Sentinel lymph node B cells can predict disease-free survival in breast cancer patients

Tumor invasion into draining lymph nodes, especially sentinel lymph nodes (SLNs), is a key determinant of prognosis and treatment in breast cancer as part of the TNM staging system. Using multicolor histology and quantitative image analysis, we quantified immune cells within SLNs from a discovery cohort of 76 breast cancer patients. We found statistically more in situ CD3⁺ T cells in tumor negative vs. tumor positive nodes (mean of 8878 vs. 6704, respectively, p = 0.006), but no statistical difference in CD20⁺ B cells or CD1a⁺ dendritic cells. In univariate analysis, a reduced hazard was seen with a unit increase in log CD3 with HR 0.49 (95% CI 0.30–0.80) and log CD20 with HR 0.37 (95% CI 0.22–0.62). In multivariate analysis, log CD20 remained significant with HR 0.42 (95% CI 0.25–0.69). When restricted to SLN tumor negative patients, increased log CD20 was still associated with improved DFS (HR = 0.26, 95% CI 0.08–0.90). The CD20 results were validated in a separate cohort of 21 patients (n = 11 good outcome, n = 10 poor outcome) with SLN negative triple-negative breast cancer (TNBC) (“good” mean of 7011 vs. “poor” mean of 4656, p = 0.002). Our study demonstrates that analysis of immune cells within SLNs, regardless of tumor invasion status, may provide additional prognostic information, and highlights B cells within SLNs as important in preventing future recurrence.

B cells within the tumor-draining lymph nodes may have an important biological role in preventing relapse of breast cancer. A team led by Peter Lee from City of Hope in Duarte, California, USA, quantified the levels of three populations of immune cells—T cells, B cells and dendritic cells—within sentinel lymph nodes biopsied from a cohort of 76 patients. They found that larger numbers of T cells and B cells were both linked to longer progression-free survival in the women. However, after statistically accounting for correlations between the two immune cell types, the researchers concluded that B cells had the dominant beneficial effect on survival times. They validated the finding that high B-cell counts are a prognostic indicator of better outcomes in a separate cohort of 21 women with triple-negative breast cancer.

Computed Tomography Features associated With the Eighth Edition TNM Stage Classification for Thymic Epithelial Tumors

PURPOSE

The eighth edition of the TNM classification of malignant tumors for the first time includes an official staging system for thymic epithelial tumors (TETs) recognized by the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC). Staging is critical for the management of TETs, and determining stage accurately from imaging has the potential to improve clinical outcomes. We examine preoperative computed tomography (CT) characteristics of TETs associated with AJCC/UICC pathologic TNM stage.

MATERIALS AND METHODS

In this retrospective study, patients were included if they met all the following criteria: (1) diagnosis of TET, (2) had primary curative intent surgery performed at Stanford University, and (3) had available preoperative CT imaging for review. Tumor pathology was staged according to the eighth edition TNM classification. Fifteen CT scan features were examined from each patient case according to the International Thymic Malignancy Interest Group standard report terms in a blinded manner. A Lasso-regularized multivariate model was used to produce a weighted scoring system predictive of pathologic TNM stage.

RESULTS

Examining the 54 patients included, the following CT characteristics were associated with higher pathologic TNM stage when using the following scoring system: elevated hemidiaphragm (score of 6), vascular endoluminal invasion (score of 6), pleural nodule (score of 2), lobulated contour (score of 2), and heterogeneous internal density (score of 1). Area under the receiver operating characteristic curve was 0.76.

CONCLUSIONS

TETs with clearly invasive or metastatic features seen on CT are associated with having higher AJCC/UICC pathologic TNM stage, as expected. However, features of lobulated contour and heterogeneous internal density are also associated with higher stage disease. These findings need to be validated in an independent cohort.

Rare Solitary Fibrous Tumor in the Pediatric Neck: A Case Report and Review of the Literature

Solitary fibrous tumors (SFT) are a rare type of mesenchymal-derived tumor not commonly found in the pediatric population, especially in the head and neck. Tumors of this nature are most commonly seen in the adult population and are identified with unique immunohistochemical markers, specifically signal transducer and activator of transcription 6 (STAT6) and hematopoietic progenitor cell antigen (CD34). Including SFTs in the differential diagnosis while working up a mass can be difficult considering their relatively non-descript appearance on imaging and the low yield immunohistochemical staining that must be ordered to confirm diagnosis. The current literature identifies only a handful of cases of SFTs occurring in the pediatric population, with a majority arising from the pleura. We present the case of a 13-year-old male who underwent radical excision of a left occipital triangle neck mass after radiological and pathological workup failed to conclusively make a diagnosis. Postoperative pathologic analysis revealed it to be an SFT. Due to the exceptionally rare presentation of SFTs in pediatric patients, the aim of this case report is to discuss diagnostic measures, solitary fibrous tumor etiology, as well as a recent risk stratification system used for the evaluation of postoperative disease progression. Our hope is that clinicians will include SFTs in their differential diagnosis when working up a neck mass in the pediatric population.

