Doença de Castleman multicêntrica: Relato de um caso

Castleman's disease (CD) is an uncommon lymphoproliferative disorder that is morphologically and clinically heterogeneous. Both a localized benign variant and a multicentric form with systemic manifestations have been described. Although there are many published cases in literature, there are a few reports about this pathology in Brazil. We describe a patient with several manifestations of multicentric CD: lymphadenopathy, weight loss, fever, arthralgia, myalgia, and hepatosplenomegaly. Pathological examination of excised cervical lymph node revealed its rarest form: a CD of the hyaline-vascular type in multicentric presentation.

K1 protein of human herpesvirus 8 suppresses lymphoma cell Fas-mediated apoptosis.

Expression of the K1 gene of human herpesvirus 8 activates nuclear factor-kappaB and induces lymph node hyperplasia and lymphomas in transgenic mice. To further delineate its role in cell survival, we determined whether K1 altered apoptosis of lymphoma cells. K1 protein is expressed in Kaposi sarcoma and primary effusion lymphoma. We retrovirally transfected BJAB lymphoma, THP-1, U937, and Kaposi sarcoma SLK cells to express K1 and a K1 mutant with the deleted immunoreceptor tyrosine-based activation motif (K1m). We challenged cells with an agonistic anti-Fas antibody, Fas ligand, irradiation, and tumor necrosis factor-related apoptosis-inducing ligand. K1 transfectants but not K1m transfectants exhibited reduced levels of apoptosis induced by the anti-Fas antibody but not apoptosis induced by the tumor necrosis factor-related apoptosis-inducing ligand or irradiation. K1 expression resulted in reduced apoptosis rates as shown in several assays. K1 induced a modest reduction in levels of Fas-associated death domain protein, and procaspase 8 recruited to the death-inducing signaling complex. Finally, K1 transfectants cleaved procaspase 8 at significantly lower rates than did K1m transfectants. K1-transfected mice, compared with vector-transfected mice, showed lower death rates after challenge with anti-Fas antibody. K1 may contribute to lymphoma development by stimulating cell survival by selectively blocking Fas-mediated apoptosis.

Trapping of naive lymphocytes triggers rapid growth and remodeling of the fibroblast network in reactive murine lymph nodes.

Adaptive immunity is initiated in T-cell zones of secondary lymphoid organs. These zones are organized in a rigid 3D network of fibroblastic reticular cells (FRCs) that are a rich cytokine source. In response to lymph-borne antigens, draining lymph nodes (LNs) expand several folds in size, but the fate and role of the FRC network during immune response is not fully understood. Here we show that T-cell responses are accompanied by the rapid activation and growth of FRCs, leading to an expanded but similarly organized network of T-zone FRCs that maintains its vital function for lymphocyte trafficking and survival. In addition, new FRC-rich environments were observed in the expanded medullary cords. FRCs are activated within hours after the onset of inflammation in the periphery. Surprisingly, FRC expansion depends mainly on trapping of naïve lymphocytes that is induced by both migratory and resident dendritic cells. Inflammatory signals are not required as homeostatic T-cell proliferation was sufficient to trigger FRC expansion. Activated lymphocytes are also dispensable for this process, but can enhance the later growth phase. Thus, this study documents the surprising plasticity as well as the complex regulation of FRC networks allowing the rapid LN hyperplasia that is critical for mounting efficient adaptive immunity.

Spectrum of Morphologic Changes of Lymph Nodes in HIV Infection

Cervical lymph nodes biopsies from 31 HIV positive patients (with or without AIDS) were studied by histologic methods and immunohistochemistry (StreptABC staining of paraffin sections) to identify cellular and extracellular matrix components. The results were the following: (1) the biopsies were included in the stages of follicular hyperplasia without fragmentation FH-FF (4 cases); follicular hyperplasia with follicular fragmentation FH+FF (16 cases); follicular involution FI (6 cases) and diffuse pattern DP (5 cases); (2) the most important alteration was the germinal centers disruption due to follicle lysis, which began in the light zone; (3) there was coincidence between intrafollicular hemorrhages and segmental hyaline mycroangiopathy; (4) during the progression of the disease occurred: (a) an increase in the number of mast cells, CD68+ and Mac387+ macrophages; (b) a diffuse augment of collagen III, elastic fibers, laminin, fibronectin and proteoglycans; (c) maintenance of Factor VIII - related antigens in the vascular endothelial cells, with decrease in the expression of Ulex-Europeus I lectin. Follicular hyperplasia (FH-FF or FH+FF) was the most common histologic pattern recognized in the lymph nodes of patients without AIDS and follicular involution and difuse pattern were seen in those who had AIDS. The results indicate that the lymph node biopsies may provide important information about the evolutive stage of the disease and its prognosis.

