Infectious complications in geriatric renal transplant patients: comparison of two immunosuppressive protocols

Immunosuppression Regimen Use and Outcomes in Older and Younger Adult Kidney Transplant Recipients: A National Registry Analysis

BACKGROUND

Although the population of older transplant recipients has increased dramatically, there are limited data describing the impact of immunosuppression regimen choice on outcomes in this recipient group.

METHODS

National data for US Medicare-insured adult kidney recipients (N = 67 362; 2005-2016) were examined to determine early immunosuppression regimen and associations with acute rejection, death-censored graft failure, and mortality using multivariable regression analysis in younger (18-64 y) and older (>65 y) adults.

RESULTS

The use of antithymocyte globulin (TMG) or alemtuzumab (ALEM) induction with triple maintenance immunosuppression (reference) was less common in older compared with younger (36.9% versus 47.0%) recipients, as was TMG/ALEM + steroid avoidance (19.2% versus 20.1%) and mammalian target of rapamycin inhibitor (mTORi)-based (6.7% versus 7.7%) treatments. Conversely, older patients were more likely to receive interleukin (IL)-2-receptor antibody (IL2rAb) + triple maintenance (21.1% versus 14.7%), IL2rAb + steroid avoidance (4.1% versus 1.8%), and cyclosporine-based (8.3% versus 6.6%) immunosuppression. Compared with older recipients treated with TMG/ALEM + triple maintenance (reference regimen), those managed with TMG/ALEM + steroid avoidance (adjusted odds ratio [aOR], 0.440.520.61) and IL2rAb + steroid avoidance (aOR, 0.390.550.79) had lower risk of acute rejection. Older patients experienced more death-censored graft failure when managed with Tac + antimetabolite avoidance (adjusted hazard [aHR], 1.411.782.25), mTORi-based (aHR, 1.702.142.71), and cyclosporine-based (aHR, 1.411.782.25) regimens, versus the reference regimen. mTORi-based and cyclosporine-based regimens were associated with increased mortality in both older and younger patients.

CONCLUSIONS

Lower-intensity immunosuppression regimens (eg, steroid-sparing) appear beneficial for older kidney transplant recipients, while mTORi and cyclosporine-based maintenance immunosuppression are associated with higher risk of adverse outcomes.

Incisional Hernia Repairs after Abdominal Organ Transplantation

Incisional hernias occur after abdominal organ transplantation with rates of 1.6 per cent to 18 per cent in kidney transplants (KTs) and 1.7 to 32.4 per cent in liver transplants (LTs). We hypothesized a difference in KTand LToutcomes in patients with and without repair of incisional hernias. We conducted a retrospective cohort study of abdominal transplants from 2012 through 2016. The difference across compared groups for continuous variables was assessed using the independent sample t test, and for binary variables, using the chi-squared test. A total of 1518 transplants were performed, including 1138 KTs and 380 LTs. There were 83 KT incisional hernias (67 repaired) and 59 LT incisional hernias (48 repaired). There was no difference between groups with regard to smoking, diabetes, age, BMI, days on dialysis (KTs), pretransplant Model for End-Stage Liver Disease (MELD) (LTs), cold ischemic time, graft survival, or recurrence rate by repair method. In the LT population, there was a statistically significant difference in days on the waitlist ( P = 0.02), drain placement ( P = 0.04), and cytomegalovirus (CMV) mismatch ( P = 0.02). Patient survival was also statistically significant for KTs ( P = 0.04) and LTs ( P = 0.01). KT and LT patients who have their incisional hernias repaired have better overall survival, regardless of the repair technique.

Immunosuppressive Compounds Affect the Fungal Growth and Viability of Defined Aspergillus Species

Immunosuppressive drugs are administered to a number of patients; e.g., to allogeneic hematopoietic stem cell transplant recipients. Immunosuppressive drugs impair the immune system and thus increase the risk of invasive fungal disease, but may exhibit antifungal activity at the same time. We investigated the impact of various concentrations of three commonly used immunosuppressive compounds—cyclosporin A (CsA), methylprednisolone (mPRED), and mycophenolic acid (MPA)—on the growth and viability of five clinically important Aspergillus species. Methods included disc diffusion, optical density of mycelium, and viability assays such as XTT. MPA and CsA had a species-specific and dose-dependent inhibitory effect on the growth of all Aspergillus spp. tested, although growth inhibition by MPA was highest in A. niger,A. flavus and A. brasiliensis. Both agents exhibited species-specific hyphal damage, which was higher when the immunosuppressants were added to growing conidia than to mycelium. In contrast, mPRED increased the growth of A. niger, but had no major impact on the growth and viability of any of the other Aspergillus species tested. Our findings may help to better understand the interaction of drugs with Aspergillus species and ultimately may have an impact on individualizing immunosuppressive therapy.

Clinical outcomes of polyvalent immunoglobulin use in solid organ transplant recipients: A systematic review and meta-analysis - Part II: Non-kidney transplant

Immunoglobulin (IG) is commonly used to desensitize and treat antibody-mediated rejection in solid organ transplant (SOT) recipients. The impact of IG on other outcomes such as infection, all-cause mortality, graft rejection, and graft loss is not clear. We conducted a similar systematic review and meta-analysis to our previously reported Part I excluding kidney transplant. A comprehensive literature review found 16 studies involving the following organ types: heart (6), lung (4), liver (4), and multiple organs (2). Meta-analysis could only be performed on mortality outcome in heart and lung studies due to inadequate data on other outcomes. There was a significant reduction in mortality (OR 0.34 [0.17-0.69]; 4 studies, n = 455) in heart transplant with hypogammaglobulinemia receiving IVIG vs no IVIG. Mortality in lung transplant recipients with hypogammaglobulinemia receiving IVIG was comparable to those of no hypogammaglobulinemia (OR 1.05 [0.49, 2.26]; 2 studies, n = 887). In summary, IVIG targeted prophylaxis may decrease mortality in heart transplant recipients as compared to those with hypogammaglobulinemia not receiving IVIG, or improve mortality to the equivalent level with those without hypogammaglobulinemia in lung transplant recipients, but there is a lack of data to support physicians in making decisions around using immunoglobulins in all SOT recipients for infection prophylaxis.