The vascular marker CD31 also highlights histiocytes and histiocyte-like cells within cutaneous tumors

OBJECTIVES

While useful in diagnosing angiosarcomas, CD31 can also highlight histiocytes within soft tissue tumors and lead to errors in diagnosis. We sought to determine how often CD31 highlights cutaneous histiocytomas and histiocytoma mimics.

METHODS

We examined eight epithelioid cell histiocytomas (ECHs), 12 xanthogranulomas (XGs), nine cases of Langerhans cell histiocytosis (LCH), eight reticulohistiocytomas, 11 xanthomas, 29 atypical fibroxanthomas, nine granular cell tumors, four cases of angiolymphoid hyperplasia with eosinophilia, nine intradermal Spitz nevi, and nine angiosarcomas with antibodies directed against CD31, CD34, CD163, and factor VIII.

RESULTS

CD31 marked cells in three of 12 XGs, four of nine cases of LCH, one of eight reticulohistiocytomas, one of 11 xanthomas, 10 of 29 atypical fibroxanthomas, four of four cases of angiolymphoid hyperplasia with eosinophilia, nine of nine angiosarcomas, zero of nine granular cell tumors, and zero of eight ECHs. CD34 and factor VIII were negative in all nonvascular cases.

CONCLUSIONS

Our results indicate that CD31 can mark lesional cells and imitate vascular tumors in cutaneous histiocytomas and histiocytoma mimics, an error that can be avoided by using a panel of antibodies.

Isolation and mutational analysis of circulating tumor cells from lung cancer patients with magnetic sifters and biochips

Detection and characterization of circulating tumor cells (CTCs) may reveal insights into the diagnosis and treatment of malignant disease. Technologies for isolating CTCs developed thus far suffer from one or more limitations, such as low throughput, inability to release captured cells, and reliance on expensive instrumentation for enrichment or subsequent characterization. We report a continuing development of a magnetic separation device, the magnetic sifter, which is a miniature microfluidic chip with a dense array of magnetic pores. It offers high efficiency capture of tumor cells, labeled with magnetic nanoparticles, from whole blood with high throughput and efficient release of captured cells. For subsequent characterization of CTCs, an assay, using a protein chip with giant magnetoresistive nanosensors, has been implemented for mutational analysis of CTCs enriched with the magnetic sifter. The use of these magnetic technologies, which are separate devices, may lead the way to routine preparation and characterization of "liquid biopsies" from cancer patients.

Spatial organization of dendritic cells within tumor draining lymph nodes impacts clinical outcome in breast cancer patients

BACKGROUND

Dendritic cells (DCs) are important mediators of anti-tumor immune responses. We hypothesized that an in-depth analysis of dendritic cells and their spatial relationships to each other as well as to other immune cells within tumor draining lymph nodes (TDLNs) could provide a better understanding of immune function and dysregulation in cancer.

METHODS

We analyzed immune cells within TDLNs from 59 breast cancer patients with at least 5 years of clinical follow-up using immunohistochemical staining with a novel quantitative image analysis system. We developed algorithms to analyze spatial distribution patterns of immune cells in cancer versus healthy intra-mammary lymph nodes (HLNs) to derive information about possible mechanisms underlying immune-dysregulation in breast cancer. We used the non-parametric Mann-Whitney test for inter-group comparisons, Wilcoxon Matched-Pairs Signed Ranks test for intra-group comparisons and log-rank (Mantel-Cox) test for Kaplan Maier analyses.

RESULTS

Degree of clustering of DCs (in terms of spatial proximity of the cells to each other) was reduced in TDLNs compared to HLNs. While there were more numerous DC clusters in TDLNs compared to HLNs,DC clusters within TDLNs tended to have fewer member DCs and also consisted of fewer cells displaying the DC maturity marker CD83. The average number of T cells within a standardized radius of a clustered DC was increased compared to that of an unclustered DC, suggesting that DC clustering was associated with T cell interaction. Furthermore, the number of T cells within the radius of a clustered DC was reduced in tumor-positive TDLNs compared to HLNs. Importantly, clinical outcome analysis revealed that DC clustering in tumor-positive TDLNs correlated with the duration of disease-free survival in breast cancer patients.

