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D E Hricik

Publications and source records attributed to D E Hricik.

At least 19 recordsLinked to original sources
PubMed2000

Kidney-pancreas transplantation for diabetic nephropathy.

Pancreas transplantation is being performed with increasing frequency and increasing technical success. The availability of new immunosuppressant agents has been associated with a reduction in the previously high rates of allograft rejection in recipients of simultaneous pancreas-kidney transplants. These lower rejection rates have, in turn, led to changes in surgical techniques and a resurgence of interest in isolated pancreas transplantation--either in nonuremic patients or, more commonly, in patients who have already received a prior kidney transplant. Pancreas transplantation has emerged as an important option for the management of patients with type I diabetes mellitus and diabetic nephropathy.

Costs and Cost Analysis↗
PubMed1999

Pretransplant frequency of donor-specific, IFN-gamma-producing lymphocytes is a manifestation of immunologic memory and correlates with the risk of posttransplant rejection episodes.

While matching for MHC Ags improves renal allograft survival, closely matched grafts sometimes fail due to rejection, and poorly matched allografts are often well tolerated by the recipient. The severity of the rejection process may partially depend on the presence of environmentally primed T cells in the recipient that cross-react with donor Ags. To test for the presence of primed, donor-specific T cells in humans before transplantation, we used an enzyme-linked immunospot assay for detection of allospecific cytokines produced by individual human PBLs. We demonstrate that this approach detects cytokine production at single cell resolution and detects production of IFN-gamma only when there is defined immunologic priming, thus representing a measure of primed donor-specific immunity. Because the environmental Ag exposure of the recipient is not a function of the HLA mismatch between donor and potential recipient, the number of HLA mismatches may not correlate with the frequency of pretransplant, donor-specific IFN-gamma-producing PBLs. Studies of donor-specific IFN-gamma-producing lymphocytes in a cohort of patients being evaluated for renal transplantation corroborated this hypothesis. Moreover, for recipients of both living and cadaver renal allografts, the pretransplant frequency of donor-specific memory cells correlated with the posttransplant risk of developing acute rejection episodes. This improved ability to define the strength of the allospecific immune response by enzyme-linked immunospot assay may allow improved pairing of recipients with donors and identification of kidney allograft donor-recipient pairs at high risk for acute rejection, thus permitting targeted interventions aimed at prolonging graft survival.

Acute Disease↗
PubMed1999

Inhibition of endothelin-converting enzyme attenuates transplant vasculopathy and rejection in rat cardiac allografts.

BACKGROUND: Transplant vasculopathy in kidney and heart allografts is associated with marked elevation of endothelin-1 (ET-1), but a role for ET-1 in the pathogenesis of transplant vasculopathy and chronic rejection has not been established. We, therefore, tested whether inhibition of ET-1-converting enzyme by phosphoramidon (PA) would attenuate rejection in a rat model of chronic cardiac allograft rejection (Lewis [LEW] to F344). METHODS: Donor LEW rats were pretreated 24 hr before transplantation with a bolus injection of vehicle (water) or PA. Twenty- four hour after transplantation, water or PA was continuously administered through an osmotic mini-pump. Plasma ET-1 levels in Fisher 344 (F344) recipients were 0.8+/-0.1 pg/ml in water-treated rats and 0.2+/-0.2 pg/ml (P<0.01) in PA-treated rats, demonstrating that the PA treatment protocol effectively lowered ET-1 biosynthesis. RESULTS: LEW cardiac allografts treated with water survived (i.e., palpable heart beat) for 16.0+/-0.5 days (n=6). Inhibition of ET-1 secretion by PA improved allograft survival to 28.8+/-3.3 days (P<0.01, n=8). An analysis of cardiac arteries demonstrated that PA treatment attenuated transplant vasculopathy. A morphometric scale of neointima formation (0-5) was 1.4+/-0.2 and 3.6+/-0.2 in PA- or water-treated rats, respectively (P<0.01). The percent of luminal occlusion, as measured by microscopic image analysis, was 19+/-6% in PA-treated animals and 38+/-6% (P<0.01) in animals treated with water. PA treatment also reduced infiltration of ED-1-positive monocytes/macrophages into the vascular neointima. CONCLUSIONS: We conclude that, even in the absence of concomitant immunosuppression, inhibition of ET-1 biosynthesis significantly attenuates transplant vasculopathy and improves survival of LEW to F344 cardiac allografts.

