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R Pollak

Publications and source records attributed to R Pollak.

At least 19 recordsLinked to original sources
PubMed2001

Ethnic differences in clinical response to corticosteroid treatment of acute renal allograft rejection.

BACKGROUND: Limited in vitro data suggest that African-Americans exhibit greater resistance to corticosteroids than do non-African-American transplant recipients. However, ethnic differences in clinical response to corticosteroids for treatment of acute rejection have not been investigated previously. The purpose of this study was to evaluate the clinical response to corticosteroid treatment for acute rejection in both African-American and non-African-American renal allograft recipients. METHODS: We retrospectively reviewed the medical records of 497 consecutive renal allograft recipients to identify patients who had received corticosteroids as initial treatment of acute rejection. One hundred and twenty patients who received corticosteroids for treatment of acute rejection were evaluated in this analysis. The study population was divided into two groups: the African-American group (n=73) and non-African-American group (n=47). All acute rejection episodes were documented by biopsy and were classified as mild-moderate histologically. Corticosteroid therapy consisted of either methylprednisolone, 500 mg intravenously for 3 days, or oral prednisone, 2 mg/kg/day rapidly tapered over 3 weeks. RESULTS: Twenty-six percent (26%) of African-Americans were considered corticosteroid treatment failures compared to an 8.0% failure rate among non-African-Americans (P<0.05). One-year graft survival was 78% in African-American versus 96% in non-African-American (P<0.05). Among African-American and non-African-American recipients, 1-year patient survival rates were 97% and 100, respectively (P=NS). CONCLUSIONS: African-American patients exhibit higher failure rates with corticosteroid treatment of acute rejection. Alternative anti-rejection therapies may need to be considered for this "high-risk" patient population to improve long-term graft survival.

Acute Disease↗
PubMed2001

Clotrimazole increases tacrolimus blood levels: a drug interaction in kidney transplant patients.

In order to substantiate a previous case report of a drug interaction between tacrolimus and clotrimazole, we randomly assigned tacrolimus-treated renal allograft recipients to therapy with either clotrimazole or nystatin for oral thrush prophylaxis immediately following transplantation. Patients receiving other agents known to interact with cytochrome P450 were excluded from the study. The clotrimazole group consisted of 17 patients and the nystatin group, which served as the control group, consisted of 18 patients. An oral loading dose (approximately 0.3 mg/kg) of tacrolimus was given pre-operatively. Post-transplant, tacrolimus (approximately 0.15 mg/kg) was orally administered twice daily. Clotrimazole therapy consisted of a 10-mg troche administered three times daily. Nystatin therapy consisted of the oral suspension (5 mL) administered as a 'swish and swallow' four times daily. We evaluated tacrolimus trough blood levels and tacrolimus doses on days 1, 3, 5, and 7 following transplantation. On post-transplant day 1, mean tacrolimus trough levels did not differ between clotrimazole- and nystatin-treated patients. Mean tacrolimus blood trough levels were significantly higher in clotrimazole-treated patients on days 3, 5, and 7 post-transplant, 42+/-14, 53+/-7, and 33+/-17 ng/mL, respectively, compared to 15+/-8, 15+/-7, and 14+/-6 ng/mL in nystatin-treated patients (p<0.05). The mean tacrolimus dose was significantly lower in the clotrimazole group by day 7 post-transplant (p<0.05). We conclude that clotrimazole therapy may cause a significant rise in tacrolimus trough blood levels. Recognition of this potential drug interaction is essential to minimize tacrolimus-associated toxicities in the early post-transplant period.

Adult↗
PubMed2001

Impact of mycophenolate mofetil on recurrent rejection in kidney transplant patients.

