Galactomannan Index Research Articles

Evaluation of Biomarkers: Galactomannan and 1,3-Beta-D-Glucan Assay for the Diagnosis of Invasive Fungal Infections in Immunocompromised Patients from a Tertiary Care Centre

Purpose: Due to limitations of traditional microbiological techniques, standardised fungal biomarker tests such as Galactomannan Index (GMI) and 1,3-beta-D-glucan (BDG) are being preferred for diagnosis of invasive fungal infections (IFIs). These tests have been extensively used in developed countries but seldom in developing countries. The present study was performed to evaluate these tests for the diagnosis of IFIs in immunocompromised patients at an Indian tertiary care centre. Materials and Methods: A retrospective hospital-based study was done in immunocompromised patients with clinical suspicion of IFI. The demographic, clinical, radiological and mycological details of the patients were recorded. The patients were categorised into proven, probable and no IFI (as per European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria). The sensitivity and specificity of BDG Fungitell and Platelia Aspergillus antigen assays was estimated. Results: A total of 70 consecutive patients were included, of which 41 had IFI (10 proven and 31 probable) while 29 had no IFI. A significant association was found between IFI and the presence of a central venous line (P = 0.035) and history of intake of T-cell immunosuppressants (P = 0.001). Median BDG values (pg/ml) in patients with proven IFI, probable IFI and no IFI were 300 (range: 70–500), 165 (range: 53–500) and 45 (range: 31–500), respectively. The receiver operating characteristic (ROC) curve analysis for BDG revealed an area under the curve of 0.995, sensitivity: 97.4% and specificity: 96.6% for IFI diagnosis. The ROC curve analysis of GMI revealed an AUC of 0.75 and 90% patients with invasive aspergillosis (IA) had positive GMI. Conclusion: BDG has good sensitivity and specificity for distinguishing IFI from no IFIs and GMI may be used for diagnosing IA.

Aspergillus PCR in Bronchoalveolar Lavage Fluid for the Diagnosis and Prognosis of Aspergillosis in Patients With Hematological and Non-hematological Conditions.

Objectives: We evaluated the usefulness of an Aspergillus fumigatus quantitative PCR assay performed in bronchoalveolar lavage fluid (BAL) for the diagnosis and prognosis of both invasive and non-invasive aspergillosis.Methods: This 4-year retrospective study involved 613 at-risk patients who had either hematological disorders or other immunosuppressive conditions, notably solid organ transplants. Thirty-five patients had proven/probable aspergillosis and thirteen had chronic non-invasive aspergillosis. We compared PCR, galactomannan index and mycological analysis of BAL.Results: For invasive aspergillosis (IA), PCR performed in BAL yielded 88.6% sensitivity and 95.5% specificity. Comparatively, galactomannan index and mycological examination yielded only 56.3 and 63.6% sensitivity and 97.6 and 94.5% specificity, respectively. Considering the 13 chronic aspergillosis cases, PCR, galactomannan index and mycological examination yielded 76.9, 15.4, and 84.6% sensitivity and 92.2, 94.9, and 93% specificity, respectively. Fungal load in BAL evaluated by PCR was able to discriminate between aspergillosis and contamination, but not between invasive and non-invasive forms. Finally, fungal load was predictive of 90-day mortality, with 23.1% mortality for patients with less than 500 copies/mL versus 68.4% for patients above that cut-off (p < 0.05).Conclusion: Our results indicate that Aspergillus PCR in BAL is of particular interest for both the diagnosis and the prognosis of IA. It is likewise an interesting tool for the diagnosis of non-invasive forms.

Urine Antigen Detection as an Aid to Diagnose Invasive Aspergillosis.

