H.E. De Wardener

LOW-DOSE ORAL PREDNISOLONE IN RENAL TRANSPLANTATION

Azathioprine and steroids (prednisone or prednisolone) form the basis of conventional immunosuppression after renal transplantation. Most of the morbidity in the early months after transplantation. Most of the attributed to steroids, which are normally give in high doses. The only justification for giving high doses is a historical one. For this reason a randomised controlled trial was carried out to compare the efficacy of high dose (39 patients) and low dose (33 patients) oral prednisolone, both in combination with azathioprine, in patients given cadaveric renal allografts. Patients were followed up for at least two years after the transplantation. Patient and graft survival were identical in the two groups and the morbidity associated with steroids was impressively lower in patients receiving a low steroid dose. Although the optimal dose of steroids is still unknown, there seems little justification for continued use of high doses of oral steroids with azathioprine after cadaveric renal transplantation.

SALT AND HYPERTENSION

Studies comparing different communities have suggested that the amount of salt in the diet may play an important role in determining blood pressure levels within a particular community. Intervention studies have also suggested that salt intake may play an important role in determining blood pressure levels in man. In animals, where more clearcut experiments can be done, an increase in salt intake both in inherited forms of hypertension and experimental hypertension causes a further rise in blood pressure. Recent work has suggested that this rise in blood pressure could be related to an inherited or imposed defect in the kidneys ability to excrete sodium, which will give rise to greater compensatory mechanisms to overcome the sodium retention. These compensatory mechanisms might eventually be responsible for the development of high blood pressure. In patients who have already developed high blood pressure, restricting the amount of salt in the diet does cause a fall in blood pressure in many patients. However, short-term reduction of salt intake in normotensive subjects causes little, if any, fall in blood pressure. The effectiveness of short term salt restriction in lowering blood pressure in adults therefore appears to be related to the severity of the high blood pressure and, probably more directly, to the suppression of the renin system that occurs as blood pressure rises.