N-terminal pro-brain natriuretic peptide in a novel screening algorithm for pulmonary arterial hypertension in systemic sclerosis: a case-control study

Introduction

Pulmonary arterial hypertension is a major cause of mortality in systemic sclerosis. N-terminal pro-brain natriuretic peptide (NT-proBNP) has emerged as a candidate biomarker that may enable the early detection of systemic sclerosis-related pulmonary arterial hypertension (SSc-PAH). The objective of our study was to incorporate NT-proBNP into a screening algorithm for SSc-PAH that could potentially replace transthoracic echocardiography (TTE) as a more convenient and less costly "first tier" test.

Methods

NT-proBNP levels were measured in patients from four clinical groups: a group with right heart catheter (RHC)-diagnosed SSc-PAH before commencement of therapy for PAH; a group at high risk of SSc-PAH based on TTE; a group with interstitial lung disease; and systemic sclerosis (SSc) controls with no cardiopulmonary complications. NT-proBNP levels were compared by using ANOVA and correlated with other clinical variables by using simple and multiple linear regression. ROC curve analyses were performed to determine the optimal cut point for NT-proBNP and other clinical variables in prediction of PAH.

Results

NT-proBNP was highest in the PAH group compared with other groups (P < 0.0001), and higher in the risk group compared with controls (P < 0.0001). NT-proBNP was positively correlated with systolic pulmonary artery pressure (PAP) on TTE (P < 0.0001), and mean PAP (P = 0.013), pulmonary vascular resistance (P = 0.005), and mean right atrial pressure (P = 0.006) on RHC. A composite model wherein patients screened positive if NT-proBNP was ≥ 209.8 pg/ml, and/or DLCO_corr was < 70.3% with FVC/DLCO_corr ≥ 1.82, had a sensitivity of 100% and specificity of 77.8% for SSc-PAH.

Conclusion

We have proposed a screening algorithm for SSc-PAH, incorporating NT-proBNP level and PFTs. This model has high sensitivity and specificity for SSc-PAH and, if positive, should lead to TTE and confirmatory testing for PAH. This screening algorithm must be validated prospectively.     

A comparison of the predictive accuracy of three screening models for pulmonary arterial hypertension in systemic sclerosis

IntroductionThere is evidence that early screening for pulmonary arterial hypertension (PAH) in systemic sclerosis (SSc) improves outcomes. We compared the predictive accuracy of two recently published screening algorithms (DETECT 2013 and Australian Scleroderma Interest Group (ASIG) 2012) for SSc-associated PAH (SSc-PAH) with the commonly used European Society of Cardiology/European Respiratory Society (ESC/ERS 2009) guidelines.MethodsWe included 73 consecutive SSc patients with suspected PAH undergoing right heart catheterization (RHC). The three screening models were applied to each patient. For each model, contingency table analysis was used to determine sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values for PAH. These properties were also evaluated in an ‘alternate scenario analysis’ in which the prevalence of PAH was set at 10%.ResultsRHC revealed PAH in 27 (36.9%) patients. DETECT and ASIG algorithms performed equally in predicting PAH with sensitivity and NPV of 100%. The ESC/ERS guidelines had sensitivity of 96.3% and NPV of only 91%, missing one case of PAH; these guidelines could not be applied to three patients who had absent tricuspid regurgitant (TR) jet. The ASIG algorithm had the highest specificity (54.5%). With PAH prevalence set at 10%, the NPV of the models was unchanged, but the PPV dropped to less than 20%.ConclusionsIn this cohort, the DETECT and ASIG algorithms out-perform the ESC/ERS guidelines, detecting all patients with PAH. The ESC/ERS guidelines have limitations in the absence of a TR jet. Ultimately, the choice of SSc-PAH screening algorithm will also depend on cost and ease of application.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0517-5) contains supplementary material, which is available to authorized users.     

Screening for Depression in Low-Income Elderly Patients at the Primary Care Level: Use of the Patient Health Questionnaire-2

Introduction

Depression is one of the most common mental disorders and a leading cause of disability worldwide. It constitutes a serious public health problem, particularly among elderly individuals. Most depressed elderly patients are treated by primary care (PC) physicians. The “Patient Health Questionnaire” (PHQ-2) is an instrument used for the detection of depression in PC settings.

Objective

Evaluate the performance of the PHQ-2 in a low-income and uneducated elderly PC population.

