Expression profiles of MYC protein and MYC gene rearrangement in lymphomas.

MYC translocations are a defining feature of Burkitt lymphoma and a group of diffuse large B-cell lymphoma (DLBCL) with inferior outcome. However, the clinical relevance of MYC gene rearrangement and its relationship with MYC protein expression has not been well characterized in lymphomas. Tissue microarrays containing 1214 lymphomas were successfully evaluated by immunohistochemistry using anti-MYC clone Y69 and a dual-color break-apart fluorescence in situ hybridization probe to detect MYC gene rearrangements. Aggressive B-cell lymphomas including Burkitt lymphoma and DLBCL showed the highest level of MYC protein staining defined as staining in >50% of lymphoma cells. A significant proportion of plasmablastic, B-lymphoblastic and T-lymphoblastic, and extranodal NK/T-cell lymphomas also showed staining in >50% of cells, whereas only occasional plasma cell myeloma, mantle cell lymphoma, and classical Hodgkin lymphoma showed a high level of staining. Small B-cell lymphomas, when positive, showed MYC protein in <50% of cells. In aggressive B-cell lymphomas, MYC rearrangement and MYC immunohistochemistry showed a high concordance rate; however, some DLBCL and all T-cell and NK-cell lymphomas with MYC protein expression lacked MYC gene rearrangements. Our results provide a baseline for MYC protein expression in lymphomas and indicate that its expression is not specific to lymphoma subtypes, cell lineage, or expected clinical behavior and is highly variable. In addition, MYC protein expression is not necessarily correlated with MYC gene rearrangements and suggests the need for caution in the interpretation of MYC immunohistochemistry in the differential diagnosis of lymphomas.

Indications and pitfalls of immunohistochemistry in head and neck cancer.

UNLABELLED: Immunohistochemistry (IHC) has been employed in the differential diagnosis of tumors. OBJECTIVE: To assess the use of IHC in cases of head and neck tumor. METHOD: This is a retrospective study of the cases included in the Cancer Registry of the institution. RESULTS: IHC was used in 76 (11%) of 704 pathology tests. Most cases were carcinomas (85.80%), and 83.66% of them were squamous cell carcinomas. All tests were done with diagnostic purposes. The most frequently used antibodies were 34BE12 (37.18%), AE1/AE3 (35.9%), 35BH11 (28.21%), CD45 (25.64%), CD20 (24.36%), CD30 (24.36%), CK7 (23.08%) and CD3 (23.08%). CONCLUSIONS: IHC was used in 10.67% of the head and neck tumor cases submitted to pathology testing, mostly for carcinoma (5.26%). In the determination of squamous cell carcinoma, IHC accounted for 18.42% of all tumors.

Indicações e limites da imunoistoquímica no câncer de cabeça e pescoço / Indications and pitfalls of immunohistochemistry in head and neck cancer

O estudo imunoistoquímico tem sido empregado para a avaliação do diagnóstico diferencial de neoplasia. OBJETIVO: Avaliar o uso do método nos casos de câncer de cabeça e pescoço. MÉTODO: Estudo retrospectivo de casos do Registro Hospitalar de Câncer da instituição. RESULTADOS: De 704 resultados anatomopatológicos, a imunoistoquímica foi realizada em 76 (11%). A maioria correspondeu a carcinomas - 85,80% e, destes, 83,66% eram epidermoides. Todos os exames foram para fins diagnósticos. Houve maior frequência para o uso de 34BE12 (37,18%), AE1/AE3 (35,90%), 35BH11 (28,21%), CD45 (25,64%), CD20 (24,36%), CD30 (24,36%), CK7 (23,08%) e CD3 (23,08%). CONCLUSÃO: A imunoistoquímica foi usada em 10,67% dos casos de câncer de cabeça e pescoço submetidos a exame anatomopatológico, sendo maior para os carcinomas -- 5,26%. Na determinação do carcinoma epidermoide, seu uso foi de 18,42% do total de neoplasias.

Immunohistochemistry (IHC) has been employed in the differential diagnosis of tumors. OBJECTIVE: To assess the use of IHC in cases of head and neck tumor. METHOD: This is a retrospective study of the cases included in the Cancer Registry of the institution. RESULTS: IHC was used in 76 (11%) of 704 pathology tests. Most cases were carcinomas (85.80%), and 83.66% of them were squamous cell carcinomas. All tests were done with diagnostic purposes. The most frequently used antibodies were 34BE12 (37.18%), AE1/AE3 (35.9%), 35BH11 (28.21%), CD45 (25.64%), CD20 (24.36%), CD30 (24.36%), CK7 (23.08%) and CD3 (23.08%). CONCLUSIONS: IHC was used in 10.67% of the head and neck tumor cases submitted to pathology testing, mostly for carcinoma (5.26%). In the determination of squamous cell carcinoma, IHC accounted for 18.42% of all tumors.

