Treatment of aspergillosis: clinical practice guidelines of the Infectious Diseases Society of America

Patterns of susceptibility of Aspergillus isolates recovered from patients enrolled in the Transplant-Associated Infection Surveillance Network

We analyzed antifungal susceptibilities of 274 clinical Aspergillus isolates from transplant recipients with proven or probable invasive aspergillosis collected as part of the Transplant-Associated Infection Surveillance Network (TRANSNET) and examined the relationship between MIC and mortality at 6 or 12 weeks. Antifungal susceptibility testing was performed by the Clinical and Laboratory Standards Institute (CLSI) M38-A2 broth dilution method for amphotericin B (AMB), itraconazole (ITR), voriconazole (VOR), posaconazole (POS), and ravuconazole (RAV). The isolate collection included 181 Aspergillus fumigatus, 28 Aspergillus niger, 27 Aspergillus flavus, 22 Aspergillus terreus, seven Aspergillus versicolor, five Aspergillus calidoustus, and two Aspergillus nidulans isolates and two isolates identified as Aspergillus spp. Triazole susceptibilities were < or = 4 microg/ml for most isolates (POS, 97.6%; ITR, 96.3%; VOR, 95.9%; RAV, 93.5%). The triazoles were not active against the five A. calidoustus isolates, for which MICs were > or = 4 microg/ml. AMB inhibited 93.3% of isolates at an MIC of < or = 1 microg/ml. The exception was A. terreus, for which 15 (68%) of 22 isolates had MICs of >1 microg/ml. One of 181 isolates of A. fumigatus showed resistance (MIC > or = 4 microg/ml) to two of three azoles tested. Although there appeared to be a correlation of higher VOR MICs with increased mortality at 6 weeks, the relationship was not statistically significant (R2 = 0.61; P = 0.065). Significant relationships of in vitro MIC to all-cause mortality at 6 and 12 weeks for VOR or AMB were not found.

Wild-type MIC distribution and epidemiological cutoff values for Aspergillus fumigatus and three triazoles as determined by the Clinical and Laboratory Standards Institute broth microdilution methods

Antifungal susceptibility testing of Aspergillus species has been standardized by both the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Recent studies suggest the emergence of strains of Aspergillus fumigatus with acquired resistance to azoles. The mechanisms of resistance involve mutations in the cyp51A (sterol demethylase) gene, and patterns of azole cross-resistance have been linked to specific mutations. Studies using the EUCAST broth microdilution (BMD) method have defined wild-type (WT) MIC distributions, epidemiological cutoff values (ECVs), and cross-resistance among the azoles. We tested a collection of 637 clinical isolates of A. fumigatus for which itraconazole MICs were < or = 2 microg/ml against posaconazole and voriconazole using the CLSI BMD method. An ECV of < or = 1 microg/ml encompassed the WT population of A. fumigatus for itraconazole and voriconazole, whereas an ECV of < or = 0.25 microg/ml was established for posaconazole. Our results demonstrate that the WT distribution and ECVs for A. fumigatus and the mold-active triazoles were the same when determined by the CLSI or the EUCAST BMD method. A collection of 43 isolates for which itraconazole MICs fell outside of the ECV were used to assess cross-resistance. Cross-resistance between itraconazole and posaconazole was seen for 53.5% of the isolates, whereas cross-resistance between itraconazole and voriconazole was apparent in only 7% of the isolates. The establishment of the WT MIC distribution and ECVs for the azoles and A. fumigatus will be useful in resistance surveillance and is an important step toward the development of clinical breakpoints.

The antifungal activity of Sarcococca saligna ethanol extract and its combination effect with fluconazole against different resistant Aspergillus species

Microbial resistance is a major drawback in chemotherapy of microbial or fungal infection disease. In this study, the antifungal activity of ethanol extract of a selected plant (Sarcococca saligna) has been investigated against clinical isolates of Aspergillus niger, Aspergillus treus, Aspergillus flavus, and Aspergillus fumigatus. Also, the enhancement of the antifungal activity of fluconazole by this extract was further evaluated against mentioned test strains. Conventional disk diffusion method was used to assay the antifungal activity of S. saligna ethanol extract in the absence and presence of fluconazole. The highest antifungal activity was observed against A. treus. The ethanol extract of S. saligna enhanced the antifungal activity of fluconazole against A. niger and A. treus and A. flavus. At the highest tested contents (4 mg/disk), 1.15-, 0.64-, and 2.47-fold increases in inhibition zone surface area were observed for A. niger, A. treus, and A. flavus, respectively. However, no enhancing effect was observed for this plant extract against Aspergillus fumigates at tested contents (0.5, 1, 2, 3, and 4 mg/disk). In a separate experiment, the general cytotoxicity of the ethanol extract of S. saligna was examined with brine shrimp assay. This plant extract showed low cytotoxicity against Artemia salina (LC(50) = 186 microg/ml).

