Histopathologic findings from 2-year protocol biopsies from a U.S. multicenter kidney transplant trial comparing tarolimus versus cyclosporine: a report of the FK506 Kidney Transplant Study Group

BACKGROUND: This paper reports the histopathologic results of 2-year protocol biopsies from patients who were enrolled in the U.S. FK506 kidney transplant study . METHODS: Recipients of cadaveric kidney transplants were randomized to tacrolimus or cyclosporine therapy. Patients active in the trial at 2 years after transplantation were approached for a protocol biopsy. Biopsies were scored by the Banff classification in a blinded fashion by one pathologist. RESULTS: A total of 144 patients (41.3% of those active at 2 years) had a 2-year protocol biopsy performed; 79 patients were treated with tacrolimus and 65 patients were treated with cyclosporine. Evidence of acute rejection was found in seven (8.9%) of the 2-year biopsies in tacrolimus-treated patients and six (9.2%) cyclosporine-treated patients. Chronic allograft nephropathy was found in 49 (62.0%) tacrolimus biopsies and 47 (72.3%) cyclosporine biopsies (P=0.155). There were no apparent histopathologic differences between the tacrolimus and cyclosporine biopsies. The occurrence of chronic allograft nephropathy was significantly higher in patients who received a graft from an older donor (P<0.01), who experienced presumed cyclosporine or tacrolimus nephrotoxicity (P<0.001), who developed a cytomegalovirus infection (P=0.038), or who experienced acute rejection in the first year after transplantation (P=0.045). A multivariate analysis showed that nephrotoxicity and acute rejection were the most significant predictors for chronic allograft nephropathy. CONCLUSIONS: The occurrence of histologic acute rejection was rare at 2 years, confirming the absence of subclinical acute rejection in these late biopsies. A majority of the biopsies showed features consistent with chronic allograft nephropathy that was associated with acute rejection (particularly in cyclosporine-treated patients), nephrotoxicity, and cytomegalovirus infection in the first year. This suggests that nonimmunologic factors, such as drug-induced toxicity, may play an important role in chronic allograft nephropathy.     

A comparison of tacrolimus (FK506) and cyclosporine for immunosuppression after cadaveric renal transplantation. FK506 Kidney Transplant Study Group

BACKGROUND: Tacrolimus (FK506), a macrolide molecule that potently inhibits the expression of interleukin 2 by T lymphocytes, represents a potential major advance in the management of rejection following solid-organ transplantation. This randomized, open-label study compared the efficacy and safety of tacrolimus-based versus cyclosporine-based immunosuppression in patients receiving cadaveric kidney transplants. METHODS: A total of 412 patients were randomized to tacrolimus (n=205) or cyclosporine (n=207) after cadaveric renal transplantation and were followed for 1 year for patient and graft survival and the incidence of acute rejection. RESULTS: One-year patient survival rates were 95.6% for tacrolimus and 96.6% for cyclosporine (P=0.576). Corresponding 1-year graft survival rates were 91.2% and 87.9% (P=0.289). There was a significant reduction in the incidence of biopsy-confirmed acute rejection in the tacrolimus group (30.7%) compared with the cyclosporine group (46.4%, P=0.001), which was confirmed by blinded review, and in the use of antilymphocyte therapy for rejection (10.7% and 25.1%, respectively; P<0.001). Impaired renal function, gastrointestinal disorders, and neurological complications were commonly reported in both treatment groups, but tremor and paresthesia were more frequent in the tacrolimus group. The incidence of posttransplant diabetes mellitus was 19.9% in the tacrolimus group and 4.0% in the cyclosporine group (P<0.001), and was reversible in some patients. CONCLUSIONS: Tacrolimus is more effective than cyclosporine in preventing acute rejection in cadaveric renal allograft recipients, and significantly reduces the use of antilymphocyte antibody preparations. Tacrolimus was associated with a higher incidence of neurologic events, which were rarely treatment limiting, and with posttransplant diabetes mellitus, which was reversible in some patients.     