Establishing rapid diagnoses of invasive aspergillosis (IA) is a priority tests that detect galactomannan and β-d-glucan are available, but are technically cumbersome and rely on invasive sampling (blood or bronchoalveolar lavage). We optimized a lateral flow dipstick assay using the galactofuranose-specific monoclonal antibody (mAb476), which recognizes urine antigens after Aspergillus fumigatus pulmonary infection in animals. Urine samples were obtained from a cohort of 78 subjects undergoing evaluation for suspected invasive fungal infections, and stored frozen until testing. Urine was processed by centrifugation through desalting columns and exposed to dipsticks. Reviewers blinded to clinical diagnoses graded results. Western blots were performed on urine samples from 2 subjects to characterize mAb476-reactive antigens. Per-patient sensitivity and specificity for diagnosis of proven or probable IA in the overall cohort was 80% (95% confidence interval [CI], 61.4%-92.3%) and 92% (95% CI, 74%-99%), respectively. In the subgroup with cancer, sensitivity was 89.5% (95% CI, 66.7%-98.7%) and specificity was 90.9% (95% CI, 58.7%-99.8%); among all others, sensitivity and specificity were 63.6% (95% CI, 30.8%-89.1%) and 92.9% (95% CI, 66.1%-99.8%), respectively. Eliminating lung transplant recipients with airway disease increased sensitivity in the noncancer cohort (85.7% [95% CI, 42.1%-99.6%]). Semiquantitative urine assay results correlated with serum galactomannan indices. Western blots demonstrated mAb476-reactive antigens in urine from cases, ranging between 26 kDa and 35 kDa in size. Urine testing using mAb476 may be used as an aid to diagnose IA in high-risk patients.

Combination Therapy with Isavuconazole and Micafungin for Treatment of Experimental Invasive Pulmonary Aspergillosis.

Invasive pulmonary aspergillosis (IPA) is an important cause of morbidity and mortality in immunocompromised patients. We hypothesized that simultaneous inhibition of biosynthesis of ergosterol in the fungal cell membrane and (1→3)-β-d-glucan in the cell wall, respectively, by the antifungal triazole isavuconazole (ISA) and the echinocandin micafungin (MFG) may result in improved outcomes in experimental IPA in persistently neutropenic rabbits. Treatments included ISA at 20 mg/kg of body weight/day (ISA20), 40 mg/kg/day (ISA40), and 60 mg/kg/day (ISA60); MFG at 2 mg/kg/day (MFG2); combinations of ISA20 and MFG2, ISA40 and MFG2, and ISA60 and MFG2; and no treatment (untreated controls [UC]). The galactomannan index (GMI) and (1→3)-β-d-glucan levels in serum were measured. The residual fungal burden (number of CFU per gram) was significantly reduced in ISA20-, ISA40-, ISA60-, ISA20-MFG2-, ISA40-MFG2-, and ISA60-MFG2-treated rabbits compared with that in MFG2-treated or UC rabbits (P < 0.01). Measures of organism-mediated pulmonary injury, lung weights, and pulmonary infarct score were lower in ISA40-MFG2-treated rabbits than in rabbits treated with ISA40 or MFG2 alone (P < 0.01). Survival was prolonged in ISA40-MFG2-treated rabbits in comparison to those treated with ISA40 or MFG2 alone (P < 0.01). These outcome variables correlated directly with significant declines in GMI and serum (1→3)-β-d-glucan levels during therapy. The GMI correlated with measures of organism-mediated pulmonary injury, lung weights (r = 0.764; P < 0.001), and pulmonary infarct score (r = 0.911; P < 0.001). In summary, rabbits receiving combination therapy with isavuconazole and micafungin demonstrated a significant dose-dependent reduction in the residual fungal burden, decreased pulmonary injury, prolonged survival, a lower GMI, and lower serum (1→3)-β-d-glucan levels in comparison to rabbits receiving isavuconazole or micafungin as a single agent.

Higher mortality of severe influenza patients with probable aspergillosis than those with and without other coinfections.