Animals↗
PubMed1999

Incidence and long-term cost of steroid-related side effects after renal transplantation.

Corticosteroids are an essential component of most immunosuppressive regimens currently used in renal transplantation because of their efficacy in reducing acute rejection and improving graft survival. Steroids, however, are associated with numerous side effects that lead to increased patient morbidity and mortality. The incidence and economic cost of steroid-related side effects have not been quantitatively assessed. Thus, based on a systematic review of the published literature, we estimated the incidence of steroid-related hypertension (15%), posttransplantation diabetes mellitus (10%), peripheral fractures (2% per year), avascular necrosis of the hip (8%), and cataracts (22%). In addition, we estimated that approximately 5% of patients who have cataracts or avascular necrosis of the hip require surgery. We used these literature-based estimates in a model to project the costs of treating side effects over a 10-year posttransplantation time frame for a 50-patient cohort that represented an average-sized renal transplant center. Steroid-induced hypertension and its complications were the most expensive side effect ($93,900), followed closely by posttransplantation diabetes ($89,700) and avascular necrosis of the hip ($61,700). Cataracts and peripheral bone fractures were less costly ($16,300 and $4,300, respectively). The cumulative projected 10-year cost of all side effects for the 50-patient cohort was $265, 900, or $5,300 per transplant patient. Steroid-related side effects add to the long-term cost of medical care of renal transplant recipients. These costs provide a rationale for further investigation of steroid-sparing immunosuppression protocols.

Adrenal Cortex Hormones↗
PubMed1999

Azathioprine monotherapy in HLA-identical live donor kidney transplant recipients.

The high success rate of HLA-identical sibling transplants and our previous experience with steroid-free immunosuppressive regimens and cyclosporine withdrawal prompted us to evaluate the safety and efficacy of monotherapy with azathioprine in 12 HLA-identical kidney transplant recipients with a serum creatinine concentration less than 176.8 mumol/L, a 1-way stimulatory index less than 2.0 in a post-transplant mixed lymphocyte culture, and a demonstrated tolerance of a minimum azathioprine dose of 1.0 mg/kg per day without leukopenia. Eleven of 12 patients were successfully converted to azathioprine monotherapy without a significant change in serum creatinine concentration for as long as 76 months. Benefits of steroid and cyclosporine withdrawal included a significant reduction in mean systolic and diastolic blood pressure, number of blood pressure medications, total serum cholesterol, and glycohemoglobin in diabetic subjects. Our results suggest that azathioprine monotherapy is safe and effective in a select group of HLA-identical sibling transplants, but these benefits must be carefully balanced against an associated risk of precipitating acute allograft rejection.

Adult↗
PubMed1998

Glomerulonephritis.

Explore the source record for details and available documents.

Glomerulonephritis↗
PubMed1998

Enzyme-linked immunosorbent assay spot detection of interferon-gamma and interleukin 5-producing cells as a predictive marker for renal allograft failure.

BACKGROUND: Despite improvements in the short-term survival of renal transplants, many allografts fail over the 5-10 years after transplantation. We sought to identify an immunologic assay that could identify those patients at high risk for future allograft failure. METHODS: Blood samples were obtained from 23 renal allograft recipients with acute and/or chronic graft dysfunction and from 22 controls. Isolated peripheral blood lymphocytes (PBLs) were tested for interferon (IFN)-gamma and interleukin (IL)-5 production using an enzyme-linked immunosorbent spot assay. IFN-gamma:IL-5 ratios were calculated and compared between groups. Among the 23 patients with graft dysfunction, the ratios were also compared with graft function at 6 months. RESULTS: IFN-gamma:IL-5 ratios of > or = 15 were associated with allograft rejection episodes in 8 of 12 cases, whereas 10 of 11 episodes of graft dysfunction from other causes (infection, drug toxicity, obstruction) were associated with values <15. All normal controls had values <15 (22/22). Among the graft recipients with acute renal failure, all patients with IFN-gamma:IL-5 ratios <15 exhibited improved renal function at 6-month follow-up (14/14), whereas 8 of 9 patients with IFN-gamma:IL-5 ratios > or = 15 developed allograft failure at 6 months (sensitivity 100%, specificity 93.3%). CONCLUSION: In renal transplant recipients with acute allograft dysfunction, mitogen-induced peripheral blood lymphocyte IFN-gamma:IL-5 ratios > or = 15 were highly predictive of allograft failure within 6 months of the assay. This test may be a useful prognostic marker for identification of transplant recipients with acute graft dysfunction who are at high risk for future graft loss and thus allow targeted therapeutic interventions to prolong graft survival.