PURPOSE: Mycophenolate mofetil (MMF) has emerged as a valuable adjunctive agent in renal transplantation. However, due to intolerable adverse effects associated with MMF use in our transplant population, we have used MMF selectively in patients at high risk for recurrent graft rejection, since these patients are known to be at risk for poor long-term graft outcomes. The purpose of this study was to assess the efficacy of MMF in preventing the recurrence of acute rejection following an initial rejection episode in kidney transplant patients in the first year following transplantation. METHODS: Forty-four kidney transplant recipients were given MMF prospectively following treatment of their initial rejection episode to prevent recurrent rejection. MMF 1-2 g/d was given. Doses were adjusted based on tolerance; MMF therapy was to be continued for at least 6 months. The control group consisted of 124 consecutive kidney transplant recipients who had received standard anti-rejection therapy without the addition of MMF. Maintenance immunosuppression consisted predominantly of cyclosporine, prednisone+/-azathioprine. Anti-rejection therapy for both groups consisted of either corticosteroids (methylprednisolone 500 mg i.v. for 3 d or oral prednisone 2 mg/kg/d with rapid taper over 3 wk), OKT3 5 mg/d for 10 d or ATG 15 mg/kg/d for 10 d. All rejection episodes were confirmed by biopsy. RESULTS: The majority of rejection episodes were characterized histologically as mild or moderate. Most patients (76%) received corticosteroids for treatment of their first rejection episode. There was a 68% reduction in the incidence of recurrent rejection episodes within the first year of transplant in patients receiving MMF; only 14% of recipients receiving MMF developed recurrent rejection compared to 44% of patients in the control group (p<0.05). Approximately 50% of patients developed MMF-associated adverse effects (leukopenia, GI toxicity). Only 52% of patients remained on MMF at 6 months. One-yr graft survival was 86% in the MMF group and 89% in the control group (p>0.05). One-year patient survival was 93 and 100%, respectively (p>0.05). CONCLUSIONS: The addition of MMF to maintenance therapy for patients experiencing acute renal allograft rejection may prevent recurrent rejection episodes in the subsequent follow-up year.

Acute Disease↗
PubMed2001

Efficacy of terbinafine for toenail onychomycosis. A multicenter trial of various treatment durations.

The efficacy of terbinafine (250 mg/day) in the treatment of toenail onychomycosis was evaluated in a large open-label, multicenter trial of 12, 18, and 24 weeks of therapy. All 1,534 patients had onychomycosis, confirmed by either positive potassium hydroxide (KOH) wet mount, positive fungal culture, or both, and all received at least 12 weeks of treatment. Treatment was continued for an additional 6 or 12 weeks, depending on the extent of the disease at follow-up. Mycologic cure rates (negative culture plus negative KOH) at week 72 were 72.1% in the 12-week treatment group, 72.5% in the 18-week group, and 77.0% in the 24-week group. In all groups, clinical cure rates were higher at week 72 than at week 48: 49.5% of the 12-week group, 49.2% of the 18-week group, and 44.6% of the 24-week group experienced clinical cure by the end of the study. Both mycologic and clinical recurrence rates were low in all treatment groups at the 72-week assessment. The results of this study confirm the efficacy of terbinafine in the treatment of toenail onychomycosis as demonstrated in previous registration and large-scale clinical trials.

Adolescent↗
PubMed2000

Organ donor or graft pretreatment to prolong allograft survival: lessons learned in the murine model.

Permanent donor-specific tolerance to allografts is the goal of transplantation research. Currently, morbid immunosuppressive therapy is used to mitigate rejection initiated in part by Ia-bearing interstitial graft dendritic or antigen-presenting cells (APCs) that are thought to migrate into the host after transplantation. We hypothesized that donor or organ immune modulation directed against graft APCs might influence graft immunogenicity and promote prolonged graft acceptance in histoincompatible hosts in the absence of immunosuppressive therapy. Haplotype-specific monoclonal antibodies (mAb), mAb specific to graft APC, adhesion or costimulatory molecules and anti-LFA-1-Ricin and anti-Iak-Ricin immunoconjugates (IC) were prepared and administered in varying doses and time intervals to donor C3H/HeJ (H-2k) mice. Thereafter, their spleens and hearts were removed at varying time intervals and used either as stimulator cells in one-way mixed lymphocyte reaction or transplanted into naive Balb/c (H-2d) recipients, respectively. Explanted C3H hearts were pretreated with anti-Iak mAb on the Langendorf apparatus. Hearts were also used from major histocompatibility complex (MHC) class I, MHC class II, and MHC class I- and II-deficient "knockout" mice. Splenocytes exposed to at least 500 microg of anti-Iak mAb in vivo for more than 4 hr were able to inhibit the mixed lymphocyte reaction to almost background levels, but only after incubation with rabbit complement in vitro. Similarly pretreated cardiac allografts (both in vivo or explanted and pretreated on the Langendorf apparatus) did not experience prolonged survival in nonimmunosuppressed Balb/C recipients when compared with control solutions, regardless of the concomitant use of complement. Splenocytes from immunoconjugate pretreated donors inhibited the mixed lymphocyte reaction completely without the use of complement; however, hearts from these donors also did not experience prolonged survival nor donor hearts exposed to mAb specific for graft APC, adhesion or costimulatory molecules. Only hearts from MHC class I and class II "knockout" mice survived significantly longer than controls. We conclude that donor or graft pretreatment with haplotype-specific anti-Ia mAb, haplotype-specific immunoconjugates, or mAb directed against graft APC, adhesion or costimulation molecules have little efficacy in promoting acceptance of cardiac allografts in nonimmunosuppressed recipients. The enhanced survival of hearts from MHC class I- and class II-deficient donors suggest that novel methods to effect the immunogenicity of the graft will be required if long-term allograft acceptance is to be achieved in the absence of host immunosuppression.