Aspergillus-associated infection might comprise up to 23-29% of severe influenza patients from the community throughout stay in an intensive care unit (ICU). In Taiwan, cases of severe influenza with aspergillosis are increasingly reported. Therefore, we describe the relative risk of mortality among severe influenza patients with aspergillosis and other coinfections compared to severe influenza patients without Aspergillus coinfections. We retrospectively reviewed 124 adult patients with severe influenza in a tertiary medical center in southern Taiwan from January 2015 through March 2016. The definition of probable aspergillosis required abnormal radiological findings and positive Aspergillus galactomannan (GM) antigen and/or Aspergillus isolation. Probable aspergillosis (detected throughout the whole course) and other coinfections (only community-acquired) were diagnosed in 21 (17%) and 38 (31%) of all patients respectively. Klebsiella pneumoniae (36.8%), Pseudomonas aeruginosa (31.6%) and Staphylococcus aureus (31.6%) were the most frequent isolates of other coinfections. In-ICU mortality of Aspergillus group (66.7%) was significantly higher than other coinfections (23.7%, p=0.001) or control group without coinfections (15.4%, p<0.001), with significant odds ratios after adjusting for important variables. The factor of GM index ≥0.6 had a 19.82 (95% CI, 4.91 to 80.07, p<0.0001) odds of expiring in an ICU among the Aspergillus group. Dual Aspergillus and influenza infection is emerging in southern Taiwan. Meanwhile, community-acquired P. aeruginosa should be listed in the common copathogens with severe influenza. The 67% mortality linked to aspergillosis highlights the need for physicians to focus attention on patients with GM≥0.6.

Assessing the risk of false positive serum galactomannan among patients receiving piperacillin/tazobactam for febrile neutropenia

Galactomannan (GM) assay is commonly used as an early diagnostic tool for invasive fungal infection (IFI) in high-risk hematology patients. False positivity is frequently observed in GM with the use of piperacillin/tazobactam. The usage of generic drugs over the original brand has a significant cost advantage. The aim of this study was to assess the performance of GM test among patients receiving original and generic piperacillin/tazobactam formulations. The study included 85 adult patients; 62.4% were male with hematological malignancy currently receiving piperacillin/tazobactam. The study group was divided into two groups: patients receiving original and generic piperacillin/tazobactam. Serum GM index was positive in one of 35 patients receiving original piperacillin/tazobactam, whereas it was positive in 46 out of 50 patients receiving generic piperacillin/tazobactam (P < .001). However, the patients receiving generic piperacillin/tazobactam underwent computed tomography (CT) scans more frequently than those receiving original piperacillin/tazobactam (P = .047). In addition, in vitro analysis of GM was performed in two generics and one original piperacillin/tazobactam vials. One generic piperacillin/tazobactam vial included high GM level. False positivity of serum GM with generic formulations of piperacillin/tazobactam is still an ongoing issue in hematology patients. A high rate of serum GM index false positivity may unexpectedly lead to a higher rate of CT scan. Selected piperacillin/tazobactam vials in each batch should be checked for GM to identify a false positivity of GM before purchase.

(1→3)-β-d-Glucan and Galactomannan for Differentiating Chemical "Black Particles" and Fungal Particles Inside Peritoneal Dialysis Tubing.

♦ Aseptic, sheet-like foreign bodies observed inside Tenckhoff (TK) catheter lumens (referred to as "black particles") are, on gross morphology, hardly distinguishable from fungal colonization because these contaminants adhere tightly to the catheter. Detection of fungal cell wall components using (1→3)-β-d-glucan (BG) and galactomannan index (GMI) might be an alternative method for differentiating the particles. ♦ Foreign particles retrieved from TK catheters in 19 peritoneal dialysis patients were examined microscopically and cultured for fungi and bacteria. Simultaneously, a Fungitell test (Associates of Cape Cod, Falmouth, MA, USA) and a Platelia Aspergillus ELISA assay (Bio-Rad Laboratories, Marnes-La-Coquette, France) were used to test the spent dialysate for BG and GMI respectively. ♦ Of the 19 patients, 9 had aseptic black particles and 10 had fungal particles in their tubing. The fungal particles looked grainy, were tightly bound to the catheter, and appeared more "colorful" than the black particles, which looked sheet-like and could easily be removed by milking the tubing. Compared with effluent from patients having aseptic particles, effluent from patients with fungal particles had significantly higher levels of BG (501 ± 70 pg/mL vs. 46 ± 10 pg/mL) and GMI (10.98 ± 2.17 vs. 0.25 ± 0.05). Most of the fungi that formed colonies inside the catheter lumen were molds not usually found in clinical practice, but likely from water or soil, suggesting environmental contamination. Interestingly, in all 10 patients with fungal colonization, visualization of black particles preceded a peritonitis episode and TK catheter removal by approximately 1-3 weeks; in patients with aseptic particles, a 17-week onset to peritonitis was observed. ♦ In all patients with particle-coated peritoneal dialysis tubing, spent dialysate should be screened for BG and GMI. Manipulation of the TK catheter by squeezing, hard flushing, or even brushing to dislodge black particles should be avoided. Replacement of the TK catheter should be suspended until a cause for the particles is determined.

