Polymerase Chain Reaction on Respiratory Tract Specimens of Immunocompromised Patients to Diagnose Pneumocystis Pneumonia: A Systematic Review and Meta-analysis.

BACKGROUND: This meta-analysis examines the comparative diagnostic performance of polymerase chain reaction (PCR) for the diagnosis of Pneumocystis pneumonia (PCP) on different respiratory tract samples, in both human immunodeficiency virus (HIV) and non-HIV populations. METHODS: A total of 55 articles met inclusion criteria, including 11 434 PCR assays on respiratory specimens from 7835 patients at risk of PCP. QUADAS-2 tool indicated low risk of bias across all studies. Using a bivariate and random-effects meta-regression analysis, the diagnostic performance of PCR against the European Organisation for Research and Treatment of Cancer-Mycoses Study Group definition of proven PCP was examined. RESULTS: Quantitative PCR (qPCR) on bronchoalveolar lavage fluid provided the highest pooled sensitivity of 98.7% (95% confidence interval [CI], 96.8%-99.5%), adequate specificity of 89.3% (95% CI, 84.4%-92.7%), negative likelihood ratio (LR-) of 0.014, and positive likelihood ratio (LR+) of 9.19. qPCR on induced sputum provided similarly high sensitivity of 99.0% (95% CI, 94.4%-99.3%) but a reduced specificity of 81.5% (95% CI, 72.1%-88.3%), LR- of 0.024, and LR+ of 5.30. qPCR on upper respiratory tract samples provided lower sensitivity of 89.2% (95% CI, 71.0%-96.5%), high specificity of 90.5% (95% CI, 80.9%-95.5%), LR- of 0.120, and LR+ of 9.34. There was no significant difference in sensitivity and specificity of PCR according to HIV status of patients. CONCLUSIONS: On deeper respiratory tract specimens, PCR negativity can be used to confidently exclude PCP, but PCR positivity will likely require clinical interpretation to distinguish between colonization and active infection, partially dependent on the strength of the PCR signal (indicative of fungal burden), the specimen type, and patient population tested.

The Presence of (1→3)-ß-D-Glucan as Prognostic Marker in Patients After Major Abdominal Surgery.

BACKGROUND: While the serological detection of (1→3)-ß-D-glucan (BDG) can indicate invasive fungal disease (IFD), false positivity occurs. Nevertheless, the presence of BDG can still be recognized by the host's innate immune system and persistent BDG antigenemia, in the absence of IFD, can result in deleterious proinflammatory immune responses. METHODS: During the XXX (INTENSE) study into the preemptive use of micafungin to prevent invasive candidiasis (IC) after abdominal surgery, the serum burden of BDG was determined to aid diagnosis of IC. Data from the INTENSE study were analyzed to determine whether BDG was associated with organ failure and patient mortality, while accounting for the influences of IC and antifungal therapy. RESULTS: A BDG concentration >100 pg/mL was associated with a significantly increased Sequential Organ Failure Assessment score (≤100 pg/mL: 2 vs >100 pg/mL: 5; P < .0001) and increased rates of mortality (≤100 pg/mL: 13.7% vs >100 pg/mL: 39.0%; P = .0002). Multiple (≥2) positive results >100 pg/mL or a BDG concentration increasing >100 pg/mL increased mortality (48.1%). The mortality rate in patients with IC and a BDG concentration >100 pg/mL and ≤100 pg/mL was 42.3% and 25.0%, respectively. The mortality rate in patients without IC but a BDG concentration >100 pg/mL was 37.3%. The use of micafungin did not affect the findings. CONCLUSIONS: The presence of persistent or increasing BDG in the patient's circulation is associated with significant morbidity and mortality after abdominal surgery, irrespective of IC. The potential lack of a specific therapeutic focus has consequences when trying to manage these patients, and when designing clinical trials involving patients where host-associated BDG concentrations may be elevated. CLINICAL TRIALS REGISTRATION: NCT01122368.

Early switch from intravenous to oral antibiotic therapy in patients with cancer who have low-risk neutropenic sepsis (the EASI-SWITCH trial): study protocol for a randomised controlled trial.