Economic considerations in the treatment of invasive aspergillosis: a review of voriconazole pharmacoeconomic studies

Invasive aspergillosis is a life-threatening fungal infection predominately affecting immunocompromised individuals. The incidence of inpatient-treated aspergillosis cases in the US is estimated to be between 3.02 and 3.80 per 10,000 hospitalized patients. The estimated difference in hospital costs of patients with an aspergillosis infection is US$36,867 to US$59,356 higher than those of patients without the infection. Voriconazole is a synthetic, broad spectrum triazole antifungal agent, with FDA-approved indications for the treatment of invasive aspergillosis, esophageal candidiasis, candidemia in nonneutropenic patients, invasive candidiasis, and infections due to Scedosporium apiospermum and Fusarium species in patients refractory to or intolerant of other therapy. Eight cost-effectiveness analyses, one cost-minimization analysis, and one cost analysis were identified from a Medline search. The 10 pharmacoeconomic analyses were conducted in six different countries comparing voriconazole to conventional amphotericin B, liposomal amphotericin B, itraconazole, and caspofungin. All the cost-effectiveness and cost-minimization analyses identified voriconazole as the most cost-effective therapy. The cost analysis demonstrated voriconazole cost-savings. While the acquisition costs of voriconazole are higher than those of conventional amphotericin B, the toxicity profile and rate of treatment success associated with voriconazole result in lower total treatment costs per successfully treated patient.

[Infectious pulmonary complications of rheumatic diseases]

Infectious complications are a central problem in the treatment of patients with rheumatic diseases. The increased infection rate is mainly caused by immunosuppressive medication, particularly glucocorticoids. A more aggressive diagnostic approach, often including bronchoscopic procedures, is often necessary to obtain samples for microbiological examinations. In immuno-compromised patients the failure of a calculated empiric antibiotic therapy is associated with a higher risk of fatal outcome. Among possible opportunistic infections Pneumocystis jirovecii pneumonia (PCP), invasive aspergillosis and CMV reactivations are most relevant. Furthermore, particularly with the use of TNF-blocking agents, reactivation of latent tuberculosis (TB) might be observed. There are only a few situations in which anti-infective chemo-prophylaxis is established: In the case of latent TB INH-prophylaxis should be given when anti-TNF-therapy is considered. There is evidence in favour of PCP prophylaxis with trimethoprim/cotrimoxazole in patients receiving intense immunosuppression with high dose glucocorticoids and cyclophosphamide.

Management of invasive aspergillosis in patients with COPD: rational use of voriconazole

Invasive pulmonary aspergillosis (IPA) is an important cause of mortality in patients with hematologic malignancies. The reported incidence of IPA in the context of chronic obstructive pulmonary disease (COPD) seems to increase. Approximately 1%-2% of overall fatal cases of IPA occur in COPD patients. The combination of factors such as lung immune imbalance, long-term corticosteroid use, increasing rate of bacterial exacerbations over time, and malnutrition are responsible for the emergence of IPA in these patients. The diagnosis of IPA is difficult to establish, which explains the delay in implementing accurate antifungal therapy and the high mortality rate. Persistent pneumonia nonresponsive to appropriate antibiotic treatment raises the concern of an invasive fungal infection. Definite diagnosis is obtained from tissue biopsy evidencing Aspergillus spp. on microscopic examination or in culture. Culture and microscopy of respiratory tract samples have a sensitivity and specificity of around 50%. Other diagnostic tools can be useful in documenting IPA: computed tomography (CT) scan, nonculture-based tests in serum and/or in bronchoalveolar lavage such as antibody/antigen tests for Aspergillus spp. More recent tools such as polymerase chain reaction or [1-->3]-beta-D-glucan have predictive values that need to be further investigated in COPD patients. Antifungal monotherapy using azole voriconazole is recommended as a first-line treatment of IPA. This review assesses the use of voriconazole in COPD patients.

A risk profile for invasive aspergillosis in liver transplant recipients

BACKGROUND

Given the high incidence (1.5%-10%) of invasive aspergillosis (IA) after liver transplantation and the associated mortality, prophylaxis according to the patients' circumstances is a reasonable approach. The purpose of this investigation was to determine the effect and significance of risk factors for IA in a specialized transplantation center.

METHODS

We collected data from patients who underwent liver transplantation at the Transplantation Center of the University Hospital Heidelberg (Germany) between December 2001 and December 2004 in a specifically designed database for retrospective analysis. Invasive aspergillosis was defined according to the European Organization for Research and Treatment of Cancer classifications. Univariate analysis and logistic regression were performed to assess the influence of each assumed risk factor.