Clinical outcomes of polyvalent immunoglobulin use in solid organ transplant recipients: A systematic review and meta-analysis

Polyvalent immunoglobulin is commonly used for desensitization and treatment of antibody-mediated rejection in kidney transplantation but its impact on other outcomes is not known. This systematic review investigated the impact of immunoglobulin prophylaxis on infection, rejection, graft loss, and death following kidney transplantation. A comprehensive literature search located 18 studies (n = 8 randomized controlled trials). None examined the effect of immunoglobulin prophylaxis in transplant recipients with hypogammaglobulinemia. Quality of included studies was variable with high to very high risk of bias. In the randomized trials, immunoglobulin use did not reduce cytomegalovirus infection (OR 0.68 [0.39, 1.21]; 6 studies, n = 295), rejection (OR 0.96 [0.50, 1.82]; 4 studies, n = 187), or graft loss (OR 1.03 [0.46, 2.30]; 6 studies, n = 265). In non-randomized studies, immunoglobulin did not reduce cytomegalovirus infection (OR 0.63 [0.20, 1.94]; 6 studies, n = 361) or death (OR 1.32 [0.05, 38.79]; 3 studies, n = 222) but reduce rejection (OR 0.47 [0.24, 0.94]; 4 studies, n = 268) and graft loss (OR 0.15 [0.05, 0.43]; 2 studies, n = 118). Data were scarce and sample size of current evidence was small. Adequately powered randomized trials are needed to determine if immunoglobulin is an effective intervention to reduce infection, rejection, graft loss, or death following kidney transplantation with and without hypogammaglobulinemia.

Chronic dialysis in patients with end-stage renal disease: Relevance to kidney xenotransplantation

Renal allotransplantation clearly offers better survival and quality of life for end-stage renal disease (ESRD) patients than chronic dialysis. The median waiting time for a deceased donor kidney in a suitable ESRD patient is 3.9 years. The initial candidates for pig kidney xenotransplantation will be those with ESRD unlikely to receive an allograft within a reasonable period of time. It is thus reasonable to ascertain whether clinical trials of xenotransplantation might likewise offer superior outcomes. Chronic dialysis in patients with ESRD is associated with poor quality of life, significant morbidity, and relatively high mortality, with only 56% surviving 3 years and 42% at 5 years. However, a significant number of these patients, because of comorbidities, frailty, etc, would not be considered for renal allotransplantation and likely not for xenotransplantation. As genetically engineered pig kidneys have satisfactorily supported life in immunosuppressed nonhuman primates for many months or even more than a year, consideration in carefully selected patients could be given to pig kidney xenotransplantation. We suggest that, in order to give a patient the best possible outcome, the pig kidney could be transplanted pre-emptively (before dialysis is initiated). If it fails at any stage, the patient would then begin chronic dialysis and continue to await an allograft. The present (limited) evidence is that failure of a pig graft would not be detrimental to a subsequent allograft.

Synergistic and antagonistic effects of immunomodulatory drugs on the action of antifungals against Candida glabrata and Saccharomyces cerevisiae

Candidemia and other forms of invasive fungal infections caused by Candida glabrata and to a lesser extent Saccharomyces cerevisiae are a serious health problem, especially if their steadily rising resistance to the limited range of antifungal drugs is taken into consideration. Various drug combinations are an attractive solution to the resistance problem, and some drug combinations are already common in the clinical environment due to the nature of diseases or therapies. We tested a few of the common antifungal-immunomodulatory drug combinations and evaluated their effect on selected strains of C. glabrata and S. cerevisiae. The combinations were performed using the checkerboard microdilution assay and interpreted using the Loewe additivity model and a model based on the Bliss independence criterion. A synergistic interaction was confirmed between calcineurin inhibitors (Fk506 and cyclosporine A) and antifungals (fluconazole, itraconazole, and amphotericin B). A new antagonistic interaction between mycophenolic acid (MPA) and azole antifungals was discovered in non-resistant strains. A possible mechanism that explains this is induction of the Cdr1 efflux pump by MPA in C. glabrata ATCC 2001. The Pdr1 regulatory cascade plays a role in overall resistance to fluconazole, but it is not essential for the antagonistic interaction. This was confirmed by the Cgpdr1Δ mutant still displaying the antagonistic interaction between the drugs, although at lower concentrations of fluconazole. This antagonism calls into question the use of simultaneous therapy with MPA and azoles in the clinical environment.

[Focusing on kidney transplantation in the elderly]

Due to the increase in life expectancy and the ageing of end-stage renal disease patients, the number of patients older than 65 years receiving a kidney transplant has been continuously growing over the last fifteen years. The benefits of renal transplantation compared to dialysis in terms of survival and quality of life have been shown in selected recipients over 65, or 70 years. However, the age remains the main limiting factor for the access to the waiting list, and the reluctance of the clinicians can be explained by the multiple comorbidities of these candidates, their limited life expectancy or the shortage of grafts. The challenge is to select the candidates who can benefit from renal transplantation, thanks to rigorous cardiovascular and neoplastic evaluation before enrolment and by taking into account the specific characteristics of elderly patients. The living donor appears to be the ideal option for elderly recipients, the alternative being the extended criteria donor, allowing waiting times to be limited. The choice of immunosuppressive therapy is also crucial in these patients at high risk of infectious and cardiovascular complications in whom the occurrence of acute rejection can have severe consequences. There are currently no specific recommendations for immunosuppression in elderly recipients, and we would need large-scale randomized studies to improve the prognosis of renal transplantation in this population.

Association Between Delayed Graft Function and Incisional Hernia after Renal Transplant

OBJECTIVES

Incisional hernias can occur after any abdominal operation, including after renal transplant. Several risk factors have been identified in nonimmunosuppressed surgical patients. We aimed to identify whether specific risk factors correlated with the development of incisional hernias after renal transplant. The existence of associations between these risk factors and postoperative complications was also reviewed.

