Ordered array of dendritic cells and CD8+ lymphocytes in portal infiltrates in chronic hepatitis C

AIMS: Despite the importance of dendritic cells in stimulating primary and secondary immune responses by presenting antigens to T-lymphocytes in draining lymph nodes and peripheral tissues, respectively, very limited information is available on the presence and localization of these cells in hepatitis C virus (HCV)-related chronic active hepatitis. Therefore, we addressed the ultrastructure, immunophenotype, distribution and relationships to lymphatics of dendritic cells in portal infiltrates of this disease. METHODS AND RESULTS: Part of percutaneous diagnostic liver biopsies (Knodell's histological assessment index: 9-13) was processed for electron microscopy and for immunohistochemical detection of immune system cell membrane antigens and of the lymphatic endothelium marker podoplanin. In portal infiltrates, cells with electron microscopical and cell marker features of dendritic cells and expressing the activation markers CD54, CD80, CD83 and CD86 were organized in a discontinuous network, that embedded CD8+ lymphocytes in close contact with dendritic cells and came in contact with hepatocytes, sometimes infiltrating beyond the limiting plate. Also, dendritic cells were found within newly formed lymphatic capillaries in thin, infiltrated septa among hepatocytes. CONCLUSIONS: This evidence strongly suggests a critical role of dendritic cells and newly formed lymphatics in the pathogenesis and organization of the immune infiltrate that characterizes HCV-related chronic active hepatitis.     

Response of CD4+ and CD8+ T lymphocytes in the evolution of Leishmania (Viannia) shawi infection

Leishmania (Viannia) shawi was recently characterized, and there are no studies of immunopathological alterations induced by this parasite. BALB/c and C57BL/6 mice were infected in the footpad with L. (V.) shawi promastigotes. The lesions were monitored during 8?weeks post-infection (pi), and at each 2?weeks pi, immunohistochemistry of skin and lymph nodes has been performed to analyze the densities of CD4+ and CD8+ T lymphocytes as well as amastigote forms. In the skin, BALB/c mice presented higher amastigote densities than C57BL/6 mice; concerning lymphocytes, there are no significant differences between CD4+ T lymphocytes densities; however, C57BL/6 mice presented elevation in densities of CD8+ T cells latter in the infection. The elevation of amastigote densities in lymph nodes of BALB/c mice at 8?weeks pi could be a reflection of suppressed density of CD4+ T. On the other hand, elevated density of CD8+ T lymphocytes in lymph nodes of C57BL/6 seems to exert some degree of resistance compared to BALB/c mice. The present work indicates that CD8+ T lymphocyte can be a key component to generation of resistance in L. (V.) shawi infections.     

Presence and maturity of dendritic cells in melanoma lymph node metastases

Immune avoidance mechanisms play a key role in the successful dissemination of melanoma. One mechanism whereby this could be achieved is by interfering with dendritic cell (DC) presentation of tumour‐associated antigens to naïve T cells. In particular, immature DCs characterized by the absence of accessory molecules are known to be immunosuppressive and to be involved in the induction of tolerance. The present study has investigated the presence and activation status of DCs within melanoma metastases in the regional lymph nodes. Using image analysis techniques, the expression of Factor XIIIa (FXIIIa), CD40, CD83 and HLA‐DR and the morphological features of DCs were examined in paraffin sections from 26 lymph nodes containing melanoma metastases. DCs expressing FXIIIa were found in 70% of the lymph nodes. The number of DCs identified was generally small but there were more concentrated areas of DCs designated as hotspots. In these areas of high FXIIIa staining, the percentage area occupied by DCs varied between 0.1% and 10%. The majority of FXIIIa‐positive cells did not express the DC maturation markers CD83 or CD40 and morphologically were rounded with few dendrites, indicating that they were immature. The cells did, however, express high levels of HLA‐DR, suggesting that they have the ability to present antigen but lack the accessory molecules required to initiate an immune response. Immature DCs, characterized by phenotypic and morphological features, are therefore present within the tumour deposits in lymph nodes infiltrated by melanoma and may specifically modulate the anti‐melanoma immune response. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Successful live cell harvest from bisected sentinel lymph nodes research report

