RESUMEN
In order to explore a new mode for the diagnosis of angioimmunoblastic T-cell lymphoma (AITL), 31 cases of AITL and 28 cases of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) were used as the study subjects. Identifying T follicular helper (TFH) cells with CD4, CD10, Bcl-6, and PD-1, identifying proliferative B cells with CD20 and EZH2, identifying proliferative follicular dendritic cells (FDCs) with CD21 and CD23, and analyzing the value of TFH/B/FDC proliferation and immunolocalization in the diagnosis of AITL. (1) Outside the inherent lymphoid follicles, simultaneous proliferation of TFH/B/FDC (a new diagnostic mode) were observed in AITL [83.87%; 26/31], with their immunolocalizations in the same site [83.87%; 26/31], while this phenomenon was not observed in 28 cases of PTCL-NOS (P<0.05). (2) The sensitivity and specificity of using this new mode to diagnose AITL were both high (83.87%, 100%), which was superior to CD2 (100%, 0%), CD3 (100%, 0%), CD4 (100%, 32.14%), CD5 (100%, 25%), CD10 (61.9%, 100%), Bcl-6 (42.86%, 100%), PD-1 (83.87%, 96.43%), and its Youden Index (0.84) was the highest. The areas under the curve (AUC) of CD10, Bcl-6, PD-1, and new mode to diagnosis AITL were 0.81, 0.71, 0.90, and 0.92, respectively, while the new mode had the highest AUC. The simultaneous proliferation of TFH/B/FDC cells outside the inherent lymphoid follicles can be used to assist in the diagnosis of AITL, and the simultaneous spatiotemporal proliferation of TFH/B/FDC cells is a specific immunomorphology of AITL.
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Proteínas Proto-Oncogénicas c-bcl-6 , Humanos , Femenino , Masculino , Persona de Mediana Edad , Anciano , Proteínas Proto-Oncogénicas c-bcl-6/metabolismo , Neprilisina/metabolismo , Linfadenopatía Inmunoblástica/diagnóstico , Linfadenopatía Inmunoblástica/patología , Células Dendríticas Foliculares/patología , Células Dendríticas Foliculares/metabolismo , Receptor de Muerte Celular Programada 1/metabolismo , Adulto , Linfoma de Células T/diagnóstico , Linfoma de Células T/patología , Linfoma de Células T/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Proliferación Celular , Linfocitos B/inmunología , Linfocitos B/metabolismo , Células T Auxiliares Foliculares/inmunología , Células T Auxiliares Foliculares/metabolismo , Receptores de Complemento 3d/metabolismo , Receptores de Complemento 3d/análisis , Antígenos CD20/metabolismo , Antígenos CD20/análisis , Linfoma de Células T Periférico/diagnóstico , Linfoma de Células T Periférico/patología , Antígenos CD4/metabolismo , Sensibilidad y Especificidad , Anciano de 80 o más Años , Inmunohistoquímica/métodos , Curva ROCRESUMEN
Acetylcholine is produced in the spleen in response to vagus nerve activation; however, the effects on antibody production have been largely unexplored. Here, we use a chronic vagus nerve stimulation (VNS) mouse model to study the effect of VNS on T-dependent B cell responses. We observed lower titers of high-affinity IgG and fewer antigen-specific germinal center (GC) B cells. GC B cells from chronic VNS mice exhibited altered mRNA and protein expression suggesting increased apoptosis and impaired plasma cell differentiation. Follicular dendritic cell (FDC) cluster dispersal and altered gene expression suggested poor function. The absence of acetylcholine-producing CD4+ T cells diminished these alterations. In vitro studies revealed that α7 and α9 nicotinic acetylcholine receptors (nAChRs) directly regulated B cell production of TNF, a cytokine crucial to FDC clustering. α4 nAChR inhibited coligation of CD19 to the B cell receptor, presumably decreasing B cell survival. Thus, VNS-induced GC impairment can be attributed to distinct effects of nAChRs on B cells.
