Borderline Result (borderline + result)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Optimizing BeLPT criteria for beryllium sensitization

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 3 2008
D.C. Middleton MD
Abstract Background The beryllium lymphocyte proliferation test (BeLPT) is used to identify persons sensitized to beryllium. ATSDR convened an expert panel of physicians and scientists in April 2006 to discuss this test and to consider what BeLPT test results actually establish beryllium sensitization. The three criteria proposed by panel members were one abnormal result, one abnormal and one borderline result, and two abnormal results. Methods Complete algorithms were developed for each of the three proposed criteria. Using single-test outcome probabilities developed by Stange et al. [2004. Am J Ind Med 46:453,462], we calculated and compared the sensitivity, specificity, and positive predictive values (PPVs) for each set of criteria. Results The overall sensitivity and specificity of the three criteria were similar. When the criteria required confirmation of an abnormal result the PPV was higher,whether the requirement was satisfied by a borderline result, or only by another abnormal result. Confirmation also reduced the likelihood of false positives. The differences between the three criteria decreased as the prevalence of sensitization increased. Conclusions A single unconfirmed abnormal is usually insufficient to establish sensitization for an apparently healthy person. When the prevalence of beryllium sensitization in a group is high, however, even a single abnormal BeLPT can be a strong predictor. Am. J. Ind. Med. 51:166,172, 2008. © 2008 Wiley-Liss, Inc. [source]

Use of Cervista HPV HR assay for detection of human papillomavirus in samples with hybrid capture borderline negative results

APMIS, Issue 9 2010
Fatima Galan-Sanchez
Galan-Sanchez F, Rodriguez-Iglesias MA. Use of Cervista HPV HR assay for detection of human papillomavirus in samples with hybrid capture borderline negative results. APMIS 2010; 118: 681,4. We have evaluated Cervista HPV HR for papillomavirus detection in 65 samples previously borderline negative by the hybrid capture method (Digene), using InnoLipa and sequencing as confirmatory techniques. Nine samples were found to be positive by Cervista HPV HR, of which five (7.6%) were confirmed by InnoLipa. Four samples (6.1%) were false positive, of which three samples were reactive for A9 probes. The Cervista HPV HR assay can detect HPV-positive samples from those with hybrid capture borderline results but can produce false-positive results when tested for reactivity with A9 probes. [source]

Variation in GH and IGF-I assays limits the applicability of international consensus criteria to local practice

CLINICAL ENDOCRINOLOGY, Issue 1 2007
A. Pokrajac
Summary Background, There is increasing reliance on consensus criteria for decision making. Recent criteria state that acromegaly is excluded by a nadir GH during an oral glucose tolerance test (OGTT) of < 1 µg/l and a normal level of IGF-I. Objective, To study GH and IGF-I assay performance close to cut-off values for active acromegaly. Design and methods, Two serum samples known to give borderline results were sent to all centres participating in the UK National External Quality Assessment Service (NEQAS). Sample A was assigned to be a nadir during an OGTT and sent for GH assessment to 104 centres. Sample B, with a clinical scenario, was sent to 23 centres that measure IGF-I, and these centres were asked to measure IGF-I, interpret the result and provide the source of their reference ranges (RRs). Results, For sample A, the median GH was 2·6 mU/l (range 1·04,3·5 mU/l). Applying a conversion factor (CF) of 2·0 (1 µg/l = 2 mU/l), the most negatively biased method classified 10% of the values consistent with acromegaly, while the most positively biased method classified all values as consistent with the diagnosis. Applying a CF of 3·0 (1 µg/l = 3 mU/l), only 11% of results were consistent with acromegaly. For sample B, the median IGF-I was 50·8 nmol/l (range 24·3,60·9 nmol/l). All centres used age-related RRs. There was a 50% variation in the upper limit of the RRs between centres. Overall, 30% of the IGF-I results were against the diagnosis. There was little agreement in the RRs quoted by centres using the same method. Conclusion, Variability in assay performance, coupled with use of inappropriate CFs and RRs, undermines the applicability of international consensus criteria to local practice. [source]