Sentinel lymph nodes provide an excellent opportunity to study early immune responses to cancer. However, harvesting live cells has not previously been possible, because it conflicts with the need to preserve tissue for histological interpretation. This study used scrape cytology on 26 sentinel and 8 non-sentinel nodes, harvested from 17 stage I/II melanoma patients undergoing sentinel node biopsy. Numbers of viable cells harvested before and after cryopreservation were measured and the effect on subsequent histology assessed. The mean number of cells harvested from 26 sentinel nodes was 7.06 x 10(6) (range 0.1-32.2), with a mean viability of 99.5% (range 87-100, lower 95% CI 98.5%). Furthermore, counts and viabilities were well maintained after cryopreservation. Flow cytometry confirmed CD3+, CD20+ and lineage-1-/HLA-DR+ subpopulations, consistent with T-lymphocytes, B-lymphocytes and dendritic cells, respectively. Importantly, there was no discernible change in histological detail and the proportion of positive sentinel nodes remained unchanged. This technique will allow more functional and quantitative approaches to sentinel lymph node research.     

L-selectin-negative CCR7- effector and memory CD8+ T cells enter reactive lymph nodes and kill dendritic cells

T lymphocytes lacking the lymph node-homing receptors L-selectin and CCR7 do not migrate to lymph nodes in the steady state. Instead, we found here that lymph nodes draining sites of mature dendritic cells or adjuvant inoculation recruited L-selectin-negative CCR7- effector and memory CD8+ T cells. This recruitment required CXCR3 expression on T cells and occurred through high endothelial venules in concert with lumenal expression of the CXCR3 ligand CXCL9. In reactive lymph nodes, recruited T cells established stable interactions with and killed antigen-bearing dendritic cells, limiting the ability of these dendritic cells to activate naive CD4+ and CD8+ T cells. The inducible recruitment of blood-borne effector and memory T cells to lymph nodes may represent a mechanism for terminating primary and limiting secondary immune responses.     

Transcript levels of DNA methyltransferases DNMT1, DNMT3A and DNMT3B in CD4+ T cells from patients with systemic lupus erythematosus

Langerin/CD207 is expressed by a subset of dendritic cells (DC), the epithelial Langerhans cells. However, langerin is also detected among lymphoid tissue DC. Here, we describe striking differences in langerin-expressing cells between inbred mouse strains. While langerin+ cells are observed in comparable numbers and with comparable phenotypes in the epidermis, two distinct DC subsets bear langerin in peripheral, skin-draining lymph nodes of BALB/c mice (CD11c(high) CD8alpha(high) and CD11c(low) CD8alpha(low)), whereas only the latter subset is present in C57BL/6 mice. The CD11c(high) subset is detected in mesenteric lymph nodes and spleen of BALB/c mice, but is virtually absent from C57BL/6 mice. Similar differences are observed in other mouse strains. CD11c(low) langerin+ cells represent skin-derived Langerhans cells, as demonstrated by their high expression of DEC-205/CD205, maturation markers, and recruitment to skin-draining lymph nodes upon imiquimod-induced inflammation. It will be of interest to determine the role of lymphoid tissue-resident compared to skin-derived langerin+ DC.     