CONCLUSIONS

These findings are the first to describe the spatial organization of DCs within TDLNs and their association with survival outcome. In addition, we characterized specific changes in number, size, maturity, and T cell co-localization of such clusters. Strategies to enhance DC function in-vivo, including maturation and clustering, may provide additional tools for developing more efficacious DC cancer vaccines.

PRC2/EED-EZH2 complex is up-regulated in breast cancer lymph node metastasis compared to primary tumor and correlates with tumor proliferation in situ

BACKGROUND

Lymph node metastasis is a key event in the progression of breast cancer. Therefore it is important to understand the underlying mechanisms which facilitate regional lymph node metastatic progression.

METHODOLOGY/PRINCIPAL FINDINGS

We performed gene expression profiling of purified tumor cells from human breast tumor and lymph node metastasis. By microarray network analysis, we found an increased expression of polycomb repression complex 2 (PRC2) core subunits EED and EZH2 in lymph node metastatic tumor cells over primary tumor cells which were validated through real-time PCR. Additionally, immunohistochemical (IHC) staining and quantitative image analysis of whole tissue sections showed a significant increase of EZH2 expressing tumor cells in lymph nodes over paired primary breast tumors, which strongly correlated with tumor cell proliferation in situ. We further explored the mechanisms of PRC2 gene up-regulation in metastatic tumor cells and found up-regulation of E2F genes, MYC targets and down-regulation of tumor suppressor gene E-cadherin targets in lymph node metastasis through GSEA analyses. Using IHC, the expression of potential EZH2 target, E-cadherin was examined in paired primary/lymph node samples and was found to be significantly decreased in lymph node metastases over paired primary tumors.

CONCLUSIONS/SIGNIFICANCE

This study identified an over expression of the epigenetic silencing complex PRC2/EED-EZH2 in breast cancer lymph node metastasis as compared to primary tumor and its positive association with tumor cell proliferation in situ. Concurrently, PRC2 target protein E-cadherin was significant decreased in lymph node metastases, suggesting PRC2 promotes epithelial mesenchymal transition (EMT) in lymph node metastatic process through repression of E-cadherin. These results indicate that epigenetic regulation mediated by PRC2 proteins may provide additional advantage for the outgrowth of metastatic tumor cells in lymph nodes. This opens up epigenetic drug development possibilities for the treatment and prevention of lymph node metastasis in breast cancer.

Altered local and systemic immune profiles underlie lymph node metastasis in breast cancer patients

Cancer-mediated immune dysfunction contributes to tumor progression and correlates with patient outcome. Metastasis to tumor draining lymph nodes (TDLNs) is an important step in breast cancer progression and is used to predict patient outcome and survival. Although lymph nodes are important immune organs, the role of immune cells in TDLNs has not been thoroughly investigated. We hypothesized that the host immune response in node negative (NN) patients is more intact and thereby can resist tumor invasion compared to node positive (NP) patients. As such, lymph node metastasis requires breakdown of the host immune response in addition to escape of cancer cells from the tumor. To investigate the immunological differences between NN and NP breast cancer patients, we purified and profiled immune cells from the three major compartments where cancer and immune cells interact: tumor, TDLNs and peripheral blood. Significant down-regulation of genes associated with immune-related pathways and up-regulation of genes associated with tumor-promoting pathways was consistently observed in NP patients' TDLNs compared to NN patients. Importantly, these signatures were seen even in NP patients' tumor-free TDLNs, suggesting that such immune changes are not driven solely by local tumor invasion. Furthermore, similar patterns were also observed in NP patients' tumor and blood immune cells, suggesting that immunological differences between NN and NP patients are systemic. Together, these findings suggest that alterations in overall immune function may underlie risk for LN metastasis in breast cancer patients.

Discordant immunophenotypic profiles of adhesion molecules and cytokines in acute myeloid leukemia involving bone marrow and skin

We investigated the role of adhesion molecules in skin involvement by acute myeloid leukemia (AML) using immunohistochemical analysis. Ten paired cases of skin and bone marrow biopsy specimens from patients with myeloid leukemia cutis (MLC) and 15 bone marrow biopsy specimens from patients without MLC were studied with antibodies directed against CD29, CD34, CD54, CD62-L, CD183, and cutaneous lymphocyte antigen (CLA). CLA was expressed in all cases of leukemia whereas CD54 was negative within blasts. CD62-L was expressed in 4 of 10 specimens of marrow infiltrates with MLC and 6 of 10 specimens of matching skin infiltrates; in marrows without MLC, only 2 of 15 were positive. CD29 was expressed in 1 of 10 marrow infiltrate specimens with MLC and 4 of 10 matching skin infiltrate specimens; in marrows without MLC, only 1 of 15 were positive. CD183 was expressed in 1 of 10 marrow infiltrate specimens with MLC and 4 of 10 matching skin infiltrate specimens; in marrows without MLC, CD183 was negative. The gain of CD62-L, CD29, and CD183 expression in bone marrow and skin infiltrates in leukemia cutis, relative to bone marrow infiltrates of cases without MLC, suggests a role for these markers in AML homing to skin.