Detection of a Serum Siderophore by LC-MS/MS as a Potential Biomarker of Invasive Aspergillosis.

Invasive aspergillosis (IA) is a life-threatening systemic mycosis caused primarily by Aspergillus fumigatus. Early diagnosis of IA is based, in part, on an immunoassay for circulating fungal cell wall carbohydrate, galactomannan (GM). However, a wide range of sensitivity and specificity rates have been reported for the GM test across various patient populations. To obtain iron in vivo, A. fumigatus secretes the siderophore, N,N',N"-triacetylfusarinine C (TAFC) and we hypothesize that TAFC may represent a possible biomarker for early detection of IA. We developed an ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for TAFC analysis from serum, and measured TAFC in serum samples collected from patients at risk for IA. The method showed lower and upper limits of quantitation (LOQ) of 5 ng/ml and 750 ng/ml, respectively, and complete TAFC recovery from spiked serum. As proof of concept, we evaluated 76 serum samples from 58 patients with suspected IA that were investigated for the presence of GM. Fourteen serum samples obtained from 11 patients diagnosed with probable or proven IA were also analyzed for the presence of TAFC. Control sera (n = 16) were analyzed to establish a TAFC cut-off value (≥6 ng/ml). Of the 36 GM-positive samples (≥0.5 GM index) from suspected IA patients, TAFC was considered positive in 25 (69%). TAFC was also found in 28 additional GM-negative samples. TAFC was detected in 4 of the 14 samples (28%) from patients with proven/probable aspergillosis. Log-transformed TAFC and GM values from patients with proven/probable IA, healthy individuals and SLE patients showed a significant correlation with a Pearson r value of 0.77. In summary, we have developed a method for the detection of TAFC in serum that revealed this fungal product in the sera of patients at risk for invasive aspergillosis. A prospective study is warranted to determine whether this method provides improved early detection of IA.

Aspergillus PCR in serum for the diagnosis, follow-up and prognosis of invasive aspergillosis in neutropenic and nonneutropenic patients

We evaluated the usefulness of a serum Aspergillus PCR assay for the diagnosis and prognosis of invasive aspergillosis in a study involving 941 patients for a total of 5146 serum samples. Fifty-one patients had proven/probable aspergillosis. We compared galactomannan (GM), PCR and mycologic analysis of pulmonary samples in both neutropenic and nonneutropenic patients. PCR performed in serum yielded 66.7% sensitivity, 98.7% specificity, 75.6% positive predictive value and 98.0% negative predictive value, while the GM index yielded 78.4% sensitivity, 87.5% specificity, 27% positive predictive value and 98.6% negative predictive value. The inclusion of PCR in the European Organization for Research and Treatment of Cancer (EORTC) and the Mycosis Study Group (MSG) mycologic criteria permitted the reclassification of nine other cases from possible to probable aspergillosis and increased the sensitivity to 71.7%. Combining the GM index with serum PCR increased the detection rate of invasive aspergillosis with 88.2% sensitivity. PCR was systematically negative in 16 patients with noninvasive forms of aspergillosis (namely aspergilloma and chronic aspergillosis). Remaining PCR positive after a period of 14 to 20 days of treatment was related to poor outcome at 30 and 90 days. Our results also indicate that, unlike the determination of the GM index, the initial fungus load as determined by PCR was highly predictive of 90-day mortality, with the rate of the latter being 15.8% for patients with <150 copies/mL vs. 73.2% for patients at or above that cutoff (p <0.0001). Therefore, PCR appears to be a powerful and interesting tool for the identification of patients with invasive aspergillosis who might benefit from more intense care.

