Renal tubular peptide catabolism in chronic vascular rejection.

Chronic vascular rejection (CR) is the commonest cause of renal transplant loss, with few clues to etiology, but proteinuria is a common feature. In diseased native kidneys, proteinuria and progression to failure are linked. We proposed a pathogenic role for this excess protein at a tubular level in kidney diseases of dissimilar origin. We demonstrated in both nephrotic patients with normal function and in those with failing kidneys increased renal tubular catabolism and turnover rates of a peptide marker, Aprotinin (Apr), linked to increased ammonia excretion and tubular injury. These potentially injurious processes were suppressed by reducing proteinuria with Lisinopril. Do similar mechanisms of renal injury and such a linkage also occur in proteinuric transplanted patients with CR, and if so, is Lisinopril then of beneficial value? We now examine these aspects in 11 patients with moderate/severe renal impairment (51CrEDTA clearance 26.2+/-3.3 mL/min/1.73 m2), proteinuria (6.1+/-1.5 g/24 h) and biopsy proven CR. Lisinopril (10-40 mg) was given daily for 2 months in 7 patients. Four others were given oral sodium bicarbonate (Na HCO3) for 2 months before adding Lisinopril. Renal tubular catabolism of intravenous 99mTc-Apr (Apr* 0.5 mg, 80MBq), was measured before and after Lisinopril by gamma-ray renal imaging and urinary radioactivity of the free radiolabel over 26 h. Fractional degradation was calculated from these data. Total 24 h urinary N-acetyl-beta-glucoaminidase (NAG) and ammonia excretion in fresh timed urine collections were also measured every two weeks from two months before treatment. After Lisinopril proteinuria fell significantly (from 7.8+/-2.2 to 3.4+/-1.9 g/24 h, p<0.05). This was associated with a reduction in metabolism of Apr* over 26 h (from 0.5+/-0.05 to 0.3+/-0.005% dose/h, p < 0.02), and in fractional degradation (from 0.04+/-0.009 to 0.02+/-0.005/h, p<0.01). Urinary ammonia fell, but surprisingly not significantly and this was explained by the increased clinical acidosis after Lisinopril, (plasma bicarbonate fell from 19.1+/-0.7 to 17.4+/-0.8 mmol/L, p < 0.01), an original observation. Total urinary NAG did fall significantly from a median of 2108 (range 1044-3816) to 1008 (76-2147) micromol/L, p < 0.05. There was no significant change in blood pressure or in measurements of glomerular hemodynamics. In the 4 patients who were given Na HCO3 before adding Lisinopril, both acidosis (and hyperkalemia) were reversed and neither recurred after adding Lisinopril. These observations in proteinuric transplanted patients after Lisinopril treatment have not been previously described.

The new chimaera: the industrialization of organ transplantation. International Forum for Transplant Ethics.

Clinical organ transplantation has evolved through advances in patient care in parallel with investigations in associated biologies. It has developed from a cottage industry to an important medical specialty driven increasingly by the availability of newer and more effective immunosuppressive drugs, and dependent on consistently close collaborations between university-based clinical scientists and the pharmaceutical industry. Particularly during the past decade, however, this industry has undergone striking changes, consolidating into huge multi-national corporations, each competing for patients, their doctors, and for support of the allied hospitals. Because of the growth of "Big Pharma," the relationship between academia and industry has changed. There have been many advantages to such mutually dependent interactions. A combination of university-based expertise and the specialized knowledge and resources of industry have produced important scientific gains in drug development. Commercial sponsorship of applied research has been crucial. The orchestration of multicenter controlled clinical drug trials has provided invaluable information about the effectiveness of newer agents. But there are also disadvantages of increasing concern. Indeed, the power of "Big Pharma" in many medical fields including transplantation is such that presentation of data can be delayed, adverse results withheld, and individual investigations hampered. Clinical trials may be protracted to stifle competition. Monetary considerations may transcend common sense. Several measures to enhance the clinical relationship between the pharmaceutical industry and those involved with organ transplantation are suggested, particularly the use of third party advisors in the production of clinical trials, support for more basic research and in the dissemination of results. In this way, the increasingly problematic phenomenon of commercialization of the field of transplantation can be tempered and controlled.

Stabilisation of diabetic retinopathy following simultaneous pancreas and kidney transplant.