Cytotoxic T lymphocyte responses against melanocytes and melanoma

Background

Vitiligo is a common toxicity associated with immunotherapy for melanoma. Cytotoxic T lymphocytes (CTLs) against melanoma commonly target melanoma-associated antigens (MAAs) which are also expressed by melanocytes. To uncouple vitiligo from melanoma destruction, it is important to understand if CTLs can respond against melanoma and melanocytes at different levels.

Methods

To understand the dichotomous role of MAA-specific CTL, we characterized the functional reactivities of established CTL clones directed to MAAs against melanoma and melanocyte cell lines.

Results

CTL clones generated from melanoma patients were capable of eliciting MHC-restricted, MAA-specific lysis against melanocyte cell lines as well as melanoma cells. Among the tested HLA-A*0201-restricted CTL clones, melanocytes evoked equal to slightly higher degranulation and cytolytic responses as compared to melanoma cells. Moreover, MAA-specific T cells from vaccinated patients responded directly ex vivo to melanoma and melanocytes. Melanoma cells express slightly higher levels of MART-1 and gp100 than melanocytes as measured by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) and immunohistochemistry.

Conclusions

Our data suggest that CTLs respond to melanoma and melanocytes equally in vitro and directly ex vivo.

Quantitative, architectural analysis of immune cell subsets in tumor-draining lymph nodes from breast cancer patients and healthy lymph nodes

Background

To date, pathological examination of specimens remains largely qualitative. Quantitative measures of tissue spatial features are generally not captured. To gain additional mechanistic and prognostic insights, a need for quantitative architectural analysis arises in studying immune cell-cancer interactions within the tumor microenvironment and tumor-draining lymph nodes (TDLNs).

Methodology/Principal Findings

We present a novel, quantitative image analysis approach incorporating 1) multi-color tissue staining, 2) high-resolution, automated whole-section imaging, 3) custom image analysis software that identifies cell types and locations, and 4) spatial statistical analysis. As a proof of concept, we applied this approach to study the architectural patterns of T and B cells within tumor-draining lymph nodes from breast cancer patients versus healthy lymph nodes. We found that the spatial grouping patterns of T and B cells differed between healthy and breast cancer lymph nodes, and this could be attributed to the lack of B cell localization in the extrafollicular region of the TDLNs.

Conclusions/Significance

Our integrative approach has made quantitative analysis of complex visual data possible. Our results highlight spatial alterations of immune cells within lymph nodes from breast cancer patients as an independent variable from numerical changes. This opens up new areas of investigations in research and medicine. Future application of this approach will lead to a better understanding of immune changes in the tumor microenvironment and TDLNs, and how they affect clinical outcomes.

CD163 expression is present in cutaneous histiocytomas but not in atypical fibroxanthomas

CD163, a hemoglobin scavenger receptor, is expressed in monocytes and macrophages. Recent work has shown that this marker is specific for neoplasms of histiocytic differentiation. Our aim was to test the ability of CD163 to separate cutaneous histiocytomas from their morphologic mimics. We tested the expression of CD163 in 78 cases, including 19 xanthogranulomas, 16 atypical fibroxanthomas, 6 reticulohistiocytomas, 8 epithelioid cell histiocytomas, 9 cases of Langerhans cell histiocytosis, 10 xanthomas, and 10 intradermal Spitz nevi. CD163 expression was seen in all xanthogranulomas and reticulohistiocytomas, 4 epithelioid cell histiocytomas, 2 cases of Langerhans cell histiocytosis, and 8 xanthomas but was absent in atypical fibroxanthomas and Spitz nevi. CD163 is an excellent marker for confirming histiocytic differentiation and is useful in eliminating morphologic mimics such as Spitz nevi from the differential diagnosis. The lack of CD163 in atypical fibroxanthomas argues against a histiocytic origin for this tumor.

