Revised definitions of invasive fungal disease from the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) Consensus Group

A novel approach to the assessment of lymphocytic bronchiolitis after lung transplantation--transbronchial brush

BACKGROUND

Lymphocytic bronchiolitis (LB) is the strongest risk factor for subsequent allograft loss due to bronchiolitis obliterative syndrome (BOS); however, it is poorly assessed by transbronchial biopsy (TBBx) because of sampling error, interpretation error and the presence of non-alloimmune airway inflammation. We hypothesized that flow cytometric evaluation of bronchiolar brushings (transbronchial brush, TBBr) may be a better approach.

METHODS

Transbronchial brushings (2 to 3 cm from the pleural surface under radiologic guidance) were obtained prior to TBBx in 32 patients and analyzed by flow cytometry. We assessed the proportion of nucleated cells that were CD3(+)CD103(+) (epithelial-specific T cells).

RESULTS

No adverse events occurred; 0.5% (0.27 to 0.84) of the cells were epithelial-specific T cells and numbers increased with episodes of Grade A1 rejection (p < 0.01) and in patients with BOS (p = 0.02). Viral and invasive fungal infection were associated with marked infiltration with CD103(-) T cells (p < 0.01).

CONCLUSION

TBBr is simple to obtain, low risk, quantitative, and can discriminate between infective and alloimmune LB. It may be a valuable addition to current lung allograft assessment.

Pathogen-specific DNA enrichment does not increase sensitivity of PCR for diagnosis of invasive aspergillosis in neutropenic patients

PCR assays designed for the diagnosis of invasive aspergillosis (IA) in high-risk patients have to detect minute amounts of target DNA to reach sufficient analytical sensitivity to be of clinical use. This prospective study assessed the use of a novel strategy for selective pathogen DNA enrichment for enhancing the performance of diagnostic PCR in a direct comparison with a highly sensitive in-house quantitative PCR (qPCR) assay and the galactomannan enzyme-linked immunosorbent assay (ELISA). Surprisingly, and in contrast to experience with other patient groups, the novel protocol for selective pathogen DNA enrichment did not enhance but instead significantly impaired sensitivity. This could be explained by the small amounts of host DNA in the specimens, which were derived mostly from severely neutropenic patients. In the qPCR assay, positive samples required an average of 43.5 amplification cycles (range, 39.2 to 50) for detection in the in-house PCR. Repetitive testing of selected samples showed test positivity to be variable, most likely due to the small amounts of target DNA. Despite this, the in-house protocol proved helpful in the diagnosis of IA, detecting 2 out of 3 patients with probable IA and 10 out of 19 patients with possible IA. Our results underline the necessity for diagnostic PCR protocols that help diagnose IA to be highly sensitive and show that selective pathogen DNA enrichment using affinity purification may not be useful in severely neutropenic patients.

Intestinal damage determines the inflammatory response and early complications in patients receiving conditioning for a stem cell transplantation

Background

Stem cell transplantation (SCT) is still complicated by the occurrence of fever and inflammatory complications attributed to neutropenia and subsequent infectious complications. The role of mucosal barrier injury (MBI) of the intestinal tract therein has received little attention.

Methods

We performed a retrospective analysis in 163 SCT recipients of which data had been collected prospectively on intestinal damage (citrulline), inflammation (C-reactive protein), and neutrophil count. Six different conditioning regimens were studied; 5 myeloablative (MA) and 1 non-myeloablative (NMA). Linear mixed model multivariate and AUC analyses were used to define the role of intestinal damage in post-SCT inflammation. We also studied the relationship between the degree of intestinal damage and the occurrence of early post-SCT complications.

Results

In the 5 MA regimen there was a striking pattern of inflammatory response that coincided with the occurrence of severe intestinal damage. This contrasted with a modest inflammatory response seen in the NMA regimen in which intestinal damage was limited. With linear mixed model analysis the degree of intestinal damage was shown the most important determinant of the inflammatory response, and both neutropenia and bacteremia had only a minor impact. AUC analysis revealed a strong correlation between citrulline and CRP (Pearson correlation r = 0.96). Intestinal damage was associated with the occurrence of bacteremia and acute lung injury, and influenced the kinetics of acute graft-versus-host disease.

Conclusion

The degree of intestinal damage after myeloablative conditioning appeared to be the most important determined the inflammatory response following SCT, and was associated with inflammatory complications. Studies should explore ways to ameliorate cytotoxic therapy-induced intestinal damage in order to reduce complications associated with myeloablative conditioning therapy.