RESULTS

A total of 195 liver transplantations were performed in 170 patients, with two patients (1.2%) developing a proven IA, seven (4.1%) developing a probable IA, and five developing a possible IA (2.9%). All patients received oral itraconazole prophylaxis. Of these 14 patients with proven, probable or possible IA, 13 died within 4 weeks after the initial diagnosis; this represents 33.3% of all patients with a fatal outcome. Univariate significant factors were retransplantation (p = 0.004), cytomegalovirus (CMV) infection (p = 0.024), dialysis (p < 0.001), renal insufficiency (p = 0.05), thrombocytopenia (p = 0.001), and leukocytopenia (p = 0.002). Multivariate analysis showed an independent influence of CMV infection (OR 6.032, 95% CI 1.446-25.163) and dialysis (OR 14.985, 95%CI 2.936-76.486).

CONCLUSION

The rate of IA found in this investigation is within the range reported in published studies. Based on our data, extended antifungal prophylaxis should be given to liver transplant patients with specific risk factors, such as renal insufficiency, requirement for dialysis, CMV infection, or thrombocytopenia. Additional focus should be on the prevention of CMV infections.

Noninvasive pulmonary Aspergillus infections

Aspergillus can cause several forms of pulmonary disease ranging from colonization to invasive aspergillosis and largely depends on the underlying lung and immune function of the host. This article reviews the clinical presentation, diagnosis, pathogenesis, and treatment of noninvasive forms of Aspergillus infection, including allergic bronchopulmonary aspergillosis (ABPA), aspergilloma, and chronic pulmonary aspergillosis (CPA). ABPA is caused by a hypersensitivity reaction to Aspergillus species and is most commonly seen in patients who have asthma or cystic fibrosis. Aspergillomas, or fungus balls, can develop in previous areas of cavitary lung disease, most commonly from tuberculosis. CPA has also been termed semi-invasive aspergillosis and usually occurs in patients who have underlying lung disease or mild immunosuppression.

Invasive Aspergillus fumigatus infection after Plasmodium falciparum malaria in an immuno-competent host: case report and review of literature

Invasive fungal infection is rarely reported in association with malaria, even though malaria-associated inhibition of phagocyte function is a well-known condition. Invasive aspergillosis is frequently found in severely immuno-compromised patients but not in healthy individuals. Here, a case of pulmonary invasive aspergillosis in a previously healthy patient with severe P. falciparum malaria is presented, who was successfully treated with voriconazol and caspofungin. This is the first survival of malaria-associated invasive aspergillosis.

Isolated diffuse invasive renal aspergillosis in an immunocompromized patient due to longstanding steroid treatment: a case report

A 53-year-old Indian lady suffered from type 2 diabetes and hypothyroidism and was on longstanding steroid therapy. She was urgently admitted to the hospital with a high white cell count and high creatinine. On imaging no space occupying lesions were shown. In spite of intensive therapy the patient died a week after admission. Post mortem examination revealed markedly enlarged kidneys with areas of necrosis, hemorrhagic infarction, inflammatory response and granulomas related to the widespread glomerular, tubulo-interstitial and vascular involvement by aspergillus. Renal disease may present as bilateral diffuse parenchymal involvement with blood vessel invasion causing organ failure.

Approaches to the Management of Invasive Fungal Infections in Hematologic Malignancy and Hematopoietic Cell Transplantation

Patients with hematologic malignancy and hematopoietic cell transplant (HCT) recipients are at increased risk for invasive fungal infection (IFI) as a result of immunosuppression or organ damage stemming from their underlying disease, its treatment, or both. Such IFIs can cause significant morbidity and mortality, and the diagnosis and treatment of infected patients frequently are clinically challenging. This article discusses the epidemiology and risk factors for IFI in patients with hematologic malignancy and HCT recipients. The pros and cons of available antifungal agents are discussed, and evolving treatment strategies and recent prophylaxis guidelines from various professional organizations are reviewed. Finally, recommendations are offered for antifungal prophylaxis according to risk group.

Invasive aspergillosis due to Neosartorya udagawae

BACKGROUND

Invasive aspergillosis (IA) is most commonly caused by the morphospecies Aspergillus fumigatus. However, genetic-based methods indicate that organisms phenotypically identified as A. fumigatus actually constitute a mold complex, designated Aspergillus section fumigati subgenus fumigati.

