Prevalence of respiratory viruses by Multiplex PCR: a four-and-a-half year retrospective study in an Italian general hospital

Viruses are frequent causal agents of acute respiratory infections and the most common are influenza virus, respiratory syncytial virus (RSV), human parainfluenza virus (HPIV), human metapneumovirus (HMPV), rhinovirus (RV), adenovirus (AdV) and the four endemic human coronaviruses (HCoV) -229E, -NL63, -OC43, -HKU1. Multiplex real-time PCR platforms are becoming increasingly common in laboratories mostly in relation to the increased diagnostic sensitivity and reduced turnaround time. The aim of our study was to determine the prevalence of respiratory viruses in a population of patients within the S.S. Antonio e Biagio e Cesare Arrigo General Hospital catchment area of Alessandria, Italy, from January 2016 to June 2020. Therefore, we retrospectively analyzed the results of multiplex real-time PCR performed on nasopharyngeal swabs collected from consecutive patients with symptoms of respiratory infection. A total of 572 patients were included in the study subdivided as follows: pediatric 197/572 (34.4%), adults 200/572 (35%) and elderly 175/572 (30.6%). Among all samples, 235/572 (41.1%) were positive for a respiratory virus, of whom 189/235 (80.4%) were monomicrobial. The prevalence was: 15.5% (89/572) of rhinovirus/enterovirus (RV/EV); 9.4% (54/572) of RSV; 8.9% (51/572) of influenza virus; 5.4% (31/572) of AdV; 3.1% (18/572) of HCoV; 2.8% (16/572) of HPIV; and 2.3% (13/572) of HMPV. RV/EV were the pathogens most frequently involved in coinfections (34.7%, 16/46), followed by AdV (19.6%, 9/46) and influenza virus (19.6%, 9/46). Samples collected from the pediatric group were more frequently positive. The prevalence of positive pediatric samples compared to adults and elderly, respectively was: 28.4% (56/197) for RV/EV vs 10.5% (21/200) vs 6.9% (12/175), p<0.0001; 18.8% (37/197) for RSV vs 2% (4/200) vs 7.4% (13/175), p<0.0001; 13.7% (27/197) for AdV vs 1% (2/200) vs 1.1% (2/175), p<0.0001; and 6.6% (13/197) for HPIV vs 0.5% (1/200) vs 1.1% (2/175), (p<0.0001). With regard to seasonality, a significantly higher prevalence of influenza virus (p<0.0001) and RSV (p=0.029) was found during winter, with peaks in January-February. AdV peaked during winter 2018-2019 (p=0.004), while HCoV were detected with a significantly higher prevalence during winter 2019-2020 (p=0.037). With regard to HPIV, a significant peak from summer to fall 2018 was observed (p=0.016). Most viral respiratory infections have seasonal patterns and the prevalence of respiratory viruses varies according to the method, geographic area and population considered. Knowledge of local epidemiology is therefore crucial for implementation of prevention and treatment strategies.

Clinical Utility of Platelet Count for Screening of Malaria

Light microscopy, immunochromatographic rapid diagnostic tests and molecular methods are widely used to diagnose malaria. The aim of this study was to find variables among commonly available urgent blood tests to identify patients with low probability of having malaria in small-scale healthcare facilities in which none of the described methods is feasible within a short time. Diagnosis of malaria was made by examining both stained thick and thin blood films by light microscopy. Two hundred and eleven samples were included. Reduced platelet count and increased values of C-reactive protein (CRP) and total bilirubin were the variables most strongly associated with malaria (P<0.0001). The best screening cut-off values obtained by receiver operating characteristic curve analysis for a negative result for malaria were: platelets ≥185,000 cells/μl; CRP ≤2 mg/dl; total bilirubin ≤0.28 mg/dl. The logistic regression model of log-transformed variables showed how platelet count was the only independent variable related to the odds of having a negative blood film result for malaria (odds ratio: 2.621; 95% confidence interval: 1.441-4.768; P=0.002). A platelet count of ≥185,000 cells/μl can be considered a screening value to identify patients with high-probability of a negative blood film result for malaria.

Dasatinib modulates sensitivity to pemetrexed in malignant pleural mesothelioma cell lines

Background

Thymidylate synthase (TS), one of the key enzymes for thymidine synthesis, is a target of pemetrexed (PEM), a key agent for the systemic therapy of malignant pleural mesothelioma (MPM) and its overexpression has been correlated to PEM-resistance. In MPM, experimental data report activation of the c-SRC tyrosine kinase suggesting it as a potential target to be further investigated.

Results

MPM cell lines showed different sensitivity, being MSTO the most and REN the least sensitive to PEM. REN cells showed high levels of both TS and SRC: dasatinib inhibited SRC activation and suppressed TS protein expression, starting from 100 nM dose, blocking the PEM-induced up regulation of TS protein levels. Dasatinib treatment impaired cells migration, and both sequential and co-administration with PEM significantly increased apoptosis. Dasatinib pretreatment improved sensitivity to PEM, downregulated TS promoter activity and, in association with PEM, modulated the downstream PI3K-Akt-mTOR signaling.

