109 resultados para Predictive positive value


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Tuberculosis (TB) in South American camelids (SAC) is caused by Mycobacterium bovis or Mycobacterium microti. Two serological methods, rapid testing (RT) and the dual-path platform (DPP) assay, were evaluated using naturally infected SAC. The study population included 156 alpacas and 175 llamas in Great Britain, Switzerland, and the United States. TB due to M. bovis (n = 44) or M. microti (n = 8) in 35 alpacas and 17 llamas was diagnosed by gross pathology examination and culture. Control animals were from herds with no TB history. The RT and the DPP assay showed sensitivities of 71% and 74%, respectively, for alpacas, while the sensitivity for llamas was 77% for both assays. The specificity of the DPP assay (98%) was higher than that of RT (94%) for llamas; the specificities of the two assays were identical (98%) for alpacas. When the two antibody tests were combined, the parallel-testing interpretation (applied when either assay produced a positive result) enhanced the sensitivities of antibody detection to 89% for alpacas and 88% for llamas but at the cost of lower specificities (97% and 93%, respectively), whereas the serial-testing interpretation (applied when both assays produced a positive result) maximized the specificity to 100% for both SAC species, although the sensitivities were 57% for alpacas and 65% for llamas. Over 95% of the animals with evidence of TB failed to produce skin test reactions, thus confirming concerns about the validity of this method for testing SAC. The findings suggest that serological assays may offer a more accurate and practical alternative for antemortem detection of camelid TB.

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Objectives  To determine the improvement in positive predictive value of immunological failure criteria for identifying virological failure in HIV-infected children on antiretroviral therapy (ART) when a single targeted viral load measurement is performed in children identified as having immunological failure. Methods  Analysis of data from children (<16 years at ART initiation) at South African ART sites at which CD4 count/per cent and HIV-RNA monitoring are performed 6-monthly. Immunological failure was defined according to both WHO 2010 and United States Department of Health and Human Services (DHHS) 2008 criteria. Confirmed virological failure was defined as HIV-RNA >5000 copies/ml on two consecutive occasions <365 days apart in a child on ART for ≥18 months. Results  Among 2798 children on ART for ≥18 months [median (IQR) age 50 (21-84) months at ART initiation], the cumulative probability of confirmed virological failure by 42 months on ART was 6.3%. Using targeted viral load after meeting DHHS immunological failure criteria rather than DHHS immunological failure criteria alone increased positive predictive value from 28% to 82%. Targeted viral load improved the positive predictive value of WHO 2010 criteria for identifying confirmed virological failure from 49% to 82%. Conclusion  The addition of a single viral load measurement in children identified as failing immunologically will prevent most switches to second-line treatment in virologically suppressed children.

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Background and Purpose—There is some controversy on the association of the National Institutes of Health Stroke Scale (NIHSS) score to predict arterial occlusion on MR arteriography and CT arteriography in acute stroke. Methods—We analyzed NIHSS scores and arteriographic findings in 2152 patients (35.4% women, mean age 66±14 years) with acute anterior or posterior circulation strokes. Results—The study included 1603 patients examined with MR arteriography and 549 with CT arteriography. Of those, 1043 patients (48.5%; median NIHSS score 5, median time to clinical assessment 179 minutes) showed an occlusion, 887 in the anterior (median NIHSS score 7/0–31), and 156 in the posterior circulation (median NIHSS score 3/0–32). Eight hundred sixty visualized occlusions (82.5%) were located centrally (ie, in the basilar, intracranial vertebral, internal carotid artery, or M1/M2 segment of the middle cerebral artery). NIHSS scores turned out to be predictive for any vessel occlusions in the anterior circulation. Best cut-off values within 3 hours after symptom onset were NIHSS scores ≥9 (positive predictive value 86.4%) and NIHSS scores ≥7 within >3 to 6 hours (positive predictive value 84.4%). Patients with central occlusions presenting within 3 hours had NIHSS scores <4 in only 5%. In the posterior circulation and in patients presenting after 6 hours, the predictive value of the NIHSS score for vessel occlusion was poor. Conclusions—There is a significant association of NIHSS scores and vessel occlusions in patients with anterior circulation strokes. This association is best within the first hours after symptom onset. Thereafter and in the posterior circulation the association is poor.

