Cardiovascular risk reduction in hypertension: angiotensin-converting enzyme inhibitors, angiotensin receptor blockers. Where are we up to?

Previously, management of hypertension has concentrated on lowering elevated blood pressure. However, the target has shifted to reducing absolute cardiovascular (CV) risk. It is estimated that two in three Australian adults have three or more CV risk factors at the same time. Moderate reductions in several risk factors can, therefore, be more effective than major reductions in one. When managing hypertension, therapy should be focused on medications with the strongest evidence for CV event reduction, substituting alternatives only when a primary choice is not appropriate. Hypertension management guidelines categorise angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) interchangeably as first-line treatments in uncomplicated hypertension. These medications have different mechanisms of action and quite different evidence bases. They are not interchangeable and their prescription should be based on clinical evidence. Despite this, currently ARB prescriptions are increasing at a higher rate than those for ACEI and other antihypertensive classes. Evidence that ACEI therapy prevents CV events and death, in patients with coronary artery disease or multiple CV risk factors, emerged from the European trial on reduction of cardiac events with perindopril in stable coronary artery disease (EUROPA) and Heart Outcomes Prevention Evaluation (HOPE) trials respectively. The consistent benefit has been demonstrated in meta-analyses. The clinical trial data for ARB are less consistent, particularly regarding CV outcomes and mortality benefit. The evidence supports the use of ACEI (Class 1a) compared with ARB despite current prescribing trends.

Prescription medications and their influence on acute kidney injury presentation and outcomes.

BACKGROUND: Acute kidney injury (AKI) is a common clinical problem. An increase in the severity of AKI is associated with increased mortality and worse prognosis. Many patients presenting with AKI also take long-term medications that may potentially exacerbate or precipitate AKI. However, no study has examined the role of such medications on AKI outcomes. AIM: Our aim was to analyse use of chronic prescription medications by patients presenting with AKI and their impact on outcomes. METHODS: A retrospective study of discharge data identified 172 patients admitted to a tertiary level metropolitan hospital with a primary diagnosis of AKI over a 2-year period. Patient characteristics, medications that could precipitate or exacerbate AKI, and outcomes based on mortality, need for renal replacement therapy (RRT) and intensive care unit admission were analysed. RESULTS: Patients taking medications (69.2%) were older (P = 0.04) with more comorbidities such as: congestive cardiac failure (P < 0.001), chronic kidney disease (P < 0.001) and diabetes (P = 0.004) than patients not consuming any. Patients taking medications were less likely to be admitted with severe AKI (P = 0.01) or require RRT (P = 0.04). Multivariate logistic regression analysis did not show a significant impact of medications on outcomes. CONCLUSION: Prescription medication use in patients presenting with AKI is common. Despite being used in older patients with more comorbidities, these medications had no detrimental effect on need for RRT, intensive care unit admission or mortality, and were associated with a decrease in the incidence of severe AKI.

Expression of HLA antigens on renal tubular cells in culture. I. Evidence that mixed lymphocyte culture supernatants and gamma interferon increase both class I and class II HLA antigens.

The altered expression of HLA antigens on tissues during rejection is of potential importance to both the initiation and effector arms of the alloimmune response. Associated with rejection episodes, renal tubular cell expression of HLA DR (class II) antigens has been observed to be markedly increased. In this study an in vitro assay using cultured renal tubular cells from normal human kidneys was developed. Monoclonal antibodies to detect HLA DR and HLA A,B,C (class I) molecules were used to identify these antigens on cultured tubular cells either by indirect immunofluorescence stains and flow cytometric analysis or by immunoperoxidase stains with cytological analysis. With these techniques normal cultured cells had little membrane or cytoplasmic HLA DR but did have membrane HLA A,B,C. Culture of renal tubular cells with either supernatants from mixed lymphocyte cultures or purified gamma interferon induced expression of HLA DR, with maximum expression occurring between day 4 and day 6. Increased HLA A,B,C expression was also observed. This increased expression of HLA antigens was shown not to be dependent upon increased cell division of the cultured cells, and removal of gamma interferon from the cultures resulted in a decay in both HLA DR and A,B,C expression within days. HLA expression was inhibited by addition of protein synthesis inhibitor cycloheximide, but not by the addition of puromycin, mitomycin C, or actinomycin D--which suggested that tubular cells had transcribed m RNA for both HLA DR and A,B,C antigens. Expression of HLA antigens was not inhibited by cyclosporine, corticosteroids, or azathioprine. These studies demonstrate that the increased expression of HLA antigens seen in renal allografts at the time of rejection episodes can be explained by the release of lymphokines, especially gamma interferon, by infiltrating cells, and that reduced HLA DR expression of transplanted kidneys in patients treated with cyclosporine is not due to the drug directly inhibiting HLA expression by graft cells.