Cell lines and Methods

In three MPM cell lines (MPP89, REN and MSTO), the effects of c-SRC inhibition, in correlation with TS expression and PEM sensitivity, were evaluated. PEM and dasatinib, a SRC inhibitor, were administered as single agents, in combination or sequentially. Cell viability, apoptosis and migration, as well as TS expression and SRC activation have been assessed.

Conclusions

These data indicate that dasatinib sensitizes mesothelioma cells to PEM through TS down-regulation.

Precision medicine in age-specific non-small-cell-lung-cancer patients: Integrating biomolecular results into clinical practice-A new approach to improve personalized translational research

OBJECTIVES

Non-small-cell-lung-cancer (NSCLC) in young adults (≤45 years-old) accounts for a very small proportion, as this disease usually occurs in people at older age. The youthful NSCLC may constitute an entity with different clinical-pathologic characteristics, having predominance of adenocarcinoma histology and affecting mostly non-smoker subjects. However, without specific guidelines, it is currently considered, both clinically and biologically, as the same disease of the older counterpart, although differences have been documented.

MATERIALS AND METHODS

Using formalin-fixed paraffin embedded diagnostic tissues (FFPE), targeted next-generation sequencing (NGS) technology allowed to provide insight the mutational pattern of 46 oncogenes and tumor-suppressor genes in 26 young patients (Y). Two additional populations, including a FFPE series of aged counterpart (A: 29 patients) and a group of healthy young controls (C: 21, blood provided), were also investigated to compare NGS profiles.

RESULTS

Clinical features of enrolled young patients harmonized with literature data, being most of patients women (58%), never-smokers (38%) and with adenocarcinoma histology (96%). C group was adopted to filter all the non-synonymous genetic variations (NS-GVs) not-associated with malignant overt disease. This skimmed selection mostly highlighted three genes: TP53, EGFR and KRAS. TP53 NS-GVs were numerically more numerous in younger, many involving specific annotated hotspot (R248, R273, G245, R249 and R282); the majority of EGFR NS-GVs was detected in young patients, with higher allelic frequency and mostly represented by exon 19 deletions. On the contrary, KRAS NS-GVs were mainly detected in aged population, with a prevalent compact pattern involving p.G12 position and associated with adenocarcinoma histology.

CONCLUSION

This retrospective study confirmed the feasibility of NGS approach for genetic characterization of NSCLC young adult patients, supporting the involvement of TP53, EGFR, and KRAS alterations in the early onset of NSCLC. Some of these GVs, or their pattern, may potentially contribute to customized targeted therapies.

Expression analysis of genes involved in DNA repair or synthesis in mixed neuroendocrine/nonneuroendocrine carcinomas

BACKGROUND

Mixed neuroendocrine/nonneuroendocrine carcinomas are heterogeneous tumors with poorly defined diagnostic and clinical features and without pathological or molecular markers of prognosis or markers predicting their response to therapy. We aimed at analyzing the pathological features and the expression of genes involved in DNA repair or synthesis in a cohort of patients with mixed carcinomas from different sites as compared to the patients' outcome.

METHODS

Relative cDNA quantification of ribonucleotide reductase, large subunit 1, excision repair cross-complementation group 1, thymidylate synthase and topoisomerase IIa genes was tested using real-time PCR on microdissected neuroendocrine and nonneuroendocrine tumor components of 42 mixed cases (from the lung as well as the gastrointestinal and genitourinary tracts) and on 45 control cases of pure neuroendocrine and nonneuroendocrine carcinomas.

RESULTS

The expression levels of all genes were stable comparing nonneuroendocrine and neuroendocrine components of mixed cases (except for topoisomerase IIa in lung samples) but significantly different as compared to control nonneuroendocrine and neuroendocrine tumors. In the multivariate analysis including all clinical and pathological parameters and gene expression levels available, a predominant nonneuroendocrine component, the administration of additional therapy other than surgery and a high thymidylate synthase expression in nonneuroendocrine tumor tissue were significantly associated with a lower risk of a patient's death.

CONCLUSIONS

Our data show that mixed neuroendocrine/nonneuroendocrine carcinomas are different at the molecular level from their pure neuroendocrine and nonneuroendocrine counterparts, and detailed analyses of their clinical, pathological and molecular features may improve the clinical strategies for the treatment of these rare and underestimated tumors.

Histone deacetylase inhibition synergistically enhances pemetrexed cytotoxicity through induction of apoptosis and autophagy in non-small cell lung cancer

Background

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. Pemetrexed, a multi-target folate antagonist, has demonstrated efficacy in NSCLC histological subtypes characterized by low thymidylate synthase (TS) expression. Among many other potential targets, histone deacetylase inhibitors (HDACi) modulate TS expression, potentially sensitizing to the cytotoxic action of anti-cancer drugs that target the folate pathway, such as pemetrexed. Since high levels of TS have been linked to clinical resistance to pemetrexed in NSCLC, herein we investigated the molecular and functional effects of combined pemetrexed and ITF2357, a pan-HDACi currently in clinical trials as an anti-cancer agent.