Methods

A non-probabilistic population sample of 142 individuals was selected from the healthcare unit''s users ≧60 years. Criterion validity was assessed by estimating the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the PHQ-2 in comparison with the structured interview using the DSM-IV. The estimates of sensitivity and specificity were obtained from varying cut-offs of the PHQ-2 score. A Receiver Operator Characteristic (ROC) curve was constructed and the area under the curve (AUC) was calculated.

Results

The group was predominantly female (73.9%), with low education level (mean 3 years of schooling). The mean age was 72.5 years old. The prevalence of depression was 26.1%. The best values of sensitivity (0.74), specificity (0.77), PPV (0.50) e NPV (0.90) were obtained with score equal to 1. The AUC was 0.77, indicating a modest performance of the test accuracy.

Conclusion

The simplicity of the PHQ-2 is an advantage for its use in PC. The high NPV indicated that 90% of those who tested negative would not need additional tests. However, the low PPV indicated that the PHQ-2 is not sufficient to screen for depression. The application of the instrument could be the first step of the screening, that would include a second step to all those with positive tests formerly.     

3q26 amplification is an effective negative triage test for LSIL: a historical prospective study

Background

Women with low grade squamous intraepithelial lesions (LSIL) at cervical cancer screening are currently referred for further diagnostic work up despite 80% having no precancerous lesion. The primary purpose of this study is to measure the test characteristics of 3q26 chromosome gain (3q26 gain) as a host marker of carcinogenesis in women with LSIL. A negative triage test may allow these women to be followed by cytology alone without immediate referral to colposcopy.

Methods and Findings

A historical prospective study was designed to measure 3q26 gain from the archived liquid cytology specimens diagnosed as LSIL among women attending colposcopy between 2007 and 2009. 3q26 gain was assessed on the index liquid sample; and sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were measured at immediate triage and at 6–16 months after colposcopic biopsy. The sensitivity of 3q26 gain measured at immediate triage from automated and manually reviewed tests in 65 non-pregnant unique women was 70% (95% CI: 35, 93) with a NPV of 89% (95% CI: 78, 96). The sensitivity and NPV increased to 80% (95% CI: 28, 99) and 98% (95% CI: 87, 100), respectively, when only the automated method of detecting 3q26 gain was used.

Conclusions

3q26 gain demonstrates high sensitivity and NPV as a negative triage test for women with LSIL, allowing possible guideline changes to routine surveillance instead of immediate colposcopy. Prospective studies are ongoing to establish the sensitivity, specificity, PPV and NPV of 3q26 gain for LSIL over time.     

Ascertaining an Appropriate Diagnostic Algorithm Using EGFR Mutation-Specific Antibodies to Detect EGFR Status in Non-Small-Cell Lung Cancer

Background

Epidermal growth factor receptor (EGFR) mutation status is the most valuable indicator in the screening of non-small-cell lung cancer (NSCLC) patients for tyrosine kinase inhibitor (TKI) therapy. Accurate, rapid and economical methods of detecting EGFR mutations have become important. The use of two mutation-specific antibodies targeting the delE746-A750 mutation in exon 19 and L858R mutation in exon 21 makes this task possible, but the lack of consensually acceptable criteria for positive results limits the application of this antibody based mutation detection.

Methods

We collected 399 specimens from NSCLC patients (145 resection specimens, 220 biopsy specimens, and 34 cytology specimens) whose EGFR mutation status had been detected by TaqMan PCR assay. Immunohistochemical (IHC) analyses using EGFR mutation-specific antibodies were employed for all samples. After staining and scoring, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated in accordance with different levels of positive grades in comparison with the results of PCR-based assay.

Results

In IHC-based analyses, 144 cases were scored 0, 104 cases were scored 1+, 103 cases were scored 2+, and 48 cases were scored 3+. With the molecular-based results were set as the “gold standard”, the prevalence of mutation was 6.94% (10/144), 23.08% (24/104), 67.96% (70/103) and 100% (48/48), respectively, for samples with scores 0, 1+, 2+ and 3+. When score 3+ was considered positive, the specificity and PPV were 100%; if only score 0 was considered negative, 93.06% NPV was obtained.

Conclusion

Patients with score 3+ have a perfect PPV (100%), and may accept TKI treatment directly without any molecular-based assays. Patients with score 0 had high NPV (93.06%), which could reach 97.22% when the detection of total EGFR was applied. However, samples with score 1+ or 2+ are unreliable and need further verification of EGFR mutation status by molecular-based assays.     