BACKGROUND: Neutropenic sepsis remains a common treatment complication for patients receiving systemic anti-cancer treatment. The UK National Institute for Health and Care Excellence have not recommended switching from empirical intravenous antibiotics to oral antibiotics within 48 h for patients assessed as low risk for septic complications because of uncertainty about whether this would achieve comparable outcomes to using intravenous antibiotics for longer. The UK National Institute for Health Research funded the EASI-SWITCH trial to tackle this uncertainty. METHODS: The trial is a pragmatic, randomised, non-inferiority trial that aims to establish the clinical and cost-effectiveness of early switching from intravenous to oral antibiotics in cancer patients with low-risk neutropenic sepsis. Patients ≥ 16 years, receiving systemic anti-cancer treatment (acute leukaemics/stem cell transplants excluded), with a temperature of > 38 °C, neutrophil count ≤ 1.0 × 109/L, MASCC (Multinational Association of Supportive Care in Cancer) score ≥ 21 and receiving IV piperacillin/tazobactam or meropenem for less than 24 h are eligible to participate. Patients are randomised 1:1 either (i) to switch to oral ciprofloxacin and co-amoxiclav within 12-24 h of commencing intravenous antibiotics, completing at least 5 days total antibiotics (intervention), or (ii) to continue intravenous antibiotics for at least 48 h, with ongoing antibiotics being continued at the physician's discretion (control). Patients are discharged home when their physician deems it appropriate. The primary outcome measure is a composite of treatment failures as assessed at day 14. The criteria for treatment failure include fever persistence or recurrence 72 h after starting intravenous antibiotics, escalation from protocolised antibiotics, hospital readmission related to infection/antibiotics, critical care support or death. Based on a 15% treatment failure rate in the control group and a 15% non-inferiority margin, the recruitment target is 230 patients. DISCUSSION: If the trial demonstrates non-inferiority of early switching to oral antibiotics, with potential benefits for patient quality of life and resource savings, this finding will have significant implications for the routine clinical management of those with low-risk neutropenic sepsis. TRIAL REGISTRATION: ISRCTN: 84288963. Registered on the 1 July 2015. https://doi.org/10.1186/ISRCTN84288963. EudraCT: 2015-002830-35.

Predicting Invasive Aspergillosis in Hematology Patients by Combining Clinical and Genetic Risk Factors with Early Diagnostic Biomarkers.

Personalized medicine provides a strategic approach to the management of IA. The incidence of IA in high-risk hematology populations is relatively low (<10%), despite unavoidable Aspergillus exposure in patients with a potentially similar clinical risk. Nonclinical variables, including genetic mutations that increase susceptibility to IA, could explain why only certain patients develop the disease. This study screened for mutations in 322 hematology patients classified according to IA status and developed a predictive model based on genetic risk, established clinical risk factors, and diagnostic biomarkers. Genetic markers were determined by real-time PCR and, with clinical risk factors and Aspergillus PCR results, subjected to multilogistic regression analysis to identify a best-fit model for predicting IA. The probability of IA was calculated, and an optimal threshold was determined. Mutations in dectin-1 (rs7309123) and DC-SIGN (rs11465384 and rs7248637), allogeneic stem cell transplantation, respiratory virus infection, and Aspergillus PCR positivity were all significant risk factors for developing IA and were combined in a predictive model. An optimal threshold requiring three positive factors generated a mean sensitivity/specificity of 70.4%/89.2% and a probability of developing IA of 56.7%. In patients with no risk factors, the probability of developing IA was 2.4%, compared to >79.1% in patients with four or more factors. Using a risk threshold of 50%, preemptive therapy would have been prescribed for 8.4% of the population. This pilot study shows that patients can be stratified according to risk of IA, providing personalized medicine based on strategic evidence for the management of IA. Further studies are required to confirm this approach.

Analytical and Clinical Evaluation of the PathoNostics AsperGenius Assay for Detection of Invasive Aspergillosis and Resistance to Azole Antifungal Drugs Directly from Plasma Samples.