Estudo das concentrações séricas de amilóide A, alpha-1 glicoproteína ácida e proteína C reativa em felinos com linfoma durante a quimioterapia / Study of amyloid A, alpha-1 acid glycoprotein and C-reactive protein concentrations in feline lymphoma during chemotherapy

Linfomas pertencem a um grupo de neoplasias que têm em comum a origem em células linforreticulares, manifestando-se geralmente em tecidos linfóides. Em sua evolução, há uma reação generalizada do organismo de forma não específica contra as alterações sistêmicas que comprometem a homeostase, conhecida como resposta de fase aguda, a qual leva a uma importante alteração na síntese de proteínas pelo fígado, resultando no aumento de algumas proteínas conhecidas como proteínas de fase aguda, sendo as de maior relevância a amiloide sérica A, α-1 glicoproteína ácida e proteína C reativa. Foram objetivos deste estudo, definir o perfil eletroforético do felino com linfoma e avaliar as concentrações séricas de amilóide sérica A (ASA), α-1 glicoproteína ácida (GPA) e proteína C reativa (PCR) destes animais durante a quimioterapia, avaliando-se como possíveis indicadores de remissão de doença. Os grupos de estudo foram constituídos por 20 felinos clinicamente normais (controle) e 16 felinos com linfoma (experimental). Foram excluídos pacientes que apresentavam tratamentos prévios e/ou doenças concomitantes. A eletroforese das proteínas séricas foi realizada em tiras de acetato de celulose. Para as mensurações de ASA, GPA e PCR utilizaram-se kits comerciais, sendo as mesmas determinadas no grupo controle, uma única vez e, no grupo experimental, quando do diagnóstico e a cada 2 semanas durante 3 meses de tratamento. A análise estatística foi realizada com testes paramétricos, sendo o teste t não pareado utilizado para comparações entre os grupos controle e experimental no momento do diagnóstico e análise de variância simples (ANOVA), seguida do teste de comparações múltiplas de Tukey, para comparar o grupo experimental no diagnóstico e semanas de tratamento. Foram observadas diferenças significantes entre os grupos controle e experimental no momento do diagnóstico, com relação à GPA (p<0,0001), ASA (p=0,0028), PCR (p=0,0003), globulina (p=0,0087), relação albumina: globulinas (p<0,0001) e α-2 globulinas (p=0,0082). Quando se compararam os achados do grupo experimental no diagnóstico e nas semanas de tratamento houve diferença nos resultados referente à GPA (p=0,0021) e ASA (p=0,0053), enquanto os níveis de PCR não se alteraram significativamente (p=0,4510). Concluiu-se que os felinos com linfoma apresentaram uma expressiva resposta de fase aguda, caracterizada por aumento das concentrações séricas de α-1 glicoproteína ácida, amiloide sérica A e proteína C reativa, sendo a amilóide sérica A e α-1 glicoproteína ácida potenciais indicadores de remissão de doença naqueles pacientes que estavam com suas concentrações elevadas quando do diagnóstico

Lymphoma belongs to a group of malignancies that have in common their origin in lymphoreticular cells, and is generally manifested in lymphoid tissues. In its evolution, there is a generalized reaction of the organism against a non-specific systemic conditions that compromises the homeostasis, known as acute phase response, which leads to a significant change in protein synthesis by the liver, resulting in an increase of some proteins known as acute phase proteins, and the most relevant are serum amyloid A, α-1 acid glycoprotein and C-reactive protein. This study was designed to define the electrophoretic profile of feline lymphoma and to evaluate serum concentrations of serum amyloid A (ASA), α-1 acid glycoprotein (GPA) and C-reactive protein (PCR) of these animals during chemotherapy, evaluated as possible indicators of disease remission. The study groups consisted of 20 clinically normal cats (control) and 16 cats with lymphoma (experimental). We excluded patients who had previous treatments and/or concomitant diseases. Electrophoresis of serum proteins was conducted on strips of cellulose acetate. For measurements of ASA, GPA and PCR we used commercial kits, which are then determined, in the control group, only once and, in the experimental group, at diagnosis and every 2 weeks during 3 months of treatment. Statistical analysis was performed with parametric tests, where unparied t test was used for comparisons between control and experimental groups at diagnosis and simple analysis of variance (ANOVA) test followed by Tukey/'s multiple comparisons to compare the experimental group in the diagnosis and weeks of treatment. There were significant differences between control and experimental groups at diagnosis of α-1 acid glycoprotein (p<0,0001), serum amyloid A (p=0,0028), C-reactive protein (p=0,0003), total globulin (p=0,0087), albumin: globulin (p<0,0001) and α-2 globulins (p=0,0082). When comparing the experimental group in the diagnosis and weeks of treatment was significant in the results of α-1 acid glycoprotein (p=0,0021) and serum amyloid A (p=0,0053), whereas C-reactive protein did not change significantly (p=0,4510). It is concluded that cats with lymphoma have an expressive acute phase response, characterized by increased in serum concentrations of serum amyloid A, α-1 acid glycoprotein and C-reactive protein, and the serum amyloid A and alpha-1 acid glycoprotein reference potential indicators of remission in those patients who were with their high concentrations at diagnosis

Growth hormone (GH) receptor antibodies with GH-like activity occur spontaneously in acromegaly.

Previous studies in our laboratory have identified a portion of big-big GH as actually being anti-GH receptor immunoglobulins. We now report the isolation of two types of anti-GH receptor antibodies from the serum of active acromegalic patients. One of them (patient A) interferes with the human GH RIA, thus overestimating the real plasma GH values. The other type of immunoglobulin G (IgG; patient B) was detected in an acromegalic patient with almost normal immunoreactive GH level. The main aim of the present study was to explore whether these anti-GH receptor IgGs possess GH-like biological activity. The IgGs of both patients were isolated by chromatography on Sephadex G-100 and then on protein-A-Sepharose. In the bioassay, cultured Nb2 lymphoma cells were incubated with hGH standards and serial dilutions of the purified IgGs, and cell proliferation was used as a measure of biological activity. The IgGs of both patients showed GH-like bioactivities, which, when calculated as equivalents of human GH, correspond to approximately 260 and 120 micrograms/L, respectively. The results suggest that biologically active anti-GH receptor antibodies may contribute in the pathology of some cases of acromegaly.