Immunohistochemical characterization of nasal-type extranodal NK/T-cell lymphoma using a tissue microarray: an analysis of 84 cases

Nasal-type extranodal natural killer (NK)/T-cell lymphoma is an uncommon malignancy. By using a tissue microarray, we characterized 84 cases of extranodal NK/T-cell lymphoma with regard to expression of 18 immunohistochemical markers and the presence of Epstein-Barr virus (EBV) RNA. In our series, CD2 was positive in 69 (93%) of 74 cases, CD3 in 68 (84%) of 81, CD5 in 22 (27%) of 81, CD20 in 0 (0%) of 82, CD29 in 75 (91%) of 82, CD30 in 29 (35%) of 84, CD43 in 81 (96%) of 84, CD54 in 58 (72%) of 81, CD56 in 46 (58%) of 79, CD62L in 23 (28%) of 83, CD183 in 66 (80%) of 83, BCL2 in 33 (39%) of 84, cutaneous lymphocyte antigen in 21 (25%) of 84, granzyme B in 70 (83%) of 84, Ki-67 in 59 (71%) of 83, linker for activation of T cells in 60 (71%) of 84, perforin in 66 (86%) of 77, TIA1 in 76 (90%) of 84, and EBV in 73 (87%) of 84. Hierarchical cluster analysis separated primary cutaneous cases from cases manifesting in other sites based on lower expression of the cell adhesion molecule CD54.

CD10 expression in peripheral T-cell lymphomas complicated by a proliferation of large B-cells

CD10 expression by the neoplastic T cells in angioimmunoblastic T-cell lymphoma was recently described. As cases of peripheral T-cell lymphoma, unspecified, fail to show similar CD10 expression, this feature helps discriminate between these two entities, particularly in cases exhibiting morphologic overlap. Given these findings, we studied CD10 expression in a subtype of peripheral T-cell lymphoma known as peripheral T-cell lymphoma complicated by a proliferation of large B cells and compared it with angioimmunoblastic T-cell lymphoma and angioimmunoblastic T-cell lymphoma with a large B-cell proliferation. A total of 33 cases were identified including peripheral T-cell lymphoma complicated by a proliferation of large B cells (10), angioimmunoblastic T-cell lymphoma (10) and angioimmunoblastic T-cell lymphoma with a large B-cell proliferation (13). Diagnoses were established by hematoxylin and eosin (H&E) stain, immunohistochemistry and/or molecular findings (polymerase chain reaction for T-cell receptor-gamma gene rearrangement). Two of 10 cases of peripheral T-cell lymphoma complicated by a proliferation of large B cells showed aberrant CD10 expression (20%) compared to 9/10 cases of angioimmunoblastic T-cell lymphoma (90%) and 8/13 of angioimmunoblastic T-cell lymphoma with a large B-cell proliferation (62%). One case each of angioimmunoblastic T-cell lymphoma and angioimmunoblastic T-cell lymphoma with a large B-cell proliferation showed a rare, but not unequivocal, CD10+ atypical cell. Four cases of angioimmunoblastic T-cell lymphoma with a large B-cell proliferation were CD10 negative. Of the 2 CD10+ peripheral T-cell lymphoma complicated by a proliferation of large B cells, one had no H&E or IHC features of angioimmunoblastic T-cell lymphoma and showed only a rare positive cell. The second case, a lung biopsy, exhibited diffuse CD10 tumor cell positivity. The predominant staining pattern in the CD10+ cases was characterized by scattered, mostly individual, morphologically neoplastic cells. A rare case showed clusters of positive cells. Our data indicate that only 20% of cases of peripheral T-cell lymphoma complicated by a proliferation of large B cells show CD10 expression by the neoplastic T cells in contrast to angioimmunoblastic T-cell lymphoma and angioimmunoblastic T-cell lymphoma with a large B-cell proliferation which exhibit CD10 staining in 90 and 62% of cases, respectively. This finding does not reach statistical significance with a P-value of 0.57 (Fisher's exact test). As these entities appear to be biologically distinct and may portend different overall survivals, CD10 expression may serve as an additional discriminating criterion.

Follicular Dendritic Cell Immunohistochemical Markers in Angioimmunoblastic T-Cell Lymphoma

Angioimmunoblastic T-cell lymphoma is characterized by a paracortical proliferation of medium to large neoplastic T cells, often with clear cytoplasm, in a background of arborizing high endothelial venules, many surrounded by follicular dendritic cells (FDCs). IHC staining may be applied to highlight these extrafollicular FDCs, traditionally using CD21, or CD23. Several alternative FDC markers have been described, including CNA.42, cystatin A/acid cysteine proteinase inhibitor (ACPI, involved in antigen presentation), and fascin (an actin binding protein). The authors stained a collection of 45 angioimmunoblastic T-cell lymphomas with CD21, CD23, CNA.42, cystatin A, and fascin for direct comparison of FDC staining characteristics in this setting. CD21 highlighted the expected dendritic network of cell processes, within residual follicles and outside of follicles, often adjacent to proliferating vessels. CD23 exhibited similar staining quality but was less sensitive than CD21. CNA.42 showed only diffuse weak labeling of FDCs. Cystatin A stained the cytoplasm of follicular dendritic cells within and outside of follicles; however, staining was often not sharply localized to dendritic cell processes, and scoring was further complicated by reactivity with other cell types in over half of the cases. Likewise, fascin stained a variety of cell types, including strong staining of interdigitating dendritic-like cells, moderate staining of endothelial cells, and only weak staining of follicular dendritic cells within and outside of follicles. Thus, CD21 remains the most reliable marker of follicular dendritic cells in angioimmunoblastic T-cell lymphoma.

