Genetic susceptibility to complex traits : moving towards informed analysis of whole-genome screens

Susceptibility to complex traits, by definition, involves aetiological polymorphisms at multiple genetic loci combined with variable contributions by environmental factors. However, the approaches taken to identifying genetic loci implicated in susceptibility to complex traits frequently overlooks the compounding contribution of multiple loci in favour of highlighting a single gene solely responsible for predisposition. It is only in a small minority of cases that this has resulted in clear disease heritability associated with polymorphisms in a single gene. More often, this approach has led to an accumulation of single-gene associations with minor contributions to disease susceptibility. As the genomic era advances and genome-wide screens become higher in resolution and throughput, the need for simultaneous consideration of multiple loci is becoming more important. With special reference to non-Hodgkin’s lymphoma (NHL), this chapter will overview the current progress made in elucidating genetic polymorphisms associated with disease susceptibility. We also present novel data from a high-resolution single nucleotide polymorphism (SNP) microarray screen for susceptibility loci that are involved in NHL. Using an ‘informed approach’, the findings are highlighted within the context of cellular pathways, and provide insight and new ideas for methods of analysis for genome-wide screens for susceptibility.

Associations between ghrelin and ghrelin receptor polymorphisms and cancer in Caucasian populations: A meta-analysis

Background There is growing evidence that the ghrelin axis, including ghrelin (GHRL) and its receptor, the growth hormone secretagogue receptor (GHSR), play a role in cancer progression. Ghrelin gene and ghrelin receptor gene polymorphisms have been reported to have a range of effects in cancer, from increased risk, to protection from cancer, or having no association. In this study we aimed to clarify the role of ghrelin and ghrelin receptor polymorphisms in cancer by performing a meta-analysis of published case–control studies. We conducted searches of the literature published up to January 2013 in MEDLINE using the PubMed search engine. Individual data on 8,430 cases and 14,008 controls from six case–control studies of an all Caucasian population were evaluated for three ghrelin gene (GHRL; rs696217, rs4684677, rs2075356) and one ghrelin receptor (GHSR; rs572169) polymorphism in breast cancer, esophageal cancer, colorectal cancer and non-Hodgkins lymphoma. Results In the overall analysis, homozygous and recessive associations indicated that the minor alleles of rs696217 and rs2075356 GHRL polymorphisms conferred reduced cancer risk (odds ratio [OR] 0.61-0.78). The risk was unchanged for breast cancer patients when analysed separately (OR 0.73-0.83). In contrast, the rs4684677 GHRL and the rs572169 GHSR polymorphisms conferred increased breast cancer risk (OR 1.97-1.98, p = 0.08 and OR 1.42-1.43, p = 0.08, respectively). All dominant and co-dominant effects showed null effects (OR 0.96-1.05), except for the rs572169 co-dominant effect, with borderline increased risk (OR 1.08, p = 0.05). Conclusions This study suggests that the rs696217 and rs2075356 ghrelin gene (GHRL) polymorphisms may protect carriers against breast cancer, and the rs4684677 GHRL and rs572169 GHSR polymorphisms may increase the risk among carriers. In addition, larger studies are required to confirm these findings.

Cancer related fatigue and self-care while undergoing chemotherapy: patients' perspectives

