Risk factors of invasive aspergillosis after heart transplantation: protective role of oral itraconazole prophylaxis

Prophylaxis of invasive mycoses in solid organ transplantation

Solid organ transplantation is emerging as a lifesaving procedure for increasing numbers of patients, and invasive fungal infections are a significant cause of mortality and morbidity for patients undergoing such procedures. Risks for developing these infections are continuing to evolve, leading to shifts in the epidemiology of invasive mycoses occurring after transplantation. Targeting preventive efforts to select solid organ transplantation groups at highest risk for invasive fungal infections is critical to optimizing prophylaxis strategies. The epidemiology of posttransplantation fungal infections, antifungal drug interactions and side effects, and new diagnostic capabilities should be considered when choosing an approach to antifungal prophylaxis for this population.

Fungal infections in transplant and oncology patients

Recent shifts in the epidemiology of invasive fungal infections (IFIs) among transplant and oncology populations have led to new recommendations on treatment; however, they have also brought new controversies. New pharmacologic therapies are being studied and guidelines for management of several IFIs have been changed accordingly. More information is being discovered about unique genetic factors that put some transplant recipients at greater risk than others for fungal infection. The role of immunomodulation continues to be investigated, and the delicate balance of maintaining some immune integrity while assuring protection of the graft remains critical. For transplant and oncology patients, the diagnosis and management of IFIs remain challenging, and improving outcomes depends on continued progress in all of these arenas. This article highlights recent advances and important factors to consider when treating transplant and oncology patients with IFIs.

Epidemiology of invasive aspergillosis and risk factors in non neutropaenic patients

INTRODUCTION

Invasive aspergillosis is a major cause of mortality in allogeneic bone marrow transplant recipients and patients treated for blood malignancies. The diagnostic tools, treatments and preventive strategies, essentially developed for neutropaenic patients, have not been assessed in populations whose immune systems are considered to be competent.

STATE OF THE ART

Beside the standard picture of chronic Aspergillus infection, the incidence of invasive aspergillosis is increasing in non neutropaenic patients, such as those with chronic lung diseases or systemic disease treated with long-term immunosuppressive drugs and solid organ transplant recipients. This study reviews the specific features of invasive aspergillosis in non neutropaenic subjects (NNS) and discusses the value of the diagnostic tools and treatment in this population.

PROSPECTS

A better understanding of the pathophysiology and the epidemiological characteristics of invasive aspergillosis would provide a means of adapting the staging and classification of the disease for NNS.

CONCLUSIONS

Invasive aspergillosis is under diagnosed in NNS who may already be colonised when they receive immunosuppressive treatment; this can lead to an adverse outcome in patients who are considered to be a moderate risk population.

Infectious and non-infectious neurologic complications in heart transplant recipients

Neurologic complications are important causes of morbidity and mortality in heart transplant (HT) recipients. New immunomodulating agents have improved survival rates, although some have been associated with a high rate of neurologic complications (infectious and non-infectious). We conducted this study to analyze the frequency of these complications, before and after the use of daclizumab induction therapy. We reviewed all neurologic complications in our HT cohort, comparing infectious with non-infectious complications over 2 periods of time in which different induction therapies were used (316 patients with OKT3 or antithymocyte globulin from 1988 to 2002, and 68 patients with daclizumab from 2003 to 2006). Neurologic complications were found in 75/384 patients (19.5%) with a total of 78 episodes. Non-infectious complications accounted for 68% of the 78 episodes of neurologic complications. A total of 51 patients and 53 episodes were detailed as follows: 25 episodes of stroke (25 of 78 total episodes, 32%; 19 ischemic, 6 hemorrhagic); 7 neuropathies; 6 seizures; 4 episodes of transient ischemic attack (TIA); 3 anoxic encephalopathy; 2 each brachial plexus palsy and metabolic encephalopathy; and 1 each myoclonia, central nervous system (CNS) lymphoma, subdural hematoma, and Cotard syndrome. Mean time to presentation of stroke, TIA, and encephalopathy was 1 day (range, 1-19 d) posttransplant. Mortality rate among non-infectious complications was 12/53 (22.6%). Infectious complications accounted for 32% of the 78 total episodes. We found 25 episodes in 24 patients: 17 herpes zoster (median, 268 d after HT), 3 CNS aspergillosis (median, 90 d after HT), 1 CNS toxoplasmosis and tuberculosis (51 d after HT), 1 pneumococcal meningitis (402 d after HT), and 2 Listeria meningitis (median, 108 d after HT). The 3 patients with CNS aspergillosis died. The mortality rate among patients with infectious neurologic complications was 12% (42.8% if the CNS was involved). When we compared the OKT3-ATG and daclizumab groups, we found that the incidence of non-infectious complications was 15.1% vs. 7.3%, respectively, and the incidence of infectious complications was 7.5% vs. 1.4%, respectively. All but 1 opportunistic infection occurred in the OKT3-ATG time period. In conclusion, a wide variety of neurologic complications affected 19.5% of HT recipients. Non-infectious causes clearly predominated, but infections still accounted for 32% of the episodes. New monoclonal induction therapies have contributed to diminished CNS opportunistic infections in our program.