BACKGROUND/AIMS: Simultaneous pancreas and kidney transplantation (SPK) has become an important option in selected IDDM patients with end stage renal disease (ESRD). Successful SPK transplants are associated with long term normoglycaemic control and improved quality of life. However, debate still continues on the benefit to patients in terms of stabilisation or amelioration of diabetic retinopathy. The progression of diabetic retinopathy (DR) in a cohort of 20 SPK transplant patients is reported. METHODS: All patients were reviewed postoperatively with corrected visual acuity, slit lamp examination, and fundal biomicroscopy. Preoperative data were collected retrospectively and DR was considered unstable if there had been a drop in Snellen acuity greater than three lines or a need for laser photocoagulation or vitrectomy in the 2 years preoperatively. RESULTS: 20 patients who received SPK transplants between March 1983 and April 1994 were reviewed (mean age 35.1 years; mean duration of IDDM = 24.6 years). 17 patients still had functioning grafts at a mean follow up of 5.1 years. Nine of these patients had unstable DR before transplantation. Of these, 89% (8/9) had stabilised DR following transplantation with only a single case requiring laser photocoagulation. Of the eight patients that had stable DR before transplantation all had stable DR following transplantation. 41% of cases (7/17) required cataract surgery during the follow up period. CONCLUSIONS: Advanced diabetic retinopathy is present in a high proportion of cases managed with SPK transplant as a consequence of the duration of IDDM and the presence of ESRD. More than 90% of cases have stable DR following transplant.

Pregnancy does not adversely affect renal transplant function.

Women with functioning transplanted kidneys often become fertile again. Indeed, renal function, endocrine status and libido rapidly improve after renal transplantation, and 1:50 women of childbearing age become pregnant. However, there is concern regarding the haemodynamic changes of pregnancy, which could lead to a decline in graft function (temporary or permanent). We examined obstetric data and renal parameters in 29 patients and 33 pregnancies. Mean serum creatinine and creatinine clearance remained stable throughout pregnancy and 1 year postpartum. However, there was a significant increase in proteinuria from a mean of 0.45 g/24 h around the time of conception to 1.11 g/24 h at delivery (p<0.05). The proteinuria resolved to baseline levels at 3 months postpartum. We highlight certain parameters to be considered before conception to allow a good obstetric outcome and prolong stable renal function: serum creatinine <150 micromol/l, proteinuria <1 g/day, absence of histological evidence of chronic allograft rejection, controlled blood pressure (140/90) and stability of maintenance immunosuppression.

Participants' judgements of the European Donor Hospital Education Programme (EDHEP): an international comparison.

The European Donor Hospital Education Programme (EDHEP) is a one-day workshop, aimed at providing guidelines for breaking the news of the death of a relative and for raising the issue of organ donation with bereaved relatives. Participants' judgements of the workshop in the Netherlands and in the United Kingdom were compared to determine whether EDHEP meets doctors' and nurses' training needs in breaking bad news and requesting organ donation. In both countries EDHEP appears to be greatly appreciated by intensive care medical and nursing staff; the judgements are more positive in the United Kingdom than in the Netherlands. It seems that, irrespective of their professional experience, intensive care staff consider EDHEP a valuable teaching programme that increases confidence in communicating with bereaved relatives about death and organ donation.

Localization of C-X-C and C-C chemokines to renal tubular epithelial cells in human kidney transplants is not confined to acute cellular rejection.

Chemokines are important mediators of leucocyte chemoattraction to inflammatory sites. Previous work has shown that the expression of some chemokines is upregulated during renal transplant rejection. The objectives of the present study were to determine whether chemokine expression is increased during renal transplant rejection. Immunohistochemistry was used to localize the C-X-C (alpha) chemokine interleukin-8 (IL-8) and the C-C (beta) chemokines monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1beta (MIP-1beta) in 30 needle biopsies of human kidney transplants taken for diagnosis of renal dysfunction. Urine samples from transplant patients taken immediately prior to biopsy were assayed for chemokine content using enzyme-linked immunosorbent assays (ELISAs). Results from groups of patients having different clinicopathological diagnoses were then compared. All three chemokines were detected in most renal transplant biopsies showing acute cellular rejection but, although infiltrating leucocytes were often positive, staining was predominantly localized to renal tubular epithelium. Staining for MCP-1 was generally weaker than for the other chemokines, and collecting tubules were usually stained more strongly than proximal convoluted tubules. Tubular epithelial staining was also found in biopsies from patients without signs of acute cellular rejection. There were significantly higher amounts of IL-8 in the urine of patients with acute cellular rejection, even when patients with urinary tract infections were excluded, but mean titres of urinary MIP-1beta did not differ between patient groups. This was also found when titres were normalized for urine volume and creatinine levels. Production of IL-8, MCP-1 and MIP-1beta is not confined to kidney transplants showing acute cellular rejection, and may be a relatively nonspecific response of tubular epithelial cells to renal damage.