C-Kit (CD117) expression in AIDS-related, classic, and African endemic Kaposi sarcoma

Kaposi sarcoma (KS) is a multicentric vascular neoplasm characterized histologically by the progressive proliferation of spindle-shaped tumor cells in all epidemiologic (AIDS-related, classic, endemic, and iatrogenic) forms. Human herpesvirus 8 (HHV8) is associated with all epidemiologic forms of KS and has been shown in vitro to induce the tyrosine receptor kinase c-kit in HHV8-infected cells. To date, c-kit immunoreactivity has not been systematically studied in KS lesions. Therefore, the aim of this study was to evaluate c-kit expression by immunohistochemistry in different proliferative stages and epidemiologic forms of KS. Archival cases of formalin-fixed, paraffin-embedded KS lesions, including 9 classic, 11 AIDS-related, and 15 African (endemic) forms at various histologic stages (5 patch, 8 plaque, 22 nodular), biopsied from different sites, were stained using immunohistochemistry with antibodies to HHV8 (LNA-1) and c-kit (CD117). C-kit immunoreactivity of lesional cells was demonstrated in 15 (43%) cases overall. A total of five (56%) classic, five (45%) AIDS-related, and five (33%) endemic KS cases were positive for c-kit. There was no difference in the intensity of c-kit staining between the different epidemiologic groups and histologic stages of KS. HHV8 (LNA-1) immunoreactivity was present in all (100%) classic, 10 (91%) AIDS-related, and 9 (60%) endemic cases. LNA-1 staining was demonstrated in 13 (93%) of the c-kit-positive and 15 (75%) of the c-kit-negative KS lesions. These findings indicate that c-kit expression in lesional cells can be detected by immunohistochemistry in different epidemiologic forms and histologic stages of KS. Furthermore, the expression of c-kit does not correspond with the presence of HHV8 (LNA-1) immunoreactivity in KS lesions.

Expression of CD163 (hemoglobin scavenger receptor) in normal tissues, lymphomas, carcinomas, and sarcomas is largely restricted to the monocyte/macrophage lineage

CD163, a hemoglobin scavenger receptor, is expressed in monocytes and macrophages. We tested the expression of the CD163 protein in 1,105 human malignancies and normal tissues using tissue microarrays and conventional paraffin-embedded tissue sections. Besides staining nonneoplastic monocytes and histiocytes (tissue macrophages), membranous/cytoplasmic staining for CD163 was primarily limited to neoplasms with monocytic/histiocytic differentiation. CD163 reactivity was not observed in normal tissues, lymphomas, carcinomas, and in a majority of mesenchymal neoplasms, including follicular dendritic cell tumors (0 of 4), although it stained admixed histiocytes. Staining for CD163 was seen in Rosai-Dorfman disease (5 of 6), histiocytic sarcoma (3 of 4), littoral cell angioma (6 of 6), and Langerhans cell histiocytosis (3 of 5). A subset of atypical fibrous histiocytomas (9 of 16), benign fibrous histiocytomas (6 of 9), and atypical fibroxanthomas (1 of 3) also showed CD163 staining. Our studies also confirm earlier work showing that CD163 is expressed in acute myeloid leukemia with monocytic differentiation (AML, FAB subtype M5) (2 of 6), as well as a majority of giant cell tenosynovial tumors (7 of 8). Its limited range of expression and tissue specificity indicate that CD163 may have significant diagnostic utility in separating specific tumors with monocytic and histiocytic derivation from other entities in their differential diagnosis.

Adenomatoid Tumors of the Female and Male Genital Tracts Express WT1

Adenomatoid tumors are benign proliferations most often encountered in the female and male genital tracts. The mesothelial phenotype of these unusual tumors has been established by a variety of ultrastructural and immunohistochemical studies, although their etiology is by no means certain. The expression of the Wilms' tumor suppressor gene, WT1, in normal, hyperplastic, and malignant mesothelial cells prompted us to analyze the expression pattern of WT1 in a series of 24 adenomatoid tumors occurring in the uterus, fallopian tube, ovary, epididymis, scrotum, and testis. Twenty-three of the tumors expressed WT1 protein and the same number expressed calretinin, another marker of mesothelial differentiation. The one tumor that failed to stain with calretinin was positive for WT1. These results provide further support for mesothelial differentiation of adenomatoid tumors and suggest that the presence of WT1 expression may be useful in the differential diagnosis of these uncommon neoplasms, especially when they present in unusual settings or expression of other mesothelial markers is absent.