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Linfocitos B , Centro Germinal , Receptores Nicotínicos , Estimulación del Nervio Vago , Receptor Nicotínico de Acetilcolina alfa 7 , Animales , Centro Germinal/metabolismo , Centro Germinal/inmunología , Estimulación del Nervio Vago/métodos , Linfocitos B/metabolismo , Linfocitos B/inmunología , Ratones , Receptores Nicotínicos/metabolismo , Receptores Nicotínicos/genética , Receptor Nicotínico de Acetilcolina alfa 7/metabolismo , Receptor Nicotínico de Acetilcolina alfa 7/genética , Células Dendríticas Foliculares/metabolismo , Células Dendríticas Foliculares/inmunología , Receptores Colinérgicos/metabolismo , Receptores Colinérgicos/inmunología , Receptores de Antígenos de Linfocitos B/metabolismo , Diferenciación Celular , Ratones Endogámicos C57BL , Inmunoglobulina G/inmunología , Nervio Vago/metabolismo , Nervio Vago/fisiología , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD4-Positivos/inmunologíaRESUMEN
Autoimmune diseases strain healthcare systems worldwide as their incidence rises, and current treatments put patients at risk for infections. An increased understanding of autoimmune diseases is required to develop targeted therapies that do not impair normal immune function. Many autoimmune diseases present with autoantibodies, which drive local or systemic inflammation. This indicates the presence of autoreactive B cells that have escaped tolerance. An important step in the development of autoreactive B cells is the germinal center (GC) reaction, where they undergo affinity maturation toward cognate self-antigen. Follicular dendritic cells (FDCs) perform the essential task of antigen presentation to B cells during the affinity maturation process. However, in recent years, it has become clear that FDCs play a much more active role in regulation of GC processes. Here, we evaluate the biology of FDCs in the context of autoimmune disease, with the goal of informing future therapeutic strategies.
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Enfermedades Autoinmunes , Células Dendríticas Foliculares , Humanos , Autoinmunidad , Centro Germinal , Linfocitos BRESUMEN
Follicular dendritic cell sarcoma (FDCS) is a rare tumor, which mainly originates from follicular dendritic cells (FDCs) in the lymph nodes. Sometimes FDCS can arise from outside the lymph nodes. FDCS is an extremely rare malignant tumor in intraperitoneal or retroperitoneal tissue. We gathered the detailed clinical data of three patients diagnosed with FDCS in the abdomen. The clinical observations and histopathologic and immunohistochemical features of FDCS were analyzed. The patients included two men and one woman aged 55 ~ 61 years old. The mesentery of the small intestine and colon was involved in case 1, spleen in case 2, and retroperitoneal tissues in case 3. Two patients presented with abdominal masses, and one presented with no obvious symptoms. Histology showed ovoid to spindle neoplastic cells arranged in fascicles and storiforms with inflammatory infiltrate as well as whorled patterns in some areas. Immunohistochemical staining was positive for CD21, CD23, CD35, and SSTR2. FDCS exhibits no characteristic clinical manifestations. Morphologically, FDCS can have overlapping features with many other entities, leading to misdiagnosis. The use of histopathology supplemented with FDC markers, such as CD21, CD23, and CD35, is useful for diagnosis and differential diagnosis.
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Sarcoma de Células Dendríticas Foliculares , Masculino , Femenino , Humanos , Persona de Mediana Edad , Sarcoma de Células Dendríticas Foliculares/diagnóstico , Sarcoma de Células Dendríticas Foliculares/patología , Células Dendríticas Foliculares/patología , Ganglios Linfáticos/patología , Intestino Delgado/patología , Diagnóstico DiferencialRESUMEN
Nerve growth factor receptor (NGFR) is expressed by follicular dendritic cells (FDCs). However, the role of NGFR in the humoral response is not well defined. Here, we study the effect of Ngfr loss on lymph node organization and function, demonstrating that Ngfr depletion leads to spontaneous germinal center (GC) formation and an expansion of the GC B cell compartment. In accordance with this effect, stromal cells are altered in Ngfr-/- mice with a higher frequency of FDCs, characterized by CD21/35, MAdCAM-1, and VCAM-1 overexpression. GCs are located ectopically in Ngfr-/- mice, with lost polarization together with impaired high-affinity antibody production and an increase in circulating autoantibodies. We observe higher levels of autoantibodies in Bcl2 Tg/Ngfr-/- mice, concomitant with a higher incidence of autoimmunity and lower overall survival. Our work shows that NGFR is involved in maintaining GC structure and function, participating in GC activation, antibody production, and immune tolerance.
