Development of an objective gene expression panel as an alternative to self-reported symptom scores in human influenza challenge trials

Background

Influenza challenge trials are important for vaccine efficacy testing. Currently, disease severity is determined by self-reported scores to a list of symptoms which can be highly subjective. A more objective measure would allow for improved data analysis.

Methods

Twenty-one volunteers participated in an influenza challenge trial. We calculated the daily sum of scores (DSS) for a list of 16 influenza symptoms. Whole blood collected at baseline and 24, 48, 72 and 96 h post challenge was profiled on Illumina HT12v4 microarrays. Changes in gene expression most strongly correlated with DSS were selected to train a Random Forest model and tested on two independent test sets consisting of 41 individuals profiled on a different microarray platform and 33 volunteers assayed by qRT-PCR.

Results

1456 probes are significantly associated with DSS at 1% false discovery rate. We selected 19 genes with the largest fold change to train a random forest model. We observed good concordance between predicted and actual scores in the first test set (r = 0.57; RMSE = −16.1%) with the greatest agreement achieved on samples collected approximately 72 h post challenge. Therefore, we assayed samples collected at baseline and 72 h post challenge in the second test set by qRT-PCR and observed good concordance (r = 0.81; RMSE = −36.1%).

Conclusions

We developed a 19-gene qRT-PCR panel to predict DSS, validated on two independent datasets. A transcriptomics based panel could provide a more objective measure of symptom scoring in future influenza challenge studies.

Trial registration Samples were obtained from a clinical trial with the ClinicalTrials.gov Identifier: NCT02014870, first registered on December 5, 2013

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1235-3) contains supplementary material, which is available to authorized users.

Subjective and objective assessments of seasonal effect in children with seasonal allergic rhinitis

BACKGROUND

Epidemiological and clinical studies suggest a relationship between rhinitis and asthma. Upper and lower airways may be influenced by a common inflammatory process.

OBJECTIVE

This study aimed to investigate the relationships between rhinitis symptom scores, and both nasal and bronchial airflow among children with seasonal allergic rhinitis (SAR) by means of spirometric and rhinomanometric measurement during and outside the pollen season.

METHODS

Twenty-nine children with both seasonal allergic rhinitis and asthma (AR+A), 30 children with SAR and no asthma (AR) and 36 non-allergic healthy children were evaluated prospectively during and outside the pollen season. Symptom severity was evaluated using both total symptom score and visual analog score (VAS). All participants also received rhinomanometric evaluation and pulmonary function testing.

RESULTS

In children with SAR the median total nasal flow, FEV1, FEF25-75 values were lower than control group during pollen season (p=0.01, p<0.001 and p<0.001 respectively). They had also higher total nasal resistance compared with control groups (p=0.01). Nasal symptom scores were higher among patients with concurrent asthma than patients who had only SAR out of pollen season (p<0.001). There was no significant difference between SAR participants with or without asthma and control group in terms of total nasal flow and total nasal resistance measured out of season (p=0.105 and p=0.19). FEF25-75 values of patients with and without asthma were significantly lower than those of controls out of season (p=0.022, p<0.001 respectively).

CONCLUSION

Our data suggests that as the presence of AR worsens asthma control, the presence of asthma may worsen symptoms of AR out of pollen season. We found that total nasal flow, FEV1, FEF25-75 values of patients with SAR were lower than those of controls out of season. FEF25-75 values of patients with asthma and without asthma were significantly lower than those of controls out of season. Thus, a careful evaluation of lower airways should be performed in even patients with seasonal allergic rhinitis alone.

Repeated assessments of symptom severity improve predictions for risk of death among patients with cancer

CONTEXT

Although prior studies show the importance of self-reported symptom scores as predictors of cancer survival, most are based on scores recorded at a single point in time.

OBJECTIVES

To show that information on repeated assessments of symptom severity improves predictions for risk of death and to use updated symptom information for determining whether worsening of symptom scores is associated with a higher hazard of death.

METHODS

This was a province-based longitudinal study of adult outpatients who had a cancer diagnosis and had assessments of symptom severity. We implemented a time-to-death Cox model with a time-varying covariate for each symptom to account for changing symptom scores over time. This model was compared with that using only a time-fixed (baseline) covariate for each symptom. The regression coefficients of each model were derived based on a randomly selected 60% of patients, and then, the predictive performance of each model was assessed via concordance probabilities when applied to the remaining 40% of patients.

RESULTS

This study had 66,112 patients diagnosed with cancer and more than 310,000 assessments of symptoms. The use of repeated assessments of symptom scores improved predictions for risk of death compared with using only baseline symptom scores. Increased pain and fatigue and reduced appetite were the strongest predictors for death.

CONCLUSION

If available, researchers should consider including changing information on symptom scores, as opposed to only baseline information on symptom scores, when examining hazard of death among patients with cancer. Worsening of pain, fatigue, and appetite may be a flag for impending death.