Pharmacokinetics and Toxicity of Tacrolimus Early After Heart and Lung Transplantation

Annually, about 8000 heart and lung transplantations are successfully performed worldwide. However, morbidity and mortality still pose a major concern. Renal failure in heart and lung transplant recipients is an essential adverse cause of morbidity and mortality, often originating in the early postoperative phase. At this time of clinical instability, the kidneys are exposed to numerous nephrotoxic stimuli. Among these, tacrolimus toxicity plays an important role, and its pharmacokinetics may be significantly altered in this critical phase by fluctuating drug absorption, changed protein metabolism, anemia and (multi‐) organ failure. Limited understanding of tacrolimus pharmacokinetics in these circumstances is hampering daily practice. Tacrolimus dose adjustments are generally based on whole blood trough levels, which widely vary early after transplantation. Moreover, whole blood trough levels are difficult to predict and are poorly related to the area under the concentration‐time curve. Even within the therapeutic range, toxicity may occur. These shortcomings of tacrolimus monitoring may not hold for the unbound tacrolimus plasma concentrations, which may better reflect tacrolimus toxicity. This review focuses on posttransplant tacrolimus pharmacokinetics, discusses relevant factors influencing the unbound tacrolimus concentrations and tacrolimus (nephro‐) toxicity in heart and lung transplantation patients.     

Distal Intestinal Obstruction Syndrome (DIOS) in Patients with Cystic Fibrosis After Lung Transplantation

Background  Cystic fibrosis (CF) is the commonest inherited life-threatening disease in Caucasians. With increased longevity, more patients with CF are developing gastrointestinal complications including the distal intestinal obstruction syndrome (DIOS), in which ileocecal obstruction is caused by viscid mucofeculent material. The optimal management of DIOS is uncertain. Methods  The medical records of all patients with CF who underwent lung transplantation at this institution during a 15-year period were reviewed. The definition of DIOS required the presence of both clinical and radiological features of ileocecal obstruction. Results  One hundred twenty-one patients with CF underwent lung transplantation during the study period. During a minimum 2-year follow-up, there were 17 episodes of DIOS in 13 (10.7%) patients. The development of DIOS was significantly associated with a past history of meconium ileus (odds ratio 20.7, 95% C.I. 5.09–83.9) or previous laparotomy (odds ratio 4.93, 95% C.I. 1.47–16.6). All six patients who developed DIOS during the transplantation admission had meconium ileus during infancy, and five had undergone pretransplant laparotomy for CF complications. First-line treatment for all patients was a combination of medication (laxatives, stool softeners, and bowel preparation formulas). This was successful in 14 of the 17 DIOS but needed to be given for up to 14 days. The other three patients required laparotomy with enterotomy and fecal disimpaction. This provided definitive resolution of DIOS except in one patient who presented late and died despite ileal decompression and ileostomy. Conclusions  DIOS occurred in approximately 10% of CF patients after lung transplantation. Patients with a history of meconium ileus or previous laparotomy are at high risk of developing DIOS. Patients with DIOS require early aggressive management with timely laparotomy with enterotomy and possible stoma formation when non-operative therapy is unsuccessful. Presented at the Forty-Eighth Annual Meeting of the Society for Surgery of the Alimentary Tract, Washington DC, May 19–23, 2007. Financial support: None     

Renal Histopathological Lesions After Lung Transplantation in Patients with Cystic Fibrosis

We have analyzed the evolution of renal status beyond the perioperative period in patients with cystic fibrosis (CF) undergoing lung transplantation and presented histological analysis of 15 patients biopsied for an episode of accelerated renal function loss (RFL).
Episodes of accelerated RFL after the perioperative period occurred in 32.5% of patients and significantly raised the risk of end-stage renal disease (ESRD) (p < 0.001). The histologic lesions associated with these episodes differed according to the time of onset. Early onset (10 cases) was associated with tubulointerstitial lesions in the form of oxalate nephropathy (50%) and/or a pigmented tubulopathy (80%). This latter was correlated with treatment with antiviral agents (p = 0.002) and aminoside and glycopeptide antibiotics (p = 0.03) administered in the month preceding biopsy. Lesions in late episodes of accelerated RFL (5 cases) were principally vascular: arteriosclerosis and arteriolosclerosis (p = 0.007, p = 0.00002), correlated with diabetic glomerulosclerosis or focal segmental glomerulosclerosis in the absence of prominent diabetic changes. Specific calcineurin-inhibitor nephrotoxicity was present in 93.3% of biopsies associated with thrombotic microangiopathy in 46.7% of cases.
The identification of specific etiologies of progressive kidney disease in patients with CF after lung transplantation should permit more effective post-transplant care of these patients.     

