Pitfalls in TCR gene clonality testing: teaching cases

Clonality testing in T-lymphoproliferations has technically become relatively easy to perform in routine laboratories using standardized multiplex polymerase chain reaction protocols for T-cell receptor (TCR) gene analysis as developed by the BIOMED-2 Concerted Action BMH4-CT98-3936. Expertise with clonality diagnostics and knowledge about the biology of TCR gene recombination are essential for correct interpretation of TCR clonality data. Several immunobiological and technical pitfalls that should be taken into account to avoid misinterpretation of data are addressed in this report. Furthermore, we discuss the need to integrate the molecular data with those from immunohistology, and preferably also flow cytometric immunophenotyping, for appropriate interpretation. Such an interactive, multidisciplinary diagnostic model guarantees integration of available data to reach the most reliable diagnosis

Mutation analysis of KRAS prior to targeted therapy in colorectal cancer: development and evaluation of quality by a European external quality assessment scheme

Contains fulltext : 96128.pdf (publisher's version ) (Closed access)In Europe, the use of anti-EGFR monoclonal antibodies is restricted to Kirsten RAS (KRAS) wild-type colorectal tumors. Information on the KRAS status of the patients tumor is thus key for clinical practice; however, there is little guidance or definition on which KRAS mutations to assess and how to assess them. To ensure the consistency and the quality of KRAS test results in Europe, an interlaboratory control network needs to be set up. This pilot study aimed to identify the variables that need to be assessed in a quality control scheme and to provide a first assessment in a selected set of laboratories. Fourteen different tumor cases were circulated between 13 laboratories by a central laboratory acting as the referent for the mutation status determination. This study illustrated that of 13 experienced laboratories that perform KRAS testing only ten correctly identified the KRAS in all 14 cases that were circulated. There was no harmonization in DNA isolation and KRAS mutation detection method between the laboratories. These results indicate that future standardization is needed in KRAS mutation detection methodology. An expansion of the European Society of Pathology KRAS program could identify areas of difficulty in KRAS testing and provide the basis for harmonization

Protein Profiling of B-Cell Lymphomas Using Tissue Biopsies: A Potential Tool for Small Samples in Pathology

Non-Hodgkin’s lymphoma comprises many related but distinct diseases and diagnosis and classification is complex. Protein profiling of lymphoma biopsies may be of potential value for use in this lymphoma classification and the discovery of novel markers. In this study, we have optimized a method for SELDI-TOF MS based protein profiling of frozen tissue sections, without dissection of tumour cells. First we have compared chip surfaces and lysis buffers. Also, we have determined the minimal input using laser dissection microscopy. Subsequently, we have analyzed and compared protein profiles of diffuse large B-cell lymphoma (n=8), follicular lymphoma (n=8) and mantle cell lymphoma (n=8). Benign, reactive lymph nodes (n=14) were used as a reference group

Direct inhibition of STAT signaling by platinum drugs contributes to their anti-cancer activity

Platinum-based chemotherapeutics are amongst the most powerful anti-cancer drugs. Although their exact mechanism of action is not well understood, it is thought to be mediated through covalent DNA binding. We investigated the effect of platinum-based chemotherapeutics on signaling through signal transducer and activator of transcription (STAT) proteins, which are involved in many oncogenic signaling pathways. We performed in vitro experiments in various cancer cell lines, investigating the effects of platinum chemotherapeutics on STAT phosphorylation and nuclear translocation, the expression of STAT-modulating proteins and downstream signaling pathways. Direct binding of platinum to STAT proteins was assessed using an AlphaScreen assay. Nuclear STAT3 expression was determined by immunohistochemistry and correlated with disease-free survival in retrospective cohorts of head and neck squamous cell carcinoma (HNSCC) patients treated with cisplatin-based chemoradiotherapy (n= 65) or with radiotherapy alone (n = 32). At clinically relevant concentrations, platinum compounds inhibited STAT phosphorylation, resulting in loss of constitutively activated STAT proteins in multiple distinct cancer cell lines. Platinum drugs specifically inhibited phospho-tyrosine binding to SH2 domains, thereby blocking STAT activation, and subsequently downregulating pro-survival- and anti-apoptotic- target genes. Importantly, we found that active STAT3 in tumors directly correlated with response to cisplatin-based chemoradiotherapy in HNSCC patients (p = 0.006). These findings provide insight into a novel, non-DNA-targeted mechanism of action of platinum drugs, and could be leveraged into the use of STAT expression as predictive biomarker for cisplatin chemotherapy and to potentiate other therapeutic strategies such as immunotherap

Gastrointestinal zygomycosis due to Rhizopus microsporus var. rhizopodiformis as a manifestation of chronic granulomatous disease.