Caspofungin for post solid organ transplant invasive fungal disease: results of a retrospective observational study

M. Winkler, J. Pratschke, U. Schulz, S. Zheng, M. Zhang, W. Li, M. Lu, D. Sgarabotto, G. Sganga, P. Kaskel, S. Chandwani, L. Ma, J. Petrovic, M. Shivaprakash. Caspofungin for post solid organ transplant invasive fungal disease: results of a retrospective observational study. Transpl Infect Dis 2010: 12: 230–237. All rights reserved

Cytomegalovirus infection in lung transplant patients: The role of prophylaxis and recipient-donor serotype matching

Cytomegalovirus (CMV) remains an important cause of morbidity and mortality in lung transplant recipients. We investigated the incidence of CMV infection in relation to CMV prophylaxis, and recipient-donor CMV serotype, in a cohort of 250 consecutive lung transplant recipients. All patients received 3 months CMV prophylaxis with acyclovir (n = 67) or gancyclovir (n = 183). Recipient-donor CMV serotype matching was performed in patients receiving acyclovir: R+/D+(n = 38), R+/D-(n = 10), R-/D+(n = 1), R- /D-(n = 16), unknown (n = 2). Recipient-donor CMV serotype matching was not performed in patients receiving gancyclovir: R+/D+(n = 71), R+/D-(n = 42), R-/D+(n = 38), R-/D-(n = 31), unknown (n = 1). The overall incidence of CMV infection was 51% (n = 34) in the acyclovir group, and 42% (n = 77) in the gancyclovir group (p = 0.14). During the first 9 months after transplantation, the rate of CMV infection was higher in the acyclovir group (42%) compared with the gancyclovir group (30%) (p = 0.005). Multivariate analysis demonstrated the incidence of CMV infection during the first 9 months was higher for acyclovir prophylaxis (p<0.001) and R-/D+ serostatus (p<0.001) and lower with R-/D- serostatus (p = 0.02). In conclusion, gancyclovir significantly delays the onset of first CMV infection among lung transplant patients. CMV surveillance and choice of prophylaxis may be modified according to donor-recipient CMV serotype.

Clostridium difficile–associated Diarrhea in Heart Transplant Recipients: Is Hypogammaglobulinemia the Answer?

BACKGROUND

Information regarding Clostridium difficile-associated diarrhea (CDAD) after solid-organ transplantation (SOT) is scarce, particularly after heart transplantation (HT). Although host immune response to C. difficile plays a substantial role in the outcome of this infection, the responsibility of hypogammaglobulinemia (HGG) as a predisposing condition for CDAD has not been studied in SOT. We analyzed the incidence, clinical presentation, outcome and risk factors, including HGG, of CDAD after HT.

METHODS

Two hundred thirty-five patients who underwent HT (1993 to 2005) were included. Transplantation procedure and immunosuppression were standard. From January 1999 HGG was systematically searched and corrected when IgG levels were <400 mg/dl or severe infection was present. Toxin-producing C. difficile was detected by means of cytotoxin assay and culture of stool samples. Patients with and without CDAD were compared for identification of risk factors.

RESULTS

CDAD was detected in 35 patients (14.9%). Incidence decreased significantly since HGG was sought and treated: 29 (20.6%) in the first period, and 6 (6.4%) in the second (p = 0.003). CDAD appeared a mean of 32 days (range 5 to 3,300 days) after HT. No related death or episode of fulminant colitis was detected. At least one episode of recurrence was noted in 28.6% of patients. Severe HGG was found to be the only independent risk factor for CDAD after HT (RR 5.8; 95% CI: 1.05 to 32.1; p = 0.04).

CONCLUSIONS

C. difficile is a significant cause of diarrhea in HT recipients and post-transplant HGG is independently associated with an increased risk. The potential role of immunoglobulin administration in this population requires further study.