Human Pentraxin 3 (PTX3) as a Novel Biomarker for the Diagnosis of Pulmonary Arterial Hypertension

Background

Although inflammation is an important feature of pulmonary arterial hypertension (PAH), the usefulness of local inflammatory markers as biomarkers for PAH is unknown. In this study, we tested whether plasma concentrations of human pentraxin 3 (PTX3), a local inflammatory marker, would be a useful biomarker for detecting PAH.

Methods

Plasma PTX3 concentrations were evaluated in 50 PAH patients (27 with idiopathic PAH, 17 with PAH associated with connective tissue disease (CTD-PAH), and six with congenital heart disease), 100 age and sex-matched healthy controls, and 34 disease-matched CTD patients without PAH. Plasma concentrations of B-type natriuretic peptide (BNP) and C-reactive protein (CRP) were also determined.

Results

Mean PTX3 levels were significantly higher in all PAH patients than in the healthy controls (4.40±0.37 vs. 1.94±0.09 ng/mL, respectively; P<0.001). Using a threshold level of 2.84 ng/mL, PTX3 yielded a sensitivity of 74.0% and a specificity of 84.0% for the detection of PAH. In CTD-PAH patients, mean PTX3 concentrations were significantly higher than in CTD patients without PAH (5.02±0.69 vs. 2.40±0.14 ng/mL, respectively; P<0.001). There was no significant correlation between plasma levels of PTX3 and BNP or CRP. Receiver operating characteristic (ROC) curves for screening PAH in patients with CTD revealed that PTX3 (area under the ROC curve 0.866) is superior to BNP. Using a PTX3 threshold of 2.85 ng/mL maximized true-positive and false-negative results (sensitivity 94.1%, specificity 73.5%).

Conclusion

Plasma concentrations of PTX3 may be a better biomarker of PAH than BNP, especially in patients with CTD.     

The Sensitivity and Specificity of Using a Computer Aided Diagnosis Program for Automatically Scoring Chest X-Rays of Presumptive TB Patients Compared with Xpert MTB/RIF in Lusaka Zambia

Objective

To determine the sensitivity and specificity of a Computer Aided Diagnosis (CAD) program for scoring chest x-rays (CXRs) of presumptive tuberculosis (TB) patients compared to Xpert MTB/RIF (Xpert).

Method

Consecutive presumptive TB patients with a cough of any duration were offered digital CXR, and opt out HIV testing. CXRs were electronically scored as normal (CAD score ≤60) or abnormal (CAD score>60) using a CAD program. All patients regardless of CAD score were requested to submit a spot sputum sample for testing with Xpert and a spot and morning sample for testing with LED Fluorescence Microscopy-(FM).

Results

Of 350 patients with evaluable data, 291 (83.1%) had an abnormal CXR score by CAD. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CXR compared to Xpert were 100% (95%CI 96.2–100), 23.2% (95%CI 18.2–28.9), 33.0% (95%CI 27.6–38.7) and 100% (95% 93.9–100), respectively. The area under the receiver operator curve (AUC) for CAD was 0.71 (95%CI 0.66–0.77). CXR abnormality correlated with smear grade (r = 0.30, p<0.0001) and with Xpert C_T(r = 0.37, p<0.0001).

Conclusions

To our knowledge this is the first time that a CAD program for TB has been successfully tested in a real world setting. The study shows that the CAD program had high sensitivity but low specificity and PPV. The use of CAD with digital CXR has the potential to increase the use and availability of chest radiography in screening for TB where trained human resources are scarce.     

Veterans Affairs databases are accurate for gout-related health care utilization: a validation study

Introduction

The aim of this study was to assess the accuracy of Veterans Affairs (VA) databases for gout-related health care utilization.

Methods

This retrospective study utilized VA administrative and clinical databases. A random sample of gout patients with visits (outpatient, inpatient or emergent/urgent care) with or without the diagnosis of gout (International Classification of Diseases, ninth revision, common modification ICD-9-CM code of 274.x or 274.xx) at the Birmingham VA hospital was selected. A blinded abstractor performed a review of VA electronic health records for the documentation of gout or gout-related terms (gouty arthritis, tophaceous gout, tophus/tophi, acute gout, chronic gout, podagra, urate stones, urate or uric acid crystals and so on) in the chief complaint, history of present illness or assessment and plan for the visit; this constituted the gold standard for gout-related utilization. The accuracy of database-derived gout-related claims was assessed by calculating sensitivity, specificity, and positive and negative predictive values (PPV and NPV).

Results

Of 108 potential visits, 85 outpatient, inpatient or urgent care/emergency room visits to a health care provider (85 patients: 84 men and 1 woman with a mean age of 63 years) and retrievable data from medical records constituted the analyzed dataset. Administrative claims for gout-related utilization with ICD-9 code for gout were accurate with a PPV of 86%, specificity of 95%, sensitivity of 86% and NPV of 95%.