Background: Cancer related fatigue (CRF) is considered the most severe, debilitating and under-managed symptom of cancer. Patients receiving chemotherapy experience high levels of CRF which profoundly impacts on their lives. Aim: 1). To explore and measure CRF and determine the most effective self-care strategies used to combat CRF in a cohort of patients with a diagnosis of cancer (breast cancer, colorectal cancer, Hodgkin’s and Non-Hodgkin’s lymphoma) 2). To explore self-care agency and its relationship to CRF. Method: A mixed methods study which incorporated a descriptive, comparative, correlational design and qualitative descriptions of patients’ (n=362) experiences gleaned through open ended questions and use of a diary. The study utilised The Revised Pipers Fatigue Scale, the Appraisal of Self-Care Agency and a researcher developed Fatigue Visual Analogue Scale, Fatigue Self-Care Survey, and Diary. Findings: Having breast cancer, Hodgkin’s lymphoma, non-Hodgkin’s lymphoma; using the strategies of counselling, taking a 20–30 minute nap, resting and sleeping, self-monitoring and complementary therapies were all associated with increased odds of developing fatigue. Increased self-care agency; being in the divorced / separated cohort; being widowed; increased length of time since commencement of chemotherapy; engagement in exercise, and socializing were associated with a reduced risk of developing fatigue. Females had 20% higher fatigue levels than males (p=<.001). Receiving support was the strategy used most frequently and rated most effective. Fatigue was very problematic and distressing, four key qualitative categories emerged: the behavioural impact, affective impact, the sensory impact, and the cognitive impact. Keeping a diary was considered very beneficial and cathartic. Conclusions: Fatigue severely impacted on the daily lives of patients undergoing chemotherapy. There are a range of self-care strategies that patients should be encouraged to use e.g. exercise, socializing, and enhancement of psychological well-being. The enhancement of self-care agency and use of diaries should also be considered.

Análise clínica e epidemiológica do transplante de medula óssea no Serviço de Oncologia Pediátrica do Hospital de Clínicas de Porto Alegre

Objetivos: Descrever o perfil e as complicações agudas mais importantes das crianças que receberam transplante de medula óssea (TMO) em nosso Serviço. Casuística e métodos: Análise retrospectiva de 41 pacientes menores de 21 anos transplantados entre Agosto de 1997 até Junho de 2002. Deste total 20 receberam transplante alogênico e 21 receberam transplante autogênico. Resultados: No TMO alogênico a média de idade foi de 8,9 + 5,4 anos, sendo 12 pacientes do sexo masculino. As fontes de células foram: medula óssea (MO) 12, sangue periférico (SP) 5, sangue de cordão umbilical não aparentado (SCU) 3. As doenças tratadas foram leucemia linfóide aguda (LLA) 7 pacientes, leucemia linfóide crônica (LMC) 2; leucemia mielóide aguda (LMA) 4; Síndrome mielodisplásica 2; Linfoma de Burkitt 1, Anemia aplástica grave 1; Anemia de Fanconi 1; Síndrome Chediak Higashi 1; Imunodeficiência congênita combinada grave 1. Um paciente desenvolveu doença do enxerto contra hospedeiro (DECH) aguda grau 2 e três DECH grau 4. Três pacientes desenvolveram DECH crônica. Todos haviam recebido SP como fonte de células. A sobrevida global foi de 70,0 + 10,3%. A principal causa do óbito foi DECH em 3 pacientes e sépse em outros 3. Todos os óbitos ocorreram antes do dia 100. Um dos pacientes que recebeu SCU está vivo em bom estado e sem uso de medicações 3 anos e 6 meses pós TMO. No TMO autogênico, a média de idade foi de 8,7 + 4,3 anos, sendo 11 pacientes do sexo masculino. As fontes de células foram SP 16, MO 3, SP + MO 2. As doenças tratadas foram: tumor de Wilms 5; tumores da família do sarcoma de Ewing 4; neuroblastomas 3; linfomas de Hodgkin 3; rabdomiossarcomas 2, tumor neuroectodérmico primitivo do SNC 2; Linfoma não Hodgkin 1; LMA 1. A sobrevida global está em 59,4 + 11,7 %. Cinco óbitos tiveram como causa a progressão da doença de base, um óbito ocorreu devido à infecção 20 meses pós TMO e dois óbitos foram precoces por sépse. As toxicidades mais comuns em ambos os grupos foram vômitos, mucosite, diarréia e dor abdominal. Infecções foram documentadas em 58,5% dos pacientes e 46,9% tiveram no mínimo um agente isolado na hemocultura. Os tempos de enxertia de neutrófilos e plaquetas correlacionaram-se com o número de células progenitoras infundidas. Conclusão: A sobrevida de nossos pacientes é semelhante à encontrada na literatura de outros serviços nacionais e internacionais. Não encontramos diferença entre os dois tipos de transplante com relação às toxicidades agudas e ás infecções.