Fungal infections in solid organ transplantation

Renal, liver, heart and lung transplantation are now considered to be the standard therapeutic interventions in patients with end-stage organ failure. Infectious complications following transplantation are relatively common due to the transplant recipients overall immunosuppressed status. The incidence of invasive mycoses following solid organ transplant ranges from 5 to 42% depending on the organ transplanted. These mycoses are associated with high overall mortality rates. Candida and Aspergillus spp. produce most of these infections. This article will review the risk factors, clinical presentation and treatment of invasive fungal infections in solid organ transplant patients, and evaluate the role of prophylactic therapy in this group of patients.

Etiology and impact of cytomegalovirus disease on solid organ transplant recipients

PURPOSE

The characteristics, etiology, natural history, and direct and indirect effects of CMV disease in solid organ transplant recipients are described.

SUMMARY

CMV is a common herpesvirus that may be present in the donor or recipient of a solid organ transplant. Even though it is rarely pathogenic in healthy patients, transplant recipients are at risk for CMV viremia and symptomatic disease due to their immune-suppressed status. In addition to symptoms directly attributed to active disease, CMV can have a variety of indirect effects. Indirect effects may include additional infectious complications, posttransplant lymphoproliferative disease, allograft rejection, allograft loss, or death. The three most prevalent risk factors for CMV infection are CMV seronegativity in a recipient of an organ from a CMV-seropositive donor, the type of organ transplanted, and the degree of immune suppression. CMV prophylaxis is effective at preventing disease, but may result in a delayed onset where CMV disease occurs once the prophylaxis is stopped.

CONCLUSION

Knowledge of risk factors for CMV infection and disease, the natural history in transplant recipients, and its direct and indirect effects will help clinicians make appropriate decisions regarding the use of preventive strategies.

Invasive fungal infections and antifungal therapies in solid organ transplant recipients

This manuscript will review the risk factors, prevalence, clinical presentation, and management of invasive fungal infections (IFIs) in solid organ transplant (SOT) recipients. Primary literature was obtained via MEDLINE (1966-April 2007) and EMBASE. Abstracts were obtained from scientific meetings or pharmaceutical manufacturers and included in the analysis. All studies and abstracts evaluating IFIs and/or antifungal therapies, with a primary focus on solid organ transplantation, were considered for inclusion. English-language literature was selected for inclusion, but was limited to those consisting of human subjects. Infectious complications following SOT are common. IFIs are associated with high morbidity and mortality rates in this patient population. Determining the best course of therapy is difficult due to the limited availability of data in SOT recipients. Well-designed clinical studies are infrequent and much of the available information is often based on case-reports or retrospective analyses. Transplant practitioners must remain aware of their therapeutic options and the advantages and disadvantages associated with the available treatment alternatives.

Aspergillosis: spectrum of disease, diagnosis, and treatment

Infections by Aspergillus species present a particular challenge. The organism, which is ubiquitous in the environment, causes allergic disease in otherwise healthy individuals and devastating disease in the immunosuppressed. This article examines the range of infections caused by Aspergillus species, the challenges of diagnosis, and current treatment options.

Fungal infections in solid organ transplantation

Fungal infections in solid organ transplant recipients continue to be a significant cause of morbidity and mortality. Candida spp. and Aspergillus spp. account for most invasive fungal infections. The incidence of fungal infection varies with type of solid organ transplant. Liver transplant recipients have highest reported incidence of candida infections while lung transplant recipients have highest rate of Aspergillus infections. Recent epidemiological studies suggest the emergence of resistant strains of candida as well as mycelial fungi other than Aspergillus in these patients. The current review incorporates the recent changes in the epidemiology of fungal infections in solid organ transplant recipients and highlights the newer data on the diagnosis, prophylaxis and treatment of fungal infections in these patients.

Treatment of solid organ transplant patients with invasive fungal infections: should a combination of antifungal drugs be used?

PURPOSE OF REVIEW

Combined antifungal drug therapy is widely used in severe invasive mycoses in solid organ transplant (SOT) recipients. We have reviewed the available data in the literature.

