Diagnostic and prognostic significance of biomarkers

In modern laboratory medicine there is a growing tendency for finding out the most specific and most sensitive biomarkers as indicators of a disease and diagnostic means for the follow-up treatment and therapeutical results. Detection of sensitive biomarkers was speeded up by world companies as manufacturers of diagnostic reagents. Today, the determination of some biochemical parameters is performed by immunodetermination which uses monoclonal antibodies and different markers, and thus achieving the desired high specificity of determination. The selections of biomarkers which are the most important for the clinical practice and which will give the best diagnostic information, requires large researches including analytical, clinical and economic properties. Thanks to statistical methods, especially to ROC analysis, the so-called cutoff-values are determined. On the basis of these values differentiation between sick people and healthy individuals is possible. In other words, the evaluation of clinical specificity requires also inclusion of patients whose clinical picture reflects the disease for which a marker is tested. The development and choice of biomarkers is also helped by IFCC with suggestion of the best procedures and preparation of reference materials. The use of selected biomarkers must be profitable in respect of the price and diagnostic information. In the paper the principles of selection, use, diagnostic and prognostic significance of biomarkers is discussed. The following biomarkers served as examples: cardiovascular (troponin T and I, myoglobin, CK-MB mass), bone (deoxypyridinolin, osteocalcin, C-terminal propeptide collagen, type I, osteo-alkaline-phosphase), malignant (PSA) and for pancreas diseases (lipase, PAM).