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

Management of invasive pulmonary aspergillosis in non-neutropenic critically ill patients

During recent years, a rising incidence of invasive pulmonary aspergillosis (IPA) in non-neutropenic critically ill patients has been reported. Critically ill patients are prone to develop disturbances in immunoregulation during their stay in the ICU, which render them more vulnerable for fungal infections. Risk factors such as chronic obstructive pulmonary disease (COPD), prolonged use of steroids, advanced liver disease, chronic renal replacement therapy, near-drowning and diabetes mellitus have been described. Diagnosis of IPA may be difficult and obtaining histo- or cytopathological demonstration of the fungus in order to meet the gold standard for IPA is not always feasible in these patients. Laboratory markers used as a non-invasive diagnostic tool, such as the galactomannan antigen test (GM), 1,3-beta-glucan, and Aspergillus PCR, show varying results. Antifungal therapy might be considered in patients with persistent pulmonary infection who exhibit risk factors together with positive cultures or sequentially positive GM and Aspergillus PCR in serum, in whom voriconazole is the drug of choice. The benefit of combination antifungal therapy lacks sufficient evidence so far, but this treatment might be considered in patients with breakthrough infections or refractory disease.

The pharmacology and clinical use of caspofungin

Caspofungin was the first echinocandin to be licensed for the treatment of invasive fungal infections. Caspofungin has in vitro and in vivo activity against Candida spp. and Aspergillus spp., which constitute the majority of medically important opportunistic fungal pathogens. Caspofungin inhibits the synthesis of the 1,3-beta-glucan, with resultant osmotic instability and lysis. The pharmacology of caspofungin is relatively complex. Trafficking of drug into tissues is an important determinant of the shape of the concentration-time relationship. Caspofungin has demonstrated efficacy in experimental models of invasive candidiasis and aspergillosis, which reflect its activity in the treatment of oropharyngeal, esophageal and disseminated candidiasis, as well as salvage therapy for patients with invasive aspergillosis.

A comparative evaluation of properties and clinical efficacy of the echinocandins

With the increase in prevalence of fungal infections, newer antifungal agents are needed to effectively treat invasive disease, and at the same time minimize adverse effects from therapy. The echinocandins comprise a novel class of antifungals; their mechanism of action involves inhibiting 1,3-beta-D-glucan synthase, which is essential in cell wall synthesis for certain fungi. All three echinocandins are US FDA-approved for the treatment of esophageal candidiasis. Caspofungin and anidulafungin are licensed for the treatment of candidemia, and other select forms of invasive candidiasis. Micafungin is at present the only echinocandin approved for prophylaxis of fungal infections in hematopoietic stem cell transplants; whereas caspofungin is approved for empiric therapy of febrile neutropenia. Although all three echinocandins are active against Aspergillus, only caspofungin is presently approved for salvage therapy in invasive aspergillosis. Combination therapy with echinocandins plus other licensed antifungal therapy shows promise in treating invasive aspergillosis. This article will explore the similarities and differences among the echinocandins.

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.

Caspofungin-resistant Aspergillus flavus after heart transplantation and mechanical circulatory support: a case report

Invasive aspergillosis (IA) is a severe complication in the post-transplant period in recipients of solid organs. Therefore, early diagnosis and specific therapy of fungal infections in these patients are indispensable. We report the case of a 49-year-old patient, who suffered from IA after cardiac transplantation, which was complicated by post-transplant right heart failure requiring mechanical circulatory support using veno-arterial extracorporeal membrane oxygenation and a right ventricular assist device. Despite antifungal treatment, the patient died 3 weeks after transplantation because of multi-organ failure secondary to IA. The isolated Aspergillus strains exhibited in vitro resistance to caspofungin.

Voriconazole in the Treatment of Invasive Aspergillosis in Kidney Transplant Recipients

BACKGROUND

Aspergillosis and other invasive mold infections are severe complications in immunosuppressed patients, and in renal transplant patients it is the most common cause of systemic fungal disease with an incidence ranging from 0.4% to 2.4% with a high mortality of 56% to 100%. We present our experience with voriconazole in a population of kidney transplant recipients with invasive aspergillosis.

PATIENTS AND METHODS

From January 2002 to December 2005, 245 kidney transplantations were performed.