RECENT FINDINGS

No single randomized study on antifungal combination therapy in SOT patients has been performed. Existing information does not support the use of combination therapy in invasive candidiasis in SOT patients. Indeed, initial combination therapy with amphotericin B and 5-flucytosine is recommended for SOT patients with central nervous system cryptococcosis, mainly with increased white blood cell counts in the cerebrospinal fluid or with altered mental status. No impact on outcome was observed with combination therapy in Scedosporium infections in SOT patients. The combination of voriconazole and terbinafine may be an attractive option for S. prolificans infections. A prospective study of voriconazole plus caspofungin as initial therapy for invasive aspergillosis in SOT patients found that combination therapy was independently associated with reduced mortality in patients with renal failure and in those with Aspergillus fumigatus infection, even when adjusted for other factors predictive of mortality in the study population.

SUMMARY

Combination therapy should be considered for severe forms of invasive fungal infections in SOT patients; however, multicenter studies of such patients are urgently needed.

IgG monitoring to identify the risk for development of infection in heart transplant recipients

Infectious complication represents a significant source of morbidity and mortality in heart transplant recipients. To assess humoral immunity markers that can predict the development of infection, 38 consecutive recipients of heart transplants performed at a single center were prospectively studied. Induction therapy included daclizumab. Immunoglobulin (IgG, IgA, IgM) and complement factors (C3, C4, and factor B) were performed by nephelometry in peripheral blood samples obtained before transplantation, and 7 days and 1 month after transplantation. During a mean follow-up of 16.9 months, 13 patients had at least one episode of infection (34.2%). Eight of these were cytomegalovirus (CMV) infections treated with intravenous ganciclovir, 2 were bacterial pneumonia, 1 patient had bacterial septicemia, 1 patient had urinary tract infection, and 1 patient had pulmonary nocardiosis. No significant association was found between infection and age, sex, immunosuppression, CMV serostatus of donor and recipient, or treated rejection episodes. Pre-transplant IgG (below median value=1140 mg/dL; relative risk [RR] 3.69; 95% confidence interval [CI] 1.01-13.54; P=0.04) and post-transplant IgG levels at day 7 (below median value=679 mg/dL; RR 11.21; CI 1.04-89.48; P=0.022) were associated with an increase in the risk for developing infections. Early monitoring of immunoglobulin levels might help to identify the risk for developing infection in heart transplantation.

Combination of Voriconazole and Caspofungin as Primary Therapy for Invasive Aspergillosis in Solid Organ Transplant Recipients: A Prospective, Multicenter, Observational Study

BACKGROUND

: The efficacy of the combination of voriconazole and caspofungin when used as primary therapy for invasive aspergillosis in organ transplant recipients has not been defined.

METHODS

: Transplant recipients who received voriconazole and caspofungin (n=40) as primary therapy for invasive aspergillosis (proven or probable) in a prospective multicenter study between 2003 and 2005 were compared to a control group comprising a cohort of consecutive transplant recipients between 1999 and 2002 who had received a lipid formulation of AmB as primary therapy (n=47). In vitro antifungal testing of Aspergillus isolates to combination therapy was correlated with clinical outcome.

RESULTS

: Survival at 90 days was 67.5% (27/40) in the cases, and 51% (24/47) in the control group (HR 0.58, 95% CI, 0.30-1.14, P=0.117). However, in transplant recipients with renal failure (adjusted HR 0.32, 95% CI: 0.12-0.85, P=0.022), and in those with A. fumigatus infection (adjusted HR 0.37, 95% CI: 0.16-0.84, P=0.019), combination therapy was independently associated with an improved 90-day survival in multivariate analysis. No correlation was found between in vitro antifungal interactions of the Aspergillus isolates to the combination of voriconazole and caspofungin and clinical outcome.

CONCLUSIONS

: Combination of voriconazole and caspofungin might be considered preferable therapy for subsets of organ transplant recipients with invasive aspergillosis, such as those with renal failure or A. fumigatus infection.

Bloodstream Infections among Heart Transplant Recipients

BACKGROUND

Heart transplant (HT) recipients are prone to life-threatening infections, including bloodstream infection (BSI), but information on this topic is particularly scarce.

METHODS

We studied 309 consecutive HT performed at our institution between 1988 and 2003. We assessed the characteristics of each episode of BSI, prophylaxis and immunosuppression used, and possible related factors.

RESULTS

Sixty episodes of BSI occurred in 15.8% of all HT recipients. Rates of BSI/transplanted patient decreased progressively throughout the study period: 21.2%, 14.3%, and 7.5% in each 5-year period (P=0.03). BSI episodes occurred a median of 51 days after transplantation. The main BSI origins were: lower respiratory tract (23%), urinary tract (20%), and catheter-related-BSI (16%). Gram-negative organisms predominated (55.3%), followed by Gram-positive (44.6%). Mortality was 59.2%, with 12.2% directly attributable to BSI. Independent risk factors for BSI after HT were: hemodialysis (OR 6.5; 95% CI 3.2-13), prolonged intensive care unit stay (OR 3.6; 95% CI 1.6-8.1), and viral infection (OR 2.1; 95% CI 1.1-4). BSI was a risk factor for mortality (OR 1.8; 95% CI 1.2-2.8).