The use of mannan antigen and anti-mannan antibodies in the diagnosis of invasive candidiasis: recommendations from the Third European Conference on Infections in Leukemia

Introduction

Timely diagnosis of invasive candidiasis (IC) remains difficult as the clinical presentation is not specific and blood cultures lack sensitivity and need a long incubation time. Thus, non-culture-based methods for diagnosing IC have been developed. Mannan antigen (Mn) and anti-mannan antibodies (A-Mn) are present in patients with IC. On behalf of the Third European Conference on Infections in Leukemia, the performance of these tests was analysed and reviewed.

Methods

The literature was searched for studies using the commercially available sandwich enzyme-linked immunosorbent assays (Platelia™, Bio-Rad Laboratories, Marnes-la-Coquette, France) for detecting Mn and A-Mn in serum. The target condition of this review was IC defined according to 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria. Sensitivity, specificity and diagnostic odds ratios (DOR) were calculated for Mn, A-Mn and combined Mn/A-Mn testing.

Results

Overall, 14 studies that comprised 453 patients and 767 controls were reviewed. The patient populations included in the studies were mainly haematological and cancer cases in seven studies and mainly intensive care unit and surgery cases in the other seven studies. All studies but one were retrospective in design. Mn sensitivity was 58% (95% confidence interval [CI], 53-62); specificity, 93% (95% CI, 91-94) and DOR, 18 (95% CI 12-28). A-Mn sensitivity was 59% (95% CI, 54-65); specificity, 83% (95% CI, 79-97) and DOR, 12 (95% CI 7-21). Combined Mn/A-Mn sensitivity was 83% (95% CI, 79-87); specificity, 86% (95% CI, 82-90) and DOR, 58 (95% CI 27-122). Significant heterogeneity of the studies was detected. The sensitivity of both Mn and A-Mn varied for different Candida species, and it was the highest for C. albicans, followed by C. glabrata and C. tropicalis. In 73% of 45 patients with candidemia, at least one of the serological tests was positive before the culture results, with mean time advantage being 6 days for Mn and 7 days for A-Mn. In 21 patients with hepatosplenic IC, 18 (86%) had Mn or A-Mn positive test results at a median of 16 days before radiological detection of liver or spleen lesions.

Conclusions

Mn and A-Mn are useful for diagnosis of IC. The performance of combined Mn/A-Mn testing is superior to either Mn or A-Mn testing.

Increasing incidence of mucormycosis in University Hospital, Belgium

To determine why incidence of mucormycosis infections was increasing in a large university hospital in Belgium, we examined case data from 2000–2009. We found the increase was not related to voriconazole use but most probably to an increase in high-risk patients, particularly those with underlying hematologic malignancies.

Incidence of bacteremias and invasive mycoses in children with acute non-lymphoblastic leukemia: results from a multi-center Italian study

BACKGROUND

Data on the epidemiology of bacteremias and invasive fungal diseases (IFD) in children with acute myeloid leukemia (AML) are scarce.

DESIGN AND METHODS

In a multi-center, retrospective study, we analyzed proportion, rate per 1,000 person-days at risk, and cumulative risk of bacteremias and IFD in children with AML.

RESULTS

Between January 1998 and December 2005, 240 children were treated for AML at 8 Italian Centers, for a total of 521 treatment courses and 63,232 person-days at risk. Bacteremia was observed in 32% of treatment courses and IFD was seen in 10% (P < 0.0001), with rates of 2.62 and 0.84, respectively (P < 0.001). There was a significantly higher frequency of IFD during relapse treatment: proportion 15% versus 9% (P = 0.05), rate 2.10 versus 0.64 (P = 0.008) and cumulative risk 32% versus 12% (P = 0.007), while there were no differences in the proportion, rate and cumulative risk of bacteremia during front-line or relapse treatment. The epidemiology of bacteremias and IFD was different during front-line therapy for M3 as compared to other types of AML, but the differences were not statistically significant.

CONCLUSIONS

Severe infectious complications are frequent during the treatment of pediatric AML, especially during relapse treatment, and bacteremias are more frequent than IFD.

Comparison of PCR-ELISA and Real-Time PCR for invasive aspergillosis diagnosis in patients with hematological malignancies

This study aimed at comparing a real-time PCR assay and a PCR-ELISA assay of both serum and bronchoalveolar lavage (BAL) samples for the diagnosis of invasive aspergillosis (IA) in patients with hematological malignancies. Using a nested case-control design, 163 patients at risk were prospectively monitored and PCR assays were performed on frozen aliquots of 459 sera which were prospectively sampled twice weekly and 42 BAL specimens sampled from 43 probable and one proven IA cases and 47 matched controls. The data from three patients classified as possible IA were excluded from the nested case-control study. The sensitivity of real-time PCR and PCR-ELISA assays in serum was 73% and 86%, respectively and specificity was 100% for both. In BAL, sensitivity was 64% for real-time PCR, 71% for PCR-ELISA and 86% for Galactomannan antigen (GMA) assays with specificities of 96%, 96%, and 93%, respectively. While slightly less sensitive, the real time-PCR assay was highly specific and considerably faster and more workable than PCR-ELISA. Combining real-time PCR and GMA detection for both serum and BAL samples enhances routine laboratory IA diagnosis.

