A quality control program for mutation detection in KIT and PDGFRA in gastrointestinal stromal tumours.

Background: Although most gastrointestinal stromal tumours (GIST) carry oncogenic mutations in KIT exons 9, 11, 13 and 17, or in platelet-derived growth factor receptor alpha (PDGFRA) exons 12, 14 and 18, around 10% of GIST are free of these mutations. Genotyping and accurate detection of KIT/PDGFRA mutations in GIST are becoming increasingly useful for clinicians in the management of the disease.

Method: To evaluate and improve laboratory practice in GIST mutation detection, we developed a mutational screening quality control program.

Germline CYBB mutations that selectively affect macrophages in kindreds with X-linked predisposition to tuberculous mycobacterial disease.

Germline mutations in CYBB, the human gene encoding the gp91(phox) subunit of the phagocyte NADPH oxidase, impair the respiratory burst of all types of phagocytes and result in X-linked chronic granulomatous disease (CGD). We report here two kindreds in which otherwise healthy male adults developed X-linked recessive Mendelian susceptibility to mycobacterial disease (MSMD) syndromes. These patients had previously unknown mutations in CYBB that resulted in an impaired respiratory burst in monocyte-derived macrophages but not in monocytes or granulocytes.

Discontinuation of imatinib in patients with advanced gastrointestinal stromal tumours after 3 years of treatment: an open-label multicentre randomised phase 3 trial.

Background: The effect of imatinib discontinuation on progression-free survival and overall survival in long-lasting responders with advanced gastrointestinal stromal tumours (GIST) is unknown. We assessed treatment interruption in patients with non-progressive disease according to the Response Evaluation Criteria In Solid Tumors criteria after 3 years of imatinib in a randomised trial.

Methods: In this open-label national multicentre phase 3 study in France, patients with GIST free of progression after 3 years of imatinib 400 mg/day were randomly assigned to continue or interrupt imatinib.

Juvenile xanthogranuloma with hematological dysfunction treated with 2CDA-AraC.

Juvenile xanthogranuloma was diagnosed in two infants aged 8 and 2 months with skin lesions, hepatosplenomegaly, and pancytopenia. Disease control was not achieved with first-line vinblastine-steroid-VP16 combination therapy. Two courses of 2-chlorodeoxyadenosine (2CDA) (0.

Additional value of EGFR downstream signaling phosphoprotein expression to KRAS status for response to anti-EGFR antibodies in colorectal cancer.

KRAS mutations are a strong predictive marker of resistance to anti-epidermal growth factor receptor (EGFR) antibodies in advanced colorectal cancer (CRC) but only a subset of wild-type (WT) KRAS patients are responders, suggesting the existence of additional markers of resistance to this treatment. The activation of EGFR downstream signaling pathways may be one of these ones. In a series of 42 patients with advanced CRC treated with cetuximab/panitumumab, for whom KRAS status was previously determined, we retrospectively analyzed the intratumor expression of EGFR downstream signaling phosphoproteins of the RAS/MAPK and PI3K/AKT pathways (pERK1/2, pMEK1, pAKT, pP70S6K and pGSK3beta) using Bio-Plex phosphoprotein array.

Diagnostic criteria, specific mutations, and genetic predisposition in gastrointestinal stromal tumors.

In 1998, gastrointestinal stromal tumor (GIST) emerged as a distinct oncogenetic entity and subsequently became a paradigm of targeted therapies in solid tumors. Diagnosis of GIST relies on both histology and immunohistochemistry. Ninety-five percent of GISTs express either KIT or DOG-1.

BRAF mutation status in gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors characterized by mutations of KIT or PDGFRA. The objectives of this study were to evaluate BRAF mutations in GISTs and then to correlate BRAF mutational status in the tumor with clinical parameters, with B-raf expression, and with activation of some cellular pathways. BRAF mutation was screened in 321 GISTs with 70 wild-type GISTs.

