Reference intervals

Albumin, the major protein of human plasma (reference interval 535-760 / M), has the properties of copper... 

Patients and blood donors are routinely screened for exposure to HIV by means of ElISA and Western blot assays of blood samples (F uie 1-7-15). The assays are designed to detect antibodies to HIV in the blood of the test subject The ELISA is used as the primary screening assay because it is very sensitive. Because the reference interval for the test is set to include everyone with antibodies to HIV, it also gives false positives and thus has a rather low positive predictive value, especially in low-risk populations. The Western blot (or immunoblot) is used as the confirmatory test for HIV exposure. In the Western blot technique, specific HIV proteins are separated by gel electrophoresis and blotted to a filter. The filter is incubated with the test sample. If the sample contains antibodies to HIV, they will bind to the proteins on the filter. The filter is next washed and incubated with a labeled goat anti-human IgG to visualize any bound human antibodies. The Western blot is highly specific. The combination of an ELISA and Western blot has a positive predictive value of greater than 99%,... 

DiPietro ES, Phillips DL, Paschal DC, et al. 1989. Determination of trace elements in human hair Reference intervals for 28 elements in nonoccupationally exposed adults in the US and effects of hair treatments. Biol Trace Elem Res 22 83-100. 

Baadenhuijsen, H., Arts, J., Somers, L., Smit, J. C. REFVALUE a software package to calculate references intervals from total hospital patient laboratory data , Elsevier, Amsterdam 1985... 

Benoit JF, Alberti C, Leclercq S, Rigal O, Jean-Luois R, Ogier de Baulny H, Porquet D, Biou D (2003) cerebrospinal fluid lactate and pyruvate concentration and their ratio in children age-related reference intervals. Clin Chem 49 487-494... 

CER (95% interval) 3.7-8.2% cholesteryl esters/h [23]. Variations among laboratories are possible so that every laboratory should determine its own reference intervals). 

Oxime derivatization was utilized by Kushnir et al. [44] to improve ESI sensitivity for testosterone measurement. Using a C18 column for separation (3-min run times) and an API 4000 they monitored MRM transitions 304—>124 and 112 for testosterone oxime and 307—>14 and 112 for the d3 internal standard. Within-run and between-run irreproducibility was < 12%. The LOD was 10 pg/ml, allowing accurate measurement of testosterone in women and children. Reference intervals for the steroid in children of different ages and different Tanner stages are given in the publication as well as values for both free and total testosterone. 

Toulsen et al. (1994) appear to use the term reference interval as synonymous with reference range. In a paper titled Trace element reference values. . . , the authors emphasize that knowledge of the reference intervals (baseline data) for the trace elements in human body fluids and tissues is of paramount importance. ... 

Improvement in the metrological area may lead to a shift in reference intervals, which needs to be taken into account by the clinicians. This shift in the framework of the physician interpreting the results is sometimes met with resistance if no additional medical benefit arises. This may complicate the acceptance of this concept of traceability in its possible practical consequences. 

Reference Intervals for Cardiac Troponins and Creatine Kinase Isoenzymes... 

Explain how the determination of reference intervals can have an impact on the number of MI cases that are defined in a given population of patients with chest pain. 

Analyte levels are compared both to the concomitant control group (using appropriate statistical methods of the group size is large enough) and additionally to laboratory-specific reference intervals for the species, strain, age and sex in question. 

Fig. 11. Serum cystatin C (top) and creatinine (bottom) in relation to age in a population of 258 children, 1 day-18 years old, and without evidence of kidney disease. The boxed area represents the serum cystatin C reference interval for children over 1 year.

N6. Norlund, L., Fex, G., Lanke, J., Von Schenck, H., Nilsson, J. E., et al., Reference intervals for the glomerular filtration rate and cell-proliferation markers Serum cystatin C and serum fe-microglobulin/cystatin C-ratio. Scand. J. Clin. Lab. Invest. 57(6), 463-470 (1997). 

Reference interval HDL cholesterol is used in the following formula to determine the risk of the development of a coronary disease ... 

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