MATERIALS AND METHODS

We reviewed 969 kidney transplants performed between February 2000 and January 2011. Thirty-nine kidney transplant recipients who were treated with rapamycin were excluded. The following potential risk factors were evaluated: recipient age, sex, body mass index at transplant, delayed graft function, diabetes, albumin, postoperative platelet count, drain placement, donor body mass index, donor type, warm ischemic time, and cold ischemic time. We performed univariate and multivariate logistic regression tests.

RESULTS

In our patient group, a total of 52 (5.4%) transplants were complicated by incisional hernia. On univariate analysis, we found that delayed graft function (P = .001) and infection (P < .001) were statistically significant predictors for development of incisional hernia. Multivariate analyses revealed that delayed graft function and length of stay remained statistically significant predictors.

CONCLUSIONS

Delayed graft function and length of stay are significant predictors of incisional hernia after kidney transplant.

Immunosuppression in the elderly renal allograft recipient: a systematic review

BACKGROUND

The Elderly are the fastest growing part of kidney transplant recipients. The best immunosuppressive strategy is unknown.

METHODS

We performed a systematic search of randomized controlled trials and observational studies focused on safety and efficacy of different immunosuppression strategies in elderly kidney recipients. Data extraction and risk of bias evaluation were systematically performed.

RESULTS

Ten studies were included: 2 randomized clinical trials and 8 observational. A marginal benefit was found for early renal function with delayed tacrolimus or complete tacrolimus avoidance using mycophenolate mofetil (MMF). Observational cohort studies looked at different antibody induction strategies, calcineurin-inhibitors based maintenance immunosuppression, calcineurin-inhibitor-free sirolimus-based therapy and use of MMF versus azathioprine. Treatment with interleukin-2 receptor antibody induction, calcineurin-inhibitor minimization with MMF and steroid minimization is advisable in the low immunologic risk elderly recipient, considering the increased risk of toxicities, infection and malignancies. In the high immunologic risk elderly recipient, taking into account the morbid consequences of acute rejection in the elderly, observational studies support antibody induction with depletive antibodies, calcineurin-inhibitor, MMF and steroids; calcineurin-inhibitor-minimization is not recommended.

CONCLUSIONS

There is very limited evidence for the benefits and harms of different immunosuppression strategies in the elderly. Most of the published literature are observational studies, and randomized controlled trials are urgently needed.

Clinical outcomes of immunoglobulin use in solid organ transplant recipients: protocol for a systematic review and meta-analysis

BACKGROUND

Transplantation improves survival and the quality of life of patients with end-stage organ failure. Infection, due to surgical issues, host factors such as diabetes, immunosuppression, and hypogammaglobulinemia, is a major post-transplant complication. Clinical outcomes of prophylaxis or treatment of hypogammaglobulinemia in solid organ transplant recipients are not well established and are in need of further study.

METHODS/DESIGN

We will conduct a systematic review of studies investigating clinically relevant outcomes of immunoglobulin use either as prophylaxis or treatment of hypogammaglobulinemia after solid organ transplantation. Both randomized and non-randomized studies (excluding case reports and case series of less than 20 subjects) will be included. Outcomes of interest will include the overall rate of infection, hospital admission, hospital length of stay, intensive care unit admission, 1-year all-cause mortality, incidence of acute organ rejection, allograft survival within 1 year, and adverse events. We will search MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, Transplant library, and the International Clinical Trials Registry Platform for randomized and non-randomized studies on adult solid organ transplant patients who received prophylactic immunoglobulin or immunoglobulin treatment. Two reviewers will conduct all screening and data collection independently. We will assess study level of risk of bias using the Cochrane Risk of Bias Assessment Tool for randomized controlled trials and for non-randomized studies. If meta-analysis of outcome data is deemed appropriate, we will use random effects models to combine data for continuous and dichotomous measures.

DISCUSSION

The results of this systematic review may inform guideline development for measuring immunoglobulin level and use of immunoglobulin in solid organ transplant patients and highlight areas for further research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015017620.

Immunosenescence and organ transplantation

Increasing numbers of elderly transplant recipients and a growing demand for organs from older donors impose pressing challenges on transplantation medicine. Continuous and complex modifications of the immune system in parallel to aging have a major impact on transplant outcome and organ quality. Both, altered alloimmune responses and increased immunogenicity of organs present risk factors for inferior patient and graft survival. Moreover, a growing body of knowledge on age-dependent modifications of allorecognition and alloimmune responses may require age-adapted immunosuppression and organ allocation. Here, we summarize relevant aspects of immunosenescence and their possible clinical impact on organ transplantation.

Effect of maintenance immunosuppressive drugs on virus pathobiology: evidence and potential mechanisms

Recent evidence suggesting a potential anti-CMV effect of mTORis is of great interest to the transplant community. However, the concept of an immunosuppressant with antiviral properties is not new, with many accounts of the antiviral properties of several agents over the years. Despite these reports, to date, there has been little effort to collate the evidence into a fuller picture. This manuscript was developed to gather the evidence of antiviral activity of the agents that comprise a typical immunosuppressive regimen against viruses that commonly reactivate following transplant (HHV1 and 2, VZV, EBV, CMV and HHV6, 7, and 8, HCV, HBV, BKV, HIV, HPV, and parvovirus). Appropriate immunosuppressive regimens posttransplant that avoid acute rejection while reducing risk of viral reactivation are also reviewed. The existing literature was disparate in nature, although indicating a possible stimulatory effect of tacrolimus on BKV, potentiation of viral reactivation by steroids, and a potential advantage of mammalian target of rapamycin (mTOR) inhibition in several viral infections, including BKV, HPV, and several herpesviruses.

Pityriasis versicolor on penile shaft in a renal transplant recipient

Pityriasis versicolor is a superficial infection of the stratum corneum, which is caused by the Malassezia species. Tge Malassezia species consist of 12 subspecies, including M. furfur, M. pachydermatis, M. symphodialis and M. globasa. The Malassezia species are classified as a normal flora, particularly in the sebum rich areas of the skin, and they convert from saprophytic yeast to parasitic mycelial morpholgic form to cause clinical disease. But majorities of their distributions are in the upper back, the neck, the thighs, and the forearm, and not in the penis. It is well known that the renal transplant patients, who take immunosuppressive agents, have impairment in the protective cell mediated immunity. Thus, they are more susceptible to infectious diseases, such as a fungal infection. Therefore, clinical manifestations show higher incidence of disease, but they mostly occur in an expected distribution. We here report a case of pityriasis versicolor in a renal transplant recipient on penile shaft, which is an unusual area.