Results

In NSCLC cell lines, HDAC inhibition by ITF2357 induced histone and tubulin acetylation and downregulated TS expression at the mRNA and protein level. In combination experiments in vitro ITF2357 and pemetrexed demonstrated sequence-dependent synergistic growth-inhibitory effects, with the sequence pemetrexed followed by ITF2357 inducing a strikingly synergistic reduction in cell viability and induction of both apoptosis and autophagy in all cell line models tested, encompassing both adenocarcinoma and squamous cell carcinoma. Conversely, simultaneous administration of both drugs achieved frankly antagonistic effects, while the sequence of ITF2357 followed by pemetrexed had additive to slightly synergistic growth-inhibitory effects only in certain cell lines. Similarly, highly synergistic growth inhibition was also observed in patient-derived lung cancer stem cells (LCSC) exposed to pemetrexed followed by ITF2357. In terms of molecular mechanisms of interaction, the synergistic growth-inhibitory effects observed were only partially related to TS modulation by ITF2357, as genetic silencing of TS expression potentiated growth inhibition by either pemetrexed or ITF2357 and, to a lesser extent, by their sequential combination. Genetic and pharmacological approaches provided an interesting link between the autophagic and apoptotic pathways, and showed that sequential pemetrexed/ITF2357 causes a toxic form of autophagy with consequent activation of a caspase-dependent apoptotic program. In vivo experiments in NSCLC xenografts confirmed that sequential pemetrexed/ITF2357 is feasible and results in increased inhibition of tumor growth and increased mice survival.

Conclusions

Overall, these data provide a strong rationale for the clinical development of sequential schedules employing pemetrexed followed by HDACi in NSCLC.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-4598-13-230) contains supplementary material, which is available to authorized users.

Tumor/stromal caveolin-1 expression patterns in pleural mesothelioma define a subgroup of the epithelial histotype with poorer prognosis

OBJECTIVES

Malignant pleural mesothelioma (MPM) is a highly aggressive disease for which new prognostic biomarkers need to be identified. Caveolin-1 (CAV1), the most important member of caveolae, has been described as deregulated in MPM at the genomic level, but detailed histologic information on its distribution and prognostic role is still lacking.

METHODS

A series of 131 MPMs (91 epithelial, 17 biphasic, and 23 sarcomatous histotype) were investigated for CAV1 expression with immunohistochemistry and correlated with clinical-pathologic variables and outcome.

RESULTS

CAV1 was detected in neoplastic cells of 70 (77%) of 91 epithelial, 17 (100%) of 17 biphasic, and 23 (100%) of 23 sarcomatous MPMs. Furthermore, in the epithelial group, CAV1 expression in spindle-shaped stromal cells was detected in 61 (67%) of 91 cases.

CONCLUSIONS

The presence of stromal CAV1 expression was associated with a worse patient outcome. In MPM, CAV1 is differentially expressed according to low- to high-grade histotypes. Furthermore, in the MPM epithelial group, additional stromal CAV1 expression is associated with a worse prognosis.

Messenger RNA and protein expression of thymidylate synthase and DNA repair genes in thymic tumors

BACKGROUND

Thymic epithelial tumors include several entities with different biologic behavior. Chemotherapy is indicated in advanced disease, but limited data exist on gene expression correlation with the response to chemotherapeutic agents.

PATIENTS AND METHODS

A series of 69 thymic neoplasms (7 A-, 6 AB-, 6 B1-, 10 B2-, 14 B3-thymomas, 22 carcinomas and 4 combined tumors) was collected to assess gene expression of thymidylate synthase (TS), excision repair cross complementing-1 (ERCC1), ribonucleotide reductase subunit 1 (RRM1), topoisomerase 2α (TOP2A) and mTOR.

RESULTS

A strong linear correlation between TS gene and protein expression was observed (P<0.0001, R=0.40). TS expression was significantly lower in pure A-thymomas and thymic carcinomas (P<0.0001) and progressively decreasing from B1-type to thymic carcinomas (B1>B2>B3>C; P<0.0001). RRM1 and TOP2A mRNA expression levels were significantly correlated with TS levels (both P=0.03) with a similar trend of expression among histotypes. RRM1 and TOP2A high levels were significantly correlated with high TS (P=0.03) and low tumor stages (I-II) (P<0.0001 and P<0.01, respectively). No relevant changes of ERCC1 and mTOR were detected.

CONCLUSIONS

Low TS and, to a minor extent, RRM1 and TOP2A expression were detected in aggressive thymic tumors. These findings should be prospectively considered in selecting the most appropriate chemotherapy.