Conclusions

VA databases are accurate for gout-related visits. These findings support their use for studies of health services and outcome studies. It remains to be seen if these findings are generalizable to other settings and databases.     

Lack of Pupil Reflex and Loss of Consciousness Predict 30-Day Neurological Sequelae in Patients with Carbon Monoxide Poisoning

Background

Predicting the neurological sequelae of carbon monoxide poisoning (COP) has not been well studied. We investigated the independent predictors of neurological sequelae in patients with COP and combined these predictors to predict the prognosis.

Methods

This study was conducted at four hospitals in Shandong Province, China. Data were retrospectively collected from 258 patients with COP between November 1990 and October 2011. Thirty-day neurological sequelae were the primary endpoints.

Results

A lack of pupil reflex and a loss of consciousness appear to be independent predictors for neurological sequelae in patients with COP. The presence of either one had a sensitivity of 77.0% (95% confidence interval [CI]: 69.3–83.2), a specificity of 47.1% (95% CI: 38.3–56.0), positive predictive value (PPV) of 62.9% (95% CI: 55.2–70.1), and a negative predictive value (NPV) of 63.6% (95% CI: 52.6–73.4). With both predictors present, the sensitivity was 11.5% (95% CI: 6.9 to 18.3), the specificity was 99.2 (95% CI: 94.7–100.0), the PPV was 94.1% (95% CI: 69.2–99.7), and the NPV was 49.0% (95% CI: 42.5–55.5).

Conclusions

The risk for neurological sequelae apparently increased with the number of independent predictors. In patients with both predictors, the risk for neurological sequelae was 94.1%. Almost all (99.2%) patients with neither predictor had no neurological sequelae. This finding may help physicians make decisions about and dispositions for patients with COP. For patients with a higher risk, earlier treatment and more appropriate utilization of health care services, including hyperbaric oxygen, should be considered.     

Customized Reference Ranges for Laboratory Values Decrease False Positive Alerts in Intensive Care Unit Patients

Background

Traditional electronic medical record (EMR) interfaces mark laboratory tests as abnormal based on standard reference ranges derived from healthy, middle-aged adults. This yields many false positive alerts with subsequent alert-fatigue when applied to complex populations like hospitalized, critically ill patients. Novel EMR interfaces using adjusted reference ranges customized for specific patient populations may ameliorate this problem.

Objective

To compare accuracy of abnormal laboratory value indicators in a novel vs traditional EMR interface.

Methods

Laboratory data from intensive care unit (ICU) patients consecutively admitted during a two-day period were recorded. For each patient, available laboratory results and the problem list were sent to two mutually blinded critical care experts, who marked the values about which they would like to be alerted. All disagreements were resolved by an independent super-reviewer. Based on this gold standard, we calculated and compared the sensitivity, specificity, positive and negative predictive values (PPV, NPV) of customized vs traditional abnormal value indicators.

Results

Thirty seven patients with a total of 1341 laboratory results were included. Experts’ agreement was fair (kappa = 0.39). Compared to the traditional EMR, custom abnormal laboratory value indicators had similar sensitivity (77% vs 85%, P = 0.22) and NPV (97.1% vs 98.6%, P = 0.06) but higher specificity (79% vs 61%, P<0.001) and PPV (28% vs 11%, P<0.001).

Conclusions

Reference ranges for laboratory values customized for an ICU population decrease false positive alerts. Disagreement among clinicians about which laboratory values should be indicated as abnormal limits the development of customized reference ranges.     

Comparison of positron emission tomography/computed tomography imaging and ultrasound in surveillance of head and neck cancer – The 3-year experience of the ENT Department in Poznan

Background

Posttreatment surveillance for the local and regional recurrence of the head and neck squamous cell carcinoma often requires a multimodality techniques that include PET combined with CT, MRI, US.

Aim

The purpose of this study is to compare the diagnostic performance of two imaging techniques (PET/CT and US), and their combined use for the detection of a subclinical regional recurrence in patients after HNSCC treatment.

Materials and methods

83 patients after completion of the HNSCC treatment underwent both US and PET/CT on the mean follow-up of 14 months after initial treatment.

Results

The sensitivity and specificity of PET/CT were 86% and 82%, respectively; US values reached 81% and 87%, respectively. PPV was 79% for PET/CT, and 83% for US. NPV was 89% for PET/CT, and 85% for US. The overall accuracy for PET/CT and US was 84% for both methods.