Dose-related reversal of acute lung rejection by aerosolized cyclosporine

This study evaluated the effectiveness of aerosolized cyclosporine as rescue therapy for refractory acute rejection in lung-transplant patients that is unresponsive to conventional therapy. Over 2 yr, nine allograft recipients with histologic evidence of persistent acute rejection and worsening pulmonary function were enrolled. Twenty-two patients with similar degrees of unremitting rejection served as historical controls. Aerosolization of cyclosporin A (300 mg in 4.8 ml propylene glycol) using an AeroTech II jet nebulizer was instituted daily for 12 consecutive days followed by a maintenance regimen of 3 d/wk. Cyclosporine and tacrolimus blood and plasma levels were maintained within therapeutic ranges throughout this trial. Efficacy was assessed by histologic grade of rejection, interleukin-6 (IL-6) mRNA expression by graft bronchoalveolar lavage cells, and pulmonary function testing before and during cyclosporine therapy. In seven patients, results were correlated to deposition of cyclosporine aerosol in the allograft(s) as measured by radioisotopic techniques. At a mean of 37 d after initiation of aerosolized cyclosporine, graft histology improved in eight of the nine patients. Cellular IL-6 mRNA expression decreased significantly in seven patients (mean IL-6/actin +/- SD, 40.96 +/- 118 versus 0.33 +/- 0.57 [p = 0.038]). Pulmonary function (FEV1), which had decreased posttransplant (over a mean of 347 d of observation) from a best value of 1.98 +/- 0.8 L to 1.59 +/- 0.6 L (p = 0.0077), improved over time (152 d) to a posttransplant value of 1.90 +/- 0.8 (p = 0.025). In the control subjects, FEV1 inexorably declined over a comparable period of observation (best posttransplant value 2.36 +/- 0.86 to 1.32 +/- 0.53, p < 0.0001). There was a strong correlation between cyclosporine deposition in the allograft and improvement in FEV1 (r = 0.900, p < 0.01). Fewer cycles of pulsed corticosteroids (1.4 +/- 0.9 versus 0.2 +/- 0.4, p = 0.011) and anti-thymocyte globulin 0.8 +/- 0.4 versus 0, p = 0.018) and reduced doses of oral prednisone (10.8 +/- 3.1 versus 6.1 +/- 4.2 mg/d, p = 0.026) were observed during treatment with aerosolized cyclosporine. Episodes of pneumonia also were reduced significantly during aerosol therapy (2.6 versus 0.95 episodes/100 d, p = 0.029). Nephrotoxicity and hepatotoxicity did not occur, and no patients withdrew from the study. Aerosolized cyclosporine appears to be safe and effective therapy for refractory acute rejection, but confirmation by a larger, randomized trial is necessary. The correlation observed between deposition of cyclosporine aerosol and physiologic improvement of lung function suggests that there is a dose-response relationship between the concentration of cyclosporine in the allograft and immunologic tolerance.     

Positive selection driving the evolution of a gene of male reproduction, Acp26Aa, of Drosophila: II. Divergence versus polymorphism

BACKGROUND: Sirolimus, a novel immunosuppressant that inhibits cytokine-driven cell proliferation and maturation, prolongs allograft survival in animal models. After a phase I trial in stable renal transplant recipients documented that cyclosporine and sirolimus have few overlapping toxicities, we conducted an open-label, single-center, phase I/II dose-escalation trial to examine the safety and efficacy of this drug combination. METHODS: Forty mismatched living-donor renal transplant recipients were sequentially assigned to receive escalating initial doses of sirolimus (0.5-7.0 mg/m2/day), in addition to courses of prednisone and a concentration-controlled regimen of cyclosporine. We conducted surveillance for drug-induced side effects among sirolimus-treated patients and compared their incidence of acute rejection episodes as well as mean laboratory values with those of a historical cohort of 65 consecutive, immediately precedent, demographically similar recipients treated with the same concentration-controlled regimen of cyclosporine and tapering doses of prednisone. RESULTS: The addition of sirolimus reduced the overall incidence of acute allograft rejection episodes to 7.5% from 32% in the immediately precedent cyclosporine/prednisone-treated patients. At 18- to 47-month follow-up periods, both treatment groups displayed similar rates of patient and graft survival, as well as morbid complications. Although sirolimus-treated patients displayed comparatively lower platelet and white blood cell counts and higher levels of serum cholesterol and triglycerides, sirolimus did not augment the nephrotoxic or hypertensive proclivities of cyclosporine. The degree of change in the laboratory values was more directly associated with whole blood trough drug concentrations than with doses of sirolimus. CONCLUSIONS: Sirolimus potentiates the immunosuppressive effects of a cyclosporine-based regimen by reducing the rate of acute rejection episodes.     