Animals↗
PubMed2000

Chondrosarcoma of the foot.

Chondrosarcomas have been seen clinically as aggressive tumors, with radiographic and histologic findings consistent with malignancy; however, they may have an insidious clinical course, with relatively benign radiographic and histopathologic findings. Rarely, a chondrosarcoma may present as a primary lesion of the foot. It is important to recognize these lesions as malignancies. The authors provide an overview of these neoplasms and describe a case of a low-grade chondrosarcoma in a 64-year-old woman.

Amputation, Surgical↗
PubMed1999

A prospective randomized trial comparing the efficacy of tacrolimus versus cyclosporine in black recipients of primary cadaveric renal transplants.

BACKGROUND: We performed a prospective randomized trial to compare the efficacy and safety of tacrolimus (FK506) versus cyclosporine (CSA) in black primary cadaveric renal transplant (CRT) recipients. METHODS: Between December 1994 and February 1997, 35 black primary CRT recipients were enrolled in this trial. All patients received 7 days of induction therapy with OKT3. Fourteen patients received FK506 and prednisone only. Twenty-one patients received CSA, azathioprine, and prednisone. The two groups were comparable in terms of age, gender, plasma renin activity, human leukocyte antigen mismatches, and cause of renal failure. RESULTS: Patient and graft survival were 12 of 14 (86%) for the FK506 group and 20 of 21 (95%) for the CSA group (P = 0.71). Three patients died owing to cardiac events with functioning grafts. Acute rejection was 2 of 14 (14%) for the FK506 and 8 of 21 (38%) for the CSA group (P = 0.25). Two other patients on CSA were converted to FK506 as rescue for OKT3-resistant rejection. Mean serum cholesterol at 1 year was 198 +/- 45 mg/dL for the FK506 group and 244 +/- 49 mg/dL for the CSA group (P = 0.03). Mean serum creatinine at 1 year was 1.39 +/- 0.38 mg/dL for the FK506 group and 1.94 +/- 0.64 mg/dL for the CSA group (P = 0.02). CONCLUSION: Patient and graft survival were similar in both groups at 1 year posttransplant. Although statistically not significant, the incidence of acute rejection was lower in the FK506 group. Furthermore, FK506-treated patients had significantly lower serum creatinine and cholesterol levels at 1 year posttransplant.

Adult↗
PubMed1999

Cyclosporine bioavailability of Neoral and Sandimmune in white and black de novo renal transplant recipients. Neoral Study Group.

Black renal transplant recipients have inferior graft outcomes when compared to whites. The relative bioavailability of cyclosporine (CsA) with the Sandimmune (SIM) formulation is lower in black recipients when compared to whites. To study relative CsA bioavailability in the Neoral formulation, 18 black and 78 white de novo renal transplant recipients were randomized in a multicenter, double-blind, parallel group study to receive either SIM or Neoral capsules twice a day for 12 weeks. After an overnight fast, CsA whole blood levels (TDx) were collected during 12 hours after the morning dose and 12 hours after the evening dose with a standardized meal. Pharmacokinetic profiles were obtained at the end of weeks 1, 4, 8, and 12. Initial CsA dose was 5 mg/kg twice a day; subsequent doses were titrated to target trough CsA levels. Area under the blood concentration vs. time curve (AUC), peak blood concentration (Cmax) and time to Cmax(Tmax) were obtained from 16 black and 73 white patients. Food conditions (fed and fasting) were averaged, and data was dose-normalized. For black recipients, Neoral was significantly more bioavailable than SIM only during week 1; there was also a consistent trend to higher cyclosporine bioavailability at weeks 4, 8, and 12. For whites, there were significant differences in favor of Neoral at all time periods. No significant differences in relative bioavailability were noted between races for either SIM or Neoral except for a higher Cmax in white patients given Neoral. Neoral is better absorbed than SIM in both blacks and whites. These data suggest that Neoral is the superior CsA preparation for all racial groups.