Conclusion

US could be regarded as complementary to PET/CT as the procedures with highest sensitivity, specificity and NPV for detecting subclinical regional recurrences after HNSCC treatment.     

Relevance of Baseline Viral Genetic Heterogeneity and Host Factors for Treatment Outcome Prediction in Hepatitis C Virus 1b-Infected Patients

Background

Only about 50% of patients chronically infected with HCV genotype 1 (HCV-1) respond to treatment with pegylated interferon-alfa and ribavirin (dual therapy), and protease inhibitors have to be administered together with these drugs increasing costs and side-effects. We aimed to develop a predictive model of treatment response based on a combination of baseline clinical and viral parameters.

Methodology

Seventy-four patients chronically infected with HCV-1b and treated with dual therapy were studied (53 retrospectively −training group−, and 21 prospectively −validation group−). Host and viral-related factors (viral load, and genetic variability in the E1–E2, core and Interferon Sensitivity Determining Region) were assessed. Multivariate discriminant analysis and decision tree analysis were used to develop predictive models on the training group, which were then validated in the validation group.

Principal Findings

A multivariate discriminant predictive model was generated including the following variables in decreasing order of significance: the number of viral variants in the E1–E2 region, an amino acid substitution pattern in the viral core region, the IL28B polymorphism, serum GGT and ALT levels, and viral load. Using this model treatment outcome was accurately predicted in the training group (AUROC = 0.9444; 96.3% specificity, 94.7% PPV, 75% sensitivity, 81% NPV), and the accuracy remained high in the validation group (AUROC = 0.8148, 88.9% specificity, 90.0% PPV, 75.0% sensitivity, 72.7% NPV). A second model was obtained by a decision tree analysis and showed a similarly high accuracy in the training group but a worse reproducibility in the validation group (AUROC = 0.9072 vs. 0.7361, respectively).

Conclusions and Significance

The baseline predictive models obtained including both host and viral variables had a high positive predictive value in our population of Spanish HCV-1b treatment naïve patients. Accurately identifying those patients that would respond to the dual therapy could help reducing implementation costs and additional side effects of new treatment regimens.     

Performance of survivin mRNA as a biomarker for bladder cancer in the prospective study UroScreen

Background

Urinary biomarkers have the potential to improve the early detection of bladder cancer. Most of the various known markers, however, have only been evaluated in studies with cross-sectional design. For proper validation a longitudinal design would be preferable. We used the prospective study UroScreen to evaluate survivin, a potential biomarker that has multiple functions in carcinogenesis.

Methods/Results

Survivin was analyzed in 5,716 urine samples from 1,540 chemical workers previously exposed to aromatic amines. The workers participated in a surveillance program with yearly examinations between 2003 and 2010. RNA was extracted from urinary cells and survivin was determined by Real-Time PCR. During the study, 19 bladder tumors were detected. Multivariate generalized estimation equation (GEE) models showed that β-actin, representing RNA yield and quality, had the strongest influence on survivin positivity. Inflammation, hematuria and smoking did not confound the results. Survivin had a sensitivity of 21.1% for all and 36.4% for high-grade tumors. Specificity was 97.5%, the positive predictive value (PPV) 9.5%, and the negative predictive value (NPV) 99.0%.

Conclusions

In this prospective and so far largest study on survivin, the marker showed a good NPV and specificity but a low PPV and sensitivity. This was partly due to the low number of cases, which limits the validity of the results. Compliance, urine quality, problems with the assay, and mRNA stability influenced the performance of survivin. However, most issues could be addressed with a more reliable assay in the future. One important finding is that survivin was not influenced by confounders like inflammation and exhibited a relatively low number of false-positives. Therefore, despite the low sensitivity, survivin may still be considered as a component of a multimarker panel.     

The value of ischemia-modified albumin compared with d-dimer in the diagnosis of pulmonary embolism

Study objective

The primary aim of this study was to investigate whether IMA levels are helpful in the diagnosis of pulmonary embolism (PE). The secondary aim was to determine whether IMA was more effective alone or in combination with clinical probability scores in the diagnosis of PE. Thirdly, the sensitivity and specificity of IMA is compared with D-dimer both with and without clinical probability scores in patients with suspected PE.

Methods

Consecutive patients presenting to the emergency department with suspected PE were prospectively recruited, and healthy volunteers were also enrolled as controls. D-dimer and IMA levels were measured for the entire study group. Wells and Geneva scores were calculated and s-CTPA was performed on all suspected PE patients.

