Rhinovirus Detection in Symptomatic and Asymptomatic Children: Value of Host Transcriptome Analysis.

RATIONALE: Rhinoviruses (RVs) are a major cause of symptomatic respiratory tract infection in all age groups. However, RVs can frequently be detected in asymptomatic individuals. OBJECTIVES: To evaluate the ability of host transcriptional profiling to differentiate between symptomatic RV infection and incidental detection in children. METHODS: Previously healthy children younger than 2 years old (n = 151) were enrolled at four study sites and classified into four clinical groups: RV- healthy control subjects (n = 37), RV+ asymptomatic subjects (n = 14), RV+ outpatients (n = 30), and RV+ inpatients (n = 70). Host responses were analyzed using whole-blood RNA transcriptional profiles. MEASUREMENTS AND MAIN RESULTS: RV infection induced a robust transcriptional signature, which was validated in three independent cohorts and by quantitative real-time polymerase chain reaction with high prediction accuracy. The immune profile of symptomatic RV infection was characterized by overexpression of innate immunity and underexpression of adaptive immunity genes, whereas negligible changes were observed in asymptomatic RV+ subjects. Unsupervised hierarchical clustering identified two main clusters of subjects. The first included 93% of healthy control subjects and 100% of asymptomatic RV+ subjects, and the second comprised 98% of RV+ inpatients and 88% of RV+ outpatients. Genomic scores of healthy control subjects and asymptomatic RV+ children were similar and significantly lower than those of RV+ inpatients and outpatients (P < 0.0001). CONCLUSIONS: Symptomatic RV infection induced a robust and reproducible transcriptional signature, whereas identification of RV in asymptomatic children was not associated with significant systemic transcriptional immune responses. Transcriptional profiling represents a useful tool to discriminate between active infection and incidental virus detection.

Whole blood gene expression profiles to assess pathogenesis and disease severity in infants with respiratory syncytial virus infection.

BACKGROUND: Respiratory syncytial virus (RSV) is the leading cause of viral lower respiratory tract infection (LRTI) and hospitalization in infants. Mostly because of the incomplete understanding of the disease pathogenesis, there is no licensed vaccine, and treatment remains symptomatic. We analyzed whole blood transcriptional profiles to characterize the global host immune response to acute RSV LRTI in infants, to characterize its specificity compared with influenza and human rhinovirus (HRV) LRTI, and to identify biomarkers that can objectively assess RSV disease severity. METHODS AND FINDINGS: This was a prospective observational study over six respiratory seasons including a cohort of infants hospitalized with RSV (n = 135), HRV (n = 30), and influenza (n = 16) LRTI, and healthy age- and sex-matched controls (n = 39). A specific RSV transcriptional profile was identified in whole blood (training cohort, n = 45 infants; Dallas, Texas, US) and validated in three different cohorts (test cohort, n = 46, Dallas, Texas, US; validation cohort A, n = 16, Turku, Finland; validation cohort B, n = 28, Columbus, Ohio, US) with high sensitivity (94% [95% CI 87%-98%]) and specificity (98% [95% CI 88%-99%]). It classified infants with RSV LRTI versus HRV or influenza LRTI with 95% accuracy. The immune dysregulation induced by RSV (overexpression of neutrophil, inflammation, and interferon genes, and suppression of T and B cell genes) persisted beyond the acute disease, and immune dysregulation was greatly impaired in younger infants (<6 mo). We identified a genomic score that significantly correlated with outcomes of care including a clinical disease severity score and, more importantly, length of hospitalization and duration of supplemental O2. CONCLUSIONS: Blood RNA profiles of infants with RSV LRTI allow specific diagnosis, better understanding of disease pathogenesis, and assessment of disease severity. This study opens new avenues for biomarker discovery and identification of potential therapeutic or preventive targets, and demonstrates that large microarray datasets can be translated into a biologically meaningful context and applied to the clinical setting. Please see later in the article for the Editors' Summary.

Comparative study of the immunohistochemical expression of tissue inhibitors of metalloproteinases 1 and 2 between clearly invasive carcinomas and "in situ" trophoblast invasion.

Tissue inhibitors of metalloproteinases (TIMPs) play an important role in extracellular matrix homeostasis by regulating MMP activity. Although they were initially considered inhibitors of tumor growth and metastasis, recently their role in cancer progression has been controversial. The aim of our study was to compare the immunohistochemical expression of TIMP1 and TIMP2 between an uncontrollably invasive phenomenon (cancer) and an "in situ" process (trophoblast invasion) in an effort to assess any differential role of these molecules between these two distinct phenomena and therefore to understand better their contribution in cancer invasion and migration. We performed an immunohistochemical analysis of 50 carcinomas (colorectal, gastric, breast, pulmonary, and renal) and 40 first trimester gestations. The marker expression was evaluated semiquantitatively, separately in cancer parenchymal and trophoblastic cells as well as in malignant stromal and decidual cells, according to a percentage scale (0, <10, 10-50, and >50%) and according to staining intensity (0, +, ++, and +++). Our results showed that there was no statistically significant difference in TIMP1 expression between cancer parenchymal cells and trophoblastic cells. On the other hand, TIMP1 was expressed more often in decidual cells than in cancer stromal cells. Immunostaining for TIMP2 was more extensive and intense both in trophoblastic and decidual cells than in cancer parenchymal and stromal cells, respectively. The reduced expression of TIMP2 in metastatic carcinomas by comparison with non-metastatic gestation specimens underlines its importance in cancer invasion and migration. On the other hand, TIMP1 was more expressed in decidua than cancer stroma, but at the same time showed no statistically significant difference between cancer parenchyma and trophoblasts, highlighting its multifunctional activity in cancer progression.

Significance of estrogen receptor 1 (ESR-1) gene imbalances in colon and hepatocellular carcinomas based on tissue microarrays analysis.

Estrogen receptor alpha-encoded by ESR1 gene-overexpression correlates with prognosis and response to specific chemotherapy in breast adenocarcinoma cases. Mechanisms of ESR-1 deregulation in carcinomas remain under investigation. To analyze ESR1 in carcinomas of different histogenesis. Using tissue microarray technology, 172 primary carcinomas including breast ductal adenocarcinomas (n=60), hepatocellular carcinomas (n=52), and colon adenocarcinomas (n=60) were cored and re-embedded in three paraffin blocks. Initial diagnosis was based on liquid based cytology (LiquiPrep/ThinPrep). Immunohistochemistry and fluorescence in situ hybridization were performed. Quantitative evaluation of ER-a protein levels was assessed by applying digital image analysis. ER-a overexpression was observed in 41/60 (68.3%), 23/52 (44.2%) and 4/60 (6.6%) cases, respectively. ESR1 gene multiple copies were confirmed in 13/60 (21.6%) breast adenocarcinomas, but high amplification only in 8/13 (62.8%). Allelic absence was identified in 3/52 (5.7%) hepatocellular carcinomas, whereas colon adenocarcinomas demonstrated gene gains in 5/60 (8.3%) cases referred to chr 6 aneuploidy and not to amplification. ER-a overall expression was associated strongly to ESR1 gene copies only in breast carcinoma (P=0.036). ESR-1 gene overexpression happens frequently in breast cancer, but only a subset of them are high amplified cases correlated to increased response rates in hormonal therapy (tamoxifen). Absence of this mechanism in hepatocellular and colon carcinomas maybe is a negative factor for applying this therapy. This is a pattern of histo-genetic depended targeted therapeutic strategy.