With the proposal to include Aspergillus PCR in the revised European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) definitions for fungal disease, commercially manufactured assays may be required to provide standardization and accessibility. The PathoNostics AsperGenius assay represents one such test that has the ability to detect a range of Aspergillus species as well as azole resistance in Aspergillus fumigatus Its performance has been validated on bronchoalveolar lavage (BAL) fluid and serum specimens, but recent evidence suggests that testing of plasma may have enhanced sensitivity over that with serum. We decided to evaluate the analytical and clinical performances of the PathoNostics AsperGenius assay for testing of plasma. For the analytical evaluations, plasma was spiked with various concentrations of Aspergillus genomic DNA before extraction following international recommendations, using two automated platforms. For the clinical study, 211 samples from 10 proven/probable invasive aspergillosis (IA) and 2 possible IA cases and 27 controls were tested. The limits of detection for testing of DNA extracted using the bioMérieux EasyMag and Qiagen EZ1 extractors were 5 and 10 genomes/0.5-ml sample, respectively. In the clinical study, true positivity was significantly greater than false positivity (P < 0.0001). The sensitivity and specificity obtained using a single positive result as significant were 80% and 77.8%, respectively. If multiple samples were required to be positive, specificity was increased to 100%, albeit sensitivity was reduced to 50%. The AsperGenius assay provided good clinical performance, but the predicted improvement of testing with plasma was not seen, possibly as a result of target degradation attributed to sample storage. Prospective testing is required to determine the clinical utility of this assay, particularly for the diagnosis of azole-resistant disease.

Determining the analytical specificity of PCR-based assays for the diagnosis of IA: What is Aspergillus?

A wide array of PCR tests has been developed to aid the diagnosis of invasive aspergillosis (IA), providing technical diversity but limiting standardisation and acceptance. Methodological recommendations for testing blood samples using PCR exist, based on achieving optimal assay sensitivity to help exclude IA. Conversely, when testing more invasive samples (BAL, biopsy, CSF) emphasis is placed on confirming disease, so analytical specificity is paramount. This multicenter study examined the analytical specificity of PCR methods for detecting IA by blind testing a panel of DNA extracted from a various fungal species to explore the range of Aspergillus species that could be detected, but also potential cross reactivity with other fungal species. Positivity rates were calculated and regression analysis was performed to determine any associations between technical specifications and performance. The accuracy of Aspergillus genus specific assays was 71.8%, significantly greater (P < .0001) than assays specific for individual Aspergillus species (47.2%). For genus specific assays the most often missed species were A. lentulus (25.0%), A. versicolor (24.1%), A. terreus (16.1%), A. flavus (15.2%), A. niger (13.4%), and A. fumigatus (6.2%). There was a significant positive association between accuracy and using an Aspergillus genus PCR assay targeting the rRNA genes (P = .0011). Conversely, there was a significant association between rRNA PCR targets and false positivity (P = .0032). To conclude current Aspergillus PCR assays are better suited for detecting A. fumigatus, with inferior detection of most other Aspergillus species. The use of an Aspergillus genus specific PCR assay targeting the rRNA genes is preferential.

An evaluation of the performance of the Dynamiker® Fungus (1-3)-ß-D-Glucan Assay to assist in the diagnosis of invasive aspergillosis, invasive candidiasis and Pneumocystis pneumonia.

