Search

Evidence about the crucial role of the kidney in the development and maintenance of the "essential" hypertension (i.e. hypertension which is accompanied with the absence of any pathological change in any of body organs) and in the regulation of "normal" blood pressure level (BP) has been accumulated. Blood pressure is expressed as a product of cardiac output (CO) and total peripheral resistance (TPR). TPR almost entirely depends on the volume of the extracellular fluid (ECFV): With increasing volume BP rises and vice versa. ECFV--due to intensive maintenance of the osmolality--almost entirely depends on the total amount of sodium in the organism. This amount is not determined by the intake of salt, which is in every civilized population always higher than necessary. Sodium balance is therefore critically determined by the output of sodium, which is carried out almost entirely by the kidney. The output depends on the quantity of the glomerular filtration and on the tubular reabsorption. Under normal circumstances, the increased sodium intake is accompanied by an increased excretion via the mechanism called "pressure natriuresis". It is based on the prompt increase of sodium excretion after an increase of BP, resulting from the increased sodium intake. Mechanism of such elevated excretion is not clear; lot of evidence has been accumulated for the existence of a humoral principle produced within the kidney. Such assumption is supported by experiments in which a kidney is transplanted from a hypertonic donor to a normotensive recipient: hypertension in the recipient develops. Similarly, kidney grafting from a normotensive animal corrects the hypertension in an originally hypertensive recipient. Important role of the renin-angiotensin (RAS) and nitric oxide (NO) systems is often stressed in this context. If kidney is unable to excrete the ingested amount of sodium at the normal BP, blood pressure must rise and the shift of the pressure-natriuresis curve to the right is the necessary consequence. If these conditions are long lasting, hypertension develops soon and becomes "fixed" by rebuilding the resistance arteries architecture.

Background: Triple-drug immunosuppression may not be necessary in a majority of stabilized patients over 1 year after kidney transplantation. In contrary steroid withdrawal may be beneficial for the patient by elimination of side-effects. The primary aim of this study was assessment of the risk of rejection after the prednisone withdrawal., Methods and Results: 88 patients 1 year after the first renal transplantation with stable graft function and serum creatinine < 160 mumol/l treated with cyclosporine-A, azathioprine and prednisone were randomized into group A (n = 46) with a prednisone withdrawal and group B (n = 42) on triple-drug therapy without change. At the time of randomization, fine-needle biopsy was carried out in all of the patients. In group A, the dose of prednisone was gradually reduced to zero in the course of six months and the patients were followed up for the next 12 months. In the group B, patients on triple-drug therapy were followed for the corresponding period of time. 3 patients (6.6%) in group A, and 2 (4.8%) in group B experienced rejection (NS). Mean values of serum creatinine were in the course of follow-up in both groups without any statistical difference. Suspect immunological activity or proved immunological activity in aspiration biopsy was present in 4 patients in each group, but one of them rejected the graft. In comparison with group B, a significant decrease of cholesterol and leukocytes was observed in group A. Prednisone withdrawal had no influence on hypertension and triglyceride., Conclusions: Gradual withdrawal of steroids is not associated with higher risks of rejection and has a beneficial effect on cholesterol levels. Aspiration biopsy was of no use for the prediction of rejection.

In the period 1966-1997 renal allografting was performed in 1746 recipients, 244 of whom were women in fertile age. In 32 of them 45 pregnancies were registered. 29 of them (64%) resulted in abortion, which was spontaneous in 4 and medically advised in 25. There were 16 labours, 4 of them free of any complications; of the latter, hypertension was the most frequent one (8). Of the former, 13 were solved by caesarean section and 3 were vaginal deliveries. Of 15 live babies 7 were immature (one died 1.5 year later of renal failure due to microcystic kidneys). No unfavourable effect of pregnancy on prognosis and on long-term graft function was found.

The authors compared in a controlled clinical study two groups of patients after a first renal transplantation treated by triple drug immunosuppressive therapy. In a group of 31 patients the triple combination comprised Sandimmune Neoral. In the control group there were 30 patients who received Sandimmune. No differences were found between the two groups as regards the effectiveness of this treatment and the authors did not confirm a lower incidence of rejections described in patients treated with Sandimmune Neoral. They confirmed, however, a lower interindividual variability of Cy-A levels assessed specifically in patients treated with Sandimmune Neoral.