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1.
Mod Pathol ; 33(2): 179-187, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31028364

RESUMO

Peripheral T-cell lymphoma not otherwise specified represents a diagnostic category comprising clinically, histologically, and molecularly heterogeneous neoplasms that are poorly understood. The genetic landscape of peripheral T-cell lymphoma not otherwise specified remains largely undefined, only a few sequencing studies having been conducted so far. In order to improve our understanding of the genetics of this neoplasm, we performed whole exome sequencing along with RNA-sequencing in a discovery set of 21 cases. According to whole exome sequencing results and mutations previously reported in other peripheral T-cell lymphomas, 137 genes were sequenced by a targeted deep approach in 71 tumor samples. In addition to epigenetic modifiers implicated in all subtypes of T-cell neoplasm (TET2, DNMT3A, KMT2D, KMT2C, SETD2), recurrent mutations of the FAT1 tumor suppressor gene were for the first time recorded in 39% of cases. Mutations of the tumor suppressor genes LATS1, STK3, ATM, TP53, and TP63 were also observed, although at a lower frequency. Patients with FAT1 mutations showed inferior overall survival compared to those with wild-type FAT1. Although peripheral T-cell lymphoma not otherwise specified remains a broad category also on molecular grounds, the present study highlights that FAT1 mutations occur in a significant proportion of cases, being provided with both pathogenetic and prognostic impact.

3.
Heliyon ; 5(11): e02643, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31840115

RESUMO

IFI16, member of the IFN-inducible PYHIN-200 gene family, modulates proliferation, survival and differentiation of different cell lineages. In particular, IFI16 expression, which is regulated during the differentiation of B cells, was recently studied in B-CLL as well. Here, we compared IFI16 expression in several lymphomas including Burkitt lymphoma, diffuse large B-cell lymphoma, follicular lymphoma, marginal zone lymphoma and mantle cell lymphoma with respect to normal cell counterparts. We observed that IFI16 expression was significantly deregulated only in mantle cell lymphoma (p < 0.05). Notably, IFI16 was associated with the expression of genes involved in interferon response, cell cycle, cell death and proliferation and, interestingly, lipid and glucose metabolism, suggesting that IFI16 deregulation might be associated with relevant changes in cell biology. In our group of mantle cell lymphoma samples a correlation between patient survival and IFI16 expression was not detected even though mantle cell lymphoma prognosis is known to be associated with cell proliferation. Altogether, these results suggest a complex relationship between IFI16 expression and MCL which needs to be analyzed in further studies.

4.
Virchows Arch ; 475(6): 771-779, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31686194

RESUMO

The aim of this study was to review the histopathological, phenotypic, and molecular characteristics of pediatric-type follicular lymphoma (PTFL) and to assess the diagnostic value of novel immunohistochemical markers in distinguishing PTFL from follicular hyperplasia (FH). A total of 13 nodal PTFLs were investigated using immunohistochemistry, fluorescence in situ hybridization (FISH), and PCR and were compared with a further 20 reactive lymph nodes showing FH. Morphologically, PTFL cases exhibited a follicular growth pattern with irregular lymphoid follicles in which the germinal centers were composed of numerous blastoid cells showing a starry-sky appearance. Immunohistochemistry highlighted preserved CD10 (13/13) and BCL6 (13/13) staining, CD20 (13/13) positivity, a K light chain predominance (7/13), and partial BCL2 expression in 6/13 cases (using antibodies 124, E17, and SP66). The germinal center (GC)-associated markers stathmin and LLT-1 were positive in most of the cases (12/13 and 12/13, respectively). Interestingly, FOXP-1 was uniformly positive in PTFL (12/13 cases) in contrast to reactive GCs in FH, where only a few isolated positive cells were observed. FISH revealed no evidence of BCL2, BCL6, or MYC rearrangements in the examined cases. By PCR, clonal immunoglobulin gene rearrangements were detected in 100% of the tested PTFL cases. Our study confirmed the unique morphological and immunophenotypic features of PTFL and suggests that FOXP-1 can represent a novel useful diagnostic marker in the differential diagnosis between PTFL and FH.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Linfoma de Células B/patologia , Linfoma Folicular/metabolismo , Linfoma Folicular/patologia , Proteínas Repressoras/metabolismo , Adolescente , Adulto , Criança , Diagnóstico Diferencial , Humanos , Imuno-Histoquímica/métodos , Imunofenotipagem/métodos , Linfoma de Células B/diagnóstico , Linfoma de Células B/metabolismo , Linfoma Folicular/diagnóstico , Masculino , Estatmina/metabolismo , Adulto Jovem
5.
Case Rep Hematol ; 2019: 8959145, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31662919