Invasive fungal disease (IFD) can be caused by a range of pathogens. Conventional diagnosis has the capacity to detect most causes of IFD, but poor performance limits impact. The introduction of non-culture diagnostics, including the detection of (1-3)-ß-D-Glucan (BDG), has shown promising performance for the detection of IFD in variety of clinical settings. Recently, the Dynamiker® Fungus (1-3)-ß-D-Glucan assay (D-BDG) was released as an IFD diagnostic test. This article describes an evaluation of the D-BDG assay for the diagnosis of invasive aspergillosis (IA), invasive candidiasis (IC) and Pneumocystis pneumonia (PCP) across several high-risk patient cohorts and provides comparative data with the Associates of Cape Cod Fungitell® and BioRad Platelia™ Aspergillus Ag (GM) assays. There were 163 serum samples from 121 patients tested, from 21 probable IA cases, 28 proven IC cases, six probable PCP cases, one probable IFD case, 14 possible IFD cases and 64 control patients. For proven/probable IFD the mean BDG concentration was 209pg/ml, significantly greater than the control population (73pg/ml; P: <.0001). The sensitivity, specificity, and diagnostic odds ratio for proven/probable IFD was 81.4%, 78.1%, and 15.5, respectively. Significant BDG false positivity (9/13) was associated post abdominal surgery. D-BDG showed fair and good agreement with the Fungitell®, and GM assays, respectively. In conclusion, the D-BDG provides a useful adjunct test to aid the diagnosis of IFD, with technical flexibility that will assist laboratories processing low sample numbers. Further, large scale, prospective evaluation is required to confirm the clinical validity and determine clinical utility.

Comparison of Performance Characteristics of Aspergillus PCR in Testing a Range of Blood-Based Samples in Accordance with International Methodological Recommendations.

Standardized methodologies for the molecular detection of invasive aspergillosis (IA) have been established by the European Aspergillus PCR Initiative for the testing of whole blood, serum, and plasma. While some comparison of the performance of Aspergillus PCR when testing these different sample types has been performed, no single study has evaluated all three using the recommended protocols. Standardized Aspergillus PCR was performed on 423 whole-blood pellets (WBP), 583 plasma samples, and 419 serum samples obtained from hematology patients according to the recommendations. This analysis formed a bicenter retrospective anonymous case-control study, with diagnosis according to the revised European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) consensus definitions (11 probable cases and 36 controls). Values for clinical performance using individual and combined samples were calculated. For all samples, PCR positivity was significantly associated with cases of IA (for plasma, P = 0.0019; for serum, P = 0.0049; and for WBP, P = 0.0089). Plasma PCR generated the highest sensitivity (91%); the sensitivities for serum and WBP PCR were 80% and 55%, respectively. The highest specificity was achieved when testing WBP (96%), which was significantly superior to the specificities achieved when testing serum (69%, P = 0.0238) and plasma (53%, P = 0.0002). No cases were PCR negative in all specimen types, and no controls were PCR positive in all specimens. This study confirms that Aspergillus PCR testing of plasma provides robust performance while utilizing commercial automated DNA extraction processes. Combining PCR testing of different blood fractions allows IA to be both confidently diagnosed and excluded. A requirement for multiple PCR-positive plasma samples provides similar diagnostic utility and is technically less demanding. Time to diagnosis may be enhanced by testing multiple contemporaneously obtained sample types.

Aspergillus Polymerase Chain Reaction: Systematic Review of Evidence for Clinical Use in Comparison With Antigen Testing.

BACKGROUND: Aspergillus polymerase chain reaction (PCR) was excluded from the European Organisation for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) definitions of invasive fungal disease because of limited standardization and validation. The definitions are being revised. METHODS: A systematic literature review was performed to identify analytical and clinical information available on inclusion of galactomannan enzyme immunoassay (GM-EIA) (2002) and ß-d-glucan (2008), providing a minimal threshold when considering PCR. Categorical parameters and statistical performance were compared. RESULTS: When incorporated, GM-EIA and ß-d-glucan sensitivities and specificities for diagnosing invasive aspergillosis were 81.6% and 91.6%, and 76.9% and 89.4%, respectively. Aspergillus PCR has similar sensitivity and specificity (76.8%-88.0% and 75.0%-94.5%, respectively) and comparable utility. Methodological recommendations and commercial PCR assays assist standardization. Although all tests have limitations, currently, PCR is the only test with independent quality control. CONCLUSIONS: We propose that there is sufficient evidence that is at least equivalent to that used to include GM-EIA and ß-d-glucan testing, and that PCR is now mature enough for inclusion in the EORTC/MSG definitions.

Clinical Performance of Aspergillus PCR for Testing Serum and Plasma: a Study by the European Aspergillus PCR Initiative.