Survival After Lung Transplantation of Cystic Fibrosis Patients Infected with Burkholderia cepacia Complex

Within the Burkholderia cepacia complex (Bcc), B. cenocepacia portends increased mortality compared with other species. We investigated the impact of Bcc infection on mortality and re-infection following lung transplant (LT). Species designation for isolates from Bcc-infected patients was determined using 16S rDNA and recA gene analyses. Of 75 cystic fibrosis patients undergoing LT from September 1992 to August 2002, 59 had no Bcc and 16 had Bcc (including 7 B. cenocepacia ) isolated in the year before LT. Of the latter, 87.5% had Bcc recovered after transplantation, and all retained their pretransplant strains. Survival was 97%, 92%, 76% and 63% for noninfected patients; 89%, 89%, 67% and 56% for patients infected with Bcc species other than B. cenocepacia; and 71%, 29%, 29% and 29% for patients with B. cenocepacia (p = 0.014) at 1 month, 1 year, 3 years and 5 years, respectively. Patients infected with B. cenocepacia before transplant were six times more likely to die within 1 year of transplant than those infected with other Bcc species (p = 0.04) and eight times than noninfected patients (p < 0.00005). Following LT, infection with Bcc species other than B. cenocepacia does not significantly impact 5-year survival whereas infection with B. cenocepacia pretransplant is associated with decreased survival.     

Lung Transplantation in Cystic Fibrosis and the Impact of Extracorporeal Circulation

Introduction

Lung disease is the major cause of death among cystic fibrosis (CF) patients, affecting 80% of the population. The impact of extracorporeal circulation (ECC) during transplantation has not been fully clarified. This study aimed to evaluate the outcomes of lung transplantation for CF in a single center, and to assess the impact of ECC on survival.

Liver Transplantation for Cystic Fibrosis in Adults

Purpose To expand our knowledge on liver transplantation for cirrhosis associated with cystic fibrosis in adults. Methods Five patients who underwent a liver transplantation due to cystic fibrosis were reviewed. The outcome of the patients in terms of age, immunosuppression regimen, patient and graft survival, and pre- and post-transplant complications were investigated. Results Five adult liver transplant patients had cystic fibrosis (0.2%). These included 4 men and 1 woman with a mean age of 31 ± 10, ranging from 22 to 52 years old at the time of transplantation. All patients had lung problems. Four patients had exocrine and two had endocrine pancreatic insufficiency. Two are currently alive with a follow-up of 5.8 years and 4 months after transplantation, respectively. There were three deaths from pulmonary embolism at 4.5 years, myocardial infarction with cyclosporine nephrotoxicity at 10.7 years, and lymphoproliferative disorder at 5 months after transplantation. No deaths occurred from lung infection. Only one patient had postoperative pulmonary infectious complications, which were successfully treated with antibiotics and did not result in mortality. Conclusion Adult liver transplantation for end-stage liver disease associated with cystic fibrosis offers encouraging results with a rapid general improvement after surgery and it is now considered to be a safe and acceptable treatment for this disease population.     

Successful Lung Transplantation in an HIV- and HBV-Positive Patient with Cystic Fibrosis

Prior to the advent of highly active antiretroviral therapy (HAART), HIV-infected patients were usually not considered as transplant candidates because of the poor prognosis of their underlying disease and concerns regarding the potential detrimental effects of immunosuppression on viral load and immune status. However, with the significant HAART-associated improvements in morbidity and mortality, good short-term outcomes after liver and kidney transplantation for patients with HIV infection have been reported. Nevertheless, HIV infection is currently considered a contraindication to lung transplantation in most transplant centers worldwide. The results of a double lung transplant performed in an HIV and HBV co-infected patient with cystic fibrosis (CF) and end-stage respiratory failure (ESRF) are presented after a 2-year follow-up. Approval of and recommendations for the management of this patient were obtained from the Italian National Center for Transplantation as an extension of the ongoing Italian protocol for liver and kidney transplantation in HIV-infected individuals. The operation was successful and the patient recovered rapidly after surgery. A cautious infectious and immunosuppressive management allowed so far the avoidance of major infectious complications and rejection. To the best of our knowledge, this is the first report of lung transplantation in an HIV and HBV co-infected patient.     