Effect of OKT3 in steroid-resistant renal transplant rejection.

Between January 1, 1982, and November 1, 1986, 169 cadaver renal graft transplantations were performed at this hospital with CsA as induction therapy. OKT3 was not available in this period. Of these grafts, 15.9% were lost within 6 months, 10.7% from acute rejection (AR). Between November 1, 1986, and October 1, 1992, 483 cadaver renal graft transplantation were performed. Induction therapy included CsA and OKT3 was available. Of these grafts, 8.7% were lost inside 6 months, 3.1% from AR. Of these last 483 grafts, 113 received 125 courses of OKT3. Ten courses were prophylactic, and 115 courses in 103 patients were for rejection resistant to steroid therapy (biopsy proven in all but 2 cases. Ninety-three percent of rejection episodes treated with OKT3 responded, at least initially. Graft survival in OKT3-treated patients was 81%, 77%, and 76% at 6 months, 1 year, and 2 years, respectively. In contrast, graft survival in steroid-resistant rejection during the first period (without OKT3) was 59%, 57%, and 57% at these intervals. There were 8 infective deaths within 6 months in the 113 OKT3-treated patients, compared with 2 in the 343 who did not receive OKT3 (P < 0.001). There were 7 viral deaths in the OKT3 group compared with none in those not receiving OKT3 (P < 0.001). Prophylaxis with oral acyclovir and cotrimoxazole was instituted in October 1990 in OKT3-treated patients and ganciclovir use was increased. Since this change, no further viral deaths have occurred. OKT3 is a very effective antirejection agent, but its use is associated with an increased mortality from viral infections. With appropriate prophylaxis and treatment, however, this mortality can be reduced.

Advanced donor-origin melanoma in a renal transplant recipient: immunotherapy, cure, and retransplantation.

BACKGROUND: A kidney transplant recipient inadvertently contracted donor-origin melanoma, which was found to be very advanced at presentation. Withdrawal of immunosuppression failed to induce rejection, and interferon-alpha was required. When florid allograft rejection was in progress, the allograft was removed, before it was recognized that the transplanted melanoma was not being simultaneously rejected. METHODS: Subsequent immunotherapy was required, which largely recapitulated treatment of recognized value in autologous melanoma and included interferon-alpha, use of cultured melanoma cells as tumor vaccine, pooled allogeneic cell vaccination, and adoptive immunotherapy using lymphokine-activated killer cells. RESULTS: Prolonged immunotherapy eradicated the widespread malignancy, and the patient went on to a successful second renal transplant, with follow-up of over 24 months. CONCLUSIONS: This unique case demonstrates the successful cure of advanced transplanted melanoma through the use of immunotherapy, which did not require sophisticated tumor vaccine technology, and successful retransplantation.

Efficacy of once-weekly epoetin alfa.

BACKGROUND: Patients with end-stage renal disease requiring hemodialysis are frequently treated with epoetin alfa (recombinant human erythropoietin, rHuEPO) for anemia. The aim of this study was to determine whether successful management of anemia could be maintained by changing the dosing schedule of epoetin alfa from 2 or 3 times per week to once-weekly administration via not only the subcutaneous (s.c.) but also the intravenous (i.v.) route. METHODS: Patients included in the study had hemodialysis for > 12 months, treatment with epoetin for > or = 6 months and adequate iron stores. The study consisted of a pre-study period (12 weeks), Phase I (4 weeks, patients continued prestudy regimen), Phase II (12 weeks, once-weekly i.v. or s.c. regimen with dose adjustments permitted to maintain target hemoglobin (Hb) concentrations) and Phase III (4 weeks, once-weekly i.v. or s.c. regimen without dose adjustments). RESULTS: The study was completed by 203 patients (per-protocol population: i.v. group, n = 115, s.c. group, n = 88). In the majority of patients (69.4% overall: i.v. group, 67.0%, s.c. group, 72.7%), the individual Phase I Hb concentrations were maintained within +/-1.0 g/dl (+/-10 g/l) during Phase III. In 79.3% of the patients (i.v. group, 75.7%, s.c. group, 84.1%), a stable Hb concentration (decrease of < or = 1 g/dl (< or = 10 g/l)) was maintained without statistically significant dose adjustments (82.4+/-33.8 - 86.8+/-42.1 IU/kg body weight/week). Hb concentrations decreased from 11.57+/-0.83 g/dl(115.7+/-8.3 g/l) in Phase I to 11.39+/-1.09 g/dl (113.9+/-10.9 g/l) in Phase III (p < 0.05) in the entire group. The weekly dose of epoetin alfa required to maintain the individual target Hb concentrations changed from 85.1+/-34.6 IU/kg in Phase I to 92.1+/-45.1 IU/kg in Phase III in the entire population (p <0.05). CONCLUSIONS: With once-weekly administration of epoetin alfa, Hb concentrations can be maintained in the majority of stable hemodialysis patients, and only minimal dose adjustments are required.