Identification of regulatory elements of human alpha 6 integrin subunit gene

BACKGROUND: A study was performed by 17 different U.S. liver transplantation centers to determine the safety and efficacy of conversion from cyclosporine to tacrolimus for chronic allograft rejection. METHODS: Ninety-one patients were converted to tacrolimus a mean of 319 days after liver transplantation. The indication for conversion was ongoing chronic rejection confirmed by biochemical and histologic criteria. Patients were followed for a mean of 251 days until the end of the study. RESULTS: Sixty-four patients (70.3%) were alive with their initial hepatic allograft at the conclusion of the study period and were defined as the responder group. Twenty-seven patients (29.7%) failed to respond to treatment, and 20 of them required a second liver graft. The actuarial graft survival for the total patient group was 69.9% and 48.5% at 1 and 2 years, respectively. The actuarial patient survival at 1 and 2 years was 84.4% and 81.2%, respectively. Two significant positive prognostic factors were identified. Patients with a total bilirubin of < or = 10 mg/dl at the time of conversion had a significantly better graft and patient survival than patients converted with a total bilirubin > 10 mg/dl (P=0.00002 and P=0.00125, respectively). The time between liver transplantation and conversion also affected graft and patient survival. Patients converted to tacrolimus < or = 90 days after transplantation had a 1-year actuarial graft and patient survival of 51.9% and 65.9%, respectively, compared with 73.2% and 87.7% for those converted > 90 days after transplantation. The mean total bilirubin level for the responder group was 7.1 mg/dl at the time of conversion and decreased significantly to a mean of 3.4 mg/dl at the end of the study (P=0.0018). Thirteen patients (14.3%) died during the study. Sepsis was the major contributing cause of death in most of these patients. CONCLUSIONS: Our results suggest that conversion to tacrolimus for chronic rejection after orthotopic liver transplantation represents an effective therapeutic option. Conversion to tacrolimus before development of elevated total bilirubin levels showed a significant impact on long-term outcome.     

Determinants of late allograft nephrectomy

When loss of graft function occurs more than six months after transplantation, allograft nephrectomy is not routinely performed at the time of graft failure. It is usually performed only on those patients who subsequently develop specific complications. However, little is known about the characteristics that make patients more likely to require allograft nephrectomy. The purpose of our study was to identify risk factors for the subsequent need for allograft nephrectomy in patients with graft failure occurring more than 6 months after transplantation. Forty-one patients were studied. Inclusion criteria were: loss of graft function > or = 6 months after transplantation, resumption of dialysis and initiation of weaning from immunosuppression. Thirty patients were treated with cyclosporine + prednisone +/- azathioprine and 11 with azathioprine + prednisone. Mean follow-up time was 17.8 months, ranging from 6 months to 6.1 years. Recipient age, sex and race, original renal disease, donor, donor source (cadaveric vs living related), HLA compatibility, levels of panel reactive antibodies, occurrence of initial delayed graft function, causes of graft failure and tapering of immunosuppression were similar in patients with and without allograft nephrectomy. Using univariate analysis, allograft nephrectomy was found to be significantly more frequent in patients with a history of 2 or more episodes of acute rejection than in patients with no rejection episode: 83% vs 30% (p = 0.03). In addition, allograft nephrectomy was found to be significantly more frequent if the immunosuppressive regimen included cyclosporine (62% vs 27.3%; p = 0.04). Using multivariate analysis however, the number of previous episodes of rejection was found to be the only significant predictor for allograft nephrectomy. None of the other variables considered in the multivariate analysis, including the type of immunosuppressive therapy, was identified as a significant predictor for the need to perform allograft nephrectomy. In summary, the need for late allograft nephrectomy was correlated with the number of previous episodes of acute rejection. Patients with a history of numerous rejection episodes should thus be considered more likely to require allograft nephrectomy once immunosuppression is withdrawn. Possible interventions to reduce or prevent the need for nephrectomy include more gradual tapering of immunosuppression at the time of graft failure or indefinite low-dose immunosuppressive therapy.     