RESUMO

Human immune deficiency virus- (HIV-) infected individuals present a higher risk of developing malignancies. Herein, we are presenting an unusual case of an untreated HIV+ patient, who developed two distinct lymphoproliferative disorders in a period of 4 years: a primary cutaneous T-cell lymphoma (PCTCL) and a diffuse large B-cell lymphoma (DLBCL) not otherwise specified (NOS), the latter developed while commencing combined antiretroviral therapy (cART). The two lymphomas also showed peculiar features: PCTCL are rarely described in HIV+ setting and particularly at such a low clinical stage, and the DLBCL showed uncommon cytology, non-GCB phenotype, EBER negativity, and absence of c-MYC translocation, all atypical features in this clinical context. This report not only confirms the increased risk of lymphoma for HIV+ patients and HIV infection being one of the major risk factors for lymphoid disorders but draws the attention on the possible occurrence of unusual features, suggesting that HIV serology should always be investigated in the clinical suspicion of lymphoma.

6.
Blood ; 134(24): 2159-2170, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31562134

RESUMO

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of mature T-cell malignancies; approximately one-third of cases are designated as PTCL-not otherwise specified (PTCL-NOS). Using gene-expression profiling (GEP), we have previously defined 2 major molecular subtypes of PTCL-NOS, PTCL-GATA3 and PTCL-TBX21, which have distinct biological differences in oncogenic pathways and prognosis. In the current study, we generated an immunohistochemistry (IHC) algorithm to identify the 2 subtypes in paraffin tissue using antibodies to key transcriptional factors (GATA3 and TBX21) and their target proteins (CCR4 and CXCR3). In a training cohort of 49 cases of PTCL-NOS with corresponding GEP data, the 2 subtypes identified by the IHC algorithm matched the GEP results with high sensitivity (85%) and showed a significant difference in overall survival (OS) (P = .03). The IHC algorithm classification showed high interobserver reproducibility among pathologists and was validated in a second PTCL-NOS cohort (n = 124), where a significant difference in OS between the PTCL-GATA3 and PTCL-TBX21 subtypes was confirmed (P = .003). In multivariate analysis, a high International Prognostic Index score (3-5) and the PTCL-GATA3 subtype identified by IHC were independent adverse predictors of OS (P = .0015). Additionally, the 2 IHC-defined subtypes were significantly associated with distinct morphological features (P < .001), and there was a significant enrichment of an activated CD8+ cytotoxic phenotype in the PTCL-TBX21 subtype (P = .03). The IHC algorithm will aid in identifying the 2 subtypes in clinical practice, which will aid the future clinical management of patients and facilitate risk stratification in clinical trials.

7.
Front Genet ; 10: 780, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31552092

RESUMO

Lennert lymphoma (LL) is a lymphoepithelioid morphological variant of peripheral T-cell lymphoma-not otherwise specified (PTCL/NOS), clinically characterized by better prognosis if compared with other PTCL/NOS. Although well characterized as far as morphology and phenotype are concerned, very little is known regarding its molecular features. In this study, we investigated the transcriptional profile of this tumor aiming 1) to identify its cellular counterparts; 2) to better define its relation with other PTCLs-and, therefore, its possible position in lymphoma classification; and 3) to define pathogenetic mechanisms, possibly unveiling novel therapeutic targets. To address these issues, we performed gene and microRNA expression profiling on LL and other PTCL/NOS cases; we identified different genes and microRNAs that discriminated LL from other PTCL/NOS. Particularly, LL revealed a molecular signature significantly enriched in helper function and clearly distinguishable from other PTCL/NOS. Furthermore, PI3K/Akt/mTOR pathway emerged as novel potential therapeutic target. In conclusion, based on the already known particular morphological and clinical features, the new molecular findings support the hypothesis that LL might be classified as a separate entity. Preclinical and clinical studies testing the efficacy of PI3K/MTOR inhibitors in this setting are warranted.