PCR diagnosis of invasive candidiasis: systematic review and meta-analysis

Invasive candidiasis (IC) is a significant cause of morbidity and mortality. Diagnosis relies on culture-based methods, which lack sensitivity and delay diagnosis. We conducted a systematic review assessing the diagnostic accuracy of PCR-based methods to detect Candida spp. directly in blood samples. We searched electronic databases for prospective or retrospective cohort and case-control studies. Two reviewers abstracted data independently. Meta-analysis was performed using a hierarchical logistic regression model. Random-effects metaregression was performed to assess the effects of study methods and infection characteristics on sensitivity or specificity values. We included 54 studies with 4,694 patients, 963 of whom had proven/probable or possible IC. Perfect (100%) sensitivity and specificity for PCR in whole-blood samples was observed when patients with cases had candidemia and controls were healthy people. When PCR was performed to evaluate patients with suspected invasive candidiasis, the pooled sensitivity for the diagnosis of candidemia was 0.95 (confidence interval, 0.88 to 0.98) and the pooled specificity was 0.92 (0.88 to 0.95). A specificity of >90% was maintained in several analyses considering different control groups. The use of whole-blood samples, rRNA, or P450 gene targets and a PCR detection limit of ≤ 10 CFU/ml were associated with improved test performance. PCR positivity rates among patients with proven or probable IC were 85% (78 to 91%), while blood cultures were positive for 38% (29 to 46%). We conclude that direct PCR using blood samples had good sensitivity and specificity for the diagnosis of IC and offers an attractive method for early diagnosis of specific Candida spp. Its effects on clinical outcomes should be investigated.

Galactomannan testing in bronchoalveolar lavage fluid facilitates the diagnosis of invasive pulmonary aspergillosis in patients with hematologic malignancies and stem cell transplant recipients

Invasive pulmonary aspergillosis (IPA) is a major cause of mortality in patients with stem cell transplants and hematologic malignancies. Timely diagnosis of IPA improves survival but is difficult to make. We evaluated the effectiveness of bronchoalveolar lavage (BAL) galactomannan (GM) in diagnosing IPA in these populations by retrospectively reviewing records of 67 consecutive patients, in whom 89 BAL GM tests were performed. For patients with IPA, only the first BAL sample linked to the IPA episode was analyzed. Eighty samples were associated with proven, 12 with probable, and 32 with possible invasive fungal infections (IFI), and 37 were associated with no IFI. Among patients with IFIs, 4 had proven, 11 probable, and 32 possible IPA. Using BAL GM ≥ 0.5 (cutoff for serum GM) and ≥ 0.85 (optimal cutoff identified by receiver-operating characteristic curve), the sensitivity in diagnosing proven or probable IPA was 73% (11/15) and 67% (10/15), respectively, and specificity was 89% (33/37) and 95% (35/37). At these cutoffs, positive and negative predictive values were 73% (11/15) and 83% (10/12), and 89% (33/37) and 87% (35/40), respectively. BAL GM was more sensitive than cytology (0%, 0/14), BAL culture (27%, 4/15), transbronchial biopsy (40%, 2/5), or serum GM (67%, 10/15) for diagnosing IPA. BAL GM was ≥ 0.85 and ≥ 0.5 in 86% (6/7) and 100% (7/7) of patients with proven or probable IPA who received a mold-active agent for ≤ 3 days. BAL GM added sensitivity to serum GM and other means of diagnosing IPA, and was not impacted by short courses of mold-active agents.

Human tissue distribution of voriconazole

Voriconazole concentrations were determined in autopsy samples of eight patients who had been treated for a median of 7 days (interquartile range [IQR], 5 days). Voriconazole penetrates well into various tissues, with median levels of 6.26 μg/g ((interquartile range [IQR], 7.87 μg/g) in the lung, 3.41 μg/g (IQR, 16.72 μg/g) in the brain, 6.89 μg/g (IQR, 24.16 μg/g) in the liver, 6.47 μg/g (IQR, 6.19 μg/g) in the kidneys, 5.60 μg/g (IQR, 11.49 μg/g) in the spleen, and 7.55 μg/g (IQR, 16.91 μg/g) in the myocardium.

Anti-pseudomonal beta-lactams for the initial, empirical, treatment of febrile neutropenia: comparison of beta-lactams

BACKGROUND

Several beta-lactams are recommended as single agents for the treatment of febrile neutropenia.