Results

The study population consisted of 130 patients with suspected PE and 59 healthy controls. Mean IMA levels were 0.362 ± 0.11 ABSU for Group A, the PE group (n = 75); 0.265 ± 0.07 ABSU for Group B, the non-PE group (n = 55); and 0.175 ± 0.05 ABSU for Group C, the healthy control group (p < 0.0001). At a cut-off point of 0.25 ABSU, IMA was 93% sensitive and 75% specific in the diagnosis of PE. PPV was 79.4% and NPV was 78.6%. Mean D-dimer levels were 12.48 ± 10.88 μg/ml for Group A; 5.36 ± 7.80 μg/ml for Group B and 0.36 ± 0.16 μg/ml for Group C (p < 0.0001). The D-dimer cut-off point was 0.81 μg/ml with a sensitivity of 98.9% and a specificity of 62.7%, PPV of 69.4% and NPV of 83.3%. The use of IMA in combination with Wells and Geneva clinical probability scores was determined to have a positive impact on these scores'' sensitivity and negative predictive values.

Conclusion

IMA is a good alternative to D-dimer in PE diagnosis in terms of both cost and efficiency. Used in combination with clinical probability scores, it has a similar positive effect on NPV and sensitivity to that of D-dimer. The PPV of IMA is better than D-dimer, but it is still unable to confirm a diagnosis of PE without additional investigation.     

Susceptibility Weighted Imaging: A New Tool in the Diagnosis of Prostate Cancer and Detection of Prostatic Calcification

Background

Susceptibility weighted imaging (SWI) is a new MRI technique which has been proved very useful in the diagnosis of brain diseases, but few study was performed on its value in prostatic diseases. The aim of the present study was to investigate the value of SWI in distinguishing prostate cancer from benign prostatic hyperplasia and detecting prostatic calcification.

Methodology/Principal Findings

23 patients with prostate cancer and 53 patients with benign prostatic hyperplasia proved by prostate biopsy were scanned on a 3.0T MR and a 16-row CT scanner. High-resolution SWI, conventional MRI and CT were performed on all patients. The MRI and CT findings, especially SWI, were analyzed and compared. The analyses revealed that 19 out of 23 patients with prostate cancer presented hemorrhage within tumor area on SWI. However, in 53 patients with benign prostatic hyperplasia, hemorrhage was detected only in 1 patient in prostate by SWI. When comparing SWI, conventional MRI and CT in detecting prostate cancer hemorrhage, out of the 19 patients with prostate cancer who had prostatic hemorrhage detected by SWI, the prostatic hemorrhage was detected in only 7 patients by using conventional MRI, and none was detected by CT. In addition, CT demonstrated calcifications in 22 patients which were all detected by SWI whereas only 3 were detected by conventional MRI. Compared to CT, SWI showed 100% in the diagnostic sensitivity, specificity, accuracy, positive predictive value(PPV) and negative predictive value(NPV) in detecting calcifications in prostate but conventional MRI demonstrated 13.6% in sensitivity, 100% in specificity, 75% in accuracy, 100% in PPV and 74% in NPV.

Conclusions

More apparent prostate hemorrhages were detected on SWI than on conventional MRI or CT. SWI may provide valuable information for the differential diagnosis between prostate cancer and prostatic hyperplasia. Filtered phase images can identify prostatic calcifications as well as CT.     

International Prostatic Symptom Score — Voiding/Storage Subscore Ratio in Association with Total Prostatic Volume and Maximum Flow Rate Is Diagnostic of Bladder Outlet-Related Lower Urinary Tract Dysfunction in Men with Lower Urinary Tract Symptoms

Objectives

The aim of this study was to investigate the predictive values of the total International Prostate Symptom Score (IPSS-T) and voiding to storage subscore ratio (IPSS-V/S) in association with total prostate volume (TPV) and maximum urinary flow rate (Qmax) in the diagnosis of bladder outlet-related lower urinary tract dysfunction (LUTD) in men with lower urinary tract symptoms (LUTS).

Methods

A total of 298 men with LUTS were enrolled. Video-urodynamic studies were used to determine the causes of LUTS. Differences in IPSS-T, IPSS-V/S ratio, TPV and Qmax between patients with bladder outlet-related LUTD and bladder-related LUTD were analyzed. The positive and negative predictive values (PPV and NPV) for bladder outlet-related LUTD were calculated using these parameters.