RESULTS

Four patients (1.6%) presented with clinical and laboratory findings of invasive aspergillosis. Three patients presented with pulmonary aspergillosis, while one patient presented with pulmonary and ocular aspergillosis. All patients underwent a therapy with voriconazole 200 mg twice a day, in combination with caspofungin in one patient. All patients are alive, with no clinical recurrence of aspergillosis at a median follow-up of 13 months. One patient lost her graft due to discontinuation of immunosuppression.

CONCLUSIONS

Voriconazole is a potent and well-tolerated antifungal drug that is extremely efficacious in the treatment of invasive aspergillosis in kidney transplant recipients. A careful monitoring of immunosuppressive drugs should be considered to avoid nephrotoxicity.

Combination antifungal therapy: what can and should we expect?

Invasive fungal infections are associated with significant morbidity and mortality among immunocompromised patients. Recent advances in antifungal development have afforded us more pharmacologic compounds to choose from when managing these fungal infections. The role of combination antifungal therapy has been well established for fungal infections such as cryptococcal meningitis. The availability of new antifungals, increased incidence of mould infections and high mortality among certain affected populations, such as hematopoietic stem cell transplant recipients, has stimulated interest in the clinical use of combination antifungal therapy. In this paper, we review supporting evidence for the use of combination antifungals in the treatment of cryptococcal meningitis, invasive candidiasis, invasive aspergillosis and zygomycosis. Several controlled clinical trials have demonstrated benefits of combination antifungal approaches for patients with cryptococcal meningitis and invasive candidiasis, but variable effects when using different agents in combination have been reported. Randomized prospective studies of combination antifungal therapy in mould infections are lacking but some series provide supportive evidence for this approach. We also describe limitations of the data and these study designs, including the fact that we still need randomized controlled multicenter studies of combination antifungal therapy for mould infections. Trials in this area should be performed with efficiency and economics in mind, and could potentially use surrogate markers as end points. Therefore, we suggest future investigations of combination antifungal therapy should include a randomized, comparative trial of primary therapy for invasive aspergillosis.

Update in infectious diseases in liver transplant recipients

The prevention and management of bacterial, fungal, and viral infections are important components in the care of the liver transplant recipient. Although much progress has been made, challenges still remain. This article provides updates on the management of bilomas and peritonitis, the prevention and management of invasive Candida and Aspergillus infections, the prevention and management of cytomegalovirus disease, and the current status of liver transplantation in HIV-infected patients.

Infecciones en el paciente con trasplante renal y pancreático

Infection can lead to graft loss and death in patients undergoing kidney and double kidney-pancreas transplantation. In this review, the prophylactic measures, the post-transplant timeline for the development of infections, and the most frequent infectious complications in patients with kidney and pancreas transplantation are described. Although great advances have been achieved in the prevention of infections, new problems have developed. Nosocomial bacterial infection with multidrug-resistant bacteria is an emerging complication. Cytomegalovirus is still the most frequent viral infection despite the advances in prevention measures. Moreover, in recent years polyomavirus type BK infection has been recognized as a major cause of renal graft loss. Knowledge of the infectious complications associated with these transplants and the risk factors for their occurrence will allow optimal therapeutic management of this patient population.

New approaches to invasive fungal infections in acute leukemia and hematopoietic stem cell transplant patients

Recognition and treatment of invasive fungal infections in acute leukemia and hematopoietic stem cell transplant patients are important clinical challenges. New diagnostic tools, such as fungal serologic assays and high-resolution CT scans, offer the hope for earlier initiation of antifungal therapy and improved treatment results. New antifungal agents offer choices that in some cases are less toxic than older drugs and in other cases are more efficacious. Combining the new diagnostic tools with new drugs, novel strategies are being evaluated to change our approaches to these deadly infections.

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.

Invasive aspergillosis following hematopoietic cell transplantation: outcomes and prognostic factors associated with mortality

BACKGROUND

Invasive aspergillosis (IA) is a leading cause of infection-related mortality following hematopoietic cell transplantation (HCT). The aim of this study was to determine the probability of survival and prognostic factors associated with outcomes over a long period of time.

METHODS

Cases of proven and probable IA diagnosed in HCT recipients at the Fred Hutchinson Cancer Research Center from 1 January 1990 through 31 December 2004 were included. Patient data were collected from a prospectively maintained database and by retrospective clinical chart review. Survival was estimated using Kaplan-Meier curves, and Cox regression models were used for multivariable analyses.