OBJECTIVES

To compare the effectiveness of different anti-pseudomonal beta-lactams as single agents in the treatment of febrile neutropenia. To compare the development of bacterial resistance, bacterial and fungal superinfections during or following treatment with the different beta-lactams.

SEARCH STRATEGY

We searched the Cochane Register of Controlled Trials (CENTRAL), Issue 3, 2010. MEDLINE, EMBASE, LILACS, FDA drug applications, conference proceedings and ongoing clinical trial databases up to August 2010. References of included studies were scanned.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing an antipseudomonal beta-lactam to another antipseudomonal beta-lactam antibiotic, both given alone or with the addition of the same glycopeptide to both study arms, for the initial treatment of fever and neutropenia among cancer patients.

DATA COLLECTION AND ANALYSIS

Two review authors applied inclusion criteria and extracted the data independently. Missing data were sought. Risk ratios (RR) were calculated with 95% confidence intervals (CI), and pooled using the fixed effect model. The primary outcome was all-cause mortality. Risk of bias was assessed using a domain-based evaluation and its effect of results was assessed through sensitivity analyses.

MAIN RESULTS

Forty-four trials were included. The antibiotics assessed were cefepime, ceftazidime, piperacillin-tazobactam, imipenem and meropenem. Adequate allocation concealment and generation were reported in about half of the trials and only two trials were double-blinded. The risk for all-cause mortality was significantly higher with cefepime compared to other beta-lactams (RR 1.39, 95% CI 1.04 to 1.86, 21 trials, 3471 participants), without heterogeneity and with higher RRs in trials at low risk for bias. There were no differences in secondary outcomes but for a non-significantly higher rate of bacterial superinfections with cefepime. Mortality was significantly lower with piperacillin-tazobactam compared to other antibiotics (RR 0.56, 95% CI 0.34 to 0.92, 8 trials, 1314 participants), without heterogeneity. Carbapenems resulted in similar all-cause mortality and a lower rate of clinical failure and antibiotic modifications as compared to other antibiotics, but a higher rate of diarrhea caused by Clostridium difficile.

AUTHORS' CONCLUSIONS

Current evidence supports the use of piperacillin-tazobactam in locations where antibiotic resistance profiles do not mandate empirical use of carbapenems. Carbapenems result in a higher rate of antibiotic-associated and Clostridium difficile-associated diarrhea. There is a high level of evidence that all-cause mortality is higher with cefepime compared to other beta-lactams and it should not be used as monotherapy for patients with febrile neutropenia.

Potential of anti-Candida antibodies in immunoprophylaxis

The need for new options for the treatment of invasive candidiasis has fuelled the use of antibodies in combination with conventional antifungal therapy. After a long period of time in which antibodies were considered irrelevant in the resistance against invasive candidiasis, it was demonstrated that a number of antibodies or their engineered derivatives directed against Candida albicans cell-wall polysaccharides and glycopeptides, as well as against some protein epitopes, confer protection against invasive candidiasis. This has confirmed this approach as a new strategy for the prophylaxis of invasive candidiasis. Of particular interest is Mycograb, a human recombinant monoclonal antibody that inhibits heat shock protein 90, and has been administrated in combination with lipid-associated amphotericin B to patients with invasive candidiasis, and the fungicidal anti-beta-glucan antibodies induced by the glycoconjugate vaccine composed of a beta-glucan polysaccharide conjugated with the diphtheria toxoid CRM 197. However, despite the promising data obtained in vitro and in animal models, at present there is very little clinical experience on the use of antibodies in Candida immunoprophylaxis.

A prospective comparison of galactomannan in bronchoalveolar lavage fluid for the diagnosis of pulmonary invasive aspergillosis in medical patients under intensive care: comparison with the diagnostic performance of galactomannan and of (1→ 3)-β-d-glucan chromogenic assay in serum samples

Diagnosis of fungal pneumonia (FP) in critically ill patients is challenging. Circulating biomarkers for the diagnosis of FP have limitations and the combination of different assays in serum samples and directly from the target organ may further improve the diagnosis of FP. We prospectively assessed the diagnostic utility of paired galactomannan (GM) in bronchoalveolar lavage fluid (BAL) and serum GM and (1→3)-β-D-glucan (BG) assays in critically ill patients at risk of FP. Patients with FP were classified according to European Organisation for Research and Treatment of Cancer-Mycoses Study Group criteria, with modifications. Out of 847 admissions, 51 patients were eligible. There were nine invasive aspergillosis (IA) cases (four proven, five probable), three proven Pneumocysitis jirovecii pneumonia (PJP) cases and one mixed FP case (probable IA and proven PJP). The diagnostic accuracy as given by the area under the receiver operating characteristic curve in IA cases (proven and probable) for GM in BAL was 0.98 (95% CI, 0.94-1.00), whilst for GM and BG in serum it was 0.85 (95% CI, 0.74-0.96) and 0.815 (95% CI, 0.66-0.96), respectively. For IA cases (proven and probable) AUC for GM in BAL was significantly higher than GM and BG in serum (p 0.025 and p 0.032, respectively). In one of four proven and one of six probable IA cases, GM in serum remained negative, whereas GM in BAL was positive. In patients with IA, GM (90%) and BG (80%) appeared a mean of 4.3 days (range, 1-10 days) before Aspergillus was cultured. GM detection in BAL appears to improve the diagnosis of IA in critical patients.