8.
Oncoimmunology ; 8(9): e1617588, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428517

RESUMO

Few studies were conducted investigating the immunological profiles in gastrointestinal stromal tumors (GIST). Adaptive and innate immune cells are present in the tumor microenvironment, indicating GIST as inflamed tumors. In addition, murine models suggested a potential interaction between immune components and imatinib. In this retrospective study, the GIST immunological profile was investigated through in silico analysis and immunohistochemistry (IHC), exploring the basis for immunotherapy approaches. Gene expression profiles (GEP) from 31 KIT/PDGFRA-mutant GIST were analyzed to evaluate the tumor microenvironment and immunotherapy predictive signatures such as the expanded IFN-γ-induced immune signature (EIIS) and the T-cell-inflamed signature (TIS). GEP and IHC supported the presence of immune infiltrate in GIST, with dominance of CD4+ and CD8+ T cells and M2 macrophages showing a remarkable similarity with melanoma microenvironment. The EIIS genes were expressed in most of GIST samples and positively correlated with PD-L1 abundance (p < .0001). Co-expression was also found between PD-L1 and CD8A (p < .0001) or CD8B (p = .0003). Moreover, the median TIS score for GIST was between the 65th and 70th percentile of the Cancer Genome Atlas dataset, in the same range of tumors responding to anti-PD-1/PD-L1. Analysis of the Gene Expression Omnibus database GIST samples pre- and post-treatment confirmed that imatinib downregulates PD-L1 and IRF1 expression through the inhibition of KIT and PDGFRA, thus contributing to counteract the suppressed adaptive immune response against GIST. The presence of a rich immune infiltrate in GIST along with the presence of TIS and EIIS suggests that GIST may benefit from immunotherapy along with tyrosine kinase inhibitors.

9.
Hematol Oncol ; 37(4): 368-374, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31325190

RESUMO

In 2009, the four laboratories of the Fondazione Italiana Linfomi (FIL) minimal residual disease (MRD) Network started a collaborative effort to harmonize and standardize their methodologies at the national level, performing quality control (QC) rounds for follicular lymphoma (FL) and mantle cell lymphoma (MCL) MRD assessment. In 16 QC rounds between 2010 and 2017, the four laboratories received 208 bone marrow (BM) samples (126 FL; 82 MCL); 187 were analyzed, according to the EuroMRD Consortium guidelines, by both nested (NEST) polymerase chain reaction (PCR) and real-time quantitative (RQ) PCR for BCL2/IGH MBR or IGHV rearrangements. Here, we aimed at analyzing the samples that challenged the interlaboratory reproducibility and data interpretation. Overall, 156/187 BM samples (83%) were concordantly classified as NEST+/RQ+ or NEST-/RQ- by all the four laboratories. The remaining 31 samples (17%) resulted alternatively positive and negative in the interlaboratory evaluations, independently of the method and the type of rearrangement, and were defined "borderline" (brd) samples: 12 proved NEST brd/RQ brd, 7 NEST-/RQ brd, 10 NEST brd/RQ positive not quantifiable (PNQ), and 2 NEST brd/RQ-. Results did not change even increasing the number of replicates/sample. In 6/31 brd samples, droplet digital PCR (ddPCR) was tested and showed no interlaboratory discordance. Despite the high interlaboratory reproducibility in the MRD analysis obtained and maintained by the QC round strategy, samples with the lowest MRD levels can still represent a challenge: 17% (31/187) of our samples showed discordant results in interlaboratory assessments, with 6.4% (12/187) remained brd even applying the two methods. Thus, although representing a minority, brd samples are still problematic, especially when a clinically oriented interpretation of MRD results is required. Alternative, novel methods such as ddPCR and next-generation sequencing have the potential to overcome the current limitations.