RESULTS

Four hundred five cases were identified. The probability of survival at 90 days after diagnosis was higher for patients identified as having IA between 2002 and 2004 than for patients whose IA was diagnosed in preceding years (45% vs. 22%; P<.001). Risk factors independently associated with all-cause mortality include impairment in pulmonary function before HCT, receipt of human leukocyte antigen-mismatched stem cells, neutropenia, elevated bilirubin and creatinine levels, receipt of corticosteroids at > or =2 mg/kg per day, disseminated and proven IA, and IA occurring >40 days after HCT. Factors associated with a decreased risk of all-cause mortality included receipt of nonmyeloablative conditioning and peripheral blood stem cells. In a subanalysis of attributable mortality restricted to patients receiving antifungal therapy, receipt of voriconazole was independently associated with protection from IA-related death.

CONCLUSIONS

There has been a significant decrease in mortality in patients with a diagnosis of IA following HCT in recent years, coinciding with multiple changes in transplantation practices, including use of nonmyeloablative conditioning regimens, receipt of peripheral blood stem cells, more prompt diagnosis of IA, and use of voriconazole.

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.

Nosocomial fungal infections: epidemiology, diagnosis, and treatment

Invasive fungal infections are increasingly common in the nosocomial setting. Furthermore, because risk factors for these infections continue to increase in frequency, it is likely that nosocomial fungal infections will continue to increase in frequency in the coming decades. The predominant nosocomial fungal pathogens include Candida spp., Aspergillus spp., Mucorales, Fusarium spp., and other molds, including Scedosporium spp. These infections are difficult to diagnose and cause high morbidity and mortality despite antifungal therapy. Early initiation of effective antifungal therapy and reversal of underlying host defects remain the cornerstones of treatment for nosocomial fungal infections. In recent years, new antifungal agents have become available, resulting in a change in standard of care for many of these infections. Nevertheless, the mortality of nosocomial fungal infections remains high, and new therapeutic and preventative strategies are needed.

Voriconazole: a broad spectrum triazole for the treatment of serious and invasive fungal infections

For many years, serious systemic fungal infections have been treated with amphotericin B or narrow-spectrum azole antifungals. These treatments have been effective in many patients, but are associated with tolerability or pharmacokinetic concerns, or suboptimal antifungal activity in some patient groups. Voriconazole is a second-generation triazole with an extended spectrum of activity offering the potential to treat life-threatening fungal infections. The drug is available for intravenous or oral administration and has been shown to be effective in invasive aspergillosis, fluconazole-susceptible and -resistant candidiasis, and infections caused by various other fungal pathogens, including some formerly refractory organisms. Voriconazole is generally well tolerated with transient visual disturbances, liver enzyme abnormalities and skin rashes being the most common adverse events reported, but these rarely lead to treatment discontinuation.

Voriconazole prophylaxis in lung transplant recipients

Lung transplant recipients have one of the highest rates of invasive aspergillosis (IA) in solid organ transplantation. We used a single center, nonrandomized, retrospective, sequential study design to evaluate fungal infection rates in lung transplant recipients who were managed with either universal prophylaxis with voriconazole (n = 65) or targeted prophylaxis (n = 30) with itraconazole +/- inhaled amphotericin in patients at high risk (pre- or posttransplant Aspergillus colonization [except Aspergillus niger]). The rate of IA at 1 year was better in lung transplant recipients receiving voriconazole prophylaxis as compared to the cohort managed with targeted prophylaxis (1.5% vs. 23%; p = 0.001). Twenty-nine percent of cases in the targeted prophylaxis group were in patients colonized with A. niger who did not receive itraconazole. A three-fold or higher increase in liver enzymes was noted in 37-60% of patients receiving voriconazole prophylaxis as compared to 15-41% of patients in the targeted prophylaxis cohort. Fourteen percent in the voriconazole group as compared to 8% in the targeted prophylaxis group had to discontinue antifungal medications due to side effects. Voriconazole prophylaxis can be used in preventing IA in lung transplant recipients. Regular monitoring of liver enzymes and serum concentrations of calcineurin inhibitors are required to avoid hepatotoxicity and nephrotoxicity.

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.

Is combination antifungal therapy for invasive aspergillosis a necessity in hematopoietic stem-cell transplant recipients?

