Basic biochemistry Blood for biochemical assays was sampled in fasting conditions upon completion of vascular studies. Plasma was separated instantly at 4°C in a refrigerated centrifuge. In both groups serum creatinine, albumin, haemoglobin, cholesterol and urinary protein level were assessed using standard laboratory methods. Plasma creatinine concentration was used to estimate creatinine clearance according to the Schwartz formula. Whole blood CsA level was assessed using a non-specific radioimmunoassay. Autonomic function testing Cardiovascular autonomic function was assessed on the same day at least 2 h after the subjects had their meal. The following Ewing’s battery of non-invasive tests was used [15]: 1. Blood pressure reaction to standing (orthostatic hypotension test). Blood pressure was recorded after 10 min of supine rest and after 2 min in the standing position. Reduction of minimum 20 mmHg in systolic and minimum 10 mmHg in diastolic pressure after standing up was considered diagnostic for orthostatic hypotension. 2. Heart rate response (HRR) to standing (30 : 15 ratio). The ECG monitoring was performed after a rest period in the supine position of 10 min, starting from 1 min before until 30 s after standing. The ECG tracings were used to determine the 30 : 15 ratio calculated as the ratio of the longest R-R interval found at about beat 30 to the shortest R-R interval found at about beat 15. 3. Valsalva manoeuvre. The ECG monitoring was performed while the patient in supine position forcibly exhaled for 15 s against a fixed resistance (40 mmHg) with open glottis. The ratio of the longest R-R interval after the manoeuvre to the shortest R-R interval during or shortly after the manoeuvre was calculated, and a ratio equal to or lower than 1.1 was considered abnormal. 4. Deep breathing test. The ECG monitoring was performed in supine position with the patient breathing deeply at a rate of 6 breaths/min. An average of 6 cycles was taken and the maximum (during inspiration) heart rate minus the minimum (during expiration) heart rate was calculated. The average difference found for 6 consecutive inspiration-expiration cycles was taken as the final result, with a value equal to or lower than 10 bpm considered abnormal. Statistical analysis Statistical analysis was performed using the STATISTICA for Windows software package (version 5.5 PL, #AXXP0105488425A55, StatSoft, Tulsa, Ohio, USA). For all analysed continuous Cyclosporine A impairs vasodilatation without autonomic neuropathy parameters that showed a normal distribution (as confirmed with Kolmogorov and Lilliefors tests), differences between means were assessed by the Student’s t-test for unpaired data. Differences in distribution were analysed by the non-parametric χ2 test, when necessary with Yates’ correction. The measurements were expressed as means (± SD). Values for p < 0.05 were considered signif- icant. The study received approval from the local independent Ethics Review Board. Informed written consent was obtained (after careful explanation) from parents or caregivers and children when applicable (over 15 years). Results Finger region temperature increase within 5 min following CST was significantly diminished in children with nephrotic syndrome treated with CsA than in the control group (0.26 ±0.26 and 0.51 ±0.29°C/min, p = 0.02), while metacarpal region temperature change was similar in both groups. Temperature in both predefined hand regions 5 min after CST was stable in both groups. Raynaud’s phenomenon was found in three children (2 girls and 1 boy) from the study group and in 2 girls from the control group (p > 0.05). Not unexpectedly, the temperature gradient between finger and metacarpal regions after CST in patients with RP was 4.81 ±0.24, while in study group subjects without RP it was 0.58 ±0.37 (p < 0.01). The temperature change after CST was similar in subjects with and without hypertension (0.19 ±0.18 vs. 0.38 ±0.36°C/min, respectively; p = 0.23). No significant differences in autonomic function tests were found between study and control groups. In detail, the test results were: Orthostatic hypotension test was positive for 4 patients in the study and 3 subjects in the control group (p = 0.79). The mean slope of blood pressure did not differ significantly (systolic: 15 ±5 vs. 13 ±3 mm Hg; diastolic 7 ±3 vs. 8 ±2 mmHg, p : 0.05). The results of HRR test 30 : 15 index (1.24 ±0.19 vs. 1.33 ±0.2), Valsalva manoeuvre (1.59 ±0.35 vs. 1.84 ±0.53) and E : I index (1.46 ±0.24 vs. 1.45 ±0.17) were also not different; all p > 0.05. The mean dose of CsA was 4.3 ±1.6 mg/kg. At the time of the study mean plasma CsA in the study group was 70.9 ±26.0 ng/ml, with concentration from the 6-month period before the study 85.7 ±40.1 ng/ml. No statistically significant correlation between CsA or steroid treatment duration or dose and temperature change after CST was found. Similarly, no correlation between plasma CsA and biochemical parameters or hand warming indices was noted either. Results of laboratory measurements are summarized in Table I. Arch Med Sci 4, August / 2010 575