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Objective:  To investigate the predictive value of the Strauss and Carpenter Prognostic Scale (SCPS) for transition to a first psychotic episode in subjects clinically at high risk (CHR) of psychosis. Method:  Two hundred and forty-four CHR subjects participating in the European Prediction of Psychosis Study were assessed with the SCPS, an instrument that has been shown to predict outcome in patients with schizophrenia reliably. Results:  At 18-month follow-up, 37 participants had made the transition to psychosis. The SCPS total score was predictive of a first psychotic episode (P < 0.0001). SCPS items that remained as independent predictors in the Cox proportional hazard model were as follows: most usual quality of useful work in the past year (P = 0.006), quality of social relations (P = 0.006), presence of thought disorder, delusions or hallucinations in the past year (P = 0.001) and reported severity of subjective distress in past month (P = 0.003). Conclusion:  The SCPS could make a valuable contribution to a more accurate prediction of psychosis in CHR subjects as a second-step tool. SCPS items assessing quality of useful work and social relations, positive symptoms and subjective distress have predictive value for transition. Further research should focus on investigating whether targeted early interventions directed at the predictive domains may improve outcomes.

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Background: In most patients with chronic heart failure (CHF), endurance training improves exercise capacity. However, some patients do not respond favourably. The purpose of this study was to explore the reasons of non-response and to determine their predictive value.Methods: We studied a cohort of 120 consecutive CHF patients with sinus rhythm (mean age 57 ± 12 years, ejection fraction 29.3 ± 9.9%, peak VO2 17.3 ± 5.1 ml/min/kg), participating in a 3-month outpatient cardiac rehabilitation programme. Responders were defined as subjects who improved peak VO2 by more than 5%, work load by more than 10%, or VE/VCO2 slope by more than 5%. Subjects who did not fulfil at least one of the above criteria were characterized as non-responders. Multivariate regression analyses were performed to identify parameters that were predictive for a response. Receiver operating characteristic (ROC) analyses were performed for predictive parameters to identify thresholds for response or non-response.Results: Multivariate regression analyses revealed heart rate (HR) reserve, HR recovery at 1 min, and peak HR as significant predictors for a positive training response. ROC curves revealed the optimal thresholds separating responders from non-responders at less than 30 bpm for HR reserve, less than 6 bpm for HR recovery and less than 101 bpm for peak HR.Conclusions: The presence of impaired chronotropic competence is a major predictor of poor training response in CHF patients with sinus rhythm.

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Objective: In 2011, the term “intratumoral budding, ITB” was used to describe the presence of tumor buds within the main tumor body and was correlated to worse clinical outcome in colorectal cancer patients. Here, we further elucidate the potential clinical role of ITB in pre-operative biopsies using pan-cytokeratin stained tissues and a quantitative scoring system. Method: 139 pre-operative biopsies from patients with colorectal cancer underwent immunohistochemistry for pancytokeratin (AE1/AE3). ITB were counted in the area of densest budding (40×) and classified as high-grade when >10 buds/HPF were observed based on receiver operating characteristic (ROC) curve analysis. Results: High-grade ITB occurred in 26.6 % of cases and was associated with right-sided tumor location (p=0.0356), more advanced pT (p=0.0198) and pN (p<0.0001) classifications, distant metastasis (p=0.0164), higher tumor grade (p=0.0037) and lymphatic invasion (p=0.0445). The specificity and positive predictive value for lymph node metastasis was 86.7 % and 75.6 %, respectively. Disease-free survival was significantly worse in patients with high-grade ITB (5-year survival=25 %) in comparison to patients with low-grade ITB (5-year survival=55 %) (p=0.0157). Conclusion: The assessment of ITB in pre-operative biopsies is predictive of local and distant metastasis in corresponding resections and should be considered in daily management of colorectal cancer patients.