Classificação citológica e imunocitoquímica dos linfomas caninos

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

Loss of Interleukin-10 Signaling and Infantile Inflammatory Bowel Disease: Implications for Diagnosis and Therapy

BACKGROUND & AIMS: Homozygous loss of function mutations in interleukin-10 (IL10) and interleukin-10 receptors (IL10R) cause severe infantile (very early onset) inflammatory bowel disease (IBD). Allogeneic hematopoietic stem cell transplantation (HSCT) was reported to induce sustained remission in 1 patient with IL-10R deficiency. We investigated heterogeneity among patients with very early onset IBD, its mechanisms, and the use of allogeneic HSCT to treat this disorder. METHODS: We analyzed 66 patients with early onset IBD (younger than 5 years of age) for mutations in the genes encoding IL-10, IL-10R1, and IL-10R2. IL-10R deficiency was confirmed by functional assays on patients' peripheral blood mononuclear cells (immunoblot and enzyme-linked immunosorbent assay analyses). We assessed the therapeutic effects of standardized allogeneic HSCT. RESULTS: Using a candidate gene sequencing approach, we identified 16 patients with IL-10 or IL-10R deficiency: 3 patients had mutations in IL-10, 5 had mutations in IL-10R1, and 8 had mutations in IL-10R2. Refractory colitis became manifest in all patients within the first 3 months of life and was associated with perianal disease (16 of 16 patients). Extraintestinal symptoms included folliculitis (11 of 16) and arthritis (4 of 16). Allogeneic HSCT was performed in 5 patients and induced sustained clinical remission with a median follow-up time of 2 years. In vitro experiments confirmed reconstitution of IL-10R-mediated signaling in all patients who received the transplant. CONCLUSIONS: We identified loss of function mutations in IL-10 and IL-10R in patients with very early onset IBD. These findings indicate that infantile IBD patients with perianal disease should be screened for IL-10 and IL-10R deficiency and that allogeneic HSCT can induce remission in those with IL-10R deficiency.

HIV-associated malignancies among children attending the Baylor Clinic in Kampala, Uganda

Introduction: HIV-associated malignancies such as Kaposi’s sarcoma and Non-Hodgkin’s lymphoma occur in children and usually lead to significant morbidity and mortality. No studies have been done to establish prevalence and outcome of these malignancies in children in a hospital setting in Uganda. ^ Research question: What proportion of children attending the Baylor-Uganda COE present with HIV-associated malignancies and what are the characteristics and outcome of these malignancies? The objective was to determine the prevalence, associated factors and outcome of HIV-associated malignancies among children attending the Baylor-Uganda Clinic in Kampala, Uganda. Study Design: This was a retrospective case series involving records review of patients who presented to the Baylor-Clinic between January 2004 and December 2008. Study Setting: The Baylor-Uganda Clinic, where I worked as a physician before coming to Houston, is a well funded, well staffed; Pediatric HIV clinic located in Mulago Hospital, Kampala, Uganda and is affiliated to Makerere University Medical School. Study Participants: Medical charts of patients aged 6 weeks to 18 years who enrolled for care at the clinic during the years 2004 to 2008 were retrieved for data abstraction. Selection Criteria: Study participants had to be patients of Baylor-Uganda seen during the study period; they had to be aged 6 weeks to 18 years; and had to be HIV positive. Patients with incomplete data or whose malignancies were not confirmed by histology were excluded. Study Variables: Data on patient’s age, sex, diagnosis, type of malignancy, anatomic location of the malignancy; pathology report, baseline laboratory results and outcome of treatment, were abstracted. Data Analysis: Cross tabulation to determine associations between variables using Pearson’s chi square at 95% level of significance was done. Proportions of malignancies among different groups were determined. In addition, Kaplan Meier survival analysis and comparison of survival distributions using the log-rank test was done. Change in CD4 percentages from baseline was assessed with the Wilcoxon signed rank test. Results: The proportion of children with malignancies during the study period was found to be 1.65%. Only 2 malignancies: Kaposi’s sarcoma and Non-Hodgkin’s lymphoma were found. 90% of the malignancies were Kaposi’s sarcoma. Lymph node involvement in children with Kaposi’s sarcoma was common, but the worst prognosis was seen with visceral involvement. Deaths during follow-up were seen in the first few weeks to months. Upon starting treatment the CD4 cell percentage increased significantly from a baseline median of 6% to 14% at 6 months and 15.8% at 12 months of follow-up.^