Adult↗
PubMed1999

Long-term outcome of a prospective trial of steroid withdrawal after kidney transplantation.

BACKGROUND: Steroid withdrawal (SW) after kidney transplantation is desirable to avoid associated serious side effects. We studied the long-term outcome of a group of kidney transplant recipients who underwent SW. METHODS: Between 1991 and 1993, kidney transplant recipients (N = 12) who had posttransplantation diabetes were entered in a prospective trial of SW. These patients were compared with a demographically similar comparison cohort (N = 66). End points of the study were patient and graft survival, incidence of late acute and chronic rejection, and changes in diabetes management. RESULTS: Previously published data from the SW group at 15 months of follow-up indicated improvement in diabetes control without any adverse effect on patient or graft actuarial survival. At long-term follow-up (mean, 56 months) the improvement in diabetes management was not detectable. The incidence of late acute rejection in SW and cohort groups was 42% and 8%, respectively (P = .006). Likewise, the incidence of chronic rejection in the SW versus cohort group was 42% and 12%, respectively (P = .014). CONCLUSIONS: Although SW appeared to be successful initially, our long-term data indicate that SW significantly increases the risk of late acute rejection and chronic rejection episodes without benefits in posttransplantation diabetes management. Steroid withdrawal in patients with posttransplantation diabetes should be approached with caution.

Acute Disease↗
PubMed1998

A prospective randomized clinical trial of perioperative treatment with octreotide in pancreas transplantation.

BACKGROUND: Technical failures continue to plague clinical pancreas transplantation. The somastatin analogue octreotide has been shown able to decrease morbidity after pancreatic resection. We studied the effect of perioperative treatment with octreotide on technical complications after pancreas transplant. PATIENTS AND METHODS: Seventeen recipients of bladder-drained transplant were randomized to receive either octreotide, 100 microg TID SQ for 5 days after transplant (n = 10) or no additional treatment (n = 7). We compared the two groups in terms of patient and graft survival and incidence of graft pancreatitis, intra-abdominal infections, and anastomotic leaks. RESULTS: In the untreated group, 1 patient developed a bladder leak and 2 had intra-abdominal infections, while no complications occurred in the octreotide-treated patients (P = 0.05). Six-month patient and pancreas survival was 100% and 90%, respectively, in octreotide-treated patients versus 86% and 86% in the control group (P = NS). CONCLUSION: Perioperative treatment with octreotide seems able to reduce the incidence of technical complications after pancreas transplantation.

Adult↗
PubMed1998

Combined coronary bypass and liver transplantation: technical considerations.

Combined coronary artery bypass grafting and orthotopic liver transplantation was carried out successfully in a 58-year-old man with angina pectoris and end-stage liver disease. To date, only 2 similar cases have been documented worldwide whereby the transplantation was performed either during cardiopulmonary bypass or with femoral-to-axillary venovenous bypass initiated at the termination of cardiopulmonary bypass. In this report we describe our experience with a simplified one-exposure approach for the combined operation using cardiopulmonary bypass in tandem with percutaneous femoral-to-right atrial venovenous bypass.

Angina Pectoris↗
PubMed1998

Kidney transplantation in recipients with mental retardation: clinical results in a single-center experience.

Mental retardation has been a controversial relative contraindication to organ transplantation. Currently, there are few data available in the literature that describe the outcome of kidney transplantation in mentally retarded patients. In a series of 1,271 kidney transplantations performed between January 1968 and March 1996, we identified eight patients (0.6%) with significant mental retardation (IQ < 70). Only cooperative patients supervised by a reliable long-term caregiver, with long life expectancy, and able to take medication under supervision, were accepted as candidates, independent of the IQ level. At a mean follow-up of 7.3 years, seven patients are alive with functioning grafts, and one lost the kidney to chronic rejection 10 years after transplantation and died of sepsis after resuming dialysis. The 1- and 5-year patient and graft survival are thus 100%. Compliance with immunosuppressive treatment and clinical follow-up was excellent in all of the recipients. The patient quality of life and health were judged by the support persons as highly improved after transplantation in comparison to dialysis. We conclude that kidney transplantation in properly selected patients with mental retardation provides excellent patient and graft survival rates and improves quality of life. In such patients, the presence of mental retardation should not be considered a contraindication to kidney transplantation.

Adolescent↗