Aspergillus PCR testing of serum provides technical simplicity but with potentially reduced sensitivity compared to whole-blood testing. With diseases for which screening to exclude disease represents an optimal strategy, sensitivity is paramount. The associated analytical study confirmed that DNA concentrations were greater in plasma than those in serum. The aim of the current investigation was to confirm analytical findings by comparing the performance of Aspergillus PCR testing of plasma and serum in the clinical setting. Standardized Aspergillus PCR was performed on plasma and serum samples concurrently obtained from hematology patients in a multicenter retrospective anonymous case-control study, with cases diagnosed according to 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 definitions (19 proven/probable cases and 42 controls). Clinical performance and clinical utility (time to positivity) were calculated for both kinds of samples. The sensitivity and specificity for Aspergillus PCR when testing serum were 68.4% and 76.2%, respectively, and for plasma, they were 94.7% and 83.3%, respectively. Eighty-five percent of serum and plasma PCR results were concordant. On average, plasma PCR was positive 16.8 days before diagnosis and was the earliest indicator of infection in 13 cases, combined with other biomarkers in five cases. On average, serum PCR was positive 10.8 days before diagnosis and was the earliest indicator of infection in six cases, combined with other biomarkers in three cases. These results confirm the analytical finding that the sensitivity of Aspergillus PCR using plasma is superior to that using serum. PCR positivity occurs earlier when testing plasma and provides sufficient sensitivity for the screening of invasive aspergillosis while maintaining methodological simplicity.

The effect of sample storage on the performance and reproducibility of the galactomannan EIA test.

Galactomannan enzyme immune assay (GM EIA) is a nonculture test for detecting invasive aspergillosis (IA) forming a key part of diagnosis and management. Recent reports have questioned the reproducibility of indices after sample storage. To investigate this, 198 serum samples (72 from cases and 126 from controls) and 61 plasma samples (24 from cases and 37 from controls), initially tested between 2010 and 2013, were retested to determine any change in index. Data were also collected on circulatory protein levels for false-positive serum samples. Serum indices significantly declined on retesting (median: initial, 0.50, retest, 0.23; P < 0.0001). This was shown to be diagnosis dependent as the decline was apparent on retesting of control samples (median: initial 0.50, retest 0.12; P < 0.0001), but was not evident with case samples (median: initial, 0.80, retest, 0.80; P = 0.724). Plasma samples showed little change on reanalysis after long-term storage at 4°C. Retesting after freezing showed a decrease in index values for controls (median: initial 0.40, retest 0.26; P = 0.0505), but no significant change in cases. Circulatory proteins showed a correlation between serum albumin concentration and difference in index value on retesting. Overall, this study suggests that a lack of reproducibility in GM EIA positivity is only significant when disease is absent. Retesting after freezing helps to differentiate false-positive GM EIA results and, with consecutive positivity, could help to improve accuracy in predicting disease status. The freezing of samples prior to testing could potentially reduce false-positivity rates and the need to retest.

Prevention and diagnosis of invasive fungal disease in high-risk patients within an integrative care pathway.

OBJECTIVES: The aim of this study was to assess the clinical utility of enhanced diagnostics on the management of invasive fungal disease in high risk patients within an integrated care pathway and to audit compliance and efficacy of antifungal prophylaxis. METHODS: A cohort of 549 high risk haematology and stem-cell transplant recipients was followed over a 5 year period. The routine standard of care involved the use of antimould prophylaxis and a neutropenic care pathway utilizing twice weekly antigen and PCR testing. RESULTS: Prophylaxis with itraconazole was poorly tolerated and therapeutic levels could not be maintained. Antigen testing and PCR showed good clinical utility in the management of invasive aspergilosis with high sensitivity (98%) and negative predictive value (99.6%) when both tests were used together, allowing a diagnosis IA to be excluded and obviating the need for empirical antifungal agents. When used serially, multiple positive PCR and antigen test results enabled accurate diagnosis of IA with a specificity of 95% and a positive likelihood ratio of 11. Biomarkers preceded clinical signs in 85% of proven and probable invasive disease. CONCLUSION: The combination of both tests showed optimum clinical utility for the diagnosis and management of IA in this high risk group.