A model for spontaneous B-lineage lymphomas in IgHμ-HOX11 transgenic mice

HOX11, a divergent homeodomain-containing transcription factor, was isolated from the breakpoint of the nonrandom t(10;14)(q24;q11) chromosome translocation found in human T cell acute lymphoblastic leukemias. The translocation places the HOX11 coding sequence under the transcriptional control of TCR α/δ regulatory elements, resulting in ectopic expression of a normal HOX11 protein in thymocytes. To investigate the oncogenic potential of HOX11, we targeted its expression in lymphocytes of transgenic mice by placing the human cellular DNA under the transcriptional control of Ig heavy chain or LCK regulatory sequences. Only IgHμ-HOX11 mice expressing low levels of HOX11 were viable. During their second year of life, all HOX11 transgenic mice became terminally ill with more than 75% developing large cell lymphomas in the spleen, which frequently disseminated to thymus, lymph nodes, and other nonhematopoietic tissues. Lymphoma cells were predominantly clonal IgM+IgD+ mature B cells. Repopulation of severe combined immunodeficient mice with cells from hyperplastic spleens indicated that the HOX11 tumor phenotype was transplantable. Before tumor development, expression of the transgene did not result in perturbations in lymphopoiesis; however, lymphoid hyperplasia involving the splenic marginal zones was present in 20% of spleens. Our studies provide direct evidence that expression of HOX11 in lymphocytes leads to malignant transformation. These mice are a useful model system to study mechanisms involved in transformation from B-lineage hyperplasia to malignant lymphoma and for testing novel approaches to therapy. They represent a novel animal model for non-Hodgkin’s lymphoma of peripheral mature B cell origin.

Clinical features and management of tumors affecting the lacrimal drainage apparatus

Purpose: To report the clinical features of a series of patients with lacrimal drainage apparatus tumors and present guidelines for management based on histopathology. Methods: A noncomparative retrospective chart review of the clinical, imaging, and pathologic findings of 37 patients presenting to four regional orbital Surgery departments with tumors affecting the lacrimal drainage apparatus between 1990 and 2004. Results: There were 37 patients, of whom 62% were male. The mean age at referral was 54 years. Epiphora, a palpable mass, and dacryocystitis were the most common presentations. Two thirds of the tumors were epithelial. with carcinomas being the most frequent (38%). followed by papillomas (27%). Lymphomas were the most common nonepithelial malignancy (30%). Epithelial tumors were more common in men (87%), whereas lymphomas were more common in women (57%). Treatment modalities included surgery, in addition to radiotherapy and/or chemotherapy and immunotherapy. Mean follow-up was 38 months. Thirty-three patients (89%) remain alive without evidence of disease and 4 patients died of recurrence and/or metastases. Conclusions: Lacrimal drainage apparatus tumors require careful initial management to ensure adequate local and systemic disease control. Atypical mucosa encountered during dacryocystorhinostomy should be biopsied and small papillomas or pedunculated tumors excised and analyzed with frozen sections. If a diffuse or infiltrative mass is encountered, it should be biopsied and managed on the basis of histopathology and extent of disease. Lymphomas should be treated according to protocols. whereas noninvasive carcinoma and extensive papillomas require complete excision of the system. Invasive disease requires en bloc excision. Long-term follow-up is essential for early detection of recurrence.

Mechanisms of hematopoietic stem cell mobilization: When innate immunity assails the cells that make blood and bone

Mobilization is now used worldwide to collect large numbers of hematopoietic stem and progenitor cells (HSPCs) for transplantation. Although the first mobilizing agents were discovered largely by accident, discovery of more efficient mobilizing agents will require a better understanding of the molecular mechanisms responsible. During the past 5 years, a number of mechanisms have been identified, shedding new light on the dynamics of the hematopoietic system in vivo and on the intricate relationship between hematopoiesis, innate immunity, and bone. After briefly reviewing the mechanisms by which circulating HSPCs home into the bone marrow and what keeps them there, the current knowledge of mechanisms responsible for HSPC mobilization in response to hematopoietic growth factors such as granulocyte colony-stimulating factor, chemotherapy, chemokines, and polyanions will be discussed together with current strategies developed to further increase HSPC mobilization. (c) 2006 International Society for Experimental Hematology.