Efficacy and safety of micafungin for treating febrile neutropenia in hematological malignancies

Less toxic antifungal drugs are required for empirical antifungal therapy. Micafungin is an echinocandin drug that is effective against both Candida and Aspergillus, and preliminary clinical studies have shown good antifungal activity. We prospectively examined the effect and safety of micafungin against febrile neutropenia with suspected fungal infection in 53 patients (median age, 56 years) who had undergone chemotherapy. The administered dose of micafungin was 150 mg/day, and its effect was evaluated as fever resolution as well as the results of chest imaging and serum fungal tests. Micafungin levels were measured on day 4 after the first administration using high-performance liquid chromatography. We also measured trough levels of micafungin. Underlying diseases comprised acute lymphoblastic leukemia (n = 4), acute myeloid leukemia (n = 20), multiple myeloma (n = 3), and non-Hodgkin's lymphoma (n = 26). The overall efficacy of micafungin was 70%. Breakthrough fungal infections were documented in two (3.8%) patients, both of whom died of invasive mycosis. None of the patients were switched to other antifungal drugs due to events unrelated to adverse effects. Plasma levels of micafungin and the degree of hepatic or renal dysfunction did not correlate. Micafungin is safe and effective for the empirical antifungal therapy of febrile neutropenia in patients with hematological malignancies.

[Management of candidemia and invasive candidiasis]

Candida species is the fourth most common cause of bloodstream infection and is the leading cause of invasive fungal infection among hospitalized patients. Acute disseminated candidiasis remains a life-threatening disease that now occurs mainly in intensive care units hospitalized patients. Delay in treatment of Candida bloodstream infections could be minimized by the development of more rapid and sensitive diagnostic techniques for the identification of Candida bloodstream infections. Current guidelines for the management of invasive candidiasis recommend fluconazole or an echinocandin as the primary therapeutic option. The optimal choice of the antifungal agent should depend on local epidemiology, prior antifungal therapy and patient's characteristics.

Efficacy outcomes in a randomised trial of liposomal amphotericin B based on revised EORTC/MSG 2008 definitions of invasive mould disease

In 2008, the European Organisation for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) published revised definitions for diagnosing invasive fungal disease. A previous prospective trial of liposomal amphotericin B for invasive mould disease (AmBiLoad) used modified EORTC/MSG 2002 criteria. We wished to re-evaluate the response and survival based on the revised definitions to compare the outcomes of early vs. late treatment. Patients who had received an allogeneic haematopoietic stem cell transplant or who were neutropaenic (absolute neutrophil count <500 μl(-1) within 14 days of study entry) had been recruited on the basis of a halo or air crescent sign on chest computerised tomography. Originally classified as probable invasive mould disease, they were categorised as possible invasive mould disease using 2008 criteria. Patients had received liposomal amphotericin B at either 3 or 10 mg kg(-1) QD for 14 days, followed by 3 mg kg(-1) QD. Response at end of treatment and the 12-week survival were re-calculated according to 2008 definitions. Six-week survival was estimated by Kaplan-Meier analysis. Of 201 patients with invasive mould disease, 118 (59%) had a diagnosis based on halo signs (possible cases). Mycological evidence was present in 83 (41%) cases (probable/proven cases). Survival rates at 12 weeks for possible vs. probable/proven cases in the 3 mg kg(-1) QD group were 82% vs. 58% (P = 0.006), and 65% vs. 50% (P = 0.15) in the 10 mg kg(-1) QD group. At 6 weeks, rates were 87% vs. 69% in the 3 mg kg(-1) QD group (P = 0.009), and 75% vs. 61% in the 10 mg kg(-1) QD group (P = 0.01). Patients with possible invasive mould disease based on EORTC/MSG 2008 criteria had improved survival rates compared with those treated for probable/proven invasive mould disease. As possible invasive mould disease probably reflects an early-stage of disease, a better outcome might be expected when treatment with liposomal amphotericin B is started preemptively.