METHODS

Multilocus sequencing and analysis was performed on fungi identified as A. fumigatus from the clinical culture collection maintained at the National Institutes of Health from 2000 through 2008, with a focus on the internal transcribed spacer 1 and 2 regions of ribosomal DNA (rDNA), beta-tubulin, and rodlet A genes. We reviewed the medical records, radiology, and histopathology of corresponding patients. To confirm identification of Neosartorya udagawae isolates, mating studies were performed with reference strains. Antifungal susceptibility testing was performed by broth microdilution and read at 48 hours.

RESULTS

Thirty-six cases of infection attributed to A. fumigatus were identified; 4 were caused by N. udagawae (3 in patients with chronic granulomatous disease and 1 in a patient with myelodysplastic syndrome). Disease due to N. udagawae was chronic, with a median duration of 35 weeks, compared with a median duration of 5.5 weeks for patients with chronic granulomatous disease who had infection due to A. fumigatus sensu stricto (P < .05 , Mann-Whitney U test). Infection spread across anatomical planes in a contiguous manner and was refractory to standard therapy. Two of the 4 patients died. N. udagawae demonstrated relatively higher minimum inhibitory concentrations to various agents, compared with those demonstrated by contemporary A. fumigatus sensu stricto isolates.

CONCLUSIONS

To our knowledge, this is the first report documenting infection due to N. udagawae. Clinical manifestations were distinct from those of typical IA. Fumigati-mimetics with inherent potential for antifungal resistance are agents of IA. Genetic identification of molds should be considered for unusual or refractory IA.

Dose tolerability of chronically inhaled voriconazole solution in rodents

Invasive pulmonary aspergillosis (IPA) is a fungal disease of the lung associated with high mortality rates in immunosuppressed patients despite treatment. Targeted drug delivery of aqueous voriconazole solutions has been shown in previous studies to produce high tissue and plasma drug concentrations as well as improved survival in a murine model of IPA. In the present study, rats were exposed to 20 min nebulizations of normal saline (control group) or aerosolized aqueous solutions of voriconazole at 15.625 mg (low dose group) or 31.25mg (high dose group). Peak voriconazole concentrations in rat lung tissue and plasma after 3 days of twice daily dosing in the high dose group were 0.85+/-0.63 microg/g wet lung weight and 0.58+/-0.30 microg/mL, with low dose group lung and plasma concentrations of 0.38+/-0.01 microg/g wet lung weight and 0.09+/-0.06 microg/mL, respectively. Trough plasma concentrations were low but demonstrated some drug accumulation over 21 days of inhaled voriconazole administered twice daily. Following multiple inhaled doses, statistically significant but clinically irrelevant abnormalities in laboratory values were observed. Histopathology also revealed an increase in the number of alveolar macrophages but without inflammation or ulceration of the airway, interstitial changes, or edema. Inhaled voriconazole was well tolerated in a rat model of drug inhalation.

Nephrogenic diabetes insipidus induced by two amphotericin B liposomal formulations

Immunocompromised patients are at risk for invasive molds and resistant fungal infections for which amphotericin B may be the only feasible treatment. Nephrogenic diabetes insipidus (DI) and renal tubular acidosis are known adverse effects of conventional amphotericin B; however, nephrogenic DI has been uncommonly associated with liposomal amphotericin B formulations. We describe an 18-year-old woman with aplastic anemia who developed invasive aspergillosis. She began treatment with high-dose (10 mg/kg/day) liposomal amphotericin B at home; however, her condition worsened, and she was hospitalized. Therapy with liposomal amphotericin B was continued until the patient began having symptoms consistent with nephrogenic DI. These symptoms resolved after discontinuation of liposomal amphotericin B; however, after rechallenge with lipid complex amphotericin B (5 mg/kg/day), the symptoms returned. The patient's nephrogenic DI was successfully treated with diuretics. Use of the Naranjo adverse drug reaction probability scale score indicated a probable relationship between liposomal amphotericin B and the development of nephrogenic DI. To our knowledge, this is the third report of nephrogenic DI induced by liposomal amphotericin B. This adverse effect is one of many severe adverse effects caused by all formulations of amphotericin B. A clear understanding of these adverse effects is vital for the clinician to successfully weigh the risks and benefits of antifungal therapy.