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Objective: We compare the prognostic strength of the lymph node ratio (LNR), positive lymph nodes (+LNs) and collected lymph nodes (LNcoll) using a time-dependent analysis in colorectal cancer patients stratified by mismatch repair (MMR) status. Method: 580 stage III-IV patients were included. Multivariable Cox regression analysis and time-dependent receiver operating characteristic (tROC) curve analysis were performed. The Area under the Curve (AUC) over time was compared for the three features. Results were validated on a second cohort of 105 stage III-IV patients. Results: The AUC for the LNR was 0.71 and outperformed + LNs and LNcoll by 10–15 % in both MMR-proficient and deficient cancers. LNR and + LNs were both significant (p<0.0001) in multivariable analysis but the effect was considerably stronger for the LNR [LNR: HR=5.18 (95 % CI: 3.5–7.6); +LNs=1.06 (95 % CI: 1.04–1.08)]. Similar results were obtained for patients with >12 LNcoll. An optimal cut off score for LNR=0.231 was validated on the second cohort (p<0.001). Conclusion: The LNR outperforms the + LNs and LNcoll even in patients with >12 LNcoll. Its clinical value is not confounded by MMR status. A cut-of score of 0.231 may best stratify patients into prognostic subgroups and could be a basis for the future prospective analysis of the LNR.

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Fluorescence microlymphography (FML) is used to visualize the lymphatic capillaries. A maximum spread of the fluorescence dye of ≥ 12 mm has been suggested for the diagnosis of lymphedema. However, data on sensitivity and specificity are lacking. The aim of this study was to investigate the accuracy of FML for diagnosing lymphedema in patients with leg swelling. Patients with lower extremity swelling were clinically assessed and separated into lymphedema and non-lymphatic edema groups. FML was studied in all affected legs and the maximum spread of lymphatic capillaries was measured. Test accuracy and receiver operator characteristic (ROC) analysis was performed to assess possible threshold values that predict lymphedema. Between March 2008 and August 2011 a total of 171 patients (184 legs) with a median age of 43.5 (IQR 24, 54) years were assessed. Of those, 94 (51.1%) legs were diagnosed with lymphedema. The sensitivity, specificity, positive and negative likelihood ratio and positive and negative predictive value were 87%, 64%, 2.45, 0.20, 72% and 83% for the 12-mm cut-off level and 79%, 83%, 4.72, 0.26, 83% and 79% for the 14-mm cut-off level, respectively. The area under the ROC curve was 0.82 (95% CI: 0.76, 0.88). Sensitivity was higher in the secondary versus primary lymphedema (95.0% vs 74.3%, p = 0.045). No major adverse events were observed. In conclusion, FML is a simple and safe technique for detecting lymphedema in patients with leg swelling. A cut-off level of ≥ 14-mm maximum spread has a high sensitivity and high specificity of detecting lymphedema and should be chosen.

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Effectively assessing subtle hepatic metabolic functions by novel non-invasive tests might be of clinical utility in scoring NAFLD (non-alcoholic fatty liver disease) and in identifying altered metabolic pathways. The present study was conducted on 39 (20 lean and 19 obese) hypertransaminasemic patients with histologically proven NAFLD {ranging from simple steatosis to severe steatohepatitis [NASH (non-alcoholic steatohepatitis)] and fibrosis} and 28 (20 lean and eight overweight) healthy controls, who underwent stable isotope breath testing ([(13)C]methacetin and [(13)C]ketoisocaproate) for microsomal and mitochondrial liver function in relation to histology, serum hyaluronate, as a marker of liver fibrosis, and body size. Compared with healthy subjects and patients with simple steatosis, NASH patients had enhanced methacetin demethylation (P=0.001), but decreased (P=0.001) and delayed (P=0.006) ketoisocaproate decarboxylation, which was inversely related (P=0.001) to the degree of histological fibrosis (r=-0.701), serum hyaluronate (r=-0.644) and body size (r=-0.485). Ketoisocaproate decarboxylation was impaired further in obese patients with NASH, but not in patients with simple steatosis and in overweight controls. NASH and insulin resistance were independently associated with an abnormal ketoisocaproate breath test (P=0.001). The cut-off value of 9.6% cumulative expired (13)CO(2) for ketoisocaproate at 60 min was associated with the highest prediction (positive predictive value, 0.90; negative predictive value, 0.73) for NASH, yielding an overall sensitivity of 68% and specificity of 94%. In conclusion, both microsomal and mitochondrial functions are disturbed in NASH. Therefore stable isotope breath tests may usefully contribute to a better and non-invasive characterization of patients with NAFLD.