Retrospective evaluation of the area over the neutrophil curve index to predict early infection in hematopoietic stem cell transplantation recipients

We investigated the impact of neutropenia on the development of early bloodstream and pulmonary infections in hematopoietic stem cell transplantation (HSCT) recipients, and evaluated the utility of an index (D-index) that reflects both the intensity and duration of neutropenia. Fifty-eight patients (23 autologous, 35 allogeneic HSCT recipients) were enrolled in this retrospective study. The D-index was defined as the area over the neutrophil curve during neutropenia. We also evaluated the utility of the cumulative D-index from the start of neutropenia until the development of infection (c-D-index), which may enable real-time assessment of the risk for infection. The patients showed 12 and 7 episodes of bloodstream and pulmonary infection, respectively. The D-index, days of neutropenia (<500/microL) and days of profound neutropenia (<100/microL) had at least a nearly significant impact on the development of both bloodstream and pulmonary infections. On the other hand, the c-D-index, cumulative days of neutropenia, and cumulative days of profound neutropenia significantly affected pulmonary infection, but not bloodstream infection. The c-D-index had a high negative predictive value of 97.4% for pulmonary infection with a cutoff of 5500, but the area under the receiver operating characteristic curve was similar to that of the cumulative days of neutropenia and profound neutropenia. Our results showed that although the c-D-index may be useful for identifying patients who are at low risk for early pulmonary infection after HSCT, its performance was similar to that of the simple duration of neutropenia.

Opportunistic fungi: a view to the future

Opportunistic fungi are a constantly evolving group of pathogens that plague a growing group of vulnerable patients. These include hospitalized patients, especially those in the intensive care unit; stem cell and solid organ transplant recipients; patients treated with immunosuppressant medications; those with advanced human immunodeficiency virus or other acquired immunodeficiency conditions; and patients with organ failure syndromes. Rapid diagnosis of invasive fungal infection is essential to optimize outcomes. Several newer nonculture-based diagnostics, including the Aspergillus galactomannan enzyme-linked immunosorbent assay, the beta-d-glucan assay and the multiplex polymerase chain reaction-based assays, may emerge as important tools facilitating early intervention with effective antifungal therapy. Newer azoles, including posaconazole, isavuconazole and ravuconazole, will potentially provide more effective therapeutic options in the future, diminishing the role for amphotericin B.

Fungal colonization in patients with chronic respiratory diseases from Himalayan region of India

Background

We screened patients with chronic respiratory diseases for microbiological and serological evidences of fungal colonisation; in order to determine its prevalence in this group of patients, examine potential clinical and radiological predictors of fungal colonisation and characterise fungal agents associated with individual diseases.

Methods

BAL samples from 60 consecutive patients were subjected to microscopy and culture for fungal agents. Serum samples were analysed for precipitin antibodies to Aspergillus antigen and Candida cytoplasmic antigen. Statistical significance in the difference of fungal recovery between patient groups was determined using the Chi-square test.

Results

The major diagnostic groups included patients with bronchogenic carcinoma (n = 31) and tubercular sequelae (n = 16). In all, 28 patients (46.7%) were culture-positive, with Candida and Aspergillus being recovered from 14 and 13 patients respectively. Twenty-one patients (35%) showed presence of precipitin antibodies. Patients with bronchogenic carcinoma showed increased predilection for colonisation with Aspergillus, while Candida was recovered more commonly in tubercular sequelae (p = 0.02). There was no statistically significant association between culture-positivity and specific risk factors/radiological findings.

Conclusion

The point-prevalence of fungal colonization was almost 50%. The combination of fungal culture and serology helped improve diagnostic sensitivity. An interesting predilection was observed for Aspergillus and Candida, to preferentially infect patients with Bronchogenic carcinoma and Tubercular sequelae respectively. In absence of specific predictors, the possibility of fungal colonization needs to be explored actively in these patients.

Aspergillus galactomannan antigen assay in bronchoalveolar lavage fluid for diagnosis of invasive pulmonary aspergillosis

OBJECTIVES

A recently developed bronchoalveolar lavage (BAL) galactomannan (GM) assay shows promising results. We evaluated the diagnostic performance of this assay and analyzed risk factors for false-positive results.

METHODS

A prospective cohort study was performed in a tertiary hospital over a 9-month period. We reviewed all adult patients who underwent GM assays of BAL. Patients were categorized with proven, probable, or possible invasive pulmonary aspergillosis (IPA) according to revised EORTC/MSG definitions. Each patient with a false-positive BAL GM result was matched with three patients with true-negative BAL GM result, and the risk factors for false-positive BAL GM results were determined.