Inflammatory cells in the formation of tumor-related sarcoid reactions

Tumor-related sarcoid reactions were analyzed in 14 lymph nodes in comparison with sarcoidosis using immunohistochemical markers to lymphocytes (CD3, CD4, CD8, and CD20), myeloid-related protein (MRP) 8 and MRP14 (S100A8 and S100A9), angiotensin I-converting enzyme (CD143), and mature or immature dendritic cells (S100, HLA-DR, fascin, CD83, and CD1a). We found that solitary epithelioid cell granuloma (ECG) first occur between lymph sinus and T-zone and that multiple ECGs mainly occur within T-zone, whereas confluent types often occupy the whole lymph node except some residual lymphoid follicles. This pattern suggests a continuous spread and growth of ECGs in sarcoid reactions along T-zone, where antigen presentation mainly takes place. Irrespective of granuloma type, a constant invasion of freshly recruited MRP8 + and MRP14 + macrophages was observed. Similar to sarcoidosis, angiotensin I-converting enzyme expression was a constant finding in epithelioid and giant cells, suggesting a common inflammatory pathway. An increasing ratio of CD4 + to CD8 + T lymphocytes (r = 0.789, P = .001) and a decreasing number of S100 + and CD83 + dendritic cells (r = 0.787, P = .001) within ECGs correlated with granuloma growth, whereas CD1a + immature dendritic cells were never observed inside ECGs. Our findings show that sarcoid reactions represent a T-cell-mediated immune response, leading to histological appearance and cell distribution similar to sarcoidosis and other granulomatous conditions, but the mechanism is different from dendritic cell-based tumor vaccination. Furthermore, mature dendritic cells occur inside ECGs especially of early sarcoid reactions but may not be required for the enlargement and further maintenance of ECGs, in contrast to CD4 + lymphocytes.     

Human regional lymph nodes draining cancer exhibit a profound dendritic cell depletion as comparing to those from patients without malignancies

Dendritic cells (DCs) are bone-marrow derived 'professional' antigen presenting cells (APC). They are considered as the most potent APC able to induce primary immune responses. DC efficiently capture and process proteic and non-proteic antigens. They are widely distributed throughout the body and occupy sentinel positions such as epithelia. Establishment of an immune response against cancer may depend of the capacity of DCs to transfer (to capture, to process and to present) tumor antigens into regional lymph nodes where they can induce a specific response leading to tumor rejection. Because host 'professional' DCs are one of the most important elements in the induction of specific anti-tumor responses and lymph nodes are the places where the immune response takes place, we investigated the densities of DCs within regional metastasis-free lymph nodes from 47 patients with different malignant epithelial tumors as comparing with lymph nodes from 11 patients without malignancies using an immunohistochemistry method with anti-S100 protein, CD86 and CD1a antibodies. By means of morphometric analysis, we observed that S100+ and CD1a+ DCs densities in regional lymph nodes from cancer patients were significatively decreased as compared with control lymph nodes (P<0.0001 and 0.003, respectively). S100+ DCs and CD86+ DCs densities in lymph nodes draining cancer were similar. Taken together, these data indicated that lymph nodes draining cancer had significantly less CD1a+ DCs than S100+ and possibly CD86+ DCs. These findings may represent another mechanism by which tumors evade the immune recognition.     

Human atherosclerotic plaques express DC-SIGN,a novel protein found on dendritic cells and macrophages

The association of autoimmune phenomena with atherosclerosis suggests that plaques may contain specialized antigen-presenting cells, dendritic cells (DCs). DC-SIGN is a C-type lectin expressed by DCs. This study assessed whether human atherosclerotic plaques expressed DC-SIGN and several other macrophage/DC markers. Plaques from human coronary and carotid arteries and aorta contained DC-SIGN-immunoreactive cells. Double-labelling showed co-expression of DC-SIGN and macrophage/DC lineage markers CD14, CD68, HLA-DR, and S100. There was no immunoreactivity for the DC activation markers CD83 or CMRF-44. Since DC-SIGN mediates adhesion to T-lymphocytes and endocytosis, its expression in atherosclerotic plaques may have functional implications. Activated DCs migrate quickly from areas of inflammation to regional lymph nodes, possibly explaining the paucity of activated DCs in atherosclerotic plaques. In conclusion, this study has shown that DC-SIGN is expressed in atherosclerosis.     