Evaluation of real-time PCR, galactomannan enzyme-linked immunosorbent assay (ELISA), and a novel lateral-flow device for diagnosis of invasive aspergillosis.

Diagnosis of invasive aspergillosis (IA) remains challenging. With a relatively low incidence of disease, the use of expensive empirical antifungal therapy exposes many patients to unnecessary toxicity. Diagnosis places emphasis on specific but temporal radiological evidence. Circulating biomarker diagnosis has shown potential, but assays show variable performance, take several hours to perform, and require a degree of technical ability. A novel and simple lateral-flow device (LFD) using monoclonal antibody JF5, which targets an extracellular glycoprotein, has been developed and potentially removes any technical requirements, reducing processing time considerably. In this study, we evaluate the performance of this LFD compared to real-time PCR (targeting the 28S rRNA gene) and galactomannan (GM) detection when testing serum from a European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group, National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG)-defined hematological population. In a proven/probable-IA population versus a no-IA population, the LFD performance was comparable to that of both PCR and galactomannan enzyme immunoassay. Specificity (98.0%) was similar to that of PCR (96.6%) and slightly superior to that of GM (91.5%). Sensitivity (81.8%) was inferior to that of PCR (95.5%) but better than that of GM (77.3%). In combination with PCR, it provided both 100% sensitivity and 100% specificity. The LFD permits rapid testing of easily obtainable specimens, to be used as an adjunct test, before confirmation by other investigations. Its simplicity provides centers without specialist diagnostics with a test with clinical performance superior to that of classical microbiological approaches and results that can be used to direct antifungal management. In summary, microbiological diagnosis of IA is difficult and options are limited, with variable performance. An LFD assay targeting a novel specific biomarker has been developed, one which is methodologically simple and provides good clinical performance, particularly if combined with PCR.

Comparison of galactomannan enzyme immunoassay performance levels when testing serum and plasma samples.

Diagnostic galactomannan (GM) enzyme immunoassay (EIA) testing is formally validated only for serum, though in practice, plasma is occasionally tested. It is assumed, but not confirmed, that results will be comparable to those for serum. GM EIA when testing plasma was evaluated, providing sensitivity (85.7%) and specificity (85.4%) comparable to those for serum. Plasma index values were higher than those for serum; if plasma GM EIA were used to define probable cases, four additional cases would have been diagnosed.

Multicenter comparison of serum and whole-blood specimens for detection of Aspergillus DNA in high-risk hematological patients.

Samples from patients at high risk for invasive aspergillosis (IA) were prospectively collected and analyzed for the presence of molecular markers of fungal infection. Serum specimens were screened for galactomannan and Aspergillus DNA, and whole-blood specimens were screened only for Aspergillus DNA. Fungal infections were categorized according to the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group, National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) criteria. Forty-seven cases (proven and probable IA) and 31 controls (no evidence of IA) were selected retrospectively for this case-control study, comprising 803 samples, in order to determine the performance of whole-blood PCR, serum PCR, and serum galactomannan testing. Although no single assay was able to detect every case of IA, a combination of different assays provided the best performance. There was no significant difference between the use of whole-blood and serum specimens for PCR-based diagnosis of IA, but there was a trend for whole blood to be more sensitive (85% versus 79%) and to yield an earlier positive result (36 days versus 15 days) than for serum. However, DNA extraction from serum specimens is easier and faster than that from whole-blood specimens, and it allows the same specimen to be used for both galactomannan and PCR assays. In conclusion, the appropriate sample type for DNA extraction should be determined by the local requirements and the technical platforms available at each individual center. A combination of biomarker tests offered the best diagnostic utility for detecting IA.

Infection in cancer and transplantation.

The range of opportunist pathogens in cancer and transplant patients continues to increase. New treatment modalities and forms of immunosuppression following transplantation have improved survival from the underlying disease but can lead to prolonged immunosuppression and increased risk of infection. NICE guidelines for the management of neutropenic sepsis are now available but have aroused some controversy, particularly over the recommendation for quinolone prophylaxis in high-risk patient groups. In addition to neutropenia, long-term defects in cell-mediated immunity are exposing patients to risk of chronic, viral, protozoal and fungal infection. Advances in diagnostic techniques have the potential to improve management and limit unnecessary empirical treatment, allowing a move towards a diagnosis-driven strategy. However, interpreting the clinical validity and utility of some of these assays can be difficult, particularly for low-prevalence infection where the positive predictive value of any diagnostic test is likely to be low and prompt empirical antibacterial therapy is still indicated in neutropenic patients.