Adult heart transplantation under tacrolimus (FK506) immunosuppression: histopathologic observations and comparison to a cyclosporine-based regimen with lympholytic (ATG) induction

BACKGROUND: Tacrolimus (FK506) is an effective immunosuppressant for human heart transplantation, but information about its effects on cardiac allograft and nonallograft kidney and liver histopathologic study is limited. METHODS: We therefore reviewed 1145 endomyocardial biopsy specimens and eight autopsy results from 80 heart transplant recipients who received tacrolimus as baseline immunosuppression. These were compared with 619 endomyocardial biopsy specimens and four autopsy results from 51 patients treated with cyclosporine-based immunosuppression with lympholytic induction (CLI) by use of rabbit anti-thymocyte globulin. Twenty-one histologic features including the International Society for Heart and Lung Transplantation histopathologic grade were retrospectively assessed without knowledge of the treatment regimen. The lymphocyte growth index on biopsy specimens obtained from these patients was also compared. RESULTS: In general, there were no qualitative differences in the histopathologic appearance of various allograft syndromes between tacrolimus- and CLI-treated patients. Thus histopathologic criteria used to diagnose various graft syndromes are applicable under tacrolimus immunosuppression. However, early (between 10 and 30 days) after transplantation, biopsy specimens from patients treated with tacrolimus showed a significantly higher percentage of inflamed fragments (p = 0.02), the inflammation tended to be more severe (p = 0.09), and the rejection grade tended to be slightly higher (p = 0.08). In contrast, during the late transplantation period (275 to 548 days), biopsy specimens from patients treated with CLI showed a significantly higher percentage of inflamed fragments (p = 0.03), more severe inflammation (p = 0.03), higher rejection grades (p = 0.01), and a higher frequency of Quilty lesions (p = 0.05). Although overall freedom from any grade 3A or higher rejection was greater in the CLI-treated arm, tacrolimus was successfully used to treat refractory rejection in three patients from the CLI-treated arm. Concern has been raised in the literature about the possibility of tacrolimus being a direct hepatotoxin and an accelerant of allograft obliterative arteriopathy. However, no evidence to support either of these contentions was detected in this patient population. In contrast, tacrolimus is clearly nephrotoxic, although similar to cyclosporine in this regard. CONCLUSIONS: Tacrolimus is an effective immunosuppressive drug for heart transplantation. The cardiac allograft histopathologic study of patients treated with tacrolimus immunosuppression does not significantly differ from those given conventional, cyclosporine-based triple therapy with lympholytic induction.     

Morphology of ischemic acute renal failure, normal function, and cyclosporine toxicity in cyclosporine-treated renal allograft recipients

To characterize morphologic changes in the early post-transplant period in cyclosporine-treated renal allograft recipients, we examined biopsies from three groups of cyclosporine-treated patients: normal function (N = 9), ischemic acute renal failure or "acute tubular necrosis" (N = 12), and cyclosporine toxicity (N = 7). Groups were compared with each other and with previously studied groups of azathioprine-treated patients and native kidney patients. The interstitial infiltrate commonly observed in normally functioning azathioprine-treated grafts was not observed in normally functioning cyclosporine-treated grafts, but two of nine such grafts had a significant venulitis, a change also seen in three of the patients with cyclosporine nephrotoxicity. "Acute tubular necrosis" (ATN) in cyclosporine-treated graft recipients was characterized by focal necrosis of complete tubular cross sections, a finding normally rare in other types of ATN, and by shedding into the tubular lumen of tubular cells with non-pyknotic nuclei, a finding supporting our previous observation of detachment of viable tubular cells in ATN but not in the normal kidney. Hyaline arteriolar thickening was the only morphologic finding on biopsy which distinguished patients with cyclosporine nephrotoxicity from other groups. In summary, the morphologic changes observed in cyclosporine-treated renal allograft recipients with ATN or normal function are quite different from those observed in azathioprine-treated patients. Cyclosporine appears to enhance the tubular injury observed in ATN. Hyaline arteriolar thickening is the main distinguishing feature of cyclosporine nephrotoxicity.     