Urgency-Code Lung Transplantation for Cystic Fibrosis: Experience and Results

Lung transplantation (LT) under urgency-code mechanical ventilation (UCMV) has been identified in the International Society for Heart and Lung Transplantation (ISHLT) Registry as a negative prognostic factor increasing the likelihood of mortality. The objective of this study was to review our experience of UCLT for with cystic fibrosis (CF) patients compared with elective LT (ELT). From October 1993 to October 2007, we performed 259 consecutive LTs in 250 patients, of whom 78 (31.20%) had CF. Our study group comprised CF patients who received UCLT (n = 23). The type of LT in the UCLT group was as follows: bipulmonary (18), left unipulmonary (2), and bilobar transplantation from cadavers (3). The UCLT group more often required cardiopulmonary bypass (CB) (P = .025), pulmonary tailoring (P = .030), and longer periods of pulmonary ischemia (P = .066) than the ELT group. We noticed a greater number of cases of pneumonia during the first postoperative month in the UCLT group. However, incidence of surgical complications, early and perioperative mortality, and episodes of acute and chronic rejection (bronchiolitis obliterans syndrome) did not differ between the groups. Survival rates at 1, 3, 5, and 10 years were 73.66%, 63.74%, 42.49%, and 42.49%, respectively, in the UCLT group (mean, 1927 [SE = 366] days) and 75.95%, 71.32%, 63.37%, and 63.37% in the ELT group (mean, 2946 [SE = 281] days; P = .3417). In our experience, UCLT in patients with CF is fully justified. Careful selection of such cases permits acceptable long-term survival rates to be achieved with no increase in early or perioperative mortality.     

Lung Transplantation for Cystic Fibrosis and Non-cystic Fibrosis Bronchiectasis: A Single-Center Experience

ObjectivesLung transplantation is a well-established treatment for selected patients with advanced cystic fibrosis (CF)- and non-cystic fibrosis (non-CF)--related bronchiectasis. Because the number of lung transplants performed for patients with non-CF bronchiectasis is much smaller than for patients with CF, little data is available regarding patient selection, choice of procedure, and outcomes.MethodsBetween November 1997 and December 2013, 42 patients with CF and 33 patients with non-CF bronchiectasis underwent lung transplantation at the Rabin Medical Center, Israel. We analyzed and compared pretransplant evaluation data and short- and long-term results in both groups.ResultsMedian survival for the CF group in our study was 8.4 years, compared with 7.1 years for the non-CF group (P = .098), similarly to that reported by the International Society for Heart and Lung Transplantation Registry data. The main survival difference between groups was in the early postoperative period. Both groups achieved similar peak forced expiratory volume in 1 second values and had stable lung function at the 3-year follow-up. Biopsy-proven rates of acute cellular rejection were low for both groups. Rates of chronic lung allograft dysfunction development did not differ between CF and non-CF recipients.ConclusionOur institutional experience confirms that lung transplantation is feasible for non-CF bronchiectasis, and results are comparable to our CF cohort. The increased early mortality in this study occurred from 1999 to 2008 and was probably related to surgical techniques used at the time. Overall, 3-year and 5-year survival were comparable with the International Society for Heart and Lung Transplantation Registry data. Non-CF bronchiectasis patients achieved and maintained satisfactory lung function.     

Pharmacokinetics for Once- Versus Twice-Daily Tacrolimus Formulations in De Novo Kidney Transplantation: A Randomized, Open-Label Trial