Disseminated protothecosis following traumatic Hickman line removal in a patient with leukaemia.

Human protothecosis is a rare infection caused by a member of the genus Prototheca, an ubiquitous alga. Traumatic inoculation can cause infections in the immunocompetent host while disseminated infection is mainly seen in patients with compromised immunity. We report here an unusual case of disseminated infection in a cancer patient. Traumatic removal of a Hickman catheter in this patient, led to the development of a severe skin and subcutaneous tissue infection with algaemia. These infections are often indolent and difficult to treat, with paucity of information available as to guidelines for diagnosis and effective therapeutic options.

Prospective study of amphotericin B formulations in immunocompromised patients in 4 European countries.

BACKGROUND: Amphotericin B is a widely used broad-spectrum antifungal agent, despite being associated with significant adverse events, including nephrotoxicity. METHODS: The present prospective study collected data on outcomes for 418 adult patients treated consecutively with polyenes in hematology and oncology wards in 20 hospitals in Europe. RESULTS: Patients initially received amphotericin B deoxycholate (62% of patients), liposomal amphotericin B (27%), or other lipid formulations of amphotericin B (11%). Of the patients initially treated with amphotericin B deoxycholate, 36% had therapy switched to lipid formulations of amphotericin B, primarily because of increased serum creatinine levels (in 45.7% of patients) or other amphotericin B-attributable adverse events (in 41.3% of patients). Nephrotoxicity, which was defined as a > or = 50% increase in the serum creatinine level, developed in 57% of patients with normal kidney function at baseline. Predictors of nephrotoxicity included formulation type and duration of treatment. Compared with patients without nephrotoxicity, patients with nephrotoxicity had a higher mortality rate (24%), and their mean length of stay in the hospital was prolonged by 8.6 days. Slight increases in the serum creatinine level (i.e., > or = 50%) were associated with a significantly longer stay in the hospital. Severe nephrotoxicity (i.e., a > or = 200% increase in the serum creatinine level) was a significant predictor of death, as were severe underlying medical conditions and documented fungal infection. CONCLUSION: This prospective study confirmed that, in European hospitals, amphotericin B formulations have a major influence on the length of stay in the hospital and nephrotoxicity-associated mortality.

The evolution and evaluation of a whole blood polymerase chain reaction assay for the detection of invasive aspergillosis in hematology patients in a routine clinical setting.

BACKGROUND: Invasive aspergillosis (IA) is associated with high mortality. Successful outcome with treatment is linked to early diagnosis. The utility of classic diagnostic methods, however, is limited. METHODS: To aid in the diagnosis of IA, we retrospectively assessed our diagnostic service, using real-time polymerase chain reaction (PCR) and galactomannan sandwich enzyme-linked immunosorbent assay (ELISA). RESULTS: A total of 203 patients at risk of invasive fungal infection were screened by PCR, and 116 of the patients were also tested by ELISA. The patient group comprised 176 patients with hematological malignancy and 28 control patients with evidence of invasive candidal infection. Consensus European Organisation for Research and Treatment of Cancer and Mycoses Study Group criteria were used to classify fungal infection, which, by definition, excluded the PCR result. The PCR method was sensitive (up to 92.3% sensitivity) and specific (up to 94.6% specificity) and had good agreement with the galactomannan ELISA (76.7%) and high-resolution computed tomography scan results. CONCLUSIONS: A negative PCR result can be used to rule out IA and to limit the need for empirical antifungal therapy; thus, it has a role in diagnosing IA infections, especially in combination with antigen testing. PCR-positive cases classified as "false positives" regularly reflect the limitations of classic microbiological procedures or restricted use of consensus clinical methods employed to classify infection.