Results

Of the 298 men, bladder outlet-related LUTD was diagnosed in 167 (56%). We found that IPSS-V/S ratio was significantly higher among those patients with bladder outlet-related LUTD than patients with bladder-related LUTD (2.28±2.25 vs. 0.90±0.88, p<0.001). TPV was similar between the two groups; however, in contrast to patients with bladder-related LUTD, patients with bladder outlet-related LUTD had higher detrusor voiding pressure, lower Qmax values, and greater postvoid residual volumes. The combination of TPV30 ml and Qmax10 ml/sec had a PPV of 68.8% and a NPV of 53.5% for bladder outlet-related LUTD. When IPSS-T12 or IPSS-T15 was considered as an additional criterion, PPV increased to 75.0% and 78.5%, respectively, and the NPV decreased to 50.9% and 50.2%, respectively. When IPSS-V/S>1 or >2 was factored into the equation instead of IPSS-T, PPV were 91.4% and 97.3%, respectively, and NPV were 54.8% and 49.8%, respectively.

Conclusions

Combination of IPSS-T with TPV and Qmax increases the PPV of bladder outlet-related LUTD. Furthermore, including IPSS-V/S>1 or >2 into the equation results in a higher PPV than IPSS-T. IPSS-V/S>1 is a stronger predictor of bladder outlet-related LUTD than IPSS-T.     

Evaluation of BACTEC MGIT 960 System for Testing Susceptibility of Mycobacterium tuberculosis to First-Line Drugs in China

Background

The purpose of this study was to evaluate the performance of the BACTEC MGIT 960 (M960) system compared with the proportion method (PM) on Löwenstein-Jensen (L-J) medium in a peripheral laboratory in China for the testing of Mycobacterium tuberculosis (MTB) susceptibility to streptomycin (SM), isoniazid (INH) rifampicin (RIF) and ethambutol (EMB) a combination known as SIRE.

Methods

The susceptibility of 205 clinical isolates of MTB to SM, INH, RIF and EMB was performed with the M960 system. The drugs were tested at the following concentrations: 1.0 µg/ml for SM, 0.1 µg/ml for INH, 1.0 µg/ml for RIF, and 5.0 µg/ml for EMB. The results were compared with those obtained by the L-J PM. The L-J PM at an arbiter site was used to resolve any discordant results.

Results

The overall consistency was 96.6% and concordance values were 95.6% for SM, 97.6% for INH, 98.0% for RIF and 95.1% for EMB. The overall sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the M960 system for PM (the standard method) was 95.6%, 97.3%, 96.2% and 96.9% respectively, and the sensitivity were 93.3% for SM, 96.9% for INH, 97.4% for RIF and 94.6% for EMB, the specificity were 96.9% for SM, 98.2% for INH, 98.4% for RIF and 95.5% for EMB, the PPV were 94.6% for SM, 97.9% for INH, 97.4% for RIF and 94.6% for EMB, the NPV were 96.2% for SM, 97.3% for INH, 98.4% for RIF and 95.5% for EMB. The turnaround time with the M960 system (median 8.0 days, ranged from 5 to 14 days) was significantly shorter than that with the PM (28 days or 42 days).

Conclusion

There was a substantial degree of agreement between the two methods. The M960 system was a reliable and rapid method for SIRE susceptibility testing of tuberculosis in China.     

Predictors of Viral Pneumonia in Patients with Community-Acquired Pneumonia

Background

Viruses are increasingly recognized as major causes of community-acquired pneumonia (CAP). Few studies have investigated the clinical predictors of viral pneumonia, and the results have been inconsistent. In this study, the clinical predictors of viral pneumonia were investigated in terms of their utility as indicators for viral pneumonia in patients with CAP.

Methods

Adult patients (≥18 years old) with CAP, tested by polymerase chain reaction (PCR) for respiratory virus, at two teaching hospitals between October 2010 and May 2013, were identified retrospectively. Demographic and clinical data were collected by reviewing the hospital electronic medical records.

Results

During the study period, 456 patients with CAP were identified who met the definition, and 327 (72%) patients were tested using the respiratory virus PCR detection test. Viral pneumonia (n = 60) was associated with rhinorrhea, a higher lymphocyte fraction in the white blood cells, lower serum creatinine and ground-glass opacity (GGO) in radiology results, compared to non-viral pneumonia (n = 250) (p<0.05, each). In a multivariate analysis, rhinorrhea (Odd ratio (OR) 3.52; 95% Confidence interval (CI), 1.58–7.87) and GGO (OR 4.68; 95% CI, 2.48–8.89) were revealed as independent risk factors for viral pneumonia in patients with CAP. The sensitivity, specificity, positive- and negative-predictive values (PPV and NPV) of rhinorrhea were 22, 91, 36 and 83%: the sensitivity, specificity, PPV and NPV of GGO were and 43, 84, 40 and 86%, respectively.