Imaging features of ocular adnexal lymphoproliferative disease

Purpose To evaluate the imaging characteristics of a cohort of patients with ocular adnexal lymphoproliferative disease (OALD). Methods A noncomparative retrospective review between 1992 and 1995 and prospective study from 1995 to 2005 of the clinical, imaging and treatment of 105 patients presenting to tertiary orbital referral centre presenting with OALD. Results One hundred and five patients (mean age 61 years, range 11-90 years) with equal gender distribution were included. Fifty-three were primary and 52 were secondary. Computed tomography (CT) usually showed a well-circumscribed lesion of greater than brain density, moulding to adjacent tissues with moderate enhancement. Aggressive histology was associated with bone destruction, while moulding was associated with indolent histology (P < 0.005). MRI in OALD showed intermediate signal intensity on T1- and T2-weighted images and moderate enhancement with gadolinium. Gallium scanning sensitivity to detect ocular adnexal disease was 25 and 57% for systemic involvement. Positron emission tomography (PET) upstaged (71%) of patients with systemic lymphoproliferative involvement, having a higher sensitivity than CT in detecting distant disease (86 vs 72%). Conclusions CT and/ or MRI are essential in the evaluation of OALD and can be used to establish that an orbital lesion may be lymphoprolifetaive in nature. Further, these imaging modalities may predict the behaviour of the lymphoma in certain cases. Gallium scanning provides no additional information to CT and does not influence patient treatment. PET represents an important addition to the assessment of OALD with real impact on patient management.

Mechanisms of Mycoplasma-induced inflammation and cellular transformation

There is a growing interest in “medical gasses” for their antibacterial and anti-inflammatory properties. Hydrogen sulfide (H2S), a member of the family of gasotransmitters, is in fact increasingly being recognized as an important signaling molecule, but its precise role in the regulation of the inflammatory response is still not clear. For this reason, the aim of the first part of this thesis was to investigate the effects of H2S on the expression of pro-inflammatory cytokines, such as MCP-1, by using an in vitro model composed by both primary monocytes-derived macrophages cultures and the human monocytic cell line U937 infected with Mycoplasma fermentans, a well-known pro-inflammatory agent. In our experiments, we observed a marked increase in the production of pro-inflammatory cytokines in infected cells. In particular, MCP-1 was induced both at the RNA and at the protein level. To test the effects of H2S on infected cells, we treated the cells with two different H2S donors (NaHS and GYY4137), showing that both H2S treatments had anti-inflammatory effects in Mycoplasma-infected cells: the levels of MCP-1, both mRNA expression and protein production, were reduced. Our subsequent studies aimed at understanding the molecular mechanisms responsible for these effects, focused on two specific molecular pathways, both involved in inflammation: the NF-κB and the Nrf2 pathway. After treatment with pharmacological inhibitors, we demonstrated that Mycoplasma fermentans induces MCP-1 expression through the TLR-NF-κB pathway with the nuclear translocation of its subunits, while treatment with H2S completely blocked the nuclear translocation of NF-κB heterodimer p65/p50. Then, once infected cells were treated with H2S donors, we observed an increased protective effect of Nrf2 and also a decrease in ROS production. These results highlight the importance of H2S in reducing the inflammatory process caused by Mycoplasma fermentans. To this regard, it should be noted that several projects are currently ongoing to develop H2S-releasing compounds as candidate drugs capable of alleviating cell deterioration and to reduce the rate of decline in organ function. In the second part of this study, we investigated the role of Mycoplasma infection in cellular transformation. Infectious agents are involved in the etiology of many different cancers and a number of studies are still investigating the role of microbiota in tumor development. Mycoplasma has been associated with some human cancers, such as prostate cancer and non-Hodgkin’s lymphoma in HIV-seropositive people, and its potential causative role and molecular mechanisms involved are being actively investigated. To this regard, in vitro studies demonstrated that, upon infection, Mycoplasma suppresses the transcriptional activity of p53, key protein in the cancer suppression. As a consequence, infected cells were less susceptible to apoptosis and proliferated more than the uninfected cells. The mechanism(s) responsible for the Mycoplasma-induced inhibitory effect on p53 were not determined. Aim of the second part of this thesis was to better understand the tumorigenic role of the microorganism, by investigating more in details the effect(s) of Mycoplasma on p53 activity in an adenocarcinoma HCT116 cell line. Treatment of Mycoplasma-infected cells with 5FU or with Nutlin, two molecules that induce p53 activity, resulted in cellular proliferation comparable to untreated controls. These results suggested that Mycoplasma infection inhibited p53 activity. Immunoprecipitation of p53 with specific antibodies, and subsequent Gas Chromatography and Mass Spectroscopy (GC-MS) assays, allowed us to identify several Mycoplasma-specific proteins interacting with p53, such as DnaK, a prokaryotic heat shock protein and stress inducible chaperones. In cells transfected with DnaK we observed i) reduced p53 protein levels; ii) reduced activity and expression of p21, Bax and PUMA, iii) a marked increase in cells leaving G1 phase. Taken together, these data show an interaction between the human p53 and the Mycoplasma protein DnaK, with the consequent decreased p53 activity and decreased capability to respond to DNA damage and prevent cell proliferation. Our data indicate that Mycoplasma could be involved in cancer formation and the mechanism(s) has the potential to be a target for cancer diagnosis and treatment(s).