Effect of antiretroviral therapy on apoptosis markers and morphology in peripheral lymph nodes of HIV-infected individuals.

BACKGROUND: CD4+ T cell depletion and destruction and the involution of the lymphoid tissue are hallmarks of HIV infection. Although the underlying mechanisms are still unclear, apoptosis appears to play a central role. The objective of this study was to investigate the effect of antiretroviral therapy on the lymph node tissue, particularly with respect to morphology and apoptosis. PATIENTS AND METHODS: Between 1997 and 1999, two inguinal lymph nodes were excised from 31 previously untreated individuals who were in an early stage of HIV infection, the first one prior to treatment and the second after 16 to 20 months of treatment. Paraffin sections were investigated for lymph node architecture, distribution of cellular and viral markers, apoptosis, and expression of apoptotic key molecules which indirectly reflect apoptotic processes. RESULTS: After 16-20 months of antiretroviral therapy, a significant decrease in highly activated HIV-driven immune response was observed in the lymph node tissue as a marked reduction in follicular hyperplasia, a normalization of the follicular dendritic cell network, a significant increase in the number of CD4+ T cells, and a significant decrease in the number of CD8+ T cells. The expression of several proapoptotic (Fas, TRAIL, and active caspase 3) and antiapoptotic (Bcl-2 and IL-7Ralpha) molecules that were reconstituted in the tissues during therapy resembled their expression in lymph nodes of HIV-negative individuals. Limitations of the study are (a) the lack of untreated patients in the late stages, (b) for ethical reasons, the lack of a control group with untreated patients, and (c) for methodological reasons, the restriction of sequential measurements of apotpotic markers to one-third of the patients. CONCLUSION: Antiretroviral therapy initiated in the early stages in HIV infection may halt the irreversible destruction of the lymph node tissue and may partially normalize apoptotic processes.

Giant proliferating trichilemmal malignant tumor

Proliferating trichilemmal cyst is a benign tumor that originates in the outer root sheath of hair follicle. Usually, it is located on the scalp in older women, but also have been reported in other sites such as back, chest, axilla, groin, gluteal region, thigh, vulva, and face. Malignant transformation of proliferating trichilemmal cyst is confirmed only on histological findings. This tumor has a variable biologic behavior with local recurrence and lymph node metastasis.

A study of the effect of sartorius transposition on lymph flow after ilioinguinal node dissection.

Ilioinguinal dissection is associated with a high rate of lymphatic complications. Prolonged lymph flow causes greatest concern and preventive strategies are needed. A retrospective study of 28 consecutive patients undergoing groin dissection for melanoma metastases was performed to evaluate the influence of sartorius muscle transposition on lymph flow. Modification of the surgical technique with transposition of the sartorius muscle was not associated with reduced drainage time (P = 0.66). A 2-staged approach, with initial sentinel lymph node resection and lymph node dissection in a second operation, however, lead to shortened duration of the lymph flow (P = 0.01). Prolonged lymphorrhea was more frequent in older (P = 0.03), obese (P = 0.02) patients affected by diabetes mellitus (P = 0.03) and hypertension (P = 0.04).

Immune response pattern of the popliteal lymph nodes of dogs with visceral leishmaniasis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of aspirin on mesenteric lymph nodes of rabbits as basis for its use on lymph nodes metastases

OBJETIVO: Avaliar os efeitos do ácido acetilsalicílico a 10% e 20% em linfonodos mesentéricos de coelhos para posterior embasamento e uso em metástases linfonodais. MÉTODOS: Um total de 20 linfonodos de 20 coelhos (divididos aleatoriamente em quatro grupos) foi avaliado. As soluções de aspirina a 10% (grupos A e C) e 20% (grupos B e D) foram injetadas em linfonodos mesentéricos de coelhos sadios e seus efeitos macroscópicos e histológicos foram avaliados em 24 horas (grupos A e B) e em sete dias (grupos C e D). RESULTADOS: Nos grupos avaliados em 24 horas (A e B) foi verificada intensa necrose e hemorragia, aumento importante de apoptose em todo o linfonodo, com alargamento dos seios medulares e aumento dos centros germinativos. Nos grupos avaliados em sete dias (C e D) também houve aumento da apoptose, com maior elevação de histiócitos e diminuição importante da necrose; a hemorragia foi ausente e aumento de células gigantes foi visualizado, conferindo processo inflamatório crônico do tipo corpo estranho. Não houve diferença entre as concentrações utilizadas (10 e 20%) em nenhuma das comparações. CONCLUSÕES: A injeção de aspirina em linfonodos causou necrose e um aumento de apoptose após 24 horas e após sete dias de tratamento, houve regeneração dos gânglios linfáticos, com diminuição intensa de necrose e grande aumento de apoptose. Uma vez que o aumento de apoptose é um dos pilares dos tratamentos antineoplásicos, estes resultados experimentais embasam eventual aplicação clínica da aspirina no tratamento de metástases linfonodais.

