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Genome-Wide Gene Expression Profiling of Patients With ITP Receiving Thrombopoietin Mimetics

2017年4月24日 更新者:James L Zehnder、Stanford University

Introduction:

Ineffective platelet production has been proven to play a role in the etiology of Immune Thrombocytopenia (ITP) in addition to increased platelet destruction. The second-generation thrombopoietin (TPO) mimetics have shown good efficacy in boosting platelet counts in the great majority of patients with chronic ITP in several clinical trials.1, 2 Nevertheless, about 20% of patients with ITP fail to respond to the TPO mimetic treatment. Those treatment-resistant patients are un-characterized and the reasons for the lack of response have not been studied. The identification of predictive blood biomarkers of patients' response to treatment will be useful in reducing both cost and potential side effects; and it will be of equal importance and interest to investigate the molecular mechanisms underlying the patients' heterogeneous responses to TPO mimetic treatment.

Specific Aims:

  1. To identify blood classifier genes which correlate with patients' response to TPO mimetic treatment.
  2. To compare the blood gene expression changes in responders and non-responders after TPO mimetic treatment and explore the possible molecular mechanisms accounting for the non-responsiveness to the treatment.

研究概览

地位

完全的

详细说明

  1. Identification and validation of response-predictive genes. The normalized pre-treatment microarray data of the training set is retrieved from SMD for statistical analysis. The supervised analysis SAM (Significance Analysis of Microarrays, two class unpaired) is performed to identify genes whose expression is significantly different between responders and non-responders. Then a Leave-one-out cross-validated gene-expression predictor for the 2 response classes is devised by the PAM (Predication Analysis of Microarrays) method based on nearest shrunken centroids. The unsupervised clustering of the independent test set is performed using the predictive genes and the prediction accuracy is calculated. Quantitative real-time PCR is performed as further validation using the un-amplified RNA samples and Taqman gene expression assays (Applied Biosciences).
  2. Gene expression changes correlated with TPO mimetic treatment and pathway analysis.

2.1. Hypothesis: The transcriptional profile of patients who respond to TPO agonists is different than those who do not respond.

Plan: The expression data of pre-treatment as well as the 1-week and 1-month after initiation of treatment samples is retrieved from SMD. The two class paired SAM analysis is performed to compare pre-treatment samples with samples collected at either 1-week or 1-month after initiation of treatment in responders and non-responders. The two class unpaired SAM analysis is also used to compare post-treatment samples of responders and non-responders at the same time point. The significant genes (q value<0.05, fold change>2.5) are subsequently analyzed by IPA (Ingenuity Pathway Analysis) system to be transformed into a set of relevant networks based on the extensive records maintained in the Ingenuity Pathway Knowledge Base. The statistically significant networks, molecular and cellular functions, top canonical pathways and toxicity lists associated with each pair of dataset will be recognized through this analysis. Hypothesis on non-response to TPO mimetics can be generated based on the different functional subsets of significant genes. Genes involved in important pathways identified by IPA analysis will be validated by QRT-PCR as in our recent publication on oxidative stress pathways in ITP4. Our goal is to develop biomarkers which predict likelihood of response to therapy and identify pathways associated with resistance to therapy which could be targeted.

2.2 Hypothesis: Since available TPO agonists have different mechanisms of action, there may be differences in responders and non-responders between the different drugs.

Plan: We recognize that TPO agonists have different mechanisms of action which could affect downstream signaling pathways and transcriptional responses. For this reason in addition to evaluating the TPO agonists as a group in 2.1 above, patients will also be analyzed by type of agonist. The conclusions of this type of analysis will be limited by the numbers of individuals treated with a particular drug but could be useful for hypothesis generation and confirmation in a larger cohort.

研究类型

观察性的

注册 (实际的)

75

联系人和位置

本节提供了进行研究的人员的详细联系信息,以及有关进行该研究的地点的信息。

学习地点

    • California
      • Stanford、California、美国、94305
        • Stanford University
    • New York
      • New York、New York、美国、10065
        • Weill Medical College, Cornell University

参与标准

研究人员寻找符合特定描述的人,称为资格标准。这些标准的一些例子是一个人的一般健康状况或先前的治疗。

资格标准

适合学习的年龄

  • 孩子
  • 成人
  • 年长者

接受健康志愿者

有资格学习的性别

全部

取样方法

非概率样本

研究人群

Patients with ITP receiving TPO agonists

描述

Inclusion Criteria:

  • clinical diagnosis of ITP TPO treatment

Exclusion Criteria:

  • thrombocytopenia not due to ITP

学习计划

本节提供研究计划的详细信息,包括研究的设计方式和研究的衡量标准。

研究是如何设计的?

设计细节

队列和干预

团体/队列
TPO responder
Patients with therapeutic response to TPO
TPO non-responder
Patients not responding to TPO agonists

研究衡量的是什么?

主要结果指标

结果测量
大体时间
1. To identify blood classifier genes which correlate with patients' response to TPO mimetic treatment.
大体时间:2 years
2 years

合作者和调查者

在这里您可以找到参与这项研究的人员和组织。

调查人员

  • 首席研究员:James L Zehnder, MD、Stanford University

出版物和有用的链接

负责输入研究信息的人员自愿提供这些出版物。这些可能与研究有关。

一般刊物

研究记录日期

这些日期跟踪向 ClinicalTrials.gov 提交研究记录和摘要结果的进度。研究记录和报告的结果由国家医学图书馆 (NLM) 审查,以确保它们在发布到公共网站之前符合特定的质量控制标准。

研究主要日期

学习开始 (实际的)

2012年7月1日

初级完成 (实际的)

2017年2月1日

研究完成 (实际的)

2017年2月1日

研究注册日期

首次提交

2012年11月12日

首先提交符合 QC 标准的

2012年11月12日

首次发布 (估计)

2012年11月16日

研究记录更新

最后更新发布 (实际的)

2017年4月26日

上次提交的符合 QC 标准的更新

2017年4月24日

最后验证

2017年4月1日

更多信息

此信息直接从 clinicaltrials.gov 网站检索,没有任何更改。如果您有任何更改、删除或更新研究详细信息的请求,请联系 register@clinicaltrials.gov. clinicaltrials.gov 上实施更改,我们的网站上也会自动更新.

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