Emergency medicine: the Italian experience

BACKGROUND: Studies using tacrolimus and corticosteroids or the combination of cyclosporine, mycophenolate mofetil, and corticosteroids have been shown to reduce the incidence of biopsy-proven acute rejection episodes in cadaveric kidney recipients compared with cyclosporine-based immunosuppression. The current study is a retrospective analysis of our experience with tacrolimus combined with mycophenolate mofetil and steroids as primary immunosuppression for kidney transplant recipients. METHODS: In a retrospective analysis, 72 patients who received primary therapy with tacrolimus, mycophenolate mofetil, and corticosteroids (triple therapy) were compared with a control group of 98 kidney recipients who received tacrolimus and corticosteroids (double therapy). RESULTS: There was a significant reduction in the incidence of biopsy-confirmed acute rejection in the triple therapy group (8.2%) compared with the double therapy group (21%; P=0.003). One-year patient and graft survival did not differ between groups. The incidence of posttransplant diabetes mellitus was 18% and 21% in the triple and double therapy groups, respectively. Leukopenia and gastrointestinal side effects were the most common cause for discontinuation of mycophenolate mofetil. CONCLUSIONS: The combination of tacrolimus with mycophenolate mofetil and corticosteroids is more effective at preventing early acute rejection than tacrolimus and corticosteroids alone. The use of mycophenolate mofetil was associated with a higher incidence of leukopenia and diarrhea, often leading to discontinuation of the drug.     

Risk factors for high blood lead levels among the general population in Taiwan

BACKGROUND: Tacrolimus (FK506) may represent a major advance in the management of allograft rejection after solid organ transplantation. In August 1994 a European heart transplantation pilot study was initiated to assess the efficacy and safety of tacrolimus when administered exclusively through an oral route. METHODS: Eighty-two heart transplant recipients were randomized to treatment (2:1 ratio) with either tacrolimus- (n=54) or cyclosporine-based therapy (n=28). RESULTS: No significant differences were evident between the two treatment groups in either rejection or survival rates at 1 year. Kaplan-Meier estimates of the freedom from rejection were 26.3% and 18.5%, respectively, for the tacrolimus and cyclosporine treatment groups (p=.444). Survival rates were 79.6% and 92.9% (p=.125). At 3 of the 5 centers, patients received antithymocyte globulin during the immediate postoperative period and fared better than those who did not (with acute rejection-free rates of 49.2% and 26.7% for tacrolimus and cyclosporine, respectively [p=.080], as opposed to 7.1% and 8.3% [p=.965]; patient survival rates of 84.6% and 93.3% [p=.382] vs 75.0% and 92.3% [p=.243]). The overall rates of infection, impaired renal function (31.5% vs 21.4%), and glucose intolerance (7.0% vs 4.3%) did not differ significantly between the tacrolimus and cyclosporine treatment groups. Tacrolimus seemed to possess an advantage with regard to a reduced requirement for antihypertensive therapy (59.5% vs 87.5%, p=.025). CONCLUSIONS: Immunosuppression with oral tacrolimus provides a viable alternative to treatment with cyclosporine, particularly when administered in conjunction with antibody therapy. Further studies are warranted to optimize the administration of tacrolimus in this indication.     

Reversal of early acute rejection with increased doses of tacrolimus in liver transplantation: a pilot study

BACKGROUND: In this pilot study, we present the results of treatment of early (3 months after liver transplantation) acute rejection episodes by increasing only the tacrolimus doses. METHODS: Ten patients who received tacrolimus as primary treatment experienced acute mild (one case), moderate (four cases), or severe (five cases) rejection episodes. Tacrolimus dosing was increased 1-2 mg every 1 or 2 days until hepatic enzymes started to improve. Steroid basic daily doses were kept unchanged. RESULTS: With the daily dose of tacrolimus increased by a median 1.89-fold (range: 1.2-5), alanine aminotransferase, bilirubin, and gamma-glutamyltranspeptidase levels rapidly reached normal values within the first month. During a median follow-up time of 19.5 months (range: 14-24), none of the 10 patients died or lost their graft. Control liver biopsies were done 13.5 months (range: 7-19) after rejection episode in all patients, and none demonstrated evidence of rejection or sequela. CONCLUSION: This pilot study suggests that increasing tacrolimus dosage could be considered as treatment against early acute rejection episodes including the severe grade.     