Tacrolimus, a cornerstone immunosuppressant, is widely available as a twice-daily formulation (Tacrolimus BID). A once-daily prolonged-release formulation (Tacrolimus QD) has been developed that may improve adherence and impart long-lasting graft protection. This study compared the pharmacokinetics (PK) of tacrolimus in de novo kidney transplant patients treated with Tacrolimus QD or Tacrolimus BID. A 6-week, open-label, randomized comparative study was conducted in centers in Europe and Australia. Eligible patients received Tacrolimus QD or Tacrolimus BID. PK profiles were obtained following the first tacrolimus dose (day 1), and twice under steady-state conditions. As secondary objectives, efficacy and safety parameters were also evaluated. Sixty-six patients completed all PK profiles (34 Tacrolimus QD, 32 Tacrolimus BID). Mean AUC_0–24 of tacrolimus on day 1 was approximately 30% lower for Tacrolimus QD than Tacrolimus BID (232 and 361 ng.h/mL, respectively), but was comparable by day 4. There was a good correlation and a similar relationship between AUC_0–24 and C_min for both formulations. Efficacy and safety data were also comparable over the 6-week period. Tacrolimus QD can be administered once daily in the morning on the basis of the same systemic exposure and therapeutic drug monitoring concept as Tacrolimus BID.     

Combined Double Lung–Liver Transplantation for Cystic Fibrosis Without Cardio-Pulmonary By-Pass

Sequential bilateral single lung-liver transplantation (SBSL-LTx) is a therapeutic option for patients with end stage lung and liver disease (ESLLD) due to cystic fibrosis (CF). A few cases have been reported, all of them were performed with the use of cardio-pulmonary by-pass (CPB). We performed SBSL-LTx in three young men affected by CF. All the recipients had respiratory failure and portal hypertension with hypersplenism. Along with lung transplants, two patients received a whole liver graft and one an extended right graft from an in situ split liver. During transplantation neither CPB nor veno-venous by-pass (VVB) were employed. Immunosuppression was based on basiliximab, tacrolimus, steroids and azathioprine. The three recipients are alive with a median follow-up of 670 days (range 244-1,533). Combined SBSL-LTx is a complex but effective procedure for the treatment of ESLLD due to CF, not necessarily requiring the use of CPB or VVB.     

Tacrolimus Exposure and Evolution of Renal Allograft Histology in the First Year After Transplantation

Tacrolimus has a narrow therapeutic window and is characterized by a large inter-individual variability in bioavailability. The impact of tacrolimus exposure on subclinical evolution of graft histology has not been studied in renal recipients. This analysis included 239 protocol biopsies (obtained at implantation, 3 and 12 months) of 120 consecutive kidney recipients treated with tacrolimus, mycophenolate mofetil (MMF) and corticosteroids. Biopsies were scored according to the Banff 2001 criteria and a chronicity score was calculated. Prospective pharmacokinetic data were included in the analysis (5544 tacrolimus predose blood concentrations and tacrolimus AUC(0-12) at 3 and 12 months). Higher donor age and higher number of human leukocyte antigen-DR (HLA-DR) mismatches were independent predictors of subclinical acute rejection at 3 months, present in 8.7% of patients. The number of HLA-DR mismatches was independently associated with biopsy-proven clinical acute rejection. Biopsy-proven acute rejection episodes and low mean tacrolimus exposure were independently associated with higher increase in chronicity scores between 3 and 12 months after transplantation. This observational study suggests that rejection phenomena and immune-mediated mechanisms remain important in the early progression of chronic allograft pathology. Tacrolimus doses or systemic exposure were not associated with lesions of calcineurin inhibitor nephrotoxicity, suggesting that other factors determine susceptibility to tacrolimus nephrotoxicity.     

Kidney Disease After Heart and Lung Transplantation

Kidney disease is a commonly recognized complication of heart and lung transplantation and is associated with increased morbidity and mortality. While the spectrum of kidney disease in this population is wide-ranging, studies indicate that between 3% and 10% of these patients will ultimately develop end-stage renal disease (ESRD). This review examines the risk factors for both acute and chronic kidney injury, with a particular emphasis on the role of calcineurin inhibitor-mediated nephrotoxicity in both these settings. Against the background of current National Kidney Foundation Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines, we have further considered and recommended appropriate strategies for long-term management of kidney disease-related manifestations in heart and lung transplant recipients. Specific aspects addressed include retarding progressive renal injury and minimizing nephrotoxicity, as well as treatment of hypertension, hyperlipidemia and anemia. Finally, for patients in this population with advanced kidney disease, renal replacement therapy options are discussed. Based on the impact of chronic kidney disease on outcomes in both heart and lung recipients, we advocate early referral to a nephrologist for patients displaying evidence of significant renal dysfunction.