Assuntos
Exame de Medula Óssea , Medula Óssea/patologia , Ensaio de Proficiência Laboratorial , Linfoma não Hodgkin/patologia , Reação em Cadeia da Polimerase , Exame de Medula Óssea/normas , Células Clonais , Rearranjo Gênico de Cadeia Pesada de Linfócito B , Genes de Imunoglobulinas , Genes bcl-2 , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Itália/epidemiologia , Linfoma não Hodgkin/genética , Neoplasia Residual , Proteínas de Fusão Oncogênica/análise , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/normas , Proteínas Proto-Oncogênicas c-bcl-2/genética , Garantia da Qualidade dos Cuidados de Saúde , Reprodutibilidade dos Testes , Translocação Genética
10.
Onco Targets Ther ; 12: 4807-4812, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354304

RESUMO

Hairy cell leukemia (HCL) is an uncommon B-cell chronic lymphoproliferative disorder whose pathogenesis and recurrence are strictly dependent on the presence of the BRAF V600E mutant. A 65-year-old male presented a monomorphic epitheliotropic intestinal T-cell lymphoma (formerly enteropathy-associated T-cell lymphoma, type II) with HCL not responding to first-line induction with cladribine. The intestinal lymphoma bears the BRAF V600E mutant, which is the molecular hallmark of HCL, being implicated in its pathogenesis. The case is of interest, as it provides the first description of a BRAF V600E-positive intestinal T-cell lymphoma, along with immunohistochemical and molecular demonstration, occurring in concomitance with HCL. A novel digital PCR-base method for HCL disease assessment is also suggested.

12.
Hum Pathol ; 90: 60-69, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31125630

RESUMO

Breast implant-associated anaplastic large cell lymphoma (BI-ALCL) is a variant of anaplastic large cell lymphoma arising within seroma effusion associated with breast implants. BI-ALCL is a rare disease, recently recognized as a new provisional entity by the 2017 revised World Health Organization classification. All BI-ALCLs tested so far showed a "triple-negative" genetic profile-negative for ALK, DUSP22, and TP63 rearrangements-and were characterized by mutational and gene expression profiles consistent with aberrant activation of the JAK/STAT pathway. The active form of STAT3 (pSTAT3) is constantly expressed in BI-ALCLs and may favor tumor immune escape by triggering the transcription of PDL1 (CD274), a gene encoding the immune-checkpoint molecule programmed cell death ligand 1 (PDL1); immunohistochemical positivity for PDL1 has been recently described in 3 BI-ALCL cases, and one of them also harbored PDL1 gene amplification. We evaluated PDL1 and pSTAT expression by immunohistochemistry and PDL1 copy number alterations (CNAs) at chromosome 9p24.1 by fluorescent in situ hybridization in a cohort of 9 BI-ALCL cases; we also investigated the presence of tumor-infiltrating programmed cell death 1 (PD1)+ T cells (tumor-infiltrating lymphocytes, or TILs) and PDL1+ tumor-associated macrophages (TAMs) in BI-ALCL microenvironment. Tumor cells expressed PDL1 in 5 (56%) of 9 cases and harbored PDL1 CNAs in 3 (33%) of 9 cases; immunohistochemistry for pSTAT3 was positive in all 6 cases tested (100%), indicative of active JAK/STAT signaling. We observed PDL1 CNAs only among PDL1-positive cases, whereas PD1+ TILs and PDL1+ TAMs were present at variable levels in both PDL1-positive and PDL1-negative BI-ALCLs. We report frequent PDL1 expression and recurrent PDL1 CNAs in BI-ALCLs: our data suggest that 9p24.1 alterations represent a common mechanism of PDL1 overexpression in this disease, likely acting in synergy with constitutive pSTAT3 signaling. In PDL1-positive cases without chromosomal aberration, PDL1 expression may be induced by JAK/STAT signaling alone and/or others alternative pathways. BI-ALCL microenvironment hosts variable amounts of PD1+ TILs and PDL1+ TAMs, suggesting the presence of an active PD1/PDL1 axis. These findings may be of therapeutic value in advanced-stage patients who may benefit from a PD1/PDL1 blocking treatment.