Conclusion

Symptom of rhinorrhea and GGO predicted viral pneumonia in patients with CAP. The high specificity of rhinorrhea and GGO suggested that these could be useful indicators for empirical antiviral therapy.     

Accuracy of five algorithms to diagnose gambiense human African trypanosomiasis

Background

Algorithms to diagnose gambiense human African trypanosomiasis (HAT, sleeping sickness) are often complex due to the unsatisfactory sensitivity and/or specificity of available tests, and typically include a screening (serological), confirmation (parasitological) and staging component. There is insufficient evidence on the relative accuracy of these algorithms. This paper presents estimates of the accuracy of five algorithms used by past Médecins Sans Frontières programmes in the Republic of Congo, Southern Sudan and Uganda.

Methodology and Principal Findings

The sequence of tests in each algorithm was programmed into a probabilistic model, informed by distributions of the sensitivity, specificity and staging accuracy of each test, constructed based on a literature review. The accuracy of algorithms was estimated in a baseline scenario and in a worst-case scenario introducing various near worst-case assumptions. In the baseline scenario, sensitivity was estimated as 85–90% in all but one algorithm, with specificity above 99.9% except for the Republic of Congo, where CATT serology was used as independent confirmation test: here, positive predictive value (PPV) was estimated at <50% in realistic active screening prevalence scenarios. Furthermore, most algorithms misclassified about one third of true stage 1 cases as stage 2, and about 10% of true stage 2 cases as stage 1. In the worst-case scenario, sensitivity was 75–90% and PPV no more than 75% at 1% prevalence, with about half of stage 1 cases misclassified as stage 2.

Conclusions

Published evidence on the accuracy of widely used tests is scanty. Algorithms should carefully weigh the use of serology alone for confirmation, and could enhance sensitivity through serological suspect follow-up and repeat parasitology. Better evidence on the frequency of low-parasitaemia infections is needed. Simulation studies should guide the tailoring of algorithms to specific scenarios of HAT prevalence and availability of control tools.     

Is 3-Tesla Gd-EOB-DTPA-Enhanced MRI with Diffusion-Weighted Imaging Superior to 64-Slice Contrast-Enhanced CT for the Diagnosis of Hepatocellular Carcinoma?

Objectives

To compare 64-slice contrast-enhanced computed tomography (CT) with 3-Tesla magnetic resonance imaging (MRI) using Gd-EOB-DTPA for the diagnosis of hepatocellular carcinoma (HCC) and evaluate the utility of diffusion-weighted imaging (DWI) in this setting.

Methods

3-phase-liver-CT was performed in fifty patients (42 male, 8 female) with suspected or proven HCC. The patients were subjected to a 3-Tesla-MRI-examination with Gd-EOB-DTPA and diffusion weighted imaging (DWI) at b-values of 0, 50 and 400 s/mm². The apparent diffusion coefficient (ADC)-value was determined for each lesion detected in DWI. The histopathological report after resection or biopsy of a lesion served as the gold standard, and a surrogate of follow-up or complementary imaging techniques in combination with clinical and paraclinical parameters was used in unresected lesions. Diagnostic accuracy, sensitivity, specificity, and positive and negative predictive values were evaluated for each technique.

Results

MRI detected slightly more lesions that were considered suspicious for HCC per patient compared to CT (2.7 versus 2.3, respectively). ADC-measurements in HCC showed notably heterogeneous values with a median of 1.2±0.5×10⁻³ mm²/s (range from 0.07±0.1 to 3.0±0.1×10⁻³ mm²/s). MRI showed similar diagnostic accuracy, sensitivity, and positive and negative predictive values compared to CT (AUC 0.837, sensitivity 92%, PPV 80% and NPV 90% for MRI vs. AUC 0.798, sensitivity 85%, PPV 79% and NPV 82% for CT; not significant). Specificity was 75% for both techniques.

Conclusions

Our study did not show a statistically significant difference in detection in detection of HCC between MRI and CT. Gd-EOB-DTPA-enhanced MRI tended to detect more lesions per patient compared to contrast-enhanced CT; therefore, we would recommend this modality as the first-choice imaging method for the detection of HCC and therapeutic decisions. However, contrast-enhanced CT was not inferior in our study, so that it can be a useful image modality for follow-up examinations.