Incidence, risk factors, and outcomes associated with cytomegalovirus disease in small bowel transplant recipients

Despite improved prophylaxis, monitoring, and more efficient immunosuppression, CMV infection remains a common opportunistic infection in transplant recipients. We assessed the incidence of CMV disease in pediatric SBT recipients, the timing of CMV disease after transplantation, and its impact on patient outcome. The medical records of 98 SBT recipients were reviewed. We performed descriptive analysis, regression analysis, and Kaplan-Meier curves to determine the time-to-event after transplantation. Fifty-three percent patients were male and 47% female, with a mean age of 38.3 months. Thirty-five percent of patients received prophylactic VGC, 55% GCV, 10% a combination of GCV/VGC, and 99% CMV immunoglobulins. A total of 24.5% recipients were CMV D+/R- (CMV serostatus donor positive/recipient negative). Seven (c. 7%) patients developed CMV disease. CMV disease was associated with 2.5 times (0.52-12.1; p = 0.25) higher rate of CMV mismatch and 11.1 times (1.3-95.9; p = 0.03) higher risk of death. CMV prophylaxis increased time-to-death (p = 0.074). Time-to-CMV disease was shorter in patients with enteritis (p < 0.0001), and CMV disease was associated with shorter time-to-death after transplantation (p = 0.001). CMV disease in SBT recipients was associated with an 11-fold mortality increase and a fourfold faster time-to-death. Time-to-death was significantly shorter with CMV enteritis.

Prophylaxis of cytomegalovirus disease in mismatched patients after heart transplantation using combined antiviral and immunoglobulin therapy

BACKGROUND

Cytomegalovirus (CMV) is a common cause of infection and morbidity after heart transplantation. Seronegative recipients (R-) of seropositive donor hearts (D+) are at high risk for CMV disease. We compared three different CMV prophylaxis regimens using combined antiviral and immunoglobulin therapy.

METHODS

In 99 patients who survived more than 30 days after heart transplant, all received induction with antilymphocytic therapy and triple-drug therapy. In group A, D+R- patients received one dose of intravenous immunoglobulin (IVIG) followed by one dose of CMV-specific immunoglobulin (CMV-IVIG), and intravenous ganciclovir (GCV) for 4 weeks followed by 11 months of oral acyclovir (ACV). In group B, D+R- patients received one dose IVIG followed by five doses of CMV-IVIG and intravenous GCV for 14 weeks followed by 9 months of oral ACV. In group C, D+R- patients were treated with the same regimen as for group B, except oral ACV was replaced with oral GCV.

RESULTS

The actuarial freedom from CMV disease for D+R- patients at 1 month, 1 year, and 2 years after transplantation in group A was 100%, 25% ± 15%, and 25% ± 15%, respectively; group B was 100%, 67% ± 27%, and 67% ± 27%; group C was 100%, 83% ± 15%, and 83% ± 15% (P < .01, groups B and C vs group A). By comparison, the actuarial freedom from CMV disease for seropositive recipients (D-R+ or D+R+) at 1 month, 1 year, and 2 years in group A was 100%, 87% ± 7%, and 82% ± 8%, respectively; group B was 100%, 88% ± 8%, and 75% ± 11%; group C was 100%, 72% ± 9%, and 72% ± 9% (P = NS among groups). Rejection rates did not differ among the three groups.

CONCLUSIONS

A longer course of intravenous GCV with multiple doses of CMV-IVIG was a more effective prophylaxis regimen against CMV disease for the high-risk group of seronegative recipients of seropositive donor hearts.

Kidney transplantation in the elderly

There is an increase in the older incident end-stage renal disease population that is associated with an increasing prevalence of end-stage renal disease in the United States. This trend is paralleled by an increasing rate of kidney transplantation in the elderly. Although patient survival is lower in older versus younger kidney recipients, the elderly benefit from a reduction in mortality rate and improved quality of life with transplantation compared with dialysis. Immunologic, physiologic, and psychosocial factors influence transplant outcomes and should be recognized in the care of the elderly transplant patient. In this review, we discuss transplantation in the elderly patient, particularly the topics of access to transplantation, patient and graft survival, the impact of donor quality on transplant outcomes, immunology and immunosuppression of aging, and ethical considerations in the development of an equitable organ allocation scheme.

Incidence and clinical predictors of primary opportunistic deep cutaneous mycoses in solid organ transplant recipients: a multicenter cohort study

BACKGROUND

Primary opportunistic deep cutaneous fungal infections may cause significant morbidity and mortality in solid organ transplant recipients (OTR), but no data exist about their incidence, timing, and clinical predictors in a long-term follow-up.

PATIENTS AND METHODS

A series of 3293 consecutive OTR including 1991 kidney, 929 heart, and 373 liver transplant recipients were enrolled. Patients were regularly followed up since time at transplantation (mean 5.5 yr +/-5.9 SD) and primary opportunistic fungal infections registered. Persons-year at risk (PYs), incidence rates (IR), incidence rate ratios (IRR), and 95% confidence intervals were computed.

RESULTS

Twenty-two cases of deep cutaneous mycoses were detected, (IR 1.2 cases per 1000 PYs) after a mean follow-up time since transplantation of 2.5 yr +/- 2.0 SD (median 1.8 yr). Six patients had subsequent systemic involvement and three patients died of systemic dissemination. A higher risk for mycoses was observed in the first two yr after transplantation, (IRR 35.9, p < 0.0001), in renal transplant recipients (IRR 5.1 p = 0.030), and in patients transplanted after the age of 50 (IRR 11.5 p = 0.020).

CONCLUSIONS

Primary deep cutaneous opportunistic mycoses in OTR occur mainly in the first two yr after transplantation, in renal transplant recipients, and in older patients.