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Receptor de Factor de Crecimiento Nervioso , Receptores de Factor de Crecimiento Nervioso , Animales , Ratones , Autoanticuerpos , Células Dendríticas Foliculares , Centro GerminalRESUMEN
Humanized immune system (HIS) mice have been developed and used as a small surrogate model to study human immune function under normal or disease conditions. Although variations are found between models, most HIS mice show robust human T cell responses. However, there has been unsuccessful in constructing HIS mice that produce high-affinity human antibodies, primarily due to defects in terminal B cell differentiation, antibody affinity maturation, and development of primary follicles and germinal centers. In this review, we elaborate on the current knowledge about and previous attempts to improve human B cell development in HIS mice, and propose a potential strategy for constructing HIS mice with improved humoral immunity by transplantation of human follicular dendritic cells (FDCs) to facilitate the development of secondary follicles.
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Formación de Anticuerpos , Centro Germinal , Humanos , Ratones , Animales , Células Dendríticas Foliculares , Inmunidad Humoral , Linfocitos TRESUMEN
EBV-positive inflammatory follicular dendritic cell sarcoma (EBV+ inflammatory FDCS) is a rare neoplasm almost exclusively located in the spleen or liver. It is characterized by a proliferation of EBV-positive spindle-shaped cells bearing follicular dendritic cell markers, associated with an abundant lymphoplasmacytic infiltrate. EBV+ inflammatory FDCS is often asymptomatic or responsible for mild symptoms. It usually displays an indolent course and its prognosis is excellent after tumor removal, although relapsing and metastatic forms exist. Herein, we describe an aggressive form of splenic EBV+ inflammatory FDCS in a 79-year-old woman presenting with abdominal pain, deterioration of general health status, major inflammatory syndrome, and symptomatic hypercalcemia. A splenectomy was performed leading to a rapid improvement in her clinical condition and normalization of laboratory abnormalities. Unfortunately, her symptoms and laboratory abnormalities reappeared 4 months later. Computed tomography showed a mass in the splenectomy site and multiple liver and peritoneal nodules. Further analyses were performed on tumor tissue and showed positive phospho-ERK staining of tumoral cells indicating activation of MAPK pathway. Inactivating mutations were found on CDKN2A and NF1 genes. Subsequently, the patient's condition deteriorated rapidly. Since interleukin-6 levels were dramatically increased, tocilizumab was used but only had a transient effect on the patient's symptoms and inflammatory syndrome. Antitumor agent gemcitabine was initiated but her clinical condition continued to deteriorate and the patient died 2 weeks later. The management of aggressive forms of EBV+ inflammatory FDCS remains challenging. However, since these tumors seem to display genetic alterations, better characterization could lead to molecular targeted therapies.
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Sarcoma de Células Dendríticas Foliculares , Neoplasias de los Tejidos Blandos , Femenino , Humanos , Anciano , Sarcoma de Células Dendríticas Foliculares/diagnóstico , Sarcoma de Células Dendríticas Foliculares/genética , Sarcoma de Células Dendríticas Foliculares/metabolismo , Bazo/patología , Herpesvirus Humano 4/genética , Recurrencia Local de Neoplasia/patología , Células Dendríticas Foliculares/metabolismo , Células Dendríticas Foliculares/patología , Neoplasias de los Tejidos Blandos/patologíaRESUMEN
This study aimed to explore the role of Akt protein in the induction and inhibition of prostaglandin (PG) in human follicular dendritic cell (FDC)-like cells. FDC-like cells and B cells were isolated from human tonsils. PG production was assessed using enzyme immunoassay, while the upstream cyclooxygenase-2 (COX-2) protein levels were measured using immunoblotting with FDC-like cells transfected with Akt siRNA to analyze the impact of Akt knockdown. The COX-2 expression and PG production induced with IL-1ß were significantly increased by Akt knockdown. However, IL-1ß did not significantly alter either total or phosphorylated Akt protein levels. Akt knockdown resulted in the augmentation of COX-2 expression induced by B cells, although the addition of B cells did not significantly modulate both total and phosphorylated Akt proteins. In contrast, IL-4 specifically exhibited a potent inhibitory effect on COX-2 protein induction and PG production via STAT6. The inhibitory activity of IL-4 was not hampered by Akt knockdown. Interestingly, COX-2 expression levels induced with IL-1ß were markedly modulated with STAT1 and STAT3 knockdown. STAT1 silencing resulted in further augmentation of COX-2, whereas STAT3 silencing prohibited IL-1ß from stimulating COX-2 expression. The current results suggest that Akt, IL-4, and STAT1 play inhibitory roles in PG production in FDC-like cells and expand our knowledge of the immune inflammatory milieu.