Human Herpesvirus-8 Latent Nuclear Antigen-1 Expression in Endemic Kaposi Sarcoma

Human herpesvirus-8 (HHV-8) infection is considered the initiating factor in all forms of Kaposi sarcoma (KS). Latent nuclear antigen (LNA-1) is constitutively expressed in all HHV-8-infected cells. An antibody to LNA-1 has recently become commercially available. The current study addresses the role of immunohistochemistry in the diagnosis of KS, particularly the endemic form. Seven recent cases of KS, 1 atypical vascular lesion in a patient subsequently diagnosed with KS, and 16 endemic cases collected in South Africa in the early 1960s were stained with an antibody to LNA-1. Nine benign vascular lesions and three angiosarcomas were also stained. All 7 recent cases expressed the antigen as did the atypical vascular lesion. Of particular interest was the finding that 10 of the 16 endemic cases were positive. None of the other vascular lesions showed staining. A subset of the endemic lesions was stained for CD31, an antigen universally expressed in KS. CD31 staining was reduced compared with a positive control suggesting that the current study may underestimate the sensitivity of LNA-1 immunohistochemistry in endemic KS because of poor antigen preservation in the archival tissue. Our results confirm the utility of LNA-1 immunohistochemistry as an aid in the diagnosis of KS.

Forecasting the future of HIV epidemics: the impact of antiretroviral therapies & imperfect vaccines

Mathematical models can be used as health policy tools and predictive tools. Here we review how mathematical models have been used both to predict the consequences of specific epidemic control strategies and to design epidemic control strategies. We review how models have been used to evaluate the potential impact on HIV epidemics of (i) combination antiretroviral therapies (ART) and (ii) imperfect vaccines. In particular, we discuss how models have been used to predict the potential effect of ART on incidence rates, and to predict the evolution of an epidemic of drug-resistant HIV. We also discuss, in detail, how mathematical models have been used to evaluate the potential impact of prophylactic, live-attenuated and therapeutic HIV vaccines. We show how HIV vaccine models can be used to evaluate the epidemic-level impact of vaccine efficacy, waning in vaccine-induced immunity, vaccination coverage level, and changes (increases or decreases) in risky behavior. We also discuss how mathematical models can be used to determine the levels of cross-immunity that vaccines will need to attain if they are to be used to control HIV epidemics in countries where more than one subtype is being transmitted.

Microinjection of morphine in the A7 catecholamine cell group produces opposing effects on nociception that are mediated by alpha1- and alpha2-adrenoceptors

Stimulation of neurons in the ventromedial medulla produces antinociception in part by inhibiting nociceptive dorsal horn neurons. This antinociceptive effect is mediated in part by spinally projecting noradrenergic neurons located in the A7 catecholamine cell group. Methionine-enkephalin-immunoreactive neurons in the ventromedial medulla project to an area that includes the A7 cell group, and these enkephalin neurons may mediate part of the antinociception produced by stimulation of sites in the ventromedial medulla. This possibility was tested by determining the effects of microinjecting morphine near the A7 cell group on nociceptive foot and tail responses. Microinjection of a 3.75 nmol dose of morphine in the A7 region did not alter nociceptive responses, but a higher dose of 7.5 nmol facilitated these responses. In contrast, a higher dose of 15 nmol of morphine did not alter nociceptive responses. Selective alpha-adrenoceptor antagonists were injected intrathecally to determine whether the hyperalgesia produced by morphine is mediated by spinally projecting noradrenergic A7 neurons. Intrathecal injection of the alpha2-adrenoceptor antagonist yohimbine did not alter the hyperalgesic effect produced by the 7.5 nmol dose of morphine, but the alpha1 antagonist WB4101 reversed the hyperalgesia and produced antinociception that lasted for nearly 30 min. Although the 15 nmol dose of morphine did not alter nociceptive responses, intrathecal injection of yohimbine after the microinjection of morphine produced a significant facilitation of nociception, and intrathecal injection of WB401 produced a significant antinociceptive effect. Intrathecal injection of the antagonists alone did not consistently alter nociception. These findings, and those of published reports, suggest that morphine indirectly activates two populations of spinally projecting A7 noradrenergic neurons that have opposing effects on nociception. One of these populations facilitates nociception by an action mediated by alpha1-adrenoceptors in the spinal cord dorsal horn and the other population inhibits nociception by an action mediated by alpha2-adrenoceptors. These results suggest that some of the methionine-enkephalin neurons located in the ventromedial medulla that project to the A7 cell group can exert bidirectional control of nociceptive responses.