13.
Mod Pathol ; 32(9): 1359-1372, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30976104

RESUMO

Merkel cell carcinoma is an aggressive neuroendocrine skin tumor, for which several non-conclusive prognostic factors of adverse clinical behavior have been reported. As promoter methylation of the immune checkpoint receptor CD279/PD-1/PDCD1(mPDCD1) has been shown to be a prognostic factor in different cancers, we investigated its role in Merkel cell carcinoma. mPDCD1was assessed retrospectively in a cohort of 69 Merkel cell carcinoma patients from the University of Bologna, University of Turin and University of Insubria. Kaplan-Meier curves and log-rank tests were calculated for all variables. To assess the influence of mPDCD1, the Cox proportional hazards model and different Royston-Parmar models were evaluated. High PDCD1 methylation (mPDCD1high) was associated with a higher overall mortality at both the univariate analysis (log rank test: χ2 = 5.17, p = 0.023; permutation test: p = 0.023) and the multivariate analysis (HR = 2.111, p = 0.042). The other variables associated with a higher overall mortality at the multivariate analysis were clinical stage III-IV (HR = 2.357, p = 0.008), size > 2 cm (HR = 2.248, p = 0.031) and Merkel cell polyomavirus (HR = 0.397, p = 0.015). Further, mPDCD1high was strongly associated with older age (81 vs 76 years, p = 0.042), absence of immune cells (92.6%, p < 0.001), no expression of PD-L1 by immune cells (70.4%, p = 0.041) and by both immune and tumor cells (70.4%, p = 0.001). mPDCD1 is a valid prognostic parameter in patients affected by Merkel cell carcinoma. In addition, it could provide an estimate of the global PD-1/PD-L1 expression with potentially relevant implications from a therapeutic point of view.

14.
Leuk Lymphoma ; 60(9): 2247-2254, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30821538

RESUMO

Residual masses in patients with mediastinal lymphoma may be positron emission tomography (PET) positive during follow-up also in cases of complete response. The aim of this retrospective study is to verify the reliability of mediastinal PET-positive findings in suggesting disease relapse or progression during follow-up by histological verification. From January 2002 to March 2016, 96 patients with mediastinal lymphoma underwent PET follow-up after front-line treatment. A surgical biopsy was performed to confirm the suspected relapse (for a total of 113 procedures). A lymphoma relapse was diagnosed in 66/102 successful procedures (64.7%). Diagnosis at relapse was concordant with the initial diagnosis in all but 3 cases. Standardized uptake value was significantly higher among patients with relapse than among those who remained in remission (10 versus 5, p < .05). PET scan helps individuate patients with a high suspect of lymphoma relapse and may guide the surgeon to the most suitable target.

17.
Haematologica ; 104(4): 729-737, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30381297

RESUMO

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic malignancy for which there is still no effective therapy. In order to identify genetic alterations useful for a new treatment design, we used whole-exome sequencing to analyze 14 BPDCN patients and the patient-derived CAL-1 cell line. The functional enrichment analysis of mutational data reported the epigenetic regulatory program to be the most significantly undermined (P<0.0001). In particular, twenty-five epigenetic modifiers were found mutated (e.g. ASXL1, TET2, SUZ12, ARID1A, PHF2, CHD8); ASXL1 was the most frequently affected (28.6% of cases). To evaluate the impact of the identified epigenetic mutations at the gene-expression and Histone H3 lysine 27 trimethylation/acetylation levels, we performed additional RNA and pathology tissue-chromatin immunoprecipitation sequencing experiments. The patients displayed enrichment in gene signatures regulated by methylation and modifiable by decitabine administration, shared common H3K27-acetylated regions, and had a set of cell-cycle genes aberrantly up-regulated and marked by promoter acetylation. Collectively, the integration of sequencing data showed the potential of a therapy based on epigenetic agents. Through the adoption of a preclinical BPDCN mouse model, established by CAL-1 cell line xenografting, we demonstrated the efficacy of the combination of the epigenetic drugs 5'-azacytidine and decitabine in controlling disease progression in vivo.