Liposomal amphotericin B: a review of its use as empirical therapy in febrile neutropenia and in the treatment of invasive fungal infections

Liposomal amphotericin B (AmBisome) is a lipid-associated formulation of the broad-spectrum polyene antifungal agent amphotericin B. It is active against clinically relevant yeasts and moulds, including Candida spp., Aspergillus spp. and filamentous moulds such as Zygomycetes, and is approved for the treatment of invasive fungal infections in many countries worldwide. It was developed to improve the tolerability profile of amphotericin B deoxycholate, which was for many decades considered the gold standard of antifungal treatment, despite being associated with infusion-related events and nephrotoxicity. In well controlled trials, liposomal amphotericin B had similar efficacy to amphotericin B deoxycholate and amphotericin B lipid complex as empirical therapy in adult and paediatric patients with febrile neutropenia. In addition, caspofungin was noninferior to liposomal amphotericin B as empirical therapy in adult patients with febrile neutropenia. For the treatment of confirmed invasive fungal infections, liposomal amphotericin B was more effective than amphotericin B deoxycholate treatment in patients with disseminated histoplasmosis and AIDS, and was noninferior to amphotericin B deoxycholate in patients with acute cryptococcal meningitis and AIDS. In adults, micafungin was shown to be noninferior to liposomal amphotericin B for the treatment of candidaemia and invasive candidiasis. Data from animal studies suggested that higher dosages of liposomal amphotericin B might improve efficacy; however, in the AmBiLoad trial in patients with invasive mould infection, there was no statistical difference in efficacy between the standard dosage of liposomal amphotericin B 3 mg/kg/day and a higher 10 mg/kg/day dosage, although the standard dosage was better tolerated. Despite being associated with fewer infusion-related adverse events and less nephrotoxicity than amphotericin B deoxycholate and amphotericin B lipid complex, liposomal amphotericin B use is still limited to some extent by these adverse events. Both echinocandins were better tolerated than liposomal amphotericin B. The cost of liposomal amphotericin B therapy may also restrict its use, but further pharmacoeconomic studies are required to fully define its cost effectiveness compared with other antifungal agents. Based on comparative data from well controlled trials, extensive clinical experience and its broad spectrum of activity, liposomal amphotericin B remains a first-line option for empirical therapy in patients with febrile neutropenia and in those with disseminated histoplasmosis, and is an option for the treatment of AIDS-associated cryptococcal meningitis, and for invasive Candida spp. or Aspergillus spp. infections. Amphotericin B, a macrocyclic, polyene antifungal agent, is thought to act by binding to ergosterol, the principal sterol in fungal cell membranes and Leishmania cells. This results in a change in membrane permeability, causing metabolic disturbance, leakage of small molecules and, as a consequence, cell death. In vitro and in vivo studies have shown that liposomal amphotericin B remains closely associated with the liposomes in the circulation, thereby reducing the potential for nephrotoxicity and infusion-related toxicity associated with conventional amphotericin B. Amphotericin B shows very good in vitro activity against a broad spectrum of clinically relevant fungal isolates, including most strains of Candida spp. and Aspergillus spp., and other filamentous fungi such as Zygomycetes. Liposomal amphotericin B has proven effective in various animal models of fungal infections, including those for candidiasis, aspergillosis, fusariosis and zygomycosis. Liposomal amphotericin B also shows immunomodulatory effects, although the mechanisms involved are not fully understood, and differ from those of amphotericin B deoxycholate and amphotericin B colloidal dispersion. In adult patients with febrile neutropenia, intravenous liposomal amphotericin B has nonlinear pharmacokinetics, with higher than dose-proportional increases in exposure being consistent with reticuloendothelial saturation and redistribution of amphotericin B in the plasma compartment. Liposomal amphotericin B is rapidly and extensively distributed after single and multiple doses, with steady-state concentrations of amphotericin B attained within 4 days and no clinically relevant accumulation of the drug following multiple doses of 1-7.5 mg/kg/day. In autopsy tissue, the highest concentrations of the drug were found in the liver and spleen, followed by the kidney, lung, myocardium and brain tissue. Elimination of liposomal amphotericin B, like that of amphotericin B deoxycholate, is poorly understood; its route of metabolism is not known and its excretion has not been studied. The terminal elimination half-life is about 7 hours. No dosage adjustment is required based on age or renal impairment. In several randomized, double-blind trials (n = 73-1095) in adult and/or paediatric patients, liposomal amphotericin B was effective as empirical therapy or as treatment for confirmed invasive fungal infections, including invasive candidiasis, candidaemia, invasive mould infection (mainly aspergillosis), histoplasmosis and cryptococcal meningitis. All agents were administered as an intravenous infusion; the typical dosage for liposomal amphotericin B was 3 mg/kg/day. Treatment was generally given for 1-2 weeks. Participants in trials evaluating empirical therapy had neutropenia and a persistent fever despite antibacterial treatment and had received chemotherapy or undergone haematopoietic stem cell transplantation. As empirical therapy in adult and paediatric patients, liposomal amphotericin B appeared to be as effective as amphotericin B deoxycholate (approximately 50% of patients in each group achieved treatment success) or amphotericin B lipid complex (approximately 40% of liposomal amphotericin B recipients experienced treatment success). Of note, in the first trial, results of the statistical test to determine equivalence between treatments were not reported. In the second trial, efficacy was assessed as an 'other' endpoint. In another trial, caspofungin was shown to be noninferior to liposomal amphotericin B, with approximately one-third of patients in each group experiencing treatment success. Liposomal amphotericin B was significantly more effective than amphotericin B deoxycholate for the treatment of moderate to severe disseminated histoplasmosis in patients with AIDS, with 88% and 64% of patients, respectively, having a successful response. Liposomal amphotericin B was noninferior to amphotericin B deoxycholate for the treatment of cryptococcal meningitis in terms of mycological success. Micafungin therapy was shown to be noninferior to liposomal amphotericin B for the treatment of adult patients with candidaemia or invasive candidiasis. In a substudy in paediatric patients, which was not powered to determine noninferiority, liposomal amphotericin B was as effective as micafungin for the treatment of candidaemia or invasive candidiasis. In this patient population, within each trial, 90% of adult patients and approximately three-quarters of paediatric patients in both treatment groups experienced a successful response. In patients with invasive mould infection (mainly aspergillosis), there was no difference in efficacy between a higher dosage of liposomal amphotericin B (10 mg/kg/day) and the standard dosage (3 mg/kg/day), with 46% and 50% of patients experiencing a favourable overall response. In well designed clinical trials, liposomal amphotericin B was generally at least as well tolerated as other lipid-associated formulations of amphotericin B and better tolerated than amphotericin B deoxycholate in adult and paediatric patients. Compared with other amphotericin B formulations, liposomal amphotericin B treatment was associated with a lower incidence of infusion-related adverse events and nephrotoxicity. A higher than recommended dosage of liposomal amphotericin B (10 mg/kg/day) was associated with an increased incidence of nephrotoxicity compared with the standard dosage (3 mg/kg/day), although the incidence of infusion-related reactions did not differ between treatment groups. In general, liposomal amphotericin B treatment was not as well tolerated as echinocandin therapy in well designed clinical trials. As empirical therapy or for the treatment of confirmed invasive fungal infections in adult patients, liposomal amphotericin B recipients experienced more infusion-related events and nephrotoxicity than caspofungin or micafungin recipients. There was no difference in the incidence of these adverse events between the liposomal amphotericin B and micafungin groups in a study in paediatric patients.