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PURPOSE: The value of adjuvant tamoxifen after chemotherapy for premenopausal women with breast cancer has not been adequately assessed. PATIENTS AND METHODS: Between 1993 and 1999, International Breast Cancer Study Group Trial 13-93 enrolled 1,246 assessable premenopausal women with axillary node-positive, operable breast cancer. All patients received chemotherapy (cyclophosphamide plus either doxorubicin or epirubicin for four courses followed by immediate or delayed classical cyclophosphamide, methotrexate, and fluorouracil for three courses), which was followed by either tamoxifen (20 mg daily) for 5 years or no further treatment. The primary end point was disease-free survival (DFS). Tumors were classified as estrogen receptor (ER) -positive (n = 735, 59%) if immunohistochemical (IHC) or ligand-binding assays (LBA) were clearly positive. The ER-negative group included all other tumors (n = 511, 41%). A subset of the ER-negative group was defined as ER absent (n = 108, 9%) if IHC staining was none or if the LBA result was 0 fmol/mg cytosol protein. The median follow-up time was 7 years. RESULTS: Tamoxifen improved DFS in the ER-positive cohort (hazard ratio [HR] for tamoxifen v no tamoxifen = 0.59; 95% CI, 0.46 to 0.75; P < .0001) but not in the ER-negative cohort (HR = 1.02; 95% CI, 0.77 to 1.35; P = .89). Tamoxifen had a detrimental effect on patients with ER-absent tumors compared with no tamoxifen in an unplanned exploratory analysis (HR = 2.10; 95% CI, 1.03 to 4.29; P = .04). Patients with ER-positive tumors who achieved chemotherapy-induced amenorrhea had a significantly improved outcome (HR for amenorrhea v no amenorrhea = 0.61; 95% CI, 0.44 to 0.86; P = .004), whether or not they received tamoxifen. CONCLUSION: Tamoxifen after adjuvant chemotherapy significantly improved treatment outcome in premenopausal patients with endocrine-responsive disease, but its use as adjuvant therapy for patients with ER-negative tumors is not recommended.

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BACKGROUND: Tumor levels of steroid hormone receptors, a factor used to select adjuvant treatment for early-stage breast cancer, are currently determined with immunohistochemical assays. These assays have a discordance of 10%-30% with previously used extraction assays. We assessed the concordance and predictive value of hormone receptor status as determined by immunohistochemical and extraction assays on specimens from International Breast Cancer Study Group Trials VIII and IX. These trials predominantly used extraction assays and compared adjuvant chemoendocrine therapy with endocrine therapy alone among pre- and postmenopausal patients with lymph node-negative breast cancer. Trial conclusions were that combination therapy provided a benefit to pre- and postmenopausal patients with estrogen receptor (ER)-negative tumors but not to ER-positive postmenopausal patients. ER-positive premenopausal patients required further study. METHODS: Tumor specimens from 571 premenopausal and 976 postmenopausal patients on which extraction assays had determined ER and progesterone receptor (PgR) levels before randomization from October 1, 1988, through October 1, 1999, were re-evaluated with an immunohistochemical assay in a central pathology laboratory. The endpoint was disease-free survival. Hazard ratios of recurrence or death for treatment comparisons were estimated with Cox proportional hazards regression models, and discriminatory ability was evaluated with the c index. All statistical tests were two-sided. RESULTS: Concordance of hormone receptor status determined by both assays ranged from 74% (kappa = 0.48) for PgR among postmenopausal patients to 88% (kappa = 0.66) for ER in postmenopausal patients. Hazard ratio estimates were similar for the association between disease-free survival and ER status (among all patients) or PgR status (among postmenopausal patients) as determined by the two methods. However, among premenopausal patients treated with endocrine therapy alone, the discriminatory ability of PgR status as determined by immunohistochemical assay was statistically significantly better (c index = 0.60 versus 0.51; P = .003) than that determined by extraction assay, and so immunohistochemically determined PgR status could predict disease-free survival. CONCLUSIONS: Trial conclusions in which ER status (for all patients) or PgR status (for postmenopausal patients) was determined by immunohistochemical assay supported those determined by extraction assays. However, among premenopausal patients, trial conclusions drawn from PgR status differed--immunohistochemically determined PgR status could predict response to endocrine therapy, unlike that determined by the extraction assay.