Myocardial acoustics in pediatric allograft rejection

BACKGROUND: Ultrasonographic tissue characterization is the assessment of physical properties of biologic tissue on the basis of quantitative analysis of its acoustic characteristics. Abnormalities in microscopic structure that occur with cardiac allograft rejection may result in characteristic alterations in myocardial acoustics. Ultrasonographic tissue characterization may allow noninvasive detection of rejection. METHODS: Findings in 22 pediatric heart transplant patients undergoing routine surveillance for rejection by endomyocardial biopsy were prospectively evaluated. Off-line ultrasonographic tissue characterization analysis was done on transthoracic echocardiograms obtained at each biopsy. Within patients, tissue characterization texture measures derived from the ultrasonographic image data were compared with histologic findings. Univariate multiple regression analysis was used to identify texture measures associated with acute allograft rejection in a subgroup (n = 8) with at least one biopsy-proven episode of moderate rejection. RESULTS: Measures of homogeneity (co-occurrence matrix correlation and heterogeneity (run-length nonuniformity) decreased with moderate rejection (p < 0.03). Homogeneity measures decreased if the patient had a previous episode of rejection. Several measures of heterogeneity (gray level difference and run-length statistics) were affected by the presence of edema. Run-length nonuniformity was the only measure that differentiated moderate rejection from edema. Discriminant analysis on all 22 patients correctly identified 96% of first rejection episodes (sensitivity 80%, specificity 64%), 93% of moderate and severe rejection episodes (sensitivity 71%; specificity 62%), and 69% of all rejection episodes (sensitivity 51%, specificity 91%). CONCLUSIONS: Histologic changes associated with moderate and severe pediatric allograft rejection as reflected by characteristic alterations in myocardial acoustics can be assessed with ultrasonographic tissue characterization. Histologic changes associated with transplantation itself (resolution of rejection and edema) also affect myocardial acoustics and must be taken into account in rejection surveillance.     

Mycophenolate mofetil decreases rejection in simultaneous pancreas-kidney transplantation when combined with tacrolimus or cyclosporine

BACKGROUND: Historically, the acute rejection rates in simultaneous pancreas-kidney (SPK) recipients have been extremely high (50-80%), with many second and third rejection episodes despite the use of quadruple immunosuppression (antibody induction and cyclosporine [CsA]-azathioprine [AZA]-based maintenance immunosuppression). Although this acute rejection has rarely led to graft loss, it has been a great cause of morbidity and of significantly increased cost. In an attempt to decrease the acute rejection rate and related morbidity in SPK transplant recipients, we compared two "state-of-the-art" immunosuppression regimens in a prospective, randomized, single-center study. METHODS: Patients who received SPK transplants were randomized to receive either tacrolimus (TAC) and mycophenolate mofetil (MMF, n=18) or CsA (Neoral formulation) and MMF (n=18). All patients received OKT3 induction and prednisone, which was tapered to 5 mg/day by 6 months after transplantation. All rejection episodes were biopsy proven. In addition, metabolic control (HgbA1C, hypertension, serum cholesterol), drug toxicity, and infection also were measured. Data were compared with that of a historical group (n=18) who received conventional CsA (Sandimmune formulation) and AZA-based immunosuppression. RESULTS: The incidence of biopsy-proven acute rejection was 11% in both the TAC-MMF and CsA-MMF groups with only two patients in each group experiencing a rejection episode. This rejection rate was significantly decreased from that of the CsA-AZA historical group (77%, P<0.01). There were no significant differences in infection rates, including cytomegalovirus, or in metabolic control (HgbA1C, hypertension, and cholesterol levels). All patients remained on their initial immunosuppression regimen for the first 3 months after transplantation. Between 3 and 6 months after transplantation, three patients were switched from TAC to CsA for recurrent migraine headaches, posttransplant diabetes, and chronic cytomegalovirus infection. Two patients in the CsA-MMF group died of nonimmunologic causes (aspiration pneumonia and arrhythmia) between 3 and 6 months after transplantation. CONCLUSIONS: The data from this study show that MMF treatment significantly decreases the incidence of biopsy-proven acute rejection in SPK transplant recipients compared with AZA-treated historical controls. In addition, we conclude that TAC and CsA (Neoral), when combined with MMF, yield similar, low acute rejection rates with similar graft function and metabolic control.     