Gene expression profiling identifies emerging oncogenic pathways operating in extranodal NK/T-cell lymphoma, nasal type.

Biopsies and cell lines of natural killer/T-cell lymphoma, nasal type (NKTCL) were subject to combined gene expression profiling and array-based comparative genomic hybridization analyses. Compared with peripheral T-cell lymphoma, not otherwise specified, NKTCL had greater transcript levels for NK-cell and cytotoxic molecules, especially granzyme H. Compared with normal NKcells, tumors were closer to activated than resting cells and overexpressed several genes related to vascular biology, Epstein-Barr Virus-induced genes, and PDGFRA.

Extragastrointestinal stromal tumors of the omentum: review apropos of a case with a novel gain-of-function KIT mutation.

Introduction: We describe a case of extragastrointestinal stromal tumor (EGIST) of the omentum harboring a novel KIT mutation and review the literature on omental EGISTs, emphasizing on molecular genetic data.

Case Presentation: A large EGIST arising from the lesser omentum was incidentally diagnosed in a 68-year-old man during emergency laparotomy for intra-abdominal hemorrhage following a car accident. The tumor was composed of CD117+/CD34+ spindle-shaped cells with low mitotic activity.

Immuno-fluorescence in situ hybridization index predicts survival in patients with diffuse large B-cell lymphoma treated with R-CHOP: a GELA study.

Purpose: To evaluate the prognostic value of cell of origin immunohistochemical markers and BCL2, BCL6, and c-MYC translocations in a homogeneous cohort of patients with diffuse large B-cell lymphoma (DLBCL) treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP).

Patients And Methods: Patients with CD20+ DLBCL were enrolled in the randomized LNH98-5 and 01-5B Groupe d'Etude des Lymphomes de l'Adulte trials. Paraffin-embedded tumor samples of 119 patients treated with R-CHOP were analyzed by immunohistochemistry for CD10, BCL6, MUM1/IRF4, LMO2, and forkhead box protein P1 (FOXP1) expression and for BCL2, BCL6, and c-MYC breakpoints by fluorescence in situ hybridization (FISH) on tissue microarray.

Target-driven exploratory study of imatinib mesylate in children with solid malignancies by the Innovative Therapies for Children with Cancer (ITCC) European Consortium.

Aim: To explore imatinib efficacy and pharmacokinetics in children and adolescents with refractory/relapsing solid tumours, expressing imatinib-sensitive receptor tyrosine kinases.

Methods: Exploratory study on imatinib in tumours expressing, at least, one of the receptors KIT or platelet-derived growth factor receptor (PDGFR). Standard radiological response evaluation, pharmacokinetics, gene mutations and positron emission tomography imaging were assessed.

Natural killer cell IFN-gamma levels predict long-term survival with imatinib mesylate therapy in gastrointestinal stromal tumor-bearing patients.

Clinical outcomes of gastrointestinal stromal tumor (GIST)-bearing patients treated with imatinib mesylate (IM) are variable. Other than the site of mutation within the c-kit gene, prognostic features of GIST remain undefined. IM can exhibit off-target effects such as triggering natural killer (NK) cell activity.

[Gastrointestinal stroma tumors (GIST): what is new in 2009?].

Advances in the field of GIST accumulate very rapidly. The objective of this short review is to underline their consequences for the diagnostic practice and for the understanding of their pathogenesis. The diagnosis of GIST still relies on histology and immunohistochemistry; this is only in the case of the very rare KIT-negative tumors that other markers (such as DOG-1 and PKCtheta) have to be considered and that the identification of mutations of KIT et PDGRA may have a diagnostic interest.

Foamy macrophages from tuberculous patients' granulomas constitute a nutrient-rich reservoir for M. tuberculosis persistence.

Tuberculosis (TB) is characterized by a tight interplay between Mycobacterium tuberculosis and host cells within granulomas. These cellular aggregates restrict bacterial spreading, but do not kill all the bacilli, which can persist for years. In-depth investigation of M.

