Volume 35, Issue 3

In 2006 the German United Society for Clinical Chemistry and Laboratory Medicine together with the German Society of Nephrology founded a working group intending to develop diagnostic pathways for the exclusion, detection and differentiation of renal diseases. Based on existing recommendations these pathways may be structured to be a basis for implementation into hospital and laboratory information systems. The present paper describes the contents of these pathways regarding glomerular filtration rate, haematuria, leucocyturia and proteinuria.

Arterial hypertension is an important public health challenge worldwide. In Germany prevalence of arterial hypertension is around 55% and therefore much higher compared to other European countries and the USA. Approx­imately 26% of all causes of death in Germany might be directly related to the consequences of an inadequately controlled blood pressure. Poor blood pressure control may be in part due to lack of awareness for potentially curable causes of hypertension. Primary aldosteronism (PA) in terms of an absolute excess of aldosterone is currently regarded as most frequent curable cause of arterial hypertension. Prevalence of PA is 5%–12% in arterial hypertension and in 17%–23% in drug-resistant hypertension. These numbers suggest that around 1.2 million people in Germany might be affected by PA. Absolute excess of aldosterone is strongly associated with higher risk of the development and progression of coronary artery disease, left ventricular hypertrophy, sudden cardiac death, chronic kidney disease and strokes. The American Endocrine Society recommends screening for PA via determination of the aldosterone to renin ratio in selected subgroups of patients. Highly standardized screening procedures are warranted in order to avoid false-positive or false-negative screening results. Accumulating evidence however suggests that aldosterone might mediate cardiovascular damage independent of the presence of PA. Dietary salt excess, lower kidney function and increased oxidative stress are important prerequisites of aldosterone induced target organ damage. The association between relative excess of aldosterone and higher cardiovascular risk puts dietary salt restriction in the perspective of cardiovascular prevention medicine. In addition, further interventional studies are warranted to elucidate beneficial effects of MR blockade in cardiovascular risk groups.

Homoarginine is a non-essential cationic amino acid, which is formed from lysine. In vitro and in vivo, homoarginine shows characteristics similar to arginine. Until recently, homoarginine has attracted little scientific interest. During the last decades it has been particularly used as an internal standard in amino acid analytics or as a tracer compound for nutrient utilization in intensive animal husbandry. Epidemiological investigations in two large independent cohorts, namely the German diabetes dialysis (4D) — study and the Ludwigshafen Risk and Cardiovascular Health (LURIC) – study have identified homoarginine as useful predictor of cardiovascular events and mortality. Yet, little is known about the pathophysiological mechanisms which may underlie this association. This article summarizes the importance of homoarginine as prognostic markers and the possible effects which homoarginine may exert on the human organism.

Therapeutic drug monitoring (TDM) of antiepileptic drugs (AEDs) has been in clinical use for more than three decades. Its value has, however, been questioned recently for several reasons, e.g., the occurrence of newer AEDs, for which the use of TDM has to be evaluated, but also because of financial strains on health systems. The current review aims at assessing the use of TDM in newer AEDs, i.e., those that entered the market since the beginning of the 1990s. As some have been licensed only recently and others are only in very limited use, either because of orphan drug status or because of limited efficacy or potentially severe adverse events, only limited data exist for some of the newer AEDs. General considerations are made in the review, and each new AED is discussed, and, in some cases preliminary, assessment of the use of TDM is given. Zusammenfassung Therapeutic drug monitoring (TDM) bei Antiepileptika (AED) ist seit mehr als drei Jahrzehnten Bestandteil der klinischen Praxis. Die Berechtigung wird jedoch immer wieder in Frage gestellt, einerseits wegen der Zulassung zahlreicher neuer AED, für die der Nutzen von TDM noch evaluiert werden muss, andererseits aber auch wegen finanzieller Einschnitte im Gesundheitswesen. Die vorliegende Übersicht soll den Nutzen von TDM bei neueren AED – also denjenigen AED, die seit dem Anfang der neunziger Jahre des 20. Jahrhunderts zugelassen wurden – darstellen. Für manche dieser Medikamente liegen nur wenige Daten vor, weil sie erst kürzlich zugelassen wurden oder weil sie Orphan drug -Status haben oder weil sie aufgrund potentiell schwerer Nebenwirkungen nur sehr selten eingesetzt werden. Zunächst werden Relevanz und Indikationen des TDM im Allgemeinen und nachfolgend für jedes neuere AED diskutiert, wobei die Einschätzung des Nutzens von TDM bei einzelnen Medikamenten gegenwärtig vorläufigen Charakter hat.