C57BL/6小鼠不同组织器官中NKT细胞的比较

目的比较C57BL/6小鼠肝脏、肺脏、脾脏和肠系膜淋巴结中NKT细胞的含量、亚型和功能的特点。方法分离正常C57BL/6小鼠肝脏、肺脏、脾脏和肠系膜淋巴结的淋巴细胞,利用细胞表面分子染色的方法,观察不同组织器官中CD3+NK1.1+NKT细胞及其亚型的含量;淋巴细胞经过PMA和离子霉素刺激后,应用细胞内细胞因子染色的方法,通过流式细胞仪观察NKT细胞IFN-γ、IL-4、IL-9和IL-17的产生情况。结果肝脏中NKT细胞的含量为(25.2±12)%,显著高于肺脏、脾脏和肠系膜淋巴结。肝脏、脾脏和肠系膜淋巴结中NKT细胞以CD4+细胞亚群为主,而肺脏中NKT细胞以CD4-CD8-亚群为主,同时肠系膜淋巴结的NKT细胞中存在CD4+CD8+亚群。不同组织器官中NKT细胞IFN-γ、IL-4、IL-9和IL-17产生的能力有差别。结论 C57BL/6小鼠肝脏、肺脏、脾脏和肠系膜淋巴结的NKT细胞在含量、表型和功能方面可能存在明显的差异。     

CD83 is a regulator of murine B cell function in vivo

The transmembrane glycoprotein CD83 has been described as a specific maturation marker for dendritic cells and several lines of evidence suggest that CD83 regulates thymic T cell maturation as well as peripheral T cell activation. Here we show for the first time that CD83 is involved also in the regulation of B cell function. CD83 is up-regulated on activated B cells in vivo, specifically in the draining lymph nodes of Leishmania major-infected mice. The ubiquitous transgenic (Tg) expression of CD83 interferes with Leishmania-specific T cell-dependent and with T cell-independent antibody production. This defect is restricted to the B cell population since the antigen-specific T cell response of CD83Tg mice to L. major infection is unchanged. The defective immunoglobulin (Ig) response is due to Tg expression of CD83 on the B cells because wild-type B cells display normal antigen-specific responses in CD83Tg hosts and CD83Tg B cells do not respond to immunization in a mixed wild-type/CD83Tg bone marrow chimera. Finally, the treatment of non-Tg C57BL/6 mice with anti-CD83 mAb induces a dramatic increase in the antigen-specific IgG response to immunization, thus demonstrating a regulatory role for naturally induced CD83 on wild-type B cells.     

IL-4 deficiency does not impair the ability of dendritic cells to initiate CD4+ and CD8+ T cell responses in vivo

Several reports have described a role of IL-4 in dendritic cell function. We have examined the number and phenotype of dendritic cells from C57Bl/6 wild-type and IL-4-/- mice, and compared their ability to induce T cell immune responses in vivo and in vitro. We observed that the number of dendritic cells in the spleens and lymph nodes of IL-4-/- mice is comparable to the number found in wild-type mice. In addition, the expression of maturation markers such as MHC II, CD40, CD80 and CD86, and of differentiation markers such as CD4, CD8 and CD11b, was also comparable in the two populations. Splenic wild-type and IL-4-/- dendritic cells were both able to present antigen to T cell receptor transgenic CD4+ or CD8+ T cells in culture. When pulsed with antigen in vitro and then injected subcutaneously into C57BL/6 host mice, both populations of dendritic cells were able to induce the division of T cell receptor transgenic CD4+ or CD8+ T cells in vivo. This was the case regardless of whether the antigen used in these experiments was a low or a high affinity T cell receptor ligand. Similarly, both populations of dendritic cells were able to activate antigen-specific cytotoxic T cell responses and initiate tumor-protective immune responses in vivo. We conclude that IL-4-/- and wild-type dendritic cells have a comparable ability to initiate T cell immune responses when in an IL-4-sufficient environment.     