Fluoroquinolones as treatment for patients with lower respiratory tract infections caused by Streptococcus pneumoniae

BACKGROUND: Mycophenolate mofetil (MMF) has been previously shown to prevent functional deterioration in an experimental model of chronic renal allograft rejection. METHODS: In this retrospective case-control study, patients with chronic rejection who were receiving cyclosporine or tacrolimus and who had MMF added to their immunosuppressive regimen were compared with patients with chronic rejection who were not receiving MMF. Patients were matched for serum creatinine levels and transplant duration at the time MMF was begun. RESULTS: In the MMF group, the average dose of MMF was 1482 mg/day with an average duration of 19.3 months. Over 36 months, including 12 months before MMF and up to 24 months on MMF, there was no difference in serum creatinine levels between the two groups. Cyclosporine levels and dose were no different. CONCLUSIONS: In this small, retrospective, preliminary study, adding MMF to maintenance immunosuppression provided no clear benefit to renal allograft recipients with established chronic rejection. Larger prospective randomized studies are needed.     

Single-center randomized trial comparing tacrolimus (FK506) and cyclosporine in the prevention of acute myocardial rejection

BACKGROUND: To compare the efficacy and safety of tacrolimus and cyclosporine in heart transplantation, this single-center, prospective, randomized, open-label clinical trial was undertaken. METHODS: Seventy-three adult patients were randomly assigned at the time of transplantation to receive either tacrolimus (n=43) or cyclosporine (n=30) as the primary immunosuppressant. Ten of the 43 patients in the tacrolimus group received the drug intravenously in the perioperative period; all other patients received only oral tacrolimus. RESULTS: With a mean follow-up of 27 months, patient survival rates (tacrolimus 83%, cyclosporine 81%) were similar. Fewer patients experienced acute rejection in the tacrolimus group (79%) than in the cyclosporine group (100%), but the difference was not statistically significant. The number of infections and dialysis and insulin requirements were similar for the 2 treatment groups, but the proportion of patients requiring multidrug antihypertensive regimens was lower in the tacrolimus group (12.5% vs 50.0% at month 6; p=.025). The interpatient variance in pharmacokinetic parameters in a subset of 10 patients was much higher after the first oral dose of tacrolimus than at steady-state (eg, first-dose time at which maximal concentration is reached (t(max)): 3.5+/-2.5h, steady-state t(max): 2.0+/-0.7h), and patients treated with intravenous tacrolimus (n=13) rather than oral tacrolimus (n=30) reached target concentrations faster and with less interpatient variability (eg, at day 0: 9.72+/-10.9 ng/mL intravenously vs 3.31+/-8.1 orally). CONCLUSIONS: Tacrolimus was associated with similar efficacy and safety profiles compared with cyclosporine. The higher interpatient variance in absorption associated with oral tacrolimus during the first few days after transplantation would suggest that intravenous tacrolimus should be used during the perioperative period.     

Efficacy and safety of prophylactic cranial irradiation in patients with small cell lung cancer

In this review we examine the complex interactions between lipoprotein metabolism, immunosuppressive drug therapy, and inflammation and the potential benefits of lipid-lowering drug therapy after heart transplantation. The newer formulations of cyclosporine, Neoral (Novartis Pharmaceuticals; Basle, Switzerland), and other newer agents such as tacrolimus may have advantages in regard to lipid metabolism as compared with traditional triple-drug immunosuppression. Lipoprotein levels may influence both the toxicity and efficacy of cyclosporine. Dyslipidemia may adversely influence inflammation and rejection in the allograft. Two recent clinical trials have shown that lipid-lowering therapy with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor alone or in combination with low-density lipoprotein apheresis may confer significant benefits toward preventing transplant coronary artery disease.     

Micronuclear and macronuclear sequences of a Euplotes crassus gene encoding a putative nuclear protein kinase

Tacrolimus (FK506) is a new immunosuppressive agent that has recently been given to recipients of liver transplants. Multicentre studies conducted in the United States and Europe have reported that tacrolimus is superior to cyclosporine in preventing allograft rejection. The absorption of tacrolimus is independent of bile, and, therefore, therapeutic blood levels are usually achieved by taking oral preparations within 72 hours of liver transplantation. Compared with the use of cyclosporine, this regimen has resulted in shorter hospital stays and reduced costs. Tacrolimus does not cause hirsutism or gingival hyperplasia, which are common disfiguring complications of cyclosporine. Serious neurological side effects, lymphoproliferative disorders and hypertrophic cardiomyopathy have recently been reported in children taking high doses of tacrolimus. When lower doses of tacrolimus are used in primary immunosuppressive therapy, the incidence of neurological side effects and lymphoproliferative disorders of tacrolimus and cyclosporine have been reported to be similar. Hence, tacrolimus is a potent immunosuppressant that has many advantages over cyclosporine but must be used cautiously, since high doses have been associated with an increased incidence of lymphoproliferative disorders and cardiomyopathy.     