RESULTS

Of 359 enrolled patients, 22 (6%) were diagnosed with IPA (1 proven, 17 probable, and 4 possible). Of the 22 patients with IPA, 17 (77%) had already received antifungal agents before the BAL GM assay was conducted. At an index cutoff value of ≥0.5, the BAL GM assay had a sensitivity of 64% (95% CI 41%-83%) and a specificity of 89% (95% CI 85%-92%). However, at an index cutoff value of ≥0.2, the BAL GM assay had a sensitivity of 86% (95% CI 65%-97%) and a specificity of 74% (95% CI 69%-79%). Of the 52 patients with positive BAL GM assay (≥0.5), 25 (7%) were false-positives. Univariate and multivariate analysis revealed that treatment with piperacillin-tazobactam or ampicillin-sulbactam was associated with false-positive BAL GM results.

CONCLUSIONS

The BAL GM assay appears promising for the diagnosis of IPA. However, treatment with certain antibiotics may interfere with the results of the BAL GM assay.

Immunogenetics of invasive aspergillosis

Invasive aspergillosis is one of the most important infections in hematopoietic stem cell transplant recipients, with an incidence rate of 5-15% and an associated mortality of 30-60%. It remains unclear why certain patients develop invasive aspergillosis while others, undergoing identical transplant regimen and similar post transplant immunosuppression, do not. Over the last decade, pattern recognition receptors such as Toll-like receptors (TLRs) and the C-type lectin receptors (CLRs) have emerged as critical components of the innate immune system. By detecting specific molecular patterns from invading microbes and initiating inflammatory and subsequent adaptive immune responses, pattern recognition receptors are strategically located at the molecular interface of hosts and pathogens. Polymorphisms in pattern recognition receptors and downstream signaling molecules have been associated with increased or decreased susceptibility to infections, suggesting that their detection may have an increasing impact on the treatment and prevention of infectious diseases in the coming years. Infectious risk stratification may be particularly relevant for patients with hematologic malignancies, because of the high prevalence and severity of infections in this population. This review summarizes the innate immune mechanisms involved in Aspergillus fumigatus detection and the role of host genetic polymorphisms in susceptibility to invasive aspergillosis.

Supportive care in children

PURPOSE OF REVIEW

To provide an update on the rational approach of febrile neutropenia in children with cancer and discuss future research aspects in the field.

RECENT FINDINGS

Clinical and laboratory variables and new biomarkers associated with an increased risk for a severe outcome including invasive bacterial infection (IBI), sepsis, and mortality have been identified for children with cancer and febrile neutropenia. These variables and biomarkers are currently being used for an early risk assessment in order to identify children at low or high risk for IBI or at high risk for sepsis and death. Early identification of children with a differential risk has allowed the implementation of selective treatment regimens. More recently, host genetic differences have been associated with a differential risk for IBI. The individual gene profile based on selected polymorphisms could further fine-tune the early risk assessment allowing tailor-made management strategies.

SUMMARY

In the last decades, efforts have focused on the stratification of the heterogeneous group of children with cancer and febrile neutropenia according to their risk for developing an IBI. This effort has allowed a less aggressive treatment strategy for children at low risk, including early hospital discharge and use of intravenous and oral antimicrobials at home. More recently, advances have been made in the early identification of children in the other spectrum of infection, those at high risk for sepsis and mortality, with the aim of rapid implementation of aggressive therapy.

Risk factors associated with invasive fungal disease in children with cancer and febrile neutropenia: a prospective multicenter evaluation

BACKGROUND

Empiric antifungal treatment has become standard of care in children with cancer and prolonged fever and febrile neutropenia (FN), with the downside that it leads to significant over treatment. We characterized epidemiologic, clinical, and laboratory features of invasive fungal disease (IFD) in children with cancer and FN with the aim to identify risk factors for IFD that can aid in better selecting children who require antifungal treatment.

METHODS

In a prospective, multicenter study, children admitted with FN at high-risk for sepsis, in 6 hospitals in Santiago, Chile were monitored from admission until the end of the FN episode. Monitoring included periodic evaluation of clinical findings, absolute neutrophil count, absolute monocyte count (AMC), serum C-reactive protein (CRP), bacterial cultures, imaging studies, and galactomannan antigen. A diagnosis of proven, probable, and possible IFD was made after episode resolution based on European Organization for Research and Treatment of Cancer classification.

RESULTS

A total of 646 high-risk FN episodes were admitted during the study period, of which 604 were enrolled. IFD was diagnosed in 35 episodes (5.8%) of which 7 (1.2%) were proven, 10 (1.6%) probable, and 18 (3.0%) possible. Four variables obtained on day 4 were significantly more common in IFD cases, which were presence of fever, absolute neutrophil count < or =500/mm, AMC < or =100/mm, and CRP > or =90 mg/L. The combination of fever, AMC < or =100/mm, and CRP > or =90 at day 4 provided a RR for IFD of 5.4 (99% CI, 3.2-9.2) with a sensitivity of 75%, specificity of 87%, positive and negative predictive values of 13% and 99%, respectively.