IMMUNOCYTOCHEMICAL DIFFERENTIATION OF REACTIVE HYPERPLASIA FROM FOLLICULAR LYMPHOMA USING MONOCLONAL-ANTIBODIES TO CELL-SURFACE AND PROLIFERATION-RELATED MARKERS

We tested the hypothesis that a panel of antibodies to cell surface, cytoplasmic, and nuclear antigens could reliably distinguish the cells composing reactive germinal centers from those composing follicular lymphoma. Immunocytochemistry was performed on deparaffinized sections of methacarn-fixed lymph node and tonsil (15 cases of reactive hyperplasia and 14 cases of follicular lymphoma) using antibodies to the nerve growth factor receptor (NGFR5), bcl-2 protein (124), proliferating cell nuclear antigen (PCNA; 19A2), and CD45RA (MT2). In 100% of cases of reactive hyperplasia, both MT2 and 124 showed positive immunostaining of mantle zone and scattered interfollicular lymphocytes, but in all cases there was a sharply demarcated absence of immunostaining of germinal center cells. However, diffuse immunostaining of follicular centers with MT2 (64%) and 124 (93%) and scattered intervening cells were seen in follicular lymphoma. The combination of antibodies to CD45RA and bcl-2 yielded positive immunostaining of follicular center cells in 93% of follicular lymphomas. The germinal center cells of reactive hyperplasia showed >75% nuclear positivity with antibodies to PCNA, in contrast to the follicular lymphoma cells, which showed variable PCNA indices ranging from 25 to >75%. A minority of follicular lymphoma cases (29%) showed PCNA indices comparable with those seen in cases of reactive hyperplasia. Antibodies to NGFR were positive in all cases of reactive hyperplasia and in 79% of cases of follicular hyperplasia, although the immunostaining intensity was generally decreased in follicular hyperplasia. In summary, antibodies to bcl-2 appear to be superior to those to CD45RA in distinguishing reactive hyperplasia from follicular lymphoma. Reactive hyperplasia cannot be discriminated from follicular hyperplasia using antibodies to PCNA or to nerve growth factor receptor.

Does quantification of USPIO uptake-related signal loss allow differentiation of benign and malignant normal-sized pelvic lymph nodes?

Ultrasmall superparamagnetic iron oxide (USPIO) particles are promising contrast media, especially for molecular and cellular imaging besides lymph node staging owing to their superior NMR efficacy, macrophage uptake and lymphotropic properties. The goal of the present prospective clinical work was to validate quantification of signal decrease on high-resolution T(2)-weighted MR sequences before and 24-36 h after USPIO administration for accurate differentiation between benign and malignant normal-sized pelvic lymph nodes. Fifty-eight patients with bladder or prostate cancer were examined on a 3 T MR unit and their respective lymph node signal intensities (SI), signal-to-noise (SNR) and contrast-to-noise (CNR) were determined on pre- and post-contrast 3D T(2)-weighted turbo spin echo (TSE) images. Based on histology and/or localization, USPIO-uptake-related SI/SNR decrease of benign vs malignant and pelvic vs inguinal lymph nodes was compared. Out of 2182 resected lymph nodes 366 were selected for MRI post-processing. Benign pelvic lymph nodes showed a significantly higher SI/SNR decrease compared with malignant nodes (p < 0.0001). Inguinal lymph nodes in comparison to pelvic lymph nodes presented a reduced SI/SNR decrease (p < 0.0001). CNR did not differ significantly between benign and malignant lymph nodes. The receiver operating curve analysis yielded an area under the curve of 0.96, and the point with optimal accuracy was found at a threshold value of 13.5% SNR decrease. Overlap of SI and SNR changes between benign and malignant lymph nodes were attributed to partial voluming, lipomatosis, histiocytosis or focal lymphoreticular hyperplasia. USPIO-enhanced MRI improves the diagnostic ability of lymph node staging in normal-sized lymph nodes, although some overlap of SI/SNR-changes remained. Quantification of USPIO-dependent SNR decrease will enable the validation of this promising technique with the final goal of improving and individualizing patient care.