Radical retropubic prostatectomy reduces symptom scores and improves quality of life in men with moderate and severe lower urinary tract symptoms

PURPOSE

We determine the impact of radical retropubic prostatectomy on lower urinary tract symptoms and quality of life due to urinary problems in men with clinically localized prostate cancer.

MATERIALS AND METHODS

The American Urological Association (AUA) symptom index, a symptom problem index and a quality of life due to urinary problems question were administered to 104 men before and 12 months after radical prostatectomy. Urinary continence and satisfaction with the decision to undergo radical prostatectomy were also examined.

RESULTS

In men with moderate or severe baseline urinary symptoms (AUA score 8 or greater) the total AUA symptom, symptom problem and quality of life question scores decreased by 51 (-6.39), 57 (-4.22) and 25% (-0.65), respectively, after radical prostatectomy. Except for nocturia statistically significant improvements were observed for all questions captured by the AUA symptom index. Radical prostatectomy did not significantly change mean AUA symptom score or symptom problem index in men with mild urinary symptoms (AUA score less than 8). In men with moderate or severe urinary symptoms radical prostatectomy significantly improved quality of life due to urinary problems. Although 10% of men exhibited some degree of clinically relevant stress incontinence, 98% were very satisfied or satisfied with the decision to undergo radical prostatectomy.

CONCLUSIONS

In men with moderate or severe urinary symptoms radical prostatectomy improves lower urinary tract symptoms and quality of life due to urinary problems. The overall beneficial impact on voiding makes radical prostatectomy an attractive treatment option for clinically localized prostate cancer.

Pathogenesis of human immunodeficiency virus (HIV)-associated nephropathy

Human immunodeficiency virus-associated nephropathy (HIVAN) is the third leading cause of end-stage renal failure in Blacks between the ages of 20 and 64. Because the incidence of HIV infection has continued to increase in Blacks as survival has improved, the pool of patients alive and at risk for developing HIVAN has vastly expanded. This suggests that HIVAN will continue to increase in importance to the end-stage renal disease program. The racial predilection for the disease in Blacks implies that genetic or environmental cofactors are involved. Evidence in human and animal models has shown that proliferation of renal epithelial cells is the predominant feature of the disease and that apoptosis occurs. The prospect that renal infection is necessary to stimulate cells to proliferate remains a possibility but is not yet proven. Cytokine dysregulation may also be involved in disease progression, but evidence is lacking that altered cytokine production is the proximate cause of HIVAN. Many issues remain to be resolved including the potential for renal infection in vivo, the mechanisms responsible for proliferation and apoptosis, and factors that provide racial susceptibility to HIVAN. Advances in our understanding of pathogenesis will be required to control the growth of HIV-related renal diseases in the ESRD population.

The human blood-brain barrier glucose transporter (GLUT1) is a glucose transporter of gray matter astrocytes

Human and monkey brain sections were examined by immunohistochemical light and electron microscopy to determine the distribution of GLUT1, a glucose transporter isoform associated with erythrocytes and endothelial cells of the human blood-brain barrier. Protein immunoblotting of fractionated human brain membranes was performed to determine the distribution of molecular forms of the transporter. GLUT1 staining was abundant in erythrocytes and cerebral endothelium of gray and white matter but was also present diffusely in gray matter neuropil when viewed by light microscopy. Immunoelectron microscopy confirmed the gray matter and vascular localization of GLUT1, with specific GLUT1 staining seen in erythrocytes, gray and white matter endothelial cells, astrocyte foot processes surrounding gray matter blood vessels, and in astrocyte processes adjacent to synaptic contacts. No astrocytic staining was identified in white matter. Astrocyte GLUT1 staining was identified only in mature gray matter regions; undifferentiated regions of preterm (22-23 weeks gestation) cortex had GLUT1 staining only in blood vessels and erythrocytes, as did germinal matrix. Immunoblots of adult human frontal cortex revealed that two forms of GLUT1 (45 and 52 kDa) were present in unfractionated brain homogenates. Immunoblots of vessel-depleted frontal lobe revealed only the 45 kDa form in gray matter fractions, and depleted in membranes prepared from white matter regions. We conclude that the GLUT1 isoform of glucose transporter is present both in endothelium of the blood-brain barrier and in astrocytes surrounding gray matter blood vessels and synapses. Furthermore, the form present in astrocytes is likely to have a lower molecular weight than the form found in cerebral endothelium. The GLUT1 transporter may play an important role not only in astrocyte metabolism, but also in astrocyte-associated pathways supporting neuronal energy metabolism.