Surgical management of invasive pulmonary fungal infection in hematology patients

BACKGROUND

The purpose of this study was to analyze our institutional results with pulmonary resection in neutropenic patients with hematologic malignancies and suspected invasive pulmonary fungal infections.

METHODS

We performed a retrospective medical record review of 25 immunocompromised patients with hematologic malignancies who underwent pulmonary resection between 2000 and 2007. We analyzed preoperative diagnostic technique, degree of pulmonary resection, and postoperative morbidity and mortality to determine whether surgery is a viable treatment option in this subset of patients.

RESULTS

Twenty-three of 25 patients had a minithoracotomy compared with 2 who had video-assisted thorascopic surgery resection only. Thirteen had wedge resections, 9 had lobectomies, and 3 had segmentectomies. Early surgical morbidity was 2 of 25, involving 1 pneumothorax and 1 empyema. In-hospital mortality was 2, with 1 death primarily related to surgery. Median survival was 342 days, and survival was significantly better in patients with only one lesion. No patient experienced late recurrence of invasive pulmonary fungal infection. Resected pulmonary tissue also provided the best chance for a proven diagnosis in 19 of 25 (76%).

CONCLUSIONS

This study confirms that pulmonary resection in high-risk immunocompromised patients with suspected invasive fungal infection can be carried out with excellent operative morbidity and mortality.

Review of Serum Voriconazole Concentrations and Correlations with Adverse Events and Efficacy

Objective:

To review the available evidence regarding the monitoring of serum voriconazole concentrations in terms of efficacy and safety.

Data Sources:

A literature search of MEDLINE was conducted (1950–February 2009), with combinations of the following search terms: voriconazole, therapeutic drug monitoring, voriconazole serum concentrations, voriconazole levels, trough, and adverse events.

Data Collection:

All studies and case reports that evaluated serum voriconazole concentrations in adults were reviewed and considered for inclusion. Citations in identified articles were searched for additional information.

Data Synthesis:

Ten studies and case reports that evaluated serum voriconazole concentrations in terms of efficacy and safety in adults were identified and included in this review. Results from efficacy studies show an association between low serum voriconazole concentrations and disease progression. One study found that a lack of response occurred more often in patients with a serum voriconazole trough of 1 μg/mL or less (p = 0.02). Another study found that patients were more likely to fail voriconazole therapy for invasive fungal infections when serum concentrations were less than or equal to 2 μg/mL. In terms of safety, 6 studies showed an association between elevated serum voriconazole concentrations and adverse events.