A subset of dendritic cells express joining chain (J-chain) protein

Joining chain (J-chain) is well known as an integrated component of dimeric immunoglobulin A (IgA) and pentameric IgM. We show here that the J-chain protein is also expressed in a subset of CD11c+ dendritic cells (DC) in C57BL/6 mice. J-chain knockout mice (J-/- mice) had a reduced fraction of CD4-/CD8alpha+ and mPDCA-1+ DC in the spleen. J-/- mice also had reduced levels of RNA for the immunoregulatory enzyme indoleamine 2,3-dioxygenase (IDO) in the spleen. Furthermore, in lymph nodes from C57BL/6 mice the majority of J-chain-expressing CD11c+ cells also expressed IDO, while the number of IDO-expressing cells in lymph nodes and the amount of IDO protein in splenic CD11c+ cells were reduced in J-/- mice. Also, J-/- mice had a lower ratio of kynurenine/tryptophan in serum compared to C57BL/6 mice, indicating a lower overall IDO activity in J-/- mice. We also show that J-/- mice are less susceptible to tolerance induction than C57BL/6 mice. In conclusion, our data show that J-chain protein is expressed outside the B-cell compartment in a subset of immunoregulatory DC that are compromised in animals that cannot express J-chain.     

Expression of the gangliosides GD3 and GD2 on lymphocytes in tissue sections of melanoma

Previous studies in vitro have shown that monoclonal antibodies (MAbs) against gangliosides GD3 and GD2 potentiate lymphocyte responses to a variety of stimuli. The purpose of the present study was to determine by immunohistological techniques whether GD3 and GD2 was expressed on lymphoid cells in vivo around melanoma cells. Studies on metastases in lymph nodes indicated that the lymphoid infiltrate around the margins of the metastases was predominantly CD4+ T cells, which were shown by dual labelling techniques to express mainly GD2 and to a lesser extent GD3. CD4+GD3+ T cells were detected more frequently in cortical regions of the lymph nodes. CD8+ T cells were less numerous than CD4+ T cells and expressed both GD3 and GD2. Expression of GD2 was also prominent on CD4+ T cells, B lymphocytes and dendritic reticular cells in germinal centres, whereas GD3 was mainly expressed on T cells in the margins of the follicles. In contrast to the predominance of CD4+ T cells in lymph nodes, CD4+ and CD8+ T cells were in approximately equal proportions about primary melanoma and metastases in skin. GD2 was largely undetectable on lymphocytes at these sites. In contrast, GD3 was detected on both CD8+ and CD4+ lymphocytes but not on B lymphocytes. The absence of GD2 on CD4+ T cells in skin suggested the latter were a different subpopulation to those in lymph nodes. There appeared to be no clear correlation, however, with subsets of CD4 T cells defined by the 2H4 and Leu 8 MAbs.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasmacytoid dendritic cells represent a major dendritic cell subset in sentinel lymph nodes of melanoma patients and accumulate in metastatic nodes

Plasmacytoid dendritic cells (pDC) represent the main source of interferon-alpha, a cytokine with antitumor activity. However, in vitro studies point to pDC as a key subset for induction of tolerance. Herein, we investigated pDC in sentinel lymph nodes (SLN) of melanoma patients. We report that pDC were constantly found in SLN and represented, with Langerhans cells, the most frequent dendritic cell subset. Their frequency in positive (with metastasis) SLN was significantly higher than in negative (without metastasis) SLN. PDC were observed in the T cell-rich areas of lymph nodes, particularly around high endothelial venules and, in metastatic nodes, they accumulated in close vicinity with melanoma nests. Finally, pDC capability to produce interferon-alpha in situ was impaired. Consistently, pDC expressed CD86, but neither CD80 nor CD83, suggesting a not complete activation in melanoma-draining lymph nodes. These results are consistent with the hypothesis of a tolerogenic role played by pDC in tumor immunology.     

