Deficiency of glycosylphosphatidylinositol (GPI)-anchored molecules on blood cells accounts for most features of paroxysmal nocturnal hemoglobinuria (PNH) but not for the expansion of PNH (GPI ؊ ) clone(s).A plausible model is that PNH clones expand by escaping negative selection exerted by autoreactive T cells against normal (GPI ؉ ) hematopoiesis. By a systematic analysis of T-cell receptor beta (TCR-␤) clonotypes of the CD8 ؉ CD57 ؉ T-cell population, frequently deranged in PNH, we show recurrent clonotypes in PNH patients but not in healthy controls: 11 of 16 patients shared at least 1 of 5 clonotypes, and a set of closely related clonotypes was present in 9 patients. The presence of T-cell clones bearing a set of highly homologous TCR-␤ molecules in most patients with hemolytic PNH is consistent with an immune process driven by the same (or similar) antigen(s)-probably a nonpeptide antigen, because patients sharing clonotypes do not all share identical HLA alleles. These data confirm that CD8 ؉ CD57 ؉ T cells play a role in PNH pathogenesis and provide strong new support to the hypothesis that the expansion of the GPI ؊ blood cell population in PNH is due to selective damage to normal hematopoiesis mediated by an autoimmune attack against a nonpeptide antigen(s) that could be the GPI anchor itself. IntroductionParoxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disorder of the hematopoietic stem cell (HSC) 1 characterized by 3 clinical hallmarks: intravascular hemolysis, tendency to venous thrombosis, and variable degrees of bone marrow failure. [2][3][4] The primary molecular lesion responsible for PNH is a somatic mutation of the X-linked PIGA gene in HSCs, 5,6 resulting in either complete or partial deficiency of all glycosylphosphatidylinositol (GPI)-linked proteins from the cell membrane of the progeny of the mutated HSC (GPI Ϫ ). 7,8 The deficiency of the GPI-linked proteins (including the complement-regulating proteins CD59 and CD55) from the surface of blood cells explains the intravascular hemolysis 9 and probably underlies the increased tendency to venous thrombosis. 10 However, a PIGA gene mutation per se does not explain the bone marrow failure and the expansion of the GPI Ϫ clone. In fact, very rare GPI Ϫ blood cells are present in healthy subjects, 11 but only in PNH patients do the GPI Ϫ cells expand and contribute to hematopoiesis to various degrees, side by side with normal (GPI ϩ ) hematopoiesis. 12,13 Clinical observations, 14,15 in vitro hematopoietic colony studies, 16,17 and data from PNH mouse models [18][19][20] indicate that GPI Ϫ HSCs do not have an absolute growth advantage. The close relationship of PNH to idiopathic aplastic anemia (IAA) has suggested that autoreactive T cells against HSCs believed to be responsible for IAA may be at work also in PNH. Specifically, it has been hypothesized that in PNH autoreactive T cells destroy selectively GPI ϩ (normal) HSCs, whereas GPI Ϫ (PNH)HSCs can escape T-cell-mediated damage, thus being able to survive and expand. 21 In r...

CTLA-4 blockade with monoclonal antibodies can lead to cancer regression in patients with metastatic melanoma (MM). CTLA-4 gene polymorphisms may influence the response to anti-CTLA-4 antibodies although few data are available regarding this issue. We analyzed six CTLA-4 single nucleotide polymorphisms (-1661A > G, -1577G > A, -658C > T, -319C > T, +49A > G, and CT60G > A) in 14 Italian MM patients and 45 healthy subjects. We found a significant association between the -1577G/A and CT60G/A genotypes and improved overall survival (Pc < 0.006, Bonferroni corrected), further confirmed by the diplotype analysis (-1577 & CT60 GG-AA diplotype, p < 0.001). A positive trend toward an association between these genotypes and response to therapy was also observed.