CONCLUSION

BSIs have decreased in HT recipients, but still contribute to mortality, mainly if related to pneumonia or polymicrobial infections. Reduction of early postoperative complications and viral infections are amenable goals that may further reduce BSI in this population.

Late-onset invasive aspergillosis in organ transplant recipients in the current era

We assessed predictive factors and characteristics of patients with late-onset invasive aspergillosis in the current era of novel immunosuppressive agents. Forty transplant recipients with invasive aspergillosis were included in this prospective, observational study initiated in 2003 at our institutions. In 50% (20/40) of these patients, the infections were late-occurring. Receipt of sirolimus in conjunction with tacrolimus for refractory rejection or cardiac allograft vasculopathy (P=0.047) was significantly associated with late-onset infection. The use of depleting or non-depleting T or B-cell antibodies, either as induction or as antirejection therapy did not correlate with time to onset of invasive aspergillosis. Mortality at 90 days was 20% (4/20) for the patients with early-onset infection and 45% (9/20) for those with late-onset infection (P=0.17). Thus, nearly one-half of the Aspergillus infections in transplant recipients in the current era are late-occurring. These data have implications relevant for prophylactic strategies and guiding clinical management of transplant recipients presenting with pulmonary infiltrates.

Aspergillus pulmonary infections in transplant recipients

Aspergillus infections are increasing in frequency in those undergoing solid organ and hematopoietic stem cell transplantation. The ongoing impact of Aspergillus infection on morbidity and mortality after transplantation makes this subject an area of intense clinical and research interest. This article discusses the evolving epidemiologic features of the infection and its management and diagnosis.

[Infections after organ transplantation]

Early postoperative infections after transplantation vary according to the transplanted organ. During the subsequent course opportunistic infections such as cytomegalovirus reactivation, Pneumocystis jiroveci pneumonia, invasive pneumococcal infection and mould infections predominate. Reactivated tuberculous infection appears to become more prevalent. Some of the opportunistic infections are preventable by chemoprophylaxis; others can be managed very effectively by monitoring and early preemptive therapy. Physicians caring for patients after organ transplantation need to early consider in the differential diagnosis rare pathogens which are often overlooked with standard diagnostic procedures.

Invasive aspergillosis in organ transplant recipients: new issues in epidemiologic characteristics, diagnosis, and management

Changing transplantation practices, novel immunosuppressive protocols, and evolving recipient characteristics have led to notable changes in the epidemiology of invasive aspergillosis in transplant recipients. The frequency of disseminated infection and of central nervous system involvement has declined significantly in organ transplant recipients in the recent years. Amongst variables that may have contributed to these trends is an overall lesser severity of illness of transplant recipients in the current era. Calcineurin-inhibitor immunosuppressive agents may also have had a role in altering the disease course and the risk of dissemination. A new paradigm in the management of post-transplant immunosuppression is the use of calcineurin-inhibitor and corticosteroid sparing regimens by pretreatment of the recipient with T-cell depleting agents (Campath 1-H or thymoglobulin) and utilization of minimal post-transplant immunosuppression. The impact of these potent lymphoablative regimens on opportunistic mycoses in organ transplant recipients remains to be fully discerned. Although still unacceptably high, the mortality rate in organ transplant recipients with invasive aspergillosis in the current era appears to have declined. A focus of a great interest and controversy is the use of combination therapy for invasive aspergillosis in transplant recipients.

Aspergillus infections in transplant recipients

Aspergillus infections are occurring with an increasing frequency in transplant recipients. Notable changes in the epidemiologic characteristics of this infection have occurred; these include a change in risk factors and later onset of infection. Management of invasive aspergillosis continues to be challenging, and the mortality rate, despite the use of newer antifungal agents, remains unacceptably high. Performing molecular studies to discern new targets for antifungal activity, identifying signaling pathways that may be amenable to immunologic interventions, assessing combination regimens of antifungal agents or combining antifungal agents with modulation of the host defense mechanisms, and devising diagnostic assays that can rapidly and reliably diagnose infections represent areas for future investigations that may lead to further improvement in outcomes.