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Células Dendríticas Foliculares , Interleucina-4 , Humanos , Células Cultivadas , Ciclooxigenasa 2/metabolismo , Células Dendríticas Foliculares/metabolismo , Interleucina-1beta/metabolismo , Interleucina-4/metabolismo , Prostaglandinas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factores de Transcripción STAT/metabolismoRESUMEN
Follicular lymphoma (FL) is the most frequent indolent lymphoma and is characterized by the abundant infiltration of tumor microenvironment (TME) cells. The activity of TME cells reportedly plays an important role in the biology of FL. TME cells that reside within neoplastic follicles, such as T-follicular helper cells and follicular dendritic cells, have been shown to aid in FL development and progression through interactions with malignant B cells, whereas regulatory T cells have unexpectedly shown an apparently favorable prognostic impact in FL. Unfortunately, the understanding of the FL TME, particularly regarding minor cell subsets, has been hampered by unknown cell heterogeneity. As with other solid and hematologic cancers, novel single-cell analysis technologies have recently been applied to FL research and have uncovered previously unrecognized heterogeneities, not only in malignant B cells but also in TME cells. These reports have greatly increased the resolution of our understanding of the FL TME and, at the same time, raised questions about newly identified TME cells. This review provides an overview of the unique aspects of FL TME cells with a clinical viewpoint and highlights recent discoveries from single-cell analysis, while also suggesting potential future directions.
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Linfoma Folicular , Linfoma no Hodgkin , Humanos , Linfoma Folicular/patología , Células Dendríticas Foliculares , Pronóstico , Microambiente TumoralRESUMEN
In this protocol, we detail how to isolate and purify human follicular dendritic cells (FDCs) from lymphoid tissues. FDCs play a vital role in antibody development by presenting antigens to B cells in germinal centers. The assay involves enzymatic digestion and fluorescence-activated cell sorting and is successfully applied to various lymphoid tissues, including tonsils, lymph nodes, and tertiary lymphoid structures. Our robust technique enables the isolation of FDCs and facilitates downstream functional and descriptive assays. For complete details on the use and execution of this protocol, please refer to Heesters et al.1.
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Células Dendríticas Foliculares , Centro Germinal , Humanos , Ganglios Linfáticos , Linfocitos B , Citometría de FlujoRESUMEN
Germinal centers (GCs) are some of the most important structures in the human immune system. As such, their cell types and functions have been thoroughly investigated. B cells, T cells, follicular dendritic cells (FDCs), and macrophages have widely been found to typically be aggregated in GCs. However, the amount of space occupied by each of these cell types has yet to be investigated. In this study, we conducted confocal laser-based 3D cell-volume quantification of typical GC cells under reactive conditions in lymphadenitis and investigated how volume proportions change during GC development. For this investigation, we used anti-CD3 (T cells), anti-CD20 and anti-Pax5 (B cells), anti-CD23 (FDCs), anti-CD68 (macrophages), and DAPI (nuclear staining). We detected average proportions of about 11% CD3, 9% CD20, 6% CD23, and 2% CD68 in the largest possible regions of interest within GCs. Interestingly, these values remained steady relatively independent of GC size. The remarkably low B cell proportion can be attributed to technical constraints given the use of the CD20 antibody in 3D. Applying the B cell marker Pax5, we found that about 44% of the volume was occupied by B cells after extrapolating the volume of B cell nuclei to that of whole B cells. We concluded that Pax5 is more suitable than anti-CD20 for 3D B cell quantification in GCs. The substantial unstained volume in GCs raises the question of whether other cell types fill these open spaces. Our 3D investigation enabled a unique morphological and volumetric evaluation of GC cells that balance their overall volumes in GCs.
