All you wanted to know about laboratory tests, but were afraid to ask

All you wanted to know about laboratory tests, but were afraid to ask The informed patient meeting the laboratory director Standardization & Traceability The problem By Dietmar Stöckl STT Consulting - 7 -

Reminder We heard laboratory testing would be a good idea, but ... All you wanted to know about laboratory tests -7-

The “Buts” You are healthy in one Lab – but sick in another All you wanted to know about laboratory tests -7-

J Clin Endocrinol Metab 25 hydroxyvitamin D • “Vitamin D assays yield markedly differing results; whether an individual is found to have low or normal vitamin D status is a function of the laboratory used. If the medical community is to make progress in correcting widespread hypovitaminosis D, vitamin D measurement must be standardized” • Binkley N, et al. Assay variation confounds the diagnosis of hypovitaminosis D: A call for standardization. J Clin Endocrinol Metab 2004;89:3152–7. All you wanted to know about laboratory tests -7-

Kidney Int Parathyroid hormone • “It appears unethical that all the companies making different PTH assays could not meet and decide how to standardize and calibrate a consistent circulating PTH measurement. Many physicians are making huge efforts to keep their patients within the target values recommended by the NKF/K-DOQI; however, most of them are misinformed by their PTH measurement”. • Torres PU. The need for reliable serum parathyroid hormone measurements. Kidney Int 2006;70:240-3. All you wanted to know about laboratory tests -7-

J Clin Endocrinol Metab Testosterone • Widely used assay methods to measure serum testosterone suffer from a lack of accuracy and sensitivity, making it difficult for physicians to appropriately diagnose and treat androgen-related disorders in women, children, and men. The February 2007 issue of the Journal of Clinical Endocrinology & Metabolism calls for standardizing the methods by which these assays are validated. • http://www.endo-society.org/media/press/2007/ • EndocrinePositionStatementCallsStandardizedTestosteroneAssays.cfm • http://www.cdc.gov/nceh/dls/hormone_standardization.htm All you wanted to know about laboratory tests -7-

Standardization • Tip of the iceberg! • 25 hydroxyvitamin D • Parathyroid hormone • Testosterone • General problem • Steroid hormones • Thyroid hormones • Protein hormones • Glyoprotein hormones • Cardiac markers • Tumor markers • New markers (Cytokines, Growth factors) • >And so much more Nearly did'nt dare to come out again! No Titanic around? All you wanted to know about laboratory tests -7-

Reference intervals • Serum sodium reference interval • "Variation in reference intervals was not related • to analytical platforms". • "The major reason for variation was simply historical, with no scientific foundation". • >Not restricted to the UK! • http://www.pathologyharmony.co.uk/graphics/Pathology%20Harmony%20Newsletter%20July%202008.pdf • Serum magnesium reference interval • Dewitte K. In search of the reference interval of serum magnesium – The last case of Hercule Poirot [in Dutch]. • BVLT Tijdschrift 2000;27:169-73. • >Origin of the Tietz reference interval • could not been traced. All you wanted to know about laboratory tests -7-

I type ... ... what science is that!? It was'nt me who said it. All you wanted to know about laboratory tests -7-

The next visit Standardization & Traceability The solution That makes me curious! All you wanted to know about laboratory tests -7-

All you wanted to know about laboratory tests, but were afraid to ask