Metastasis to sentinel lymph nodes in breast cancer is associated with maturation arrest of dendritic cells and poor co-localization of dendritic cells and CD8+ T cells

The regional immune systems of patients with breast cancer are immunosuppressed. Dendritic cells are professional antigen-presenting cells and present cancer-associated antigens to the adaptive immune system in sentinel lymph nodes. Dendritic cells may promote, or inhibit, an adaptive immune response to specific antigens. Our aim was to assess whether dendritic cells were associated with nodal metastasis in patients with breast cancer. Sentinel lymph nodes of 47 patients with breast cancer with varying degrees of nodal disease and ten controls were evaluated using immunohistochemistry for the accumulation of dendritic cells in general (CD1a⁺), mature dendritic cells (CD208⁺), and plasmacytoid dendritic cells (CD123⁺). Cytotoxic T cell and regulatory T cell accumulation were also evaluated. Sentinel lymph nodes with macrometastases demonstrated fewer mature dendritic cells than sentinel lymph nodes without metastasis (p = 0.028), but not controls. There were fewer mature dendritic cells to cytotoxic T cells in sentinel lymph nodes with metastasis than those without (p = 0.033). Also, there were more regulatory T cells to mature dendritic cells in sentinel lymph nodes with metastasis than those without (p = 0.02). In conclusion, our study suggests that sentinel lymph nodes with metastasis have arrest of maturation of dendritic cells, fewer mature dendritic cell interactions with cytotoxic T cells, and more regulatory T cells than sentinel lymph nodes without metastasis in patients with breast cancer. These findings extend our understanding of regional immunosuppression and suggest that most regional immunosuppressive changes are associated with nodal metastasis in breast cancer.     

Plasmacytoid monocytes (so-called plasmacytoid T-cells) in Kikuchi's lymphadenitis. An immunohistologic study

Three cases of Kikuchi's lymphadenitis were studied immunohistochemically on paraffin-embedded material in order to compare the plasmacytoid monocyte aggregates occurring in this disorder with plasmacytoid monocyte clusters in nonspecific reactive lymphadenitis. One of the cases was also analyzed on frozen material. In Kikuchi's lymphadenitis, plasmacytoid monocytes expressed the CD38 and LN1 antigens in addition to their monocyte/macrophage antigens found in nonspecific reactive lymph nodes. These plasmacytoid monocyte aggregates contained large numbers of Mac387+ lysozyme+ macrophages, scattered HLADR+ dendritic cells, and high numbers of CD8+ T-lymphocytes. Collections of T-immunoblasts or areas of necrosis were observed within these aggregates. The authors speculate that the histologic feature of Kikuchi's lymphadenitis is the morphologic substrate of a T-cell-mediated cytotoxic immune reaction occurring in plasmacytoid monocyte aggregates and resulting in plasmacytoid monocyte damage and necrosis.     

Regulation of T-cell function in lung tissue by pulmonary alveolar macrophages.