Direct Detection of Mycobacterium bovis in Bovine Lymph Nodes by PCR

P>Thirty-five lymph node samples were taken from animals with macroscopic lesions consistent with Mycobacterium bovis infection. The animals were identified by postmortem examination in an abattoir in the northwestern region of state of Parana, Brazil. Twenty-two of the animals had previously been found to be tuberculin skin test positive. Tissue samples were decontaminated by Petroff`s method and processed for acid-fast bacilli staining, culture in Stonebrink and Lowenstein-Jensen media and DNA extraction. Lymph node DNA samples were amplified by PCR in the absence and presence (inhibitor controls) of DNA extracted from M. bovis culture. Mycobacterium bovis was identified in 14 (42.4%) lymph node samples by both PCR and by culture. The frequency of PCR-positive results (54.5%) was similar to that of culture-positive results (51.5%, P > 0.05). The percentage of PCR-positive lymph nodes increased from 39.4% (13/33) to 54.5% (18/33) when samples that were initially PCR-negative were reanalysed using 2.5 mu l DNA (two samples) and 1 : 2 diluted DNA (three samples). PCR sensitivity was affected by inhibitors and by the amount of DNA in the clinical samples. Our results indicate that direct detection of M. bovis in lymph nodes by PCR may be a fast and useful tool for bovine tuberculosis epidemic management in the region.

Absence of lymph nodes in the resected specimen after radical surgery for distal rectal cancer and neoadjuvant chemoradiation therapy: What does it mean?

Purpose: The number of retrieved lymph nodes during radical surgery has been considered of great importance to ensure adequate staging and radical resection. However, this finding may not be applicable after neoadjuvant therapy in which, not only is there a decrease in lymph nodes recovered, but also a subgroup of patients with absence of lymph nodes in the resected specimen. Methods: Patients with absence of lymph nodes were compared with patients with ypN0 disease and patients with ypN+ disease. Results: Thirty-two patients (11 percent) had absence of lymph nodes, 171 patients (61 percent) had ypN0 disease, and 78 patients (28 percent) had ypN+ disease. Patients with absence of lymph nodes had significantly lower ypT status (ypT0-1, 40 vs. 13 percent; P < 0.001) and decreased risk of perineural invasion (6 vs. 21 percent; P = 0.04) compared with ypN0 patients. Five-year disease-free survival (74 percent) was similar to patients with ypN0 (59 percent; P = 0.2), and both were significantly better than patients with ypN+ disease (30 percent; P < 0.001). Conclusions: Absence of lymph nodes retrieved from the resected specimen is associated with favorable pathologic features (ypT and perineural invasion status) and good disease-free survival rates. In this setting, absence of retrieved lymph nodes may reflect improved response to neoadjuvant chemoradiation therapy rather than inappropriate or suboptimal oncologic radicality.

Polymorphisms of Lewis and Secretor genes are related to breast cancer and metastasis in axillary lymph nodes

ABH and Lewis antigen expression has been associated with cancer development and prognosis, tumor differentiation, and metastasis. Considering that invasive ductal breast carcinoma (IDC) presents multiple molecular alterations, the aim of the present study was to determine whether the polymorphism of ABO, Lewis, and Secretor genes, as well as ABO phenotyping, could be associated with tumor differentiation and lymph nodes metastasis. Seventy-six women with IDC and 78 healthy female blood donors were submitted to ABO phenotyping/genotyping and Lewis and Secretor genotyping. Phenotyping was performed by hemagglutination and genotyping by the polymerase chain reaction with sequence-specific primers. ABO, Lewis, and Secretor genes were classified by individual single nucleotide polymorphism at sites 59, 1067, 202, and 314 of the Lewis gene, 428 of the Secretor gene, and 261 (O1 allele), 526 (O2 and B allele), and 703 (B allele). No association was found between breast cancer and ABO antigen expression (P = 0.9323) or genotype (P = 0.9356). Lewis-negative genotype was associated with IDC (P = 0.0126) but not with anatomoclinical parameters. Nonsecretor genotype was associated with axillary lymph node metastasis (P = 0.0149). In conclusion, Lewis and Secretor genotyping could be useful to predict respectively breast cancer susceptibility and axillary lymph nodes metastasis.