PURPOSE OF REVIEW

The use of combination antifungal therapy in hematopoietic stem-cell transplantation patients is controversial and limited by a paucity of controlled data. The recent literature is reviewed and the relative arguments for and against combination antifungal therapy are outlined with summative recommendations to assist practitioners in decision-making.

RECENT FINDINGS

There is an abundance of in-vitro and murine in-vivo combination antifungal literature, whereas clinical data are less abundant and controlled. Of the published case series there is a suggested benefit to combination therapy over monotherapy, although there are limitations to the available literature. Other issues in the combination debate that are addressed include the following: improved response rates and a survival advantage have been demonstrated in recent monotherapy studies; response rates in most published combination therapy studies do not suggest large gains over monotherapy; the lack of sustained survival advantage to combination therapy studies; and finally the consideration of host defenses in treatment responses.

SUMMARY

Based on available data, combination therapy is not warranted at the initial diagnosis of invasive aspergillosis. Randomized, controlled trials with rigorous study design are needed.

The rationale of combination antifungal therapy in severely immunocompromised patients: empiricism versus evidence-based medicine

PURPOSE OF REVIEW

Despite expansion of the antifungal armamentarium over the past decade, the mortality rate for invasive fungal infections remains high in severely immunocompromised patients. Furthermore, in recent years, difficult-to-treat invasive infections caused by rare molds and yeasts have emerged in high-risk patients receiving antifungal prophylaxis or empirical treatment. Antifungal combinations are increasingly used in clinical practice to improve outcomes for refractory mycoses because of the suboptimal efficacy of current antifungal agents. Herein we review recent advances in the area of antifungal combinations in high-risk patients to separate empiricism from evidence-based medicine.

RECENT FINDINGS

Thus far, the benefits of combination antifungal therapy have been difficult to prove for invasive fungal infections other than cryptococcal meningitis. The recent introduction of a new class of antifungal agents (the echinocandins) and extended-spectrum triazoles has rejuvenated interest in studying those combinations for difficult-to-treat aspergillosis, as recent observational studies show promise.

SUMMARY

In view of the evolving epidemiology of invasive fungal infections, combination antifungal therapy could be most valuable in preemptive management of carefully selected high-risk patients; however, this should be studied in appropriate trials.

Invasive aspergillosis in the recipients of liver retransplantation

Retransplantation is a major risk factor for invasive aspergillosis in liver transplant recipients. However, the risk for invasive aspergillosis with time elapsed since retransplantation, clinical characteristics, and outcome of patients who develop this infection after retransplantation of the liver has not been defined. Patients comprised 17 liver retransplant recipients with invasive aspergillosis between 1990 and 2004. Retransplantation was considered early if it was performed within 30 days and late if performed after 30 days of the first or primary transplant. Retransplant recipients comprised 25% of all cases of invasive aspergillosis after liver transplantation. Fifty-three percent of the Aspergillus infections occurred within 30 days, and 76% within 90 days of retransplantation. In all, 53% (9/17) of the patients were late retransplant recipients. Late compared to early retransplant recipients with invasive aspergillosis were more likely to have central nervous system involvement with invasive aspergillosis (56% vs. 0%, P = 0.03). Mortality rate was 100% for late and 63% for early retransplant recipients with Aspergillus infections. In conclusion, time-varying risk for invasive aspergillosis after retransplantation has implications relevant for guiding antifungal prophylaxis. Given a greater risk for disseminated infection and poor outcome in late retransplant recipients with aspergillosis, potent and aggressive antifungal therapy should be considered upfront in these patients.

Prophylaxis and Treatment for Invasive Fungal Infections in Solid Organ Transplant Recipients

Solid organ transplantation is becoming increasingly common in Japan. Despite invasive fungal infections being less common than bacterial and viral infections, fungal infections still result in a higher mortality rate. Empiric and pre-emptive therapy plays an important role in management of invasive fungal infections, because successful treatment is difficult after a definite diagnosis of an invasive disease, especially invasive aspergillosis. Given this situation, to improve outcome, high risk patients need to be identified and antifungal prophylaxis is mandatory in preventing the development of the disease. However, antifungal prophylaxis for solid organ transplant recipients remains controversial. New antifungal agents might change the choice of fungal prevention and treatment.