Linfoma primário da vagina – revisão da literatura a propósito de um caso clínico

Os tumores primários malignos da vagina são raros, contribuindo apenas para cerca de 1%-2% dos cancros ginecológicos. O linfoma não-Hodgkin (LNH) primário da vagina é raríssimo (existindo aproximadamente 100 casos descritos na literatura). A sua associação com infecção pelo vírus Epstein Barr (VEB) foi descrita em escassos casos. Os autores pretendem fazer uma revisão da literatura de linfoma primário da vagina, com base num caso clínico de LNH-B de grandes células numa mulher nulípara de 25 anos de idade.

Factores preditivos de linfoma no síndrome de Sjögren : a propósito de um caso clínico

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Comparación farmacoeconómica (costo – utilidad / beneficio / efectividad) del Rituximab, con el tratamiento convencional para pacientes con Linfoma No Hodgkins

El Linfoma no Hodgkin es un cáncer maligno que tiene baja incidencia a nivel nacional pero altos costos en la atención catalogándose por su manejo como enfermedad de alto costo. El tratamiento de acuerdo a fase de tratamiento, clasificación histológica y respuesta a tratamiento se consideran las alternativas de tratamiento determinadas en guías clínicas en este trabajo se revisará el tratamiento con quimioterapia (CHOP) y el tratamiento con Rituximab + CHOP Objetivo: Evaluar comparativamente el tratamiento con quimioterapia y el Rituximab en cuanto a costo beneficio / utilidad /efectividad y el efecto de ambas terapias sobre la calidad de vida y carga de enfermedad, desde la perspectiva del marco normativo vigente y la aplicación del mismo en una EPS Resultados: en los análisis de costo beneficio, utilidad y efectividad, se evidenció que los costos del tratamiento del Rituximab superan los de quimioterapia, pero al comparar los resultados obtenidos mediante AVISA, y QALY, confirmaron los resultados evidenciados en literatura, siendo estas las variables más sensibles para determinación de protocolos de manejo de Linfoma No Hodgkin. Conclusiones: aunque el Rituximab es una buena opción terapéutica para el Linfoma No Hodgkin, los costos que se ocasionan por este medicamento sobrepasan la compensación recibida por estos usuarios, es necesario que las políticas públicas relacionen este tipo de análisis para adecuar los ingresos a los egresos y permitir el equilibrio económico de la atención, no permitir que por cuestiones de economía empresarial se tomen alternativas equivocas que pueden ir el menos cabo de la salud de los usuarios.