Frequent EGFR Positivity and Overexpression in High-Grade Areas of Human MPNSTs.

Malignant peripheral nerve sheath tumours (MPNSTs) are highly malignant and resistant. Transformation might implicate up regulation of epidermal growth factor receptor (EGFR). Fifty-two MPNST samples were studied for EGFR, Ki-67, p53, and survivin expression by immunohistochemistry and for EGFR amplification by in situ hybridization.

KIT mutations induce intracellular retention and activation of an immature form of the KIT protein in gastrointestinal stromal tumors.

Purpose: Gastrointestinal stromal tumors (GIST) are frequently associated with gain-of-function mutations of KIT, which can be inhibited by imatinib both in vitro and in vivo. The survival of patients with GIST, following imatinib therapy, has been correlated with the nature of mutations but not with KIT expression.

Experimental Design: Subcellular localization, activation, and trafficking of the mature and the immature forms of KIT were investigated in GIST samples and in NIH3T3 cells infected with two different GIST-type exon 11-mutated human KIT cDNA.

Clinical, biologic, and pathologic features in 157 patients with angioimmunoblastic T-cell lymphoma treated within the Groupe d'Etude des Lymphomes de l'Adulte (GELA) trials.

To evaluate the prognostic significance of clinicobiologic and pathological features in angioimmunoblastic T-cell lymphoma (AITL), 157 AITL patients were retrieved from the GELA LNH87-LNH93 randomized clinical trials. One hundred forty-seven patients received a cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-like regimen with intensified courses in half of them. Histologically, 41 cases were classified as "rich in large cells" and 116 as "classic" (including 19 rich in epithelioid cells, 14 rich in clear cells, and 4 with hyperplastic germinal centers).

Prosthetic hip infection caused by Tropheryma whipplei.

We report a case of prosthetic hip infection due to Tropheryma whipplei in a 74-year-old man not previously known to have Whipple's disease. Diagnosis was based on systematic 16S rRNA gene amplification and sequencing of samples obtained during revision hip arthroplasty.

IFN-gamma mediates the rejection of haematopoietic stem cells in IFN-gammaR1-deficient hosts.

Background: Interferon-gamma receptor 1 (IFN-gammaR1) deficiency is a life-threatening inherited disorder, conferring predisposition to mycobacterial diseases. Haematopoietic stem cell transplantation (HSCT) is the only curative treatment available, but is hampered by a very high rate of graft rejection, even with intra-familial HLA-identical transplants. This high rejection rate is not seen in any other congenital disorders and remains unexplained.

KRAS mutations as an independent prognostic factor in patients with advanced colorectal cancer treated with cetuximab.

Purpose: Cetuximab is efficient in advanced colorectal cancer (CRC). We previously showed that KRAS mutations were associated with resistance to cetuximab in 30 CRC patients. The aim of this study was to validate, in an independent larger series of 89 patients, the prognostic value of KRAS mutations on response to cetuximab and survival.

Importance of T cells, gamma interferon, and tumor necrosis factor in immune control of the rapid grower Mycobacterium abscessus in C57BL/6 mice.

Mycobacterium abscessus is an emerging rapidly growing mycobacterium that causes tuberculous-like lesions in humans. We studied the immune control of this organism in C57BL/6 mice challenged intravenously with 10(7) CFU. Bacteria were eliminated from both the spleen and the liver within 90 days, and liver histology showed organized granulomatous lesions.

Expansion of regulatory T cells in patients with Langerhans cell histiocytosis.

Background: Langerhans cell histiocytosis (LCH) is a rare clonal granulomatous disease that affects mainly children. LCH can involve various tissues such as bone, skin, lung, bone marrow, lymph nodes, and the central nervous system, and is frequently responsible for functional sequelae. The pathophysiology of LCH is unclear, but the uncontrolled proliferation of Langerhans cells (LCs) is believed to be the primary event in the formation of granulomas.