Adult↗
PubMed1998

Steroid withdrawal in renal transplant recipients: pro point of view.

Steroid-free immunosuppression remains an attractive goal in an era in which the transplant community should be promoting long-term allograft survival by reducing cardiovascular risk and maximizing long-term patient survival. In the cyclosporine era, the risks of steroid withdrawal outweighed the benefits of steroid withdrawal in a substantial minority of patients. A number of new immunosuppressants may prove to be more steroid sparing than cyclosporine alone and promise to increase the safety of steroid-free immunosuppression for renal transplant recipients.

Costs and Cost Analysis↗
PubMed1998

Withdrawal of immunosuppression: implications for composite tissue allograft transplantation.

Complete or partial withdrawal of immunosuppression is a desirable goal for physicians managing solid organ transplant recipients and has particular appeal for the management of composite tissue allograft recipients. Experience to date with steroid withdrawal or cyclosporine withdrawal in organ transplant recipients suggests that the risks of acute rejection are minimized with slow tapering of the drugs and when drug withdrawal is attempted many months or years after transplantation. Unfortunately, the full benefits of withdrawing any component of a multidrug immunosuppression regimen can probably be achieved only when the drug is withdrawn relatively early after transplantation. Thus, there is a need for improved immunologic monitoring to facilitate withdrawal of immunosuppression in any setting. Because steroid withdrawal might be particularly advantageous to the recipient of a composite tissue allograft, further experience is needed to determine the safety of steroid withdrawal with newer immunosuppressants such as tacrolimus, mycophenolate mofetil, and sirolimus.

Animals↗
PubMed1998

Immunosuppressive drugs in pregnancy.

Successful pregnancies are now common in female organ transplant recipients. Despite high rates of success, pregnancy in an organ transplant recipient should be managed as a high-risk condition with emphasis on prevention and prompt treatment of rejection episodes. The number of immunosuppressive drugs and drug combinations has increased in recent years. Data accrued by a national registry indicate that pregnancy is generally successful in patients maintained on some combination of cyclosporine, azathioprine, and steroids. Relatively little information is available regarding the safety of some of the newer immunosuppressive agents in pregnancy. Until additional information is collected, transplant physicians and obstetricians must balance the efficacy of immunosuppressants in preventing allograft rejection in the mother against possible adverse drug reactions in both the mother and fetus.

Adult↗
PubMed1998

Free pentosidine and neopterin as markers of progression rate in diabetic nephropathy. Collaborative Study Group.

BACKGROUND: Patients with diabetic nephropathy experience a progressive and usually inexorable decline in renal function. The presence of the structurally defined advanced glycation end product (AGE) pentosidine on tissue and circulating proteins has been correlated with the severity of diabetic complications. METHODS: To delineate a role for this AGE in the progression of diabetic nephropathy, glycohemoglobin and free and protein-bound pentosidine were measured in baseline stored serum and urine from a subgroup of patients with diabetes mellitus and proteinuria originally followed by the Collaborative Study Group Trial. To delineate a potential role for an immune-activation response to AGEs, the inflammatory markers, interleukin-6 (IL-6), C-reactive protein (CRP), and the monocyte activation marker marker neopterin were also measured at baseline. The patients chosen represented 67 subjects whose creatinine levels had "doubled" over the course of the study whether or not they later were treated with captopril, and 67 paired "non-doublers." RESULTS: Baseline disease activity, as manifested by glycohemoglobin, serum creatinine and degree of proteinuria was equal in the two groups, as was protein-bound pentosidine and the immune-markers IL-6 and CRP. At baseline the "doublers" as compared to the "non-doublers" had elevated serum levels of free pentosidine and neopterin. Baseline increases in these two parameters were also associated with an increased rate of "doubling" of serum creatinine by the proportional hazards method. CONCLUSION: Differences in individual responsiveness to AGEs, as manifested by either the production of free pentosidine or its release from a protein-bound form, and by evidence of monocyte/macrophage activation, are associated with progression of diabetic nephropathy.