Adhesion molecules (E-selectin and ICAM-1) in pulmonary allograft rejection

Vascular endothelial cells act as antigen-presenting cells in the lung allograft and stimulate alloreactive host lymphocytes. Activated lymphocytes and cytokines can induce expression of leukocyte-endothelial adhesion molecules that facilitate invasion of the allograft by circulating leukocytes. To define the role of endothelial HLA class II antigen and adhesion molecule expression in lung allograft rejection, we prospectively analyzed endothelial expression of HLA class II, E-selectin, and intercellular adhesion molecule-1 (ICAM-1) antigens in 52 transbronchial biopsy specimens from 24 lung allograft recipients as compared to normal control subjects. Thirty-one of 52 specimens showed histologic rejection and 8 of 24 patients developed histologic obliterative bronchiolitis (OB) by the end of the study period. Increased expression of HLA class II antigen was seen in 32 of 52 (62%) lung allograft specimens, but increased expression did not correlate with acute rejection or OB. In contrast, E-selectin expression was seen in 30 of 52 (58%) biopsy specimens and was associated with acute rejection (p < 0.005) and with the development of OB (p < 0.05). Increased expression of ICAM-1 was seen in only 18 of 52 (35%) biopsy specimens and did not correlate with acute rejection or OB. These data suggest that E-selectin expression may be a tissue marker of acute and chronic lung rejection possibly by promoting leukocyte adhesion to the allograft endothelium. The high levels of endothelial HLA class II expression may reflect long-term antigenic stimulation of the allograft even in the absence of rejection.     

A new rat infection-heart transplant model: effect of infection on graft survival studies

Considerable progress has been made in survival rates of heart transplant recipients; however, infections continue to be a major cause of death after transplantation. Although infection itself appears to cause immunologic suppression in some nontransplantation studies, the lack of an infection-transplant animal model has limited further investigation of this observation. We evaluated the utility of a heterotopic rat infection heart-transplant model by studying the effect of infection and limited administration of two immunosuppressive agents, cyclosporine and FK506, on allograft rejection and survival. Lewis rats received ACI heart allografts, and intraperitoneal infection was induced by cecal ligation. Infection was confirmed by blood and ascitic fluid cultures. Results showed that graft survival was slightly, but significantly, higher (p < 0.05) in group II (transplantation with infection) when compared to the control group I (transplantation only). Histologic rejection scores were less (p < 0.05) in group II 6 days after transplantation. The second phase of the study compared the effect of infection after transplantation in rats given a 1-week course of cyclosporine or FK506, which were discontinued after the induction of infection. Although the cyclosporine group had prolonged survival when compared to the FK506 group (p < 0.05), the respective infection groups receiving immunosuppression revealed no significant difference in allograft survival or histologic rejection scores when compared to the control groups. In this preliminary study, infection without immunosuppression resulted in a slight, but statistically significant, increase in allograft survival and reduced acute cellular rejection. In those groups receiving immunosuppressive agents, no additive immunosuppressive effect was attributable to bacterial infection.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preventive effect of germinated barley foodstuff on diarrhea induced by water-soluble dietary fiber in rats

The two cases presented illustrate the diagnostic difficulties and recommend an approach to use in patients in whom features of acute renal allograft rejection and posttransplant lymphoproliferative disorder (PTLD) appear simultaneously in allograft biopsies. Both patients developed acute allograft rejection episodes in the early post-transplant period followed by severe immunosuppression (OKT-3) and active Epstein-Barr virus infection. In addition to early recognition of light microscopic features of PTLD, immunohistology and in situ hybridization for EBV complement the diagnostic work-up and provide clues to the prompt diagnosis of rapidly developing PTLD affecting the allograft even in the face of persisting rejection.