Current status of renal transplantation.

The success rate of renal transplantation has improved considerably during the past decade, with substantial improvements in both graft and patient survival. The quality of graft function, however, and not graft survival alone is increasingly determining the standards by which transplantation outcome is being judged. As the demand for kidney transplants continues to rise and transplants are being offered to an ever-increasing number of patients, organs are being sought from new supply pools and efforts are being made to use current resources more efficiently. Improvements in clinical management have allowed short-term complications such as infection and rejection to be better prevented or better diagnosed and treated. Fundamental advances in the understanding of the immunologic processes underlying both allograft rejection and acceptance and the introduction of new immunosuppressive agents have allowed a better use of drug therapy and have moved the goal of acquired transplant tolerance closer to attainment. With improved initial transplant success rates, the long-term transplantation outcome is becoming more important. The role of tissue matching in preventing chronic rejection is becoming more appreciated, and the long-term risks of malignancy, arteriosclerosis, and chronic rejection are being better recognized and managed.

Immunomodulation of human fetal cells by the fungal metabolite gliotoxin.

Gliotoxin (GT) is a fungal metabolite that reduces the ability of murine macrophages to react immunologically in vitro. It is also capable of modulating the immunogenicity of murine bone marrow cells, so that the onset of graft-versus-host disease in fully allogeneic bone marrow chimeras is delayed. The present study examines the effect of GT on human fetal cells, both in terms of reduction of immunogenicity and toxicity. GT (10 micrograms/ml) significantly decreased the responsiveness in mixed lymphocyte cultures of cells derived from human fetal pancreas, spleen, liver and bone marrow. This concentration of GT was, however, mildly toxic to explants of the pancreas, with a significant reduction in insulin secretion from this tissue during the first day of its organ culture, but not thereafter. GT-treated pancreatic explants were lighter and contained less insulin than the untreated controls 3 months after the tissue had been implanted beneath the renal capsule of nude mice. This difference was not apparent 3 weeks after transplantation into these animals. It is hypothesized that the immunomodulating effect of GT (at a concentration less than 10 micrograms/ml) may be of benefit in treating allografted human fetal pancreas before it is transplanted, as it has for murine adult bone marrow cells.

Sclerosing peritonitis with gross peritoneal calcification: a case report.

We report the case of a patient on dialysis for 13 years, including continuous ambulatory peritoneal dialysis (CAPD) for 11 years, who developed sclerosing peritonitis with gross peritoneal calcification. The patient first presented with abdominal pain in January 1990, when peritoneal calcification was detected for the first time. Her symptoms settled spontaneously and 1 year later she presented with acute peritonitis and adynamic ileus. The peritonitis settled with antibiotics and Tenchkoff catheter removal, but the ileus persisted. She was commenced on long-term parenteral nutrition, but never recovered useful bowel function. After 8 weeks of hemodialysis and total parenteral nutrition, a further laparotomy for an acute abdomen showed what appeared to be extensive bowel infarction and peritoneal calcification. She died several days later. Of significance, peritoneal calcification was first noted on x-ray and computed tomography (CT) scan while the patient was still largely asymptomatic and before peritoneal ultrafiltration capacity was significantly impaired. Unlike other reported cases of calcifying peritonitis, sclerosing peritonitis was present and calcification was far more extensive. It was not associated with factors such as frequent infective peritonitis or acetate dialysate. Calciphylaxis was not present nor was there any abnormality of calcium-phosphate metabolism. The outcome of this case suggests that patients with recurrent or persistent bowel symptoms on long-term CAPD should have early abdominal x-ray or CT scanning to exclude sclerosing peritonitis or bowel calcification. If present, consideration should be given to transferring the patient to another therapeutic dialysis modality if possible.