Mycophenolate mofetil: effects on cellular immune subsets, infectious complications, and antimicrobial activity

Mycophenolate mofetil (MMF) is one of the most frequently used immunosuppressive drugs in solid organ transplant recipients. MMF is an inhibitor of inosine-5'-monophosphate, and is able to preferentially inhibit B-cell and T-cell function. The immunosuppressive abilities of MMF have made it one of the most successful anti-rejection drugs in transplant patients, but patients also appear to have increased susceptibility to infections, specifically cytomegalovirus and BK virus. Despite its association with an increased risk of infection, MMF has also exhibited antimicrobial activity against pathogens including hepatitis C, Pneumocystis jirovecii, and human immunodeficiency virus. A thorough understanding of the functions of MMF on the immune system and interaction with infectious pathogens could be helpful in implementing preventative strategies against opportunistic infections in transplant patients.

Renal transplantation in the elderly

Elderly patients are increasingly being considered for kidney transplantation due to a global explosion of the aging population with end-stage renal disease (ESRD). However, mounting scarcity of available organs for transplant has led to a wider disparity between organ supply and demand. Consequently, the criteria for accepting kidneys for transplantation have been extended in an attempt to allow the use of organs from elderly donors or those with significant co-morbidities, so-called "expanded criteria donor" (ECD) kidneys. Excellent outcomes have been achieved from ECD kidneys with appropriate donor and recipient profiling and selection. With increasing recovery efforts directed at older donors, the concept of age-matching is becoming more accepted as a method of optimizing utilization of organs in elderly donors and recipients. Utilization of pulsatile perfusion has further improved ECD outcomes and helped the decision-making process for the UNOS (United Network for Organ Sharing) offer. However, age-related immune dysfunction and associated co-morbidities make the elderly transplant recipients ever more susceptible to complications associated with immunosuppressive agents. Consequently, the elderly population is at a higher risk to develop infections and malignancy in the post-transplant period notwithstanding improved transplant outcomes. Appropriate immunosuppressive agents and dosages should be selected to minimize adverse events while reducing the risk of acute rejections and maximizing patient and renal allograft survival.

Immunosuppression of the elderly kidney transplant recipient

The growing number of elderly patients with end-stage kidney disease awaiting transplantation has resulted in a corresponding rise in the number of elderly transplant recipients. In this paper, we review existing literature on age-related changes, transplant outcomes, and complications in the elderly in an attempt to propose a tailored approach to immunosuppression management in this group of patients. Despite the fact that the benefit of transplantation in the elderly is well established, clinical trials evaluating the safety and efficacy of immunosuppression regimens are lacking. Until such data exists, immunosuppression of the elderly transplant recipient should be based on the traditional principles which guide all transplant protocols and consideration of factors that are unique to the elderly. There are limited data regarding age-related changes in immune function and metabolism of immunosuppression agents in this population. Results of registry data analyses suggest that the risk of acute rejection decreases with age; however, the impact of acute rejection on long-term allograft function is greater in this population. There is also an increased risk of infection and adverse events posttransplantation among these patients. Elderly patients are more likely to receive organs from extended criteria donors and the impact of donor factors on transplant outcomes must therefore be considered. Taking these factors into consideration, we propose an approach to immunosuppression in the elderly based on individual risk stratification of treatment failure and the potential for adverse events.

Early mortality rates in older kidney recipients with comorbid risk factors

BACKGROUND

There are over 60,000 candidates on the deceased donor kidney wait-list and the percentage of candidates over age 50 years continues to grow each year. National data have not previously been used to evaluate the association of comorbidities with mortality in older patients.

METHODS

A multivariate analysis of 30,262 deceased donor primary kidney recipients aged 18-59 years and 8,895 aged >or=60 years evaluated the association of six recipient comorbidities on 90- and 365-day patient mortality rates. The additional effects of expanded criteria donors (ECD) and development of delayed graft function (DGF) were also evaluated.

RESULTS

The 365-day mortality rate for recipients aged >or=60 years (10.5%) was more than twice that of recipients aged 18-59 years (4.4%) and comorbidities significantly increased mortality rates even higher (10.6-21.4%). The 365-day mortality rate for recipients aged >or=60 years who received an ECD kidney was 14.4% and who developed DGF was 15.9% while recipients with comorbidities but no DGF and no ECD ranged from 16.0 to 42.3%. The 365-day transplant mortality rate of recipients aged >or=60 years with comorbidities is higher than the 365-day wait-list mortality for patients with the same comorbidities, suggesting a lack of survival benefit from transplantation.

CONCLUSIONS

Mortality rates for patients aged >or=60 years with comorbidities are higher than for those without comorbidities, significantly higher than for younger patients, and higher than for wait-listed patients. Thus, utility may be poorly served by allocating kidneys to older patients with comorbidities, and perhaps discussion of exclusionary listing criteria is warranted.

Younger age and antibody induction increase the risk for infection in pediatric renal transplantation: a NAPRTCS report

Infections now exceed rejection as a cause of hospitalization in the first 2 years post-renal transplantation. We analyzed data from the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) to determine risks for hospitalization for infection (HI), either bacterial (HBI) or viral (HVI). 3106 children transplanted between 1996 and 2002 with 2-year follow-up were analyzed. Univariate and multivariate logistic regression analyses identified factors for cause-specific hospitalization.

RESULTS

23.4% experienced HBI, 23.9% HVI; 8.9% were hospitalized for both. Children 0-1 years age at transplant had higher rates of HI (64.2%), HBI (40.3%) and HVI (43.3%) compared to >12 years (31%, 17.5% and 18.9%, p < 0.0001). In comparison to no induction, patients receiving monoclonal or polyclonal antibody were more likely to have HI (>42% vs. 34.0%), HBI (>24% vs. 21%) or HVI (>29% vs. 21%, all p < 0.003) but had equivalent graft survival (p = NS). Higher rates of HI, HBI and HVI were also seen with prophylactic antimicrobial use and with >5 transfusions pretransplant. Since antibody induction in recent era was not associated with better graft or patient survival but was associated with more HI and HVI, the need for routine antibody induction in children needs to be reassessed.