Contains fulltext : 70218.pdf (publisher's version ) (Closed access)A case of gastrointestinal zygomycosis in a 10-month-old boy with chronic granulomatous disease (CGD) is presented. Zygomycetes are an uncommon cause of fungal disease in CGD patients and gastrointestinal zygomycosis has not been previously described in individuals with CGD. To improve outcome, a timely and correct diagnosis is of utmost importance

Improvement of hospital care for patients with non-Hodgkin's lymphoma: protocol for a cluster randomized controlled trial (PEARL study)

Contains fulltext : 118620.pdf (publisher's version ) (Open Access)BACKGROUND: Malignant lymphomas constitute a diverse group of cancers of lymphocytes. One well-known disease is Hodgkin's lymphoma; the others are classified as non-Hodgkin's lymphoma (NHL). NHLs are the most common hematologic neoplasms in adults worldwide, and in 2012 over 170,000 new cases were estimated in the United States and Europe.In previous studies, several practice gaps in hospital care for patients with NHL have been identified. To decrease this variation in care, the present study aims to perform a problem analysis in which barriers to and facilitators for optimal NHL care will be identified and, based on these findings, to develop (tailored) improvement strategies. Subsequently, we will assess the effectiveness, feasibility and costs of the improvement strategies. METHODS/DESIGN: Barriers and facilitators will be explored using the literature, using interviews and questionnaires among physicians involved in NHL care, and patients diagnosed with NHL. The results will be used to develop a tailored improvement strategy. A cluster randomized controlled trial involving 19 Dutch hospitals will be conducted. Hospitals will be randomized to receive either an improvement strategy tailored to the barriers and facilitators found or, a standard strategy of audit and feedback.The effects of both strategies will be evaluated using previously developed quality indicators. Adherence to the indicators will be measured before and after the intervention period based on medical records from newly diagnosed NHL patients. To study the feasibility of both strategies, a process evaluation will be additionally performed. Data about exposure to the different elements of the strategies will be collected using questionnaires. Economic evaluation from a healthcare perspective will compare the two implementation strategies, where the costs of the implementation strategy and changes in healthcare consumption will be assessed. DISCUSSION: The presence of variation in the use of diagnostic tests, treatment, and follow-up between different physicians in different hospitals in the Netherlands is important for patients. To reduce the existing variation in care, implementation of tailored interventions to improve NHL care is necessary. TRIAL REGISTRATION: This trial is registered at ClinicalTrial.gov as the PEARL study, registration number NCT01562509

Platinum-based drugs disrupt STAT6-mediated suppression of immune responses against cancer in humans and mice

Tumor microenvironments feature immune inhibitory mechanisms that prevent T cells from generating effective antitumor immune responses. Therapeutic interventions aimed at disrupting these inhibitory mechanisms have been shown to enhance antitumor immunity, but they lack direct cytotoxic effects. Here, we investigated the effect of cytotoxic cancer chemotherapeutics on immune inhibitory pathways. We observed that exposure to platinum-based chemotherapeutics markedly reduced expression of the T cell inhibitory molecule programmed death receptor-ligand 2 (PD-L2) on both human DCs and human tumor cells. Downregulation of PD-L2 resulted in enhanced antigen-specific proliferation and Th1 cytokine secretion as well as enhanced recognition of tumor cells by T cells. Further analysis revealed that STAT6 controlled downregulation of PD-L2. Consistent with these data, patients with STAT6-expressing head and neck cancer displayed enhanced recurrence-free survival upon treatment with cisplatin-based chemoradiation compared with patients with STAT6-negative tumors, demonstrating the clinical relevance of platinum-induced STAT6 modulation. We therefore conclude that platinum-based anticancer drugs can enhance the immunostimulatory potential of DCs and decrease the immunosuppressive capability of tumor cells. This dual action of platinum compounds may extend their therapeutic application in cancer patients and provides a rationale for their use in combination with immunostimulatory compounds

Hypermutation in mantle cell lymphoma does not indicate a clinical or biological subentity.

Contains fulltext : 80422.pdf (publisher's version ) (Closed access)Mantle cell lymphoma is a prime example of a well-defined entity based on morphology, phenotype, genetics and also clinical features. Although most patients have an adverse clinical course, some have a better survival than others. The most consistently reported adverse prognostic parameter is a high mitotic rate. Recently, it has been shown that hypermutation in the immunoglobulin heavy-chain gene occurs in a subset of mantle cell lymphomas. It is, however, unclear whether the mutational status is stable over time within a given case, whether hypermutation might be influenced by therapy and how it is related to other relevant biological features of mantle cell lymphoma. In this study, we analyzed 23 typical mantle cell lymphoma cases with respect to mutational status and compared the results with clinicopathological and genetic data to determine whether the presence of mutation indicates a subentity with clinical or pathological relevance. We found somatic hypermutation in 26% of our cases and, interestingly, one case showed ongoing somatic hypermutation. In tumor cells of both mutated and unmutated cases, we found a preferential usage of V(H)3-21 (23%) and V(H)4-34 (19%). No significant correlations were found between mutation status and the other morphological and genetic features analyzed. In conclusion, our results provide additional evidence that mutation status in mantle cell lymphoma is better interpreted as a feature within the spectrum of disease that seems to have little clinical or pathological relevance