Adult↗
PubMed1998

Elevated neointimal endothelin-1 in transplantation-associated arteriosclerosis of renal allograft recipients.

BACKGROUND: Chronic renal allograft rejection is characterized histologically by transplantation-associated arteriosclerosis and glomerulosclerosis (Tx-AA and Tx-AGS). Recent studies in animal models implicate the mitogenic and pressor actions of endothelin-1 (ET-1) in Tx-AA. In humans, however, a link between elevated ET-1 secretion and Tx-AA or Tx-AGS remains unclear. In this study we analyzed expression of ET-1 in the vasculature of renal transplant patients with chronic or acute rejection and in normal controls. METHODS: Renal vascular and glomerular ET-1 was assessed by immunohistochemistry in 12 patients with clinically and histologically defined chronic rejection, in 11 patients with acute rejection, and in 5 normal kidneys. ET-1 staining was also correlated with various clinical parameters and with a morphometric index of neointima formation. ET-1 secretion was measured by ELISA in cultured human vascular cell types treated with T cell- and macrophage-associated cytokines. RESULTS: We found that renal allografts with chronic rejection and Tx-AA expressed 6.1-fold more ET-1 in the vasculature relative to allografts with acute rejection or to normal kidneys (P < 0.01). In Tx-AA, ET-1 was detected predominantly in the neointima, which contained mostly endothelial cells and smooth muscle cells. A strong positive correlation (r = 0.82, P < 0.01) was observed between vascular ET-1 peptide expression and hypertension in patients with chronic rejection. We also showed that macrophage-associated cytokines, but not T cell-associated cytokines, stimulated ET-1 secretion in human endothelial cells, vascular smooth muscle and mesangial cells. CONCLUSIONS: These results demonstrate that elevated ET-1 in the neointima is associated with Tx-AA and chronic rejection. In addition, these results point to an important role for endothelial dysfunction in chronic renal allograft rejection.

Adolescent↗
PubMed1998

Resolution of hepatitis B viremia in a renal transplant recipient treated with alpha-2b interferon.

A renal transplant patient developed symptomatic hepatitis after withdrawal from corticosteroids. Tests for hepatitis B e antigen and hepatitis B viral DNA were both positive prior to treatment with 1 million units alpha interferon three times weekly for 3 weeks followed by an increase to 3 million units alpha interferon three times weekly for a total of 16 weeks. At the end of treatment, hepatitis had clinically resolved with conversion to a hepatitis B e antibody positive and hepatitis B e antigen and viral DNA negative state. The renal allograft function remained excellent throughout the course of therapy with interferon.

Adult↗
PubMed1998

Benefits of pre-emptive dose reduction for Sandimmune to Neoral conversion in stable renal transplant recipients.

In an effort to minimize nephrotoxicity resulting from greater exposure to cyclosporine after Sandimmune to Neoral conversion, we compared two conversion regimens using different dosing ratios. Serial serum creatinine concentrations and trough cyclosporine levels were measured in 26 patients converted from Sandimmune to Neoral using a 1:0.8 dosing ratio (Group 1) and compared to those of 26 patients converted using a 1:1 dosing ratio (Group 2). The percentage change in peak serum creatinine concentration after conversion was greater in Group 2. However, at last follow-up, the dose reductions in each group were comparable. Following conversion, patients in Group 1 required fewer dose adjustments and follow-up blood tests. Compared to conversion using a 1:1 dosing ratio, conversion from Sandimmune to Neoral using a 1:0.8 ratio results in comparable dose reductions and less short-term nephrotoxicity, while requiring less frequent laboratory monitoring.