No abstract

BackgroundTrastuzumab is a humanized monoclonal antibody (mAb) currently used for the treatment of breast cancer (BC) patients with HER-2 overexpressing tumor subtype. Previous data reported the involvement of FcγRIIIA/IIA gene polymorphisms and/or antibody-dependent cellular cytotoxicity (ADCC) in the therapeutic efficacy of trastuzumab, although results on these issues are still controversial. This study was aimed to evaluate in vitro the functional relationships among FcγRIIIA/IIA polymorphisms, ADCC intensity and HER-2 expression on tumor target cells and to correlate them with response to trastuzumab.Patients and methodsTwenty-five patients with HER-2 overexpressing BC, receiving trastuzumab in a neoadjuvant (NEO) or metastatic (MTS) setting, were genotyped for the FcγRIIIA 158V>F and FcγRIIA 131H>R polymorphisms by a newly developed pyrosequencing assay and by multiplex Tetra-primer-ARMS PCR, respectively. Trastuzumab-mediated ADCC of patients’ peripheral blood mononuclear cells (PBMCs) was evaluated prior to therapy and measured by 51Chromium release using as targets three human BC cell lines showing different levels of reactivity with trastuzumab.ResultsWe found that the FcγRIIIA 158F and/or the FcγRIIA 131R variants, commonly reported as unfavorable in BC, may actually behave as ADCC favorable genotypes, in both the NEO (P ranging from 0.009 to 0.039 and from 0.007 to 0.047, respectively) and MTS (P ranging from 0.009 to 0.032 and P = 0.034, respectively) patients. The ADCC intensity was affected by different levels of trastuzumab reactivity with BC target cells. In this context, the MCF-7 cell line, showing the lowest reactivity with trastuzumab, resulted the most suitable cell line for evaluating ADCC and response to trastuzumab. Indeed, we found a statistically significant correlation between an increased frequency of patients showing ADCC of MCF-7 and complete response to trastuzumab in the NEO setting (P = 0.006).ConclusionsAlthough this study was performed in a limited number of patients, it would indicate a correlation of FcγR gene polymorphisms to the ADCC extent in combination with the HER-2 expression levels on tumor target cells in BC patients. However, to confirm our findings further experimental evidences obtained from a larger cohort of BC patients are mandatory.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-015-0680-0) contains supplementary material, which is available to authorized users.

Background The demonstration of EGFR T790M gene mutation in plasma is crucial to assess the eligibility of Non Small Cell Lung Cancer (NSCLC) patients, who have acquired resistance to first or second generation Tyrosine Kinase Inhibitors (TKIs), to receive a subsequent treatment with osimertinib. Since circulating tumor DNA (ctDNA) is present in very low amounts in plasma, high sensitive and specific methods are required for molecular analysis. Improving sensitivity of T790M mutation detection in plasma ctDNA enables a larger number of NSCLC patients to receive the appropriate therapy without any further invasive procedure. Methods A tag-based next generation sequencing (NGS) platform capable of tagging rare circulating tumor DNA alleles was employed in this study for the identification of T790M mutation in 42 post-TKI NSCLC patients. Results Compared to Real Time PCR, tag-based NGS improved the T790M detection rate (42.85% versus 21.4%, respectively), especially in those cases with a low median mutation abundance (i.e. 0.24, range 0.07–0.78). Moreover, the tag-based NGS identified EGFR activating mutations more efficiently than Real Time PCR (85.7% versus 61.9% detection rate, respectively), particularly of the L858R variant type (0.06–0.75 mutation abundance range). Patients in whom the T790M mutation was detected in plasma, achieved an objective response to osimertinib (9/14, 64.28%). Conclusions Tag-based NGS represents an accurate and sensitive tool in a clinical setting for non-invasive assessment and monitoring of T790M variant in NSCLC patients. Electronic supplementary material The online version of this article (10.1186/s10020-019-0082-5) contains supplementary material, which is available to authorized users.