We have examined by limit dilution analysis the frequency of several types of DBA/2-specific precursor cells found in the draining lymph nodes of BALB/c mice following anterior chamber or subconjunctival inoculations of P815 tumour cells. Assays for precursors of cytotoxic T cells (pTc) and T-helper cells [interleukin-2 (IL-2)- and IL-4-producing cells] were conducted periodically during a 6-month interval after injection of tumour cells. The results indicate that nodes of both sets of recipients contained primed P815-specific CD8+ pTc that were detectable within 2 weeks of tumour implantation, and persisted throughout the 6-month observation period. Early after tumour inoculation, but not thereafter, these CD8+ cells also secreted Il-2. By contrast, only lymph nodes from mice that received P815 cells into the subconjunctival space contained CD4+ cells that secreted both IL-2 and IL-4; eventually, IL-4-secreting cells formed the vast majority of P815-specific CD4+ cells in these mice. Lymph nodes of mice that received P815 cells in the anterior chamber contained CD4+ T cells that were clonally expanded, and secreted IL-2, but not IL-4. These IL-2-secreting cells proved to be short-lived and were not present 6 months after inoculation. It is proposed that the IL-2- and IL-4-secreting T cells found in lymph nodes of subconjunctival tumour recipients are in vivo homologues of Th0 cells, that these cells can mediate delayed hypersensitivity responses, and that they are the forerunners of, or are themselves, memory T cells. These data indicate that the failure of mice that receive P815 tumour cells in the anterior chamber to display antigen-specific delayed hypersensitivity results from an inability to convert antigen-activated, IL-2-only-secreting CD4+ T cells (pTh) into Th0 cells. These findings also imply that mice with anterior chamber-associated immune deviation (ACAID) fail to develop memory CD4+ T cells.     

The effect of neoadjuvant therapy on the size,number, and distribution of mesorectal lymph nodes

The current therapeutic approach to patients with locally advanced rectal cancer is neoadjuvant radiotherapy or chemoradiotherapy followed by total mesorectal excision. We aimed to investigate the number, size, and distribution of metastatic and nonmetastatic lymph nodes within the mesorectum; whether neoadjuvant therapy has any impact on the number and size of the lymph nodes; and the impact of metastatic lymph node localization on overall and disease-free survival. Specimens from 50 consecutive patients with stage II/III rectal cancer receiving either neoadjuvant radiotherapy or chemoradiotherapy were investigated. Lymph node dissection was carried out by careful visual inspection and palpation. The localization of the each lymph node within the mesorectum and the relation with the tumor site were noted. The size and the number of lymph nodes retrieved decreased significantly with neoadjuvant therapy. Majority of the metastatic and nonmetastatic lymph nodes were located at or proximally to the tumor level and posterior side of the mesorectum. No relation was observed between the overall and disease-free survival, and the localization of the metastatic lymph nodes. Presence of lymph node metastases proximal to the tumor level has no impact on survival compared with the presence of lymph node metastasis only in the peritumoral region of the mesorectum. Although neoadjuvant therapy decreases the size and the number of lymph nodes, reaching an ideal number of lymph nodes for accurate staging is still possible with careful naked eye examination and dissection of perirectal fat. As the majority of metastatic and nonmetastatic lymph nodes are located in peritumoral and proximal compartment, and posterior side of the mesorectum, these regions should be the major interest of dissection.     

Detection of endogenous cytokines in sera or in lymph nodes obtained from patients with sarcoidosis.

To investigate the possible role of endogenous cytokines in the immunopathogenesis of sarcoidosis, a study of cytokines in lymph nodes obtained from patients with active pulmonary sarcoidosis was carried out using immunoperoxidase staining and radioimmunoassays (RIA). Cells stained for interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha), which appeared to be CD3+ cells and CD14+ cells, respectively, were seen scattered around granulomas. In contrast, cells positive for interleukin-1 beta (IL-1 beta) were located in CD11c+ cells within granulomas. Lymph nodes of patients with sarcoidosis contained significantly higher amounts of IFN-gamma, TNF-alpha and IL-1 beta than control lymph nodes. The levels of IFN-gamma and TNF-alpha in extracts of lymph nodes were correlated with the histological status of the granulomas. IFN-gamma was detected in all stages, while the highest level of TNF-alpha was obtained from lymph nodes containing many active granulomas. The level of serum IFN-gamma was always lower than in lymph node extract and correlated significantly with either serum angiotensin-converting enzyme or serum lysozyme. Patients with positive gallium-67 uptake or bilateral hilar lymphadenopathy had high levels of either serum IFN-gamma or lysozyme. These results suggest that quantitative analyses of IFN-gamma and TNF-alpha in sera and lymph nodes may serve to elucidate the pathophysiology of sarcoidosis.