Renal transplantation: older recipients and donors

The majority of patients receiving a renal allograft, including a kidney from an older donor, do well. Renal transplantation from a living donor is associated with distinct advantages, including prolonged allograft survival. When live donors are not available, however, deceased donor kidneys provide suitable renal function that frequently lasts the lifetime of elderly recipients. Elderly patients who receive a kidney transplant enjoy improved survival, better quality of life, and lower medical costs than those who remain on dialysis.

The advantage of allocating kidneys from old cadaveric donors to old recipients: a single-center experience

BACKGROUND

In January 1999 a new kidney allocation program was launched by the Eurotransplant Foundation, the 'Eurotransplant Senior Program' (ESP). Cadaveric donors above the age of 65 yr are allocated to kidney transplant recipients of the same age group.

METHODS

Using a single-center database, 91 patients who underwent first renal transplantation at the age of 65 yr and older in the years 1999-2002 were identified. Fifty-six patients were transplanted through ESP allocation (study group) and 35 patients (control group) via normal Eurotransplant Kidney Allocation System (ETKAS) procedure.

RESULTS

Age, sex and comorbid conditions did not differ by group. The rate of acute rejection episodes, primary non-function, delayed graft function, perioperative mortality did not differ by group. Serum creatinine was significantly lower in the ETKAS group (1.3 vs. 1.9 mg/dL; p=0.015) from six months after the transplantation on. Overall graft survival at six yr was 56% in the ETKAS group and 52% in the ESP group. With 73% in the ETKAS group and 71% in the ESP group, cumulative patient survival according to the Kaplan-Meier estimation was not statistically different at five yr.

CONCLUSIONS

We did not find a relevant difference in the outcome between young and old kidney transplants in old recipients after this long observation period.

Transplantation rénale du sujet âgé

For ten years, an increase in the number of elderly patients on renal transplant waiting lists has occured. In an attempt to close the widening gap between supply and demand and because the demand for kidneys for younger patients already surpasses the supply, transplant physicians nowadays accept organs from older donors that might have been deemed inappropriate in the past. Programs of age matching between donors and recipients and of dual-kidneys transplantation have emerged. The initial results of these programs are encouraging with excellent patient and graft survival at one and three years.

The prevention of infection post-transplant: the role of prophylaxis, preemptive and empiric therapy

The close linkage of infection with the nature and intensity of the transplant immunosuppressive program has led to the concept of the therapeutic prescription. This has two components: an immunosuppressive one to prevent or treat rejection and graft-versus-host disease and an antimicrobial one to make it safe. This review provides a conceptual framework to approach the risk and risk periods for infection in solid organ and hematopoietic stem cell transplant recipients as well as an approach to antimicrobial use in this population.

Pharmacokinetic Considerations Relating to Tacrolimus Dosing in the Elderly

Relaxation of the upper age limits for solid organ transplantation coupled with improvements in post-transplant survival have resulted in greater numbers of elderly patients receiving immunosuppressant drugs such as tacrolimus. Tacrolimus is a potent agent with a narrow therapeutic window and large inter- and intraindividual pharmacokinetic variability. Numerous physiological changes occur with aging that could potentially affect the pharmacokinetics of tacrolimus and, hence, patient dosage requirements. Tacrolimus is primarily metabolised by cytochrome P450 (CYP) 3A enzymes in the gut wall and liver. It is also a substrate for P-glycoprotein, which counter-transports diffused tacrolimus out of intestinal cells and back into the gut lumen. Age-associated alterations in CYP 3A and P-glycoprotein expression and/or activity, along with liver mass and body composition changes, would be expected to affect the pharmacokinetics of tacrolimus in the elderly. However, interindividual variation in these processes may mask any changes caused by aging. More investigation is needed into the impact aging has on CYP and P-glycoprotein activity and expression. No single-dose, intense blood-sampling study has specifically compared the pharmacokinetics of tacrolimus across different patient age groups. However, five population pharmacokinetic studies, one in kidney, one in bone marrow and three in liver transplant recipients, have investigated age as a co-variate. None found a significant influence for age on tacrolimus bioavailability, volume of distribution or clearance. The number of elderly patients included in each study, however, was not documented and may have been only small. It is likely that inter- and intraindividual pharmacokinetic variability associated with tacrolimus increase in elderly populations. In addition to pharmacokinetic differences, donor organ viability, multiple co-morbidity, polypharmacy and immunological changes need to be considered when using tacrolimus in the elderly. Aging is associated with decreased immunoresponsiveness, a slower body repair process and increased drug adverse effects. Elderly liver and kidney transplant recipients are more likely to develop new-onset diabetes mellitus than younger patients. Elderly transplant recipients exhibit higher mortality from infectious and cardiovascular causes than younger patients but may be less likely to develop acute rejection. Elderly kidney recipients have a higher potential for chronic allograft nephropathy, and a single rejection episode can be more devastating. There is a paucity of information on optimal tacrolimus dosage and target trough concentration in the elderly. The therapeutic window for tacrolimus concentrations may be narrower. Further integrated pharmacokinetic-pharmacodynamic studies of tacrolimus are required. It would appear reasonable, based on current knowledge, to commence tacrolimus at similar doses as those used in younger patients. Maintenance dose requirements over the longer term may be lower in the elderly, but the increased variability in kinetics and the variety of factors that impact on dosage suggest that patient care needs to be based around more frequent monitoring in this age group.

Living with a functioning kidney transplant at 74 yr or older: a national epidemiological study

The number of older patients living with a functioning kidney graft is increasing. However the safety of the immunosuppressive treatment and quality of life in this population have not yet been determined. All patients grafted in France since 1969, born before the January 1 1926 and living with a functioning graft on January 1 2000 were included in this national study including all 34 French transplant centers. Renal function, immunosuppressive treatment, comorbid conditions and quality of life were assessed. From the initial population of 446 patients, 113 (26.2%) were still alive in 2000 (study population). Mean age was 76 yr (range: 74-80) with a mean post-transplant follow-up of 9.9 yr (0.1-28.7). Average serum creatinine level was 129 micromol/L (55-286). Immunosuppression was heterogeneous and included triple therapy (18.6%), dual therapy (41.6%) and monotherapy (40.8%). A history of cancer was noted in 36 of the 113 patients (32.1%) whereas hypertension was the most frequent co-morbid condition (80.3%). Estimated quality of life using the Karnofsky scale was between 80 and 100 in 78.4% of the patients. The immunosuppressive regimen in older renal transplant recipients living with a functioning graft varied widely among the 34 French transplant centers. Renal function in this group of patients was good and quality of life seemed excellent. Cardiovascular disease and malignancies were the main co-morbid conditions.