CONCLUSIONS

Fever persisting at day 4 of admission, together with AMC < or =100 and CRP > or =90 significantly increased the risk for IFD in children with cancer.

Invasive fungal disease in patients treated for newly diagnosed acute leukemia

Invasive fungal disease (IFD) is a significant cause of morbidity and mortality in patients undergoing treatment for acute leukemia (AL). Antifungal prophylactic strategies are associated with significant toxicities and cost. We performed a retrospective study of the incidence and risk factors for IFD among patients newly diagnosed with and treated for AL between January 1, 2004 and July 1, 2006. Patient follow up concluded January 1, 2007. Among 231 patients with newly diagnosed AL, 31 (13.4%) developed IFD by the end of follow up, 24 (10.4%) of whom developed IFD within the first 100 days after diagnosis of AL. The cumulative probability of developing IFD was 5.9% by 30 days and 11.1% at 100 days after AL diagnosis. Patients who had persistent leukemia after an initial course of induction chemotherapy were significantly more likely to develop IFD than those who did not have evidence of persistent leukemia (14/65 (21.5%) vs. 15/148 (10.1%), P = 0.03). In a time-dependent Cox model, the adjusted hazard ratio for developing IFD within the first 100 days of AL diagnosis based on the number of days of neutropenia in that period was 4.85 (95% confidence interval: 1.52, 15.4). Those patients with more days of neutropenia in the first 100 days after AL diagnosis, such as those who did not achieve remission after a first course of induction chemotherapy, were more likely to develop IFD.

Difficulties in using 1,3-β-d-glucan as the screening test for the early diagnosis of invasive fungal infections in patients with haematological malignancies – high frequency of false-positive results and their analysis

We have evaluated the contribution of the 1,3-β-d-glucan (BG) assay for the screening of invasive fungal infections (IFIs) in patients with haematological malignancies. Serum samples from patients at risk of IFI were collected twice a week and retrospectively tested using the BG assay. BG screening was performed on 1143 samples from 91 patients during 104 anticancer treatment cycles. Proven and probable cases of IFI occurred in 9 (8.7 %) treatment cycles. Depending on the criterion of positivity used (1× >60 pg ml−1, 1× >80 pg ml−1, 2× >60 pg ml−1 or 2× >80 pg ml−1) the sensitivity and specificity were 89, 89, 67 and 44 %, and 20, 48, 33 and 56 %, respectively. Although the test was marked as positive in 82, 68, 54 and 45 % of all the treatment cycles, in the majority of cases, these positivities were probably false. The major limit of the BG test was an extremely low positive predictive value (10 to 12 %). We have analysed mucositis, candida colonization, bacteraemia, use of antimicrobials, erythrocyte and thrombocyte filtered blood products, collecting tubes or sampling via venous catheters. Even though no factor is a major source of BG, it could at least partially influence BG assay performance. Thus, BG detection has a limited usefulness as a screening method for IFIs in patients with haematological malignancies.

Dectin-1 Y238X polymorphism associates with susceptibility to invasive aspergillosis in hematopoietic transplantation through impairment of both recipient- and donor-dependent mechanisms of antifungal immunity

The C-type lectin receptor Dectin-1 plays a pivotal role in antifungal immunity. In this study, the recently characterized human DECTIN1 Y238X early stop codon polymorphism leading to diminished Dectin-1 receptor activity was studied in relation to invasive aspergillosis susceptibility and severity in patients receiving hematopoietic stem cell transplantation. We found that the presence of the DECTIN1 Y238X polymorphism in either donors or recipients of hematopoietic stem cell transplantation increased susceptibility to aspergillosis, with the risk being highest when the polymorphism was present simultaneously in both donors and recipients (adjusted hazard ratio = 3.9; P = .005). Functionally, the Y238X polymorphism impaired the production of interferon-γ and interleukin-10 (IL-10), in addition to IL-1β, IL-6, and IL-17A, by human peripheral mononuclear cells and Dectin-1 on human epithelial cells contributed to fungal recognition. Mechanistically, studies on preclinical models of infection in intact or bone marrow-transplanted Dectin-1 knockout mice revealed that protection from infection requires a distinct, yet complementary, role of both donor and recipient Dectin-1. This study discloses Dectin-1 deficiency as a novel susceptibility factor for aspergillosis in high-risk patients and identifies a previously unsuspected role for Dectin-1 in antifungal immunity that is the ability to control both resistance and tolerance to the fungus contingent on hematopoietic/nonhematopoietic compartmentalization.