WITHIN-PATIENT VARIABILITY OF HORMONE AND CYTOKINE CONCENTRATIONS IN HEART-FAILURE

Several studies on disease and treatment effects on neurohormones have been conducted with small numbers of patients, using one blood sample as representative of their states. The aim of this study was to asses s the within-patient variability of plasma concentrations of several h ormones and cytokines of recent interest, in patients with moderate he art failure and controlled stable background therapy over 3 weeks. Blo od for neurohormone and cytokine assays was sampled in duplicate from 18 patients with moderate heart failure. After an initial visit, the p atients were kept on stable therapy until the second blood sampling 21 +/- 3 days later. The plasma concentrations of several neurohormones (endothelin, renin, angiotensin II, aldosterone, norepinephrine) and c ytokines (interleukin-6 (IL-6), interleukin-13 (IL-13), ciliary neurot rophic factor (CNTF), leukemia inhibitory factor (LIF) and soluble rec eptor type I of tumour necrosis factor-alpha (sTNF-RI) were measured w ith immunochemical methods. Some cytokines (IL-13, CNTF and LIF) were not detected. Despite clinically satisfactory ACE inhibition, circulat ing angiotensin II and aldosterone levels were still elevated in some patients, suggesting aldosterone escape. The between-visit agreement o f plasma concentrations measured in duplicate was less than 35% for al l circulating factors, except renin which showed a higher variability throughout the 3-week study period. (C) 1998 The Italian Pharmacologic al Society.