The influence of renin-angiotensin system genotypes on the antiproteinuric response to high doses of olmesartan in non-diabetic proteinuric nephropathies.

OBJECTIVE: To assess the antiproteinuric response to multifactorial treatment based on high doses of angiotensin II receptor antagonists (ARBs) (olmesartan) in patients with non-diabetic proteinuric nephropathies, according to three renin-angiotensin system (RAS) polymorphisms: insertion/deletion of the angiotensin converting enzyme (ACE) gene, the angiotensinogen gene M235T and the angiotensin II type 1 receptor (AT1R) A1166C. MATERIAL AND METHOD: We studied 53 patients with non-diabetic proteinuric nephropathy with a mean progression time of 84.4±15 months. 41 were males (77.4%); mean age 49.7±3 years, body mass index 30±6kg/m2. All received olmesartan (40mg/12h) associated with a mean of 2.4±1.6 antihypertensive drugs for a median period of 13 months (interquartile range 7-25 months). RESULTS: Systolic blood pressure (BP) decreased from 145±14mmHg to 128±14mmHg (P<.001) and diastolic BP from 85±11mmHg to 79±7mmHg (P<.01). Pulse pressure decreased from 53.5±14mmHg to 48±12mmHg (P<.05). Proteinuria decreased from 2.74±1.6g/24h to 0.9±1g/24h (P<.001), representing a mean decrease of 67.1%. According to RAS polymorphisms, antiproteinuric response was: angiotensinogen gene polymorphism: genotype TT: 76.8%; genotype MM: 67.3%; genotype MT: 65.8%, significantly higher (P<.05) for genotype TT compared to genotypes MM and MT. Polymorphism of the ACE gene: genotype DD: 71.4%; genotype ID: 60.6%, genotype II: 34.8%, significantly higher (P<.05) for genotype DD compared to genotypes ID and II, and also (P<.05) for genotype ID compared to II. AT1R gene polymorphism: genotype AC: 85.2%; genotype CC: 73.7%; genotype AA: 62.7%; significantly higher for genotype AC (P<.05) compared to genotypes AA and CC. The differences between initial and final proteinuria for the follow-up period were significant (P<.01) for genotypic associations DD/AA, DD/MT, DD/MM, DD/TT and DD/AC, although the association with the highest antiproteinuric effect was DD/AC (89.9%, P<.05%). CONCLUSIONS: Administering high doses of olmesartan in patients with non-diabetic proteinuric nephropathy results in significant reductions in proteinuria. This decrease was independent of blood pressure control and other confounding factors. RAS polymorphisms may modulate the antiproteinuric response to treatment with ARBs.

Kidney transplantation with grafts from type III Maastricht non-beating-heart donors.

Kidney transplantation (KT) with kidneys from non-beating-heart donors (NBHD) is a growing trend in Spain. The majority of these kidneys come from type II Maastricht patients, although in recent years, organ donations from patients awaiting cardiac arrest following limitation of life-sustaining therapy has already been in practice in certain European and North American countries, involving type III Maastricht patients. We present a series of 6 KT using kidneys from NHBD as a consequence of limitation of life-sustaining therapy in three different hospitals in the sector of Malaga. After agreeing upon a protocol for evaluating the potential of a patient for organ donation after the decision for limiting life-sustaining therapy, the patients' families were given the option of organ donation. Kidneys were preserved using a Porges double balloon catheter, which was placed prior to cardiac arrest. In two cases, the limitation of life-sustaining therapy took place in the intensive care unit, and in the third case, in the operating room. The interval between limitation of life-sustaining therapy and cardiac arrest ranged between 15 minutes and 40 minutes, with an interval of circulatory arrest prior to perfusion of 5-11 minutes. Perfusion-cooling of the kidneys was initially carried out using saline solution, followed by organ preservation solution (Celsior or Belzer) and extraction of the kidney using a rapid surgical technique. True or functional hot ischaemia times were 60 minutes, 59 minutes, and 50 minutes, respectively, for each of the three donors. Kidneys were evaluated for viability using time intervals for the procedure (including hypotension prior to cardiac arrest), macroscopic appearance, and histopathology of a sample taken from each kidney. The recipients of these 6 kidneys had given their consent to receive organs from expanded-criteria donors. Cold ischaemia lasted between 9 hours and 20 hours (mean: 14.6 hours). One recipient developed haemorrhagic complications during the immediate postoperative period and required a transplantectomy. The other five currently retain functioning grafts. All had delayed graft function, necessitating haemodialysis. The range of estimated glomerular filtration rates at the most recent follow-up evaluation was 23.0-106 ml/min/1.73 m(2). In conclusion, type III Maastricht donors provide valid kidneys for transplantation, although this series showed that supported functional hot ischaemia was very important, the consequence of accumulated ischaemic damage starting in the agonal phase, circulatory arrest, and organ preservation using cold solutions. As such, to improve the quality of results obtained using kidneys from these types of donors would involve a very careful selection of optimal donors and minimisation of total functional ischaemia times.