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Células Dendríticas Foliculares , Linfadenitis , Humanos , Células Dendríticas Foliculares/metabolismo , Linfocitos T , Centro Germinal , Macrófagos , Linfadenitis/metabolismoRESUMEN
Germinal centers (GCs) require sustained availability of antigens to promote antibody affinity maturation against pathogens and vaccines. A key source of antigens for GC B cells are immune complexes (ICs) displayed on follicular dendritic cells (FDCs). Here we show that FDC spatial organization regulates antigen dynamics in the GC. We identify heterogeneity within the FDC network. While the entire light zone (LZ) FDC network captures ICs initially, only the central cells of the network function as the antigen reservoir, where different antigens arriving from subsequent immunizations colocalize. Mechanistically, central LZ FDCs constitutively express subtly higher CR2 membrane densities than peripheral LZ FDCs, which strongly increases the IC retention half-life. Even though repeated immunizations gradually saturate central FDCs, B cell responses remain efficient because new antigens partially displace old ones. These results reveal the principles shaping antigen display on FDCs during the GC reaction.
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Células Dendríticas Foliculares , Centro Germinal , Antígenos , Linfocitos B , Complejo Antígeno-Anticuerpo/metabolismoRESUMEN
Background and Objectives: Even if they are cells of controversial origin (mesenchymal, perivascular, or fibroblastic), follicular dendritic cells (FDC) are present in all organs. The aim of this study was to establish the FDC expression pattern and its interrelation with HPV 18 expression in laryngeal squamous cell carcinoma (LSCC). Materials and Methods: Fifty-six cases of LSCC were evaluated by simple and double immunostaining. The following score was used: 0 (negative or few positive cells), 1 (10-30% of positive cells), 2 (30-50% of cells), and 3 (over 50% of cells). Results: The expression of CD 21-positive cells with dendritic morphology (CDM) was noticed in the intratumoral area of conventional (well and poorly differentiated types and HPV 18 positive cases with a value of 2 for the score) and papillary types (HPV-18 negative cases with a score of 1). The highest value of 2 for the score of CDM in HPV-18 positive cases was found in the peritumoral area of well- and poorly-differentiated conventional LSCCs. A significant correlation was found between scores of CDM from the intratumoral area and those of the peritumoral area (p = 0.001), between CDM and non-dendritic morphology cells (NDM) of the intratumoral area (p = 0.001), and between HPV-18 status and peritumoral NDM cells (p = 0.044). Conclusions: The FDC and NDM cell score values of intratumoral and peritumoral areas may represent important parameters of LSCCs. This may contribute to a better stratification of laryngeal carcinoma cases and the individualized selection of clinical treatment protocols.
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Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Laringe , Infecciones por Papillomavirus , Humanos , Carcinoma de Células Escamosas de Cabeza y Cuello , Papillomavirus Humano 18 , Carcinoma de Células Escamosas/patología , Células Dendríticas Foliculares/metabolismo , Células Dendríticas Foliculares/patología , Laringe/metabolismo , Laringe/patologíaRESUMEN
B cell zone reticular cells (BRCs) form stable microenvironments that direct efficient humoral immunity with B cell priming and memory maintenance being orchestrated across lymphoid organs. However, a comprehensive understanding of systemic humoral immunity is hampered by the lack of knowledge of global BRC sustenance, function and major pathways controlling BRC-immune cell interactions. Here we dissected the BRC landscape and immune cell interactome in human and murine lymphoid organs. In addition to the major BRC subsets underpinning the follicle, including follicular dendritic cells, PI16+ RCs were present across organs and species. As well as BRC-produced niche factors, immune cell-driven BRC differentiation and activation programs governed the convergence of shared BRC subsets, overwriting tissue-specific gene signatures. Our data reveal that a canonical set of immune cell-provided cues enforce bidirectional signaling programs that sustain functional BRC niches across lymphoid organs and species, thereby securing efficient humoral immunity.