Does mycophenolate mofetil increase the incidence of infections in stable renal transplant recipients initially treated with a two-drug regimen?

BACKGROUND

A drug regimen including a calcineurin inhibitor (cyclosporine or tacrolimus) and prednisone has been the mainstay of maintenance immunosuppression in our renal transplant recipients for more than 10 years. After the introduction of mycophenolate mofetil (MMF), a new, potent immunosuppressant that may reduce the incidence of late rejection in renal transplant recipients, the immunosuppressive protocol in some recipients was changed to an MMF-based regimen. We sought to ascertain whether the addition of MMF lead to greater susceptibility to infectious complications.

PATIENTS AND METHODS

Between May 1991 and November 2002, all renal transplant recipients who received a two-drug regimen initially for more than 6 months were changed to an MMF-based regimen. The study includes patients with functional grafts for more than 6 months thereafter. Differences in the incidence, etiology, and outcome of infections were compared during the non-MMF versus the MMF periods.

RESULTS

Eighty patients of mean age of 38.6 years (range 13 to 69) included 43 men and 37 women. The mean daily MMF dose was 663 mg/patient (range 250 to 1500 mg). The mean follow-up time of non-MMF period and MMF periods were 3.4 and 2.1 years, respectively. The overall incidence of infections in the two periods was similar (0.2 infections/patient in the non-MMF period and 0.25 infections/patient in the MMF period, P = .57). No mortality was associated with these infectious complications. In conclusion, addition of MMF, a more potent immunosuppressive protocol, did not increase the incidence of infections in stable renal transplant recipients initially treated with a two-drug regimen.

The impact of sirolimus, mycophenolate mofetil, cyclosporine, azathioprine, and steroids on wound healing in 513 kidney-transplant recipients

BACKGROUND

The aim of this study was to determine whether there has been an increase in the incidence or severity of wound-healing complications that can be attributed to the introduction of newer immunosuppressive drugs.

METHODS

Consecutive series of adult kidney-only transplant recipients were selected from our Unified Transplant Database backward from September 2002. There were 513 patients divided into groups on the basis of their maintenance immunosuppression given for at least the first 30 days posttransplant. Group I (152) was given sirolimus, mycophenolate mofetil, and prednisone (SRL/MMF/P) between March 2000 and September 2002; group II (168) was given cyclosporine A (CsA)/MMF/P between January 1999 and July 2002; and group III (193) was given azathioprine (AzA)/CsA/P between January 1993 and December 1997. A classification system for wound-healing problems was developed, and each of the three groups was analyzed by univariate and multivariate analysis.

RESULTS

From groups III to II to I, there was a significant increase in mean age (42.4 vs. 49 years), percent of patients diabetic (17% vs. 29%), mean body mass index (BMI) (24.2 vs. 27.1 kg/m2), and percent BMI greater than 30 (13.5% vs. 27%). The cumulative percentage of all wound-healing problems between group I (19.7%) vs. group II (16.1%) and group III (15.6%) was not significantly different. The most significant risk factor was a recipient BMI greater than 30 (P=0.0012) and delayed graft function (P=0.0041).

CONCLUSIONS

During a 10-year period marked by changing recipient demographics, the introduction of MMF and SRL did not result in a significant increase in transplant wound-healing complications. The most significant risk factor associated with transplant wound-healing complications remains body weight, which was the major influence for each of the immunosuppressive drug combinations described.

Drug Therapy in Transplant Recipients

Elderly patients with end-stage organ failure are now more frequently undergoing transplantation. Medication management in this population is challenging because of the combination of multiple comorbidities, polypharmacy, and immunological, pharmacokinetic and pharmacodynamic changes attributable to the aging process. Immunosuppressive medications can exacerbate pre-existing medical conditions and promote the development of disease processes. Cardiovascular disorders, such as hypertension, coronary artery disease, congestive heart failure and arrhythmias are common in elderly transplant recipients, and account for most of the deaths in this population. Blood pressure, blood glucose and cholesterol control is of particular concern because elderly transplant recipients frequently have or develop these complications. Elderly transplant recipients are commonly receiving anticoagulation therapy with warfarin and are at a higher risk of bleeding, especially if they have renal dysfunction. Infectious complications occur frequently in the transplanted population, with pneumonia being the most common infection seen in hospitalised patients. Attention to vaccination for the prevention of influenza and pneumococcal infections is important because of the increased risk of these diseases in this population. Depression itself has been associated with decreased survival in older individuals, and depression in elderly transplant recipients may be reversible with the administration of pharmacological agents. Effective long-term care of transplant recipients demands an understanding of how particular medications affect clinical evaluation and treatment. This article addresses some of the practical issues surrounding medication management and prevention of these particular problems in elderly transplant recipients.

Old-for-old kidney allocation allows successful expansion of the donor and recipient pool

Allocation of kidneys from donors older than 64 years to recipients older than 64 years was started in 1999 to improve use of older donor kidneys. Kidneys are allocated locally without HLA-matching to keep cold ischemia short. We compared survival and rejection rates in elderly patients allocated in the old-for-old program (ESP) to patients aged 60 years and older based on HLA-matching, expected ischemia and waiting time (ETKAS). The 69 ESP patients were older (67.9 +/- 2.5 vs. 63.9 +/- 2.9 years), had older donors (71.2 +/- 3.9 vs. 44.6 +/- 14.5 years) and more HLA-mismatches (4.2 +/- 1.2 vs. 1.6 +/- 1.7) than the 71 ETKAS patients, while ischemia was shorter (7.8 +/- 3.4 vs. 14.2 +/- 5.5 h). ESP and ETKAS had similar graft (1-year: 83.6% vs. 86.9%) and patient survival (85.2% vs. 89.5%). With the introduction of ESP, use of older recipients and donors rose from less than 2% to 16% and 11%, respectively. Incidence of acute rejections was significantly higher in the ESP group (1 year: 43.2% vs. 27.4%) and significantly correlated with the degree of HLA-matching. Introduction of old-for-old allocation allows successful expansion of the donor and recipient pool without affecting patient and graft survival. HLA-matching should not be ignored, as the risk of acute rejection in elderly patients is substantial.