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PURPOSE: We estimated the diagnostic accuracy of ultrasound detrusor thickness measurement for BOO and investigated whether this method can replace PFS for the diagnosis of BOO in some patients with lower urinary tract symptoms. MATERIALS AND METHODS: Detrusor thickness was measured by linear ultrasound (7.5 MHz) at a filling volume of greater than 50% of cystometric capacity in 102 men undergoing PFS for LUTS. All patients with prior treatment for bladder outlet obstruction and those with underlying neurological disorders were excluded from analysis. Detrusor thickness was correlated with PFS data. Obstruction was defined according to the Abrams-Griffiths nomogram. RESULTS: Detrusor thickness was significantly higher (p <0.0001) in obstructed (61 cases, median detrusor thickness 2.7 mm, IQR 2.4 to 3.3) compared to unobstructed (18 cases, median detrusor thickness 1.7 mm, IQR 1.5 to 2) as well as equivocal (23 cases, median detrusor thickness 1.8 mm, IQR 1.5 to 2.2) cases. A weak to medium Spearman correlation was found between detrusor thickness and PFS parameters. For a diagnosis of BOO, detrusor thickness of 2.9 mm or greater had a positive predictive value of 100%, a negative predictive value of 54%, specificity of 100% and sensitivity of 43%. ROC analysis revealed that detrusor thickness had a high predictive value for BOO with an AUC of 0.88 (95% CI 0.81-0.94). CONCLUSIONS: In men with LUTS without prior treatment and/or neurological disorders, ultrasonographically assessed detrusor thickness 2.9 mm or greater has a high predictive value for BOO and can replace PFS for the diagnosis of BOO. However, this cutoff value needs to be validated in a larger study population.

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OBJECTIVE: To determine whether pharmacogenetic tests such as N-acetyltransferase 2 (NAT2) and cytochrome P450 2E1 (CYP2E1) genotyping are useful in identifying patients prone to antituberculosis drug-induced hepatotoxicity in a cosmopolite population. METHODS: In a prospective study we genotyped 89 patients treated with isoniazid (INH) for latent tuberculosis. INH-induced hepatitis (INH-H) or elevated liver enzymes including hepatitis (INH-ELE) was diagnosed based on the clinical diagnostic scale (CDS) designed for routine clinical practice. NAT2 genotypes were assessed by fluorescence resonance energy transfer probe after PCR analysis, and CYP2E1 genotypes were determined by PCR with restriction fragment length polymorphism analysis. RESULTS: Twenty-six patients (29%) had INH-ELE, while eight (9%) presented with INH-H leading to INH treatment interruption. We report no significant influence of NAT2 polymorphism, but we did find a significant association between the CYP2E1 *1A/*1A genotype and INH-ELE (OR: 3.4; 95% CI:1.1-12; p = 0.02) and a non significant trend for INH-H (OR: 5.9; 95% CI: 0.69-270; p = 0.13) compared with other CYP2E1 genotypes. This test for predicting INH-ELE had a positive predictive value (PPV) of 39% (95% CI: 26-54%) and a negative predictive value (NPV) of 84% (95% CI: 69-94%). CONCLUSION: The genotyping of CYP2E1 polymorphisms may be a useful predictive tool in the common setting of a highly heterogeneous population for predicting isoniazid-induced hepatic toxicity. Larger prospective randomized trials are needed to confirm these results.