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Linfocitos B , Células del Estroma , Ratones , Humanos , Animales , Inmunidad Humoral , Células Dendríticas Foliculares , HomeostasisRESUMEN
BACKGROUND: Renal cell carcinoma (RCC), one of the top 10 causes of cancer death, is responsible for more than 90% of all cases of primary renal cancer worldwide. Follicular dendritic cell-secreted protein (FDC-SP) specifically binds to activated B cells and regulates the generation of antibodies. It is also thought to promote cancer cell invasion and migration, which could help with tumor metastases. This study aimed to assess the efficacy of FDC-SP in the diagnosis and prognosis of RCC and to investigate the relationship between immune infiltration in RCC and these outcomes. RESULTS: RCC tissues had significantly higher levels of FDC-SP protein and mRNA than normal tissues. The high level of FDC-SP expression was linked to the T stage, histological grade, pathological stage, N stage, M stage, and OS event. Functional enrichment analysis identified the major pathways that were enriched as immune response regulation, complement, and coagulation. Immunological checkpoints and immune cell infiltration were observed to substantially correlate with the levels of FDC-SP expression. FDC-SP expression levels showed the ability to precisely distinguish high-grade or high-stage renal cancer (area under the curve (AUC) = 0.830, 0.722), and RCC patients with higher FDC-SP expression levels had worse prognoses. The AUC values for one-, two-, and five-year survival rates were all greater than 0.600. Moreover, the FDC-SP expression is an independent predictive biomarker of OS in RCC patients. CONCLUSION: FDC-SP may be a prospective therapeutic target in RCC as well as a possible diagnostic and prognostic biomarker associated with immune infiltration.
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Carcinoma de Células Renales , Neoplasias Renales , Humanos , Carcinoma de Células Renales/patología , Células Dendríticas Foliculares/metabolismo , Células Dendríticas Foliculares/patología , Pronóstico , Proteínas/metabolismo , Neoplasias Renales/patologíaRESUMEN
A variety of B cell clones seed the germinal centers, where a selection stringency expands the fitter clones to generate higher affinity antibodies. However, recent experiments suggest that germinal centers often retain a diverse set of B cell clones with a range of affinities and concurrently carry out affinity maturation. Amid a tendency to flourish germinal centers with fitter clones, how several B cell clones with differing affinities can be concurrently selected remains poorly understood. Such a permissive selection may allow non-immunodominant clones, which are often rare and of low-affinity, to somatically hypermutate and result in a broad and diverse B cell response. How the constituent elements of germinal centers, their quantity and kinetics may modulate diversity of B cells, has not been addressed well. By implementing a state-of-the-art agent-based model of germinal center, here, we study how these factors impact temporal evolution of B cell clonal diversity and its underlying balance with affinity maturation. While we find that the extent of selection stringency dictates clonal dominance, limited antigen availability on follicular dendritic cells is shown to expedite the loss of diversity of B cells as germinal centers mature. Intriguingly, the emergence of a diverse set of germinal center B cells depends on high affinity founder cells. Our analysis also reveals a substantial number of T follicular helper cells to be essential in balancing affinity maturation with clonal diversity, as a low number of T follicular helper cells impedes affinity maturation and also contracts the scope for a diverse B cell response. Our results have implications for eliciting antibody responses to non-immunodominant specificities of the pathogens by controlling the regulators of the germinal center reaction, thereby pivoting a way for vaccine development to generate broadly protective antibodies.
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Centro Germinal , Células T Auxiliares Foliculares , Linfocitos B , Antígenos , Células Dendríticas FolicularesRESUMEN
Follicular dendritic cell sarcoma (FDCS) is a rare malignant neoplasm, postulated to arise from follicular dendritic cells, with approximately 343 reported cases. Less than 100 cases of FDCS were in the gastrointestinal tract, with only four cases described in the stomach, none of them diagnosed on fine needle aspiration (FNA) cytology. We report here the first case of FDCS of the stomach diagnosed on FNA. Our patient is a 31-year-old male who presented with several years history of intermittent abdominal pain prompting occasional emergency-room visits. Imaging showed a 10.6 cm mass arising from the stomach, concerning for gastrointestinal stromal tumor. FNA cytology was performed using five passes with a 22-gauge needle. The smears were moderately cellular consisting of sheets and large, loosely cohesive clusters of ovoid to spindle cells with indistinct cytoplasmic borders and abundant cytoplasm, peppered with numerous small mature lymphocytes. The nuclei of the tumor cells were oval with finely granular chromatin with frequent nuclear grooves, pseudoinclusions, and easily recognizable mitotic figures. The tumor cells were positive for FDCS markers (CD21, CD23, and CD35).