Adult↗
PubMed1997

Long-term renal function in type I diabetics after kidney or kidney-pancreas transplantation: influence of number, timing, and treatment of acute rejection episodes.

BACKGROUND: Previous studies comparing renal function in diabetic subjects receiving either a kidney or kidney-pancreas transplant generally have indicated no differences; however, these studies have been limited by inclusion of either a small number of patients or selected patients followed for relatively short periods of time. METHODS: To compare long-term renal function and factors affecting renal function in type I diabetic patients receiving either kidney or kidney-pancreas transplants, the slopes of regression lines generated by plotting the reciprocal of serum creatinine (1/Cr) versus time were measured in 109 consecutive patients followed for at least 12 and up to 102 months after transplantation. Multivariate analyses included linear regression using the slope of 1/Cr versus time as the dependent variable and logistic regression using a positive or negative slope as the dependent variable. RESULTS: Significant differences between kidney-pancreas (n=64) and kidney recipients (n=45) included a smaller proportion of African-Americans, lower rates of HLA matching, lower levels of panel-reactive antibodies, shorter cold ischemia times, a lower incidence of delayed graft function, and a higher incidence of acute renal allograft rejection episodes in the kidney-pancreas group. Trough cyclosporine blood levels were significantly higher in the kidney-pancreas group for the first 12 posttransplant months. The slopes of 1/Cr versus time were negative in each group with a trend toward a more negative slope in the kidney-pancreas group. Multivariate analyses indicated that a concomitant pancreas allograft did not influence long-term renal function. The total number of renal rejection episodes was the best independent predictor of a negative slope of 1/Cr versus time. However, use of OKT3 for the treatment of rejection within the first 3 months of transplantation exerted a surprisingly beneficial effect on long-term renal function, a phenomenon that was most apparent in the kidney-alone group. CONCLUSIONS: The frequency and timing of acute rejection episodes are more important than the influence of a simultaneously transplanted pancreatic allograft in determining long-term function of the transplanted kidney. A concerning trend toward late deterioration of renal function in kidney-pancreas recipients suggests that the benefits of sustained euglycemia, shorter cold ischemia times, lower rates of sensitization, and early use of OKT3 ultimately may be outweighed by the negative effects of more frequent renal rejection episodes.

Acute Disease↗
PubMed1997

Safety and tolerability of cyclosporine microemulsion versus cyclosporine: two-year data in primary renal allograft recipients: a report of the Neoral Study Group.

BACKGROUND: The new microemulsion formulation of cyclosporine (CsA-ME) is more bioavailable than cyclosporine (CsA) in de novo renal transplant patients. Therefore, it was of interest to compare the safety profile of each formulation in such patients. METHODS: In a multicenter, double-blind, parallel-group study, 101 renal transplant recipients were randomized after transplantation to receive either CsA (n=50) or CsA-ME (n=51) capsules twice daily for 2 years. Of these patients, 54 (CsA, n=26; CsA-ME, n=28) completed 1 year of the study and entered the second-year, double-blind extension. Initial dose at the time of transplantation was 5 mg/kg b.i.d.; doses were titrated to target trough levels. METHODS: The mean (+/- SD) doses at the end of 2 years were 4.6 +/- 1.8 and 3.8 +/- 1.1 mg/kg per day for CsA- and CsA-ME-treated patients, respectively. The mean (+/- SD) CsA trough levels at end point were 187 +/- 63 and 210 +/- 95 ng/ml for CsA- and CsA-ME-treated patients, respectively. At least one adverse event was reported by 25/26 (96%) of CsA- and 27/28 (96%) of CsA-ME-treated patients. No patient discontinued the study because of adverse events. No deaths occurred during the study. Renal function, as measured by serum creatinine levels, and blood pressure were comparable over time in both treatment groups. CONCLUSIONS: There was no significant difference in safety and tolerability between CsA- and CsA-ME-treated kidney recipients for 2 years after transplantation.

Adolescent↗