes those benign conditions or entities known to mimic malignancy in exfoliative respiratory cytology and fine-needle aspiration biopsy of the lung. Entities are grouped by the type of malignancy they mimic, and guidelines are presented for avoiding specific pitfalls.

Diagnostic correlation of fiberoptic bronchoscopic biopsy and bronchoscopic cytology performed simultaneously

The reliability of bronchoscopic cytology relative to biopsy is controversial. Some still consider biopsy the definitive procedure. Comparative studies are few and limited in scope. Therefore, we compared simultaneously obtained biopsies and cytologies for 224 cases. One hundred and sixty-six cases (74.6%) correlated completely. Forty-four cases (19.6%) did not correlate and cytology was diagnostic in 24 of these. Biopsy was diagnostic in sarcoidosis and vasculitis, whereas cytology only excluded the presence of neoplasm or infection. In 14 cases (5.8%), biopsy and cytology showed pathologic changes, but one or the other was more definitive. Rarely, the 2 techniques provided complementary information. A specific diagnosis was obtained more often from the combination of cytology and biopsy than from either alone. However, when biopsy is contraindicated it is reassuring that cytology usually yields the same information as biopsy, and can detect neoplastic and infectious diseases when the biopsy is non-diagnostic.

Unilateral up-regulation of glutamate receptors in limbic regions of amygdaloid-kindled rats

Quantitative autoradiography was used to examine central binding sites for L-[3H]glutamate in amygdaloid-kindled rats since receptors for excitatory amino acids have been implicated in epileptiform activity and seizure behaviors. In tissue from rats killed five days after two kindled seizures, the ipsilateral hippocampus, entorhinal, perirhinal and parietal cortices had significantly (35-100%) greater densities of binding sites for L-[3H]glutamate than the opposite, contralateral side or operated, unstimulated controls. These regions receive excitatory inputs from the amygdala via the entorhinal cortex. Dissociation constants were not altered and significant differences were not observed in the binding parameters for L-[3H]glutamate between control and kindled rats or ipsilateral and contralateral sides of the amygdala, corpus striatum, nucleus accumbens or substantia nigra. The proportion and affinity of N-methyl-D-aspartate (NMDA)-sensitive binding sites for L-[3H]glutamate was unchanged after kindling, as were the relative proportions of kainate- and AMPA-(DL-alpha-amino-3-hydroxy-5- methyl-4-isoxazolepropionic acid) sensitive sites. However, the density of NMDA and non-NMDA receptor subtypes was increased in the ipsilateral hippocampus, entorhinal, perirhinal and parietal cortices of kindled rats. These findings of specific, unilateral glutamate receptor up-regulation may indicate adaptive responses to the enhanced excitation found in kindling, and are consistent with other neuronal changes reported in early kindling.

Differential diagnosis of cystic neoplasms of the pancreas by fine-needle aspiration

Fine-needle aspiration biopsy of pancreatic lesions is becoming widespread. Pathologists need to be familiar with the cytologic features of pancreatic tumors, of which cystic neoplasms are a distinct subset. Of our 31 pancreatic aspirates diagnostic of neoplasia, six were diagnosed as cystic by radiographic imaging. These cases were compared. Similar symptoms were experienced by all of these patients, although those with malignant tumors lost the most weight. Loss of border definition, ascites, and liver metastases were the only radiologic clues to malignancy. Each entity had distinguishing cytologic features. These cases illustrate the importance of knowing the clinical, radiologic, and cytologic features of pancreatic cystic neoplasms to arrive at a preoperative diagnosis and determine proper treatment.