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Sarcoma de Células Dendríticas Foliculares , Tumores del Estroma Gastrointestinal , Masculino , Humanos , Adulto , Sarcoma de Células Dendríticas Foliculares/diagnóstico , Sarcoma de Células Dendríticas Foliculares/patología , Biopsia con Aguja Fina , Tumores del Estroma Gastrointestinal/diagnóstico , Tumores del Estroma Gastrointestinal/patología , Células Dendríticas Foliculares/patología , Estómago/patologíaRESUMEN
BACKGROUND: Follicular dendritic cell sarcoma is a malignant neoplasm derived from germinal center follicular dendritic cells, which both share a characteristic immunophenotype (namely CD21, CD23, and CD35). Cytomorphologic descriptions are few, consisting of only 26 prior cases from 24 publications. Identification by cytologic means appears challenging as the majority of previous reports disclose an erroneous or indeterminate initial cytologic diagnosis. Herein, we present the largest cytology series to date with the aim of expanding upon this small body of literature and discuss possible factors resulting in misinterpretation. MATERIALS AND METHODS: A retrospective search was conducted from 2 academic medical centers to identify histologically confirmed cases of follicular dendritic cell sarcoma with an associated cytologic component. Clinicopathologic data were tabulated and a comparative analysis of cytomorphologic and immunohistochemical features was performed. RESULTS: Seven separate cases were identified. All cases showed cohesive tumor cells with a characteristic voluminous, ill-defined cytoplasm with interconnecting fibrillary processes and intimately admixed mature lymphocytes. Features were maintained across various cytologic preparations, including conventional smear, liquid-based cytology, and touch imprint. Unusual immunohistochemical profiles were noted in a subset of cases. CONCLUSIONS: Cytomorphology is highly conserved across cases and preparations; however, a propensity for aberrant immunoexpression may contribute to diagnostic errors. Cytomorphologic features, supported by immunohistochemistry, suggest fine-needle aspiration as a reasonable diagnostic modality. Tumors with these features should include CD21, CD23, and/or CD35 in the workup.
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Sarcoma de Células Dendríticas Foliculares , Humanos , Sarcoma de Células Dendríticas Foliculares/diagnóstico , Sarcoma de Células Dendríticas Foliculares/patología , Estudios Retrospectivos , Células Dendríticas Foliculares/patología , Biopsia con Aguja Fina , InmunohistoquímicaRESUMEN
Extranodal follicular dendritic cell sarcomas are infrequent diagnostically challenging tumors. Because of their rarity, heterogeneous histomorphologic features and variable histologic grades a significant number of extranodal lesions are prone to be misdiagnosed. Even though they have a characteristic immunoprofile, expression of a range of nonspecific markers is well documented. Even though they are typically negative for keratins, few authors have reported lesions expressing keratin. Keratin expressing tumors are more likely to be misinterpreted by pathologists further deterring their inclusion in the differential diagnosis. We report an intraabdominal mesenteric follicular dendritic cell sarcoma in a 44-year-old male that immunophenotypically expressed keratin antigens. The lesion showed a high-grade pleomorphic epithelioid appearance and the initial differential diagnosis included lymphoma, sarcomas, melanoma, and carcinomas. Follicular dendritic cell sarcoma was not considered. Expression of epithelial membrane antigen and keratin further deterred the diagnosis which was reached only after extensive use of immunomarkers. The tumor cells expressed CD21, CD23, and D2-40. Morphologically, the tumor showed some thymoma-like features with occasional TDT-expressing background T-lymphocytes. These features were hints to reconsider our differential diagnosis to include follicular dendritic cell tumors. Awareness of this aberrant staining of epithelial immunomarkers and attention to certain clues should encourage pathologists to consider this entity. Speculative assumptions may explain this unusual keratin expression in some lesions. The histomorphologic and immunohistochemical heterogeneity may suggest different variants and grades of follicular dendritic cell sarcomas. The prevalence, importance, and histogenesis of keratin expression in follicular dendritic cell sarcomas warrant further studies.