Conclusions:

Available data suggest that serum voriconazole concentrations of 1 μg/mL or less are associated with therapeutic failures, whereas serum voriconazole concentrations of 6 μg/mL or more are associated with adverse events. Studies show that monitoring serum voriconazole concentrations may decrease the incidence of adverse events while increasing efficacy.

Allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is an immunologic pulmonary disorder caused by hypersensitivity to Aspergillus fumigatus. Clinically, a patient presents with chronic asthma, recurrent pulmonary infiltrates, and bronchiectasis. The population prevalence of ABPA is not clearly known, but the prevalence in asthma clinics is reported to be around 13%. The disorder needs to be detected before bronchiectasis has developed because the occurrence of bronchiectasis is associated with poorer outcomes. Because many patients with ABPA may be minimally symptomatic or asymptomatic, a high index of suspicion for ABPA should be maintained while managing any patient with bronchial asthma whatever the severity or the level of control. This underscores the need for routine screening of all patients with asthma with an Aspergillus skin test. Finally, there is a need to update and revise the criteria for the diagnosis of ABPA. This review summarizes the advances in the diagnosis and management of ABPA using a systematic search methodology.

The role of bronchoalveolar lavage galactomannan in the diagnosis of pediatric invasive aspergillosis

BACKGROUND

: Molecular biomarkers such as the galactomannan assay are of increasing interest in clinical settings for diagnosis of invasive aspergillosis (IA). The use of bronchoalveolar lavage galactomannan (BAL GM) is being validated in adult populations, but has not been systematically evaluated in pediatric patients.

METHODS

: A retrospective analysis was performed of patients for whom GM assays from BAL were submitted between November 1, 2006 and November14, 2007 at Childrens Hospital Los Angeles. Medical charts were reviewed and patients were categorized as having no, possible, probable, and proven IA, per established definitions.

RESULTS

: Of 85 pediatric patients who had a BAL GM submitted during the study, 59 were immunocompromised. Three patients were identified as having proven IA, 6 had probable IA, 37 had possible IA, and 39 had no evidence of IA; 38 had a concurrent serum GM performed. A positive, linear correlation was established between BAL and serum GM, using OD index values (rho = 0.48, P = 0.002). Among immunocompromised patients, receiver operating characteristic curves demonstrated an optimal BAL GM OD cut-off value of 0.87, that yielded a sensitivity for probable/proven IA of 78% and a specificity of 100%. At 0.87, the positive and negative predictive values among immunocompromised patients were 58% and 96%, respectively.

CONCLUSIONS

: We found a correlation between BAL GM values and a diagnosis of IA. We also noted a linear relationship between serum and BAL GM values. Receiver operating characteristic curves obtained from our pediatric data validate the current cut off for serum and suggest a possible cut off for BAL specimens.

Invasive aspergillosis: diagnosis, prophylaxis and treatment

PURPOSE OF REVIEW

Invasive aspergillosis is a common cause of morbidity and mortality in hematopoietic stem cells transplant recipients. Owing to its intrinsic high mortality rate, early diagnosis and treatment are critical. This review will therefore address the most important recent advances in diagnosing, preventing and treating invasive aspergillosis in hematopoietic stem cells transplant.

RECENT FINDINGS

The present review will focus on therapeutic and prophylactic aspects, with particular regard to clinical use of drugs other than voriconazole (which has a well known and consolidated role for first-line therapy), combination therapy and prophylactic regimens, particularly with posaconazole. This review will also briefly deal with the clinical role of diagnostic tests such as the detection of galactomannan in body fluids other than blood, beta-D-glucan in serum and fungal DNA by PCR in body fluids.

SUMMARY

Galactomannan antigen detection is a rather reliable diagnostic test for invasive aspergillosis, particularly when a lower threshold of sensitivity is used. PCR is still to be validated. Liposomal amphotericin B at 3 mg/kg per day showed a similar efficacy in invasive aspergillosis as reported for voriconazole. Therapeutic drug monitoring of Aspergillus-active azoles should be implemented whenever possible in order to maximize the antifungal effect and minimize toxicity. Posaconazole showed to be active in prophylaxis, though its effectiveness in the global patient population is still controversial.