19.
Mod Pathol ; 32(1): 37-47, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30140037

RESUMO

Follicular T cell lymphoma is derived from follicular T-helper cells. In many cases, neoplastic T cells form rosettes around Hodgkin-Reed-Sternberg-like cells, which can lead to the misdiagnosis of classical Hodgkin lymphoma. The aim of the present study was to obtain a better understanding of this rosetting phenomenon and to recognize features that are helpful in the differential diagnosis of classical Hodgkin lymphoma. Sixteen mostly elderly follicular T cell lymphoma patients (mean 66 years) were analyzed. Fifteen of the 16 follicular T cell lymphoma cases presented with Hodgkin-Reed-Sternberg-like cells, which were CD20-positive in 27% of the cases and Epstein-Barr virus-infected in nearly all cases. Frequently, the immunophenotype of rosetting neoplastic T cells differed from the bulk neoplastic cells with less numerous T-follicular helper cell markers expressed, suggesting a modulation of T-follicular helper cell marker expression in the neoplastic T cells. In 75% of the cases, variable CD30 expression was encountered in the neoplastic T cells, likely reflecting an activation state in these cells. Hodgkin-Reed-Sternberg-like cells were positive for CCL17, and follicular T cell lymphoma tumor cells expressed its receptor CCR4 at variable intensity, thus potentially explaining the phenomenon of the tumor cells' rosetting around Hodgkin-Reed-Sternberg-like cells. In summary, this study confirms the presence of Hodgkin-Reed-Sternberg-like cells in a high number of cases of follicular T cell lymphoma, suggesting that Hodgkin-Reed-Sternberg-like cells may contribute to the development of this lymphoma. Hodgkin-Reed-Sternberg-like cells in follicular T cell lymphoma cannot reliably be differentiated from the Hodgkin-Reed-Sternberg cells of classical Hodgkin lymphoma based on their immunophenotype. In contrast, demonstration of a T-follicular helper cell phenotype with CD10 and frequent CD30 expression in the neoplastic T cell population can help to establish the diagnosis of follicular T cell lymphoma, and may even indicate CD30 as a therapeutic target for these patients.


Assuntos
Biomarcadores Tumorais/análise , Doença de Hodgkin/diagnóstico , Antígeno Ki-1/biossíntese , Linfoma Folicular/diagnóstico , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Antígeno Ki-1/análise , Masculino , Pessoa de Meia-Idade , Linfócitos T/patologia
20.
Curr Top Med Chem ; 18(24): 2127-2132, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30569865

RESUMO

BACKGROUND: Pseudomonas aeruginosa is a gram-negative pathogen, associated with a severe mortality rate. It is also difficult to treat due to numerous resistance mechanisms to a wide range of antibiotics. OBJECTIVE: Evaluate the activity of pexiganan, an antimicrobial peptide, in combination with two clinical antibiotics (azithromycin and tigecycline) that are not active against P. aeruginosa. METHODS: Ten clinical P. aeruginosa were isolated from urinary tract infections, blood culture, skin infections and respiratory tract infections. Minimum inhibitory concentrations (MICs) and synergies were evaluated by broth microdilution, checkerboard assays and time-kill studies. In vitro synergy was confirmed with an in vivo experiment using a murine model of sepsis. RESULTS: Pexiganan MICs were included between 2 and 16 mg/L. Tigecycline and azithromycin MICs were high as expected (4-64 mg/L and 32-256 mg/L, respectively). Pexiganan and azithromycin combination resulted to be additive or indifferent while tigecycline and pexiganan combination was synergic against seven out of ten P. aeruginosa and additive against the other strains. In vivo experiment confirmed the in vitro synergy, denoting a significative reduction of bacteria in mice treated with pexiganan and tigecycline combination. CONCLUSION: Antimicrobial peptides are molecules that could be useful in the fight against infections and pexiganan seems to be one of the most promising. Our results demonstrated that, in association with tigecycline, pexiganan administration could overcome antibiotic resistance and increase the effectiveness of treatment against P. aeruginosa sepsis.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Sepse/tratamento farmacológico , Sepse/microbiologia , Tigeciclina/farmacologia , Animais , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Quimioterapia Combinada , Células HeLa , Humanos , Injeções Intraperitoneais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Tigeciclina/administração & dosagem , Tigeciclina/uso terapêutico
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