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BACKGROUND AND STUDY AIMS: The reference surveillance method in patients with Barrett's esophagus is careful endoscopic observation, with targeted as well as random four-quadrant biopsies. Autofluorescence endoscopy (AFE) may make it easier to locate neoplasia. The aim of this study was to elucidate the diagnostic accuracy of surveillance with AFE-guided plus four-quadrant biopsies in comparison with the conventional approach. PATIENTS AND METHODS: A total of 187 of 200 consecutive Barrett's esophagus patients who were initially enrolled (73 % male, mean age 67 years, mean Barrett's segment length 4.6 cm), who underwent endoscopy for Barrett's esophagus in four study centers, were randomly assigned to undergo either AFE-targeted biopsy followed by four-quadrant biopsies or conventional endoscopic surveillance, also including four-quadrant biopsies (study phase 1). After exclusion of patients with early cancer or high-grade dysplasia, who underwent endoscopic or surgical treatment, as well as those who declined to participate in phase 2 of the study, 130 patients remained. These patients were examined again with the alternative method after a mean of 10 weeks, using the same methods described. The main study parameter was the detection of early cancer/adenocarcinoma or high-grade dysplasia (HGD), comparing both approaches in study phase 1; the secondary study aim in phase 2 was to assess the additional value of the AFE-guided approach after conventional surveillance, and vice versa. Test accuracy measures were derived from study phase 1. RESULTS: In study phase 1, the AFE and conventional approaches yielded adenocarcinoma/HGD rates of 12 % and 5.3 %, respectively, on a per-patient basis. With AFE, four previously unrecognized adenocarcinoma/HGD lesions were identified (4.3 % of the patients); with the conventional approach, one new lesion (1.1 %) was identified. Of the 19 adenocarcinoma/HGD lesions detected during AFE endoscopy in study phase 1, eight were visualized, while 11 were only detected using untargeted four-quadrant biopsies (sensitivity 42 %). Of the 766 biopsies classified at histology as being nonneoplastic, 58 appeared suspicious (specificity 92 %, positive predictive value 12 %, negative predictive value 98.5 %). In study phase 2, AFE detected two further lesions in addition to the initial alternative approach in 3.2 % of cases, in comparison with one lesion with conventional endoscopy (1.7 %). CONCLUSIONS: In this referral Barrett's esophagus population with a higher prevalence of neoplastic lesions, the AFE-guided approach improved the diagnostic yield for neoplasia in comparison with the conventional approach using four-quadrant biopsies. However, AFE alone was not suitable for replacing the standard four-quadrant biopsy protocol.

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OBJECTIVES: This study sought to evaluate the diagnostic accuracy of coronary binary in-stent restenosis (ISR) with angiography using 64-slice multislice computed tomography coronary angiography (CTCA) compared with invasive coronary angiography (ICA). BACKGROUND: A noninvasive detection of ISR would result in an easier and safer way to conduct patient follow-up. METHODS: We performed CTCA in 81 patients after stent implantation, and 125 stented lesions were scanned. Two sets of images were reconstructed with different types of convolution kernels. On CTCA, neointimal proliferation was visually evaluated according to luminal contrast attenuation inside the stent. Lesions were graded as follows: grade 1, none or slight neointimal proliferation; grade 2, neointimal proliferation with no significant stenosis (<50%); grade 3, neointimal proliferation with moderate stenosis (> or =50%); and grade 4, neointimal proliferation with severe stenosis (> or =75%). Grades 3 and 4 were considered binary ISR. The diagnostic accuracy of CTCA compared with ICA was evaluated. RESULTS: By ICA, 24 ISRs were diagnosed. Sensitivity, specificity, positive predictive value, and negative predictive value were 92%, 81%, 54%, and 98% for the overall population, whereas values were 91%, 93%, 77%, and 98% when excluding unassessable segments (15 segments, 12%). For assessable segments, CTCA correctly diagnosed 20 of the 22 ISRs detected by ICA. Six lesions without ISR were overestimated as ISR by CTCA. As the grade of neointimal proliferation by CTCA increases, the median value of percent diameter stenosis increased linearly. CONCLUSIONS: Binary ISR can be excluded with high probability by CTCA, with a moderate rate of false-positive results.