Resource utilization among kidney transplant recipients

BACKGROUND

Hospitalization consumes a significant portion of the end-stage renal disease (ESRD) program, which includes kidney transplant recipients. Identification of kidney transplant recipients at risk of increased resource utilization could lead to appropriate interventions to attenuate the complications related to kidney transplant, which may reduce resource utilization.

METHODS

This retrospective cohort study of kidney transplant recipients was performed to identify risk factors for hospital utilization. The study population consisted of patients who received kidney transplant at our center between October 1990 and September 1999 and were followed in the outpatient clinic.

RESULTS

Of the 220 patients, 171 (78%) were hospitalized during a median follow-up of 36 months. The number of hospitalizations, hospital days, and outpatient visits per patient-year at risk were 1.1, 6.3, and 21.6, respectively. Infection episodes were the leading cause of hospitalization. In a multivariate regression analysis, cytomegalovirus (CMV)-positive status of donor (RR 1.58; 95% CI 1.15, 2.18) and a higher number of hospital days during the transplant hospitalization (RR 1.10 per 7 days increase; 95% CI 1.03, 1.19) were associated with a higher risk of hospitalization, while higher serum albumin (RR 0.84 per 0.5 g/dL increase; 95% CI 0.73, 0.97), higher hematocrit (RR 0.95 per 1% increase; 95% CI 0.92, 0.98), higher glomerular filtration rate (GFR) (RR 0.91 per 10 mL/min/1.73 m2; 95% CI 0.85, 0.99), and an increased interval since transplant (RR 0.84 per 6 months increase; 95% CI 0.75, 0.93) were associated with a lower risk of hospitalization. CMV-positive status of the donor (RR 1.11; 95% CI 1.00, 1.21) and presence of cardiovascular disease (RR 1.12; 95% CI 1.00, 1.24) were associated with a higher risk of outpatient visits, while Caucasian race (RR 0.82; 95% CI 0.73, 0.94), higher serum albumin (RR 0.88 per 0.5 g/dL increase; 95% CI 0.84, 0.93), higher hematocrit (RR 0.96 per 1% increase; 95% CI 0.95, 0.97), and an increased interval since transplant (RR 0.79 per 6 months increase; 95% CI 0.76, 0.83) were associated with a lower risk of outpatient visits.

CONCLUSION

Identification of risk factors associated with increase resource utilization among kidney transplant recipients could aid in the development of targeted interventions to improve clinical and economic outcomes.

Epidemiology of systemic mycoses among renal-transplant recipients in India

BACKGROUND

Systemic mycoses have a high impact on tropical renal-transplant recipients.

METHODS

Data from 1,476 primary renal-transplant recipients was prospectively recorded from 1986 to 2000 at a single center. Cumulative incidence of systemic mycoses, its time of occurrence, risk factors, outcome, and postmortem findings in 30 patients with systemic mycoses were analyzed.

RESULTS

A total of 110 episodes of systemic mycoses occurred in 98 patients. The fungal genera Aspergillus, Cryptococcus, and Candida constituted 61% of pathogens, 45% localizing to the lungs. Cytomegalovirus (CMV) disease caused a 5-fold and chronic liver disease a 2-fold increase in systemic mycoses. Tuberculosis (TB) with or without nocardiosis was a significant coinfection. Cyclosporine (CsA) was associated with nearly a 4-fold risk of systemic mycoses less than 6 months from the time of transplantation as compared with prednisolone+azathioprine (PRED+AZA) therapy. Overall, the probability of survival with systemic mycoses was 73.4%, 60.8%, 39.5%, and 25.6% and was 92.5%, 87.5%, 80.0%, and 75.5% without systemic mycoses at 1, 2, 5, and 10 years, respectively (P<0.0001). An extended Cox model with time-independent and dependent covariates showed greater than 15 times the risk of death among those who develop systemic mycoses. Similarly, Posttransplantation (postTX) TB+/-Nocardiosis, preTX TB, CMV disease, diabetes mellitus, PTDM, chronic liver disease (>40 months), and Pred+AZA immunosuppression (>2 years) had 3.5, 1.5, 2.9, 1.9, 1.4, 1.6, 2.3 times the risk for death, respectively, as compared with those who did not have those risk factors.

CONCLUSIONS

There is a recent predominance of Aspergillus among the transplant recipients. The risk factors for systemic mycoses are CMV disease, chronic liver disease, and hyperglycemia, and TB is an important coinfection. Systemic mycoses increased in the early postTX period with CsA. The risk factors for death are systemic mycoses, CMV disease, chronic liver disease (>40 months), diabetes mellitus, and Pred+AZA immunosuppression (>2 years). Overall, the probability of survival with systemic mycoses was poor; however, survival has recently improved.

[Vacuum sealing of extensive wound healing disorders after kidney transplantation]

With the introduction of mycophenolate mofetil (MMF) in renal transplantation, acute rejection episodes diminished and short-term graft survival improved. Better graft outcome, however, is followed by several surgical complications attributed to MMF. Patients with risk factors (adiposity, diabetes mellitus, advanced age) show an increased rate of healing by second intention. We treated two patients with the vacuum sealing technique so that after 15 days a secondary suture became possible in each case. To date the vacuum sealing technique has been used mainly in traumatology, abdominal surgery, surgery for acute infections of soft tissue and bone, and problem wounds with reduced wound-healing capacity (chronic leg ulcer). This article presents two cases of successful application of the vacuum sealing technique in renal transplantation after prolonged wound healing.