Echinocandin activity against Aspergillus spp. and the importance of pharmacodynamics

Echinocandins represent a safe and well tolerated option for the therapy of invasive aspergillosis in patients who are unable to tolerate other agents or have refractory disease. In vitro and animal model data provide useful insights into the activity, appropriate dose, and potential role of these agents in invasive aspergillosis. These studies reveal a potentially concerning lack of tissue sterilization when echinocandins are used as monotherapy but clearly show improved survival with increasing doses. Furthermore pharmacodynamic studies suggest that echinocandin doses currently in widespread clinical use may optimize outcomes in invasive aspergillosis. A paucity of clinical data exists examining these agents as monotherapy for invasive aspergillosis and virtually no clinical data exists for using these agents as primary therapy. Further data examining the role of echinocandin monotherapy for invasive aspergillosis is unlikely to be forthcoming in the foreseeable future due to several factors including the aforementioned issues, the relatively small number patients with this infection, and the belief that these agents are potentially best used as part of combination therapy regimens for invasive aspergillosis.

Voriconazole pharmacokinetic variability in cystic fibrosis lung transplant patients

BACKGROUND

Aspergillosis is a high-risk complication in cystic fibrosis (CF) lung transplant patients. Azole antifungal drugs inhibit CYP3A4, resulting in significant metabolic drug-drug interactions. Voriconazole (VRZ) was marketed without therapeutic drug monitoring (TDM) recommendations, consistent with favorable pharmacokinetics, but regular determinations of plasma VRZ concentration were introduced in our center to manage interactions with calcineurin inhibitors and to document the achievement of therapeutic levels.

METHODS

VRZ TDM data analysis for trough concentration (C0) and peak concentration (C2) was carried out, using validated liquid chromatography assay with ultraviolet detection, for 35 CF lung transplant patients (mean age 25 years, mean weight 47 kg, balanced sex ratio) since 2003. Therapeutic range (C0: 1.5 +/- 0.5 - C2 : 4.0 +/- 1.0 mg/L) was expressed relative to pivotal pharmacokinetic trial data.

RESULTS

The duration of VRZ treatment ranged from 9 days to 22 months. The recommended standard dose of VRZ (200 mg twice a day, following the loading dose) resulted in significant plasma concentrations (>0.5 mg/L) in 20% of CF lung transplant patients. Therapeutic concentrations were obtained using higher doses (average 570 +/- 160 mg/day, +43%, P<0.01). Despite adaptation, C0 remained <0.5 mg/L (11%), even when the drug was administered intravenously, highlighting the variability of VRZ pharmacokinetics, possibly enhanced by CYP2C19 polymorphism. The risk of inefficacy during periods of underdosage was overcome by treatment with antifungal drug combinations (caspofungin, n=10). The therapeutic index was limited by neurologic effects (14%) and hepatic abnormalities (30%). VRZ concentrations correlated significantly (P<0.01) with aspartate aminotransferase levels but not with bilirubin levels. VRZ acted as a metabolic inhibitor of tacrolimus (C0 to dose ratio 5.8 +/- 2.6, n=31/VRZ versus 1.7 +/- 0.9 alone, P<0.001). Large changes in azole concentration affected the magnitude of the drug-drug interactions and adjustment requirements.

CONCLUSIONS

TDM is required because VRZ levels are often undetectable in treated CF lung transplant patients, supporting the use of antifungal drug combinations until achievement of VRZ C0 at a steady state between 1 and 2 mg/L. Plasma VRZ concentrations should be determined for the quantitative, individualized management of drug-drug interactions in lung transplant patients, in particular immunosuppressant such as tacrolimus, considering VRZ to be both a target and an inhibitor of CYP3A4.

Use of PCR for diagnosis of invasive aspergillosis: systematic review and meta-analysis

A systematic review and meta-analysis was done on the use of PCR tests for the diagnosis of invasive aspergillosis. Data from more than 10000 blood, serum, or plasma samples obtained from 1618 patients at risk for invasive aspergillosis were retrieved from 16 studies. Overall, the mean diagnostic odds ratios (DORs) of PCR for proven and probable cases were similar whether two consecutive positive samples were required to define positivity (DOR 15.97 [95% CI 6.83-37.34]) or a single positive PCR test was required (DOR 16.41 [95% CI 6.43-41.88]). Sensitivity and specificity of PCR for two consecutive positive samples were 0.75 (95% CI 0.54-0.88) and 0.87 (95% CI 0.78-0.93), respectively, and if only a single positive sample was required, these values were 0.88 (95% CI 0.75-0.94) and 0.75 (95% CI 0.63-0.84), respectively. Whereas specificity based on a single positive test was significantly lower (p=0.027) than two positive tests, the sensitivity and DOR did not differ significantly. A single PCR-negative result is thus sufficient to exclude a diagnosis of proven or probable invasive aspergillosis. However, two positive tests are required to confirm the diagnosis because the specificity is higher than that attained from a single positive test. Populations at risk varied and there was a lack of homogeneity of the PCR methods used. Efforts are underway to devise a standard for Aspergillus sp PCR for screening, which will help enable formal validation of PCR and estimate its use in patients most likely to benefit.