Pharmacokinetics and Concentration-Dependent Efficacy of Isavuconazole for Treatment of Experimental Invasive Pulmonary Aspergillosis

We studied the pharmacokinetics and efficacy of the broad-spectrum triazole isavuconazole for the treatment of experimental invasive pulmonary aspergillosis (IPA) in persistently neutropenic rabbits. Treatment started 24 h after endotracheal administration of Aspergillus fumigatus inoculum; study subjects included rabbits receiving orally administered prodrug isavuconazonium sulfate (BAL8557) equivalent to active moiety isavuconazole (ISA; BAL4815) at 20 (ISA20), 40 (ISA40), and 60 (ISA60) mg/kg (of body weight)/day, with an initial loading dose of 90 mg/kg (ISA90), and untreated rabbits (UC). There were significant concentration-dependent reductions of residual fungal burden (log CFU/gram) and of organism-mediated pulmonary injury, lung weights, and pulmonary infarct scores in ISA40- and ISA60-treated rabbits in comparison to those of UC (P < 0.001). ISA20-treated (P < 0.05), ISA40-treated, and ISA60-treated (P < 0.001) rabbits demonstrated significantly prolonged survival in comparison to that of UC. ISA40- and ISA60-treated animals demonstrated a significant decline of serum (1→3)-β-d-glucan levels (P < 0.05) and galactomannan indices (GMIs) during therapy following day 4 in comparison to progressive GMIs of UC (P < 0.01). There also were significantly lower concentration-dependent GMIs in bronchoalveolar lavage (BAL) fluid from ISA40- and ISA60-treated rabbits (P < 0.001). There was a direct correlation between isavuconazole plasma area under the concentration-time curve from 0 to 24 h (AUC0-24) and residual fungal burdens in lung tissues, pulmonary infarct scores, and total lung weights. In summary, rabbits treated with isavuconazole at 40 and 60 mg/kg/day demonstrated significant dose-dependent reduction of residual fungal burden, decreased pulmonary injury, prolonged survival, lower GMIs in serum and BAL fluid, and lower serum (1→3)-β-d-glucan levels.

Pharmacodynamics of Voriconazole in Children: Further Steps along the Path to True Individualized Therapy.

Voriconazole is the agent of choice for the treatment of invasive aspergillosis in children at least 2 years of age. The galactomannan index is a routinely used diagnostic marker for invasive aspergillosis and can be useful for following the clinical response to antifungal treatment. The aim of this study was to develop a pharmacokinetic-pharmacodynamic (PK-PD) mathematical model that links the pharmacokinetics of voriconazole with the galactomannan readout in children. Twelve children receiving voriconazole for treatment of proven, probable, and possible invasive fungal infections were studied. A previously published population PK model was used as the Bayesian prior. The PK-PD model was used to estimate the average area under the concentration-time curve (AUC) in each patient and the resultant galactomannan-time profile. The relationship between the ratio of the AUC to the concentration of voriconazole that induced half maximal killing (AUC/EC50) and the terminal galactomannan level was determined. The voriconazole concentration-time and galactomannan-time profiles were both highly variable. Despite this variability, the fit of the PK-PD model was good, enabling both the pharmacokinetics and pharmacodynamics to be described in individual children. (AUC/EC50)/15.4 predicted terminal galactomannan (P= 0.003), and a ratio of >6 suggested a lower terminal galactomannan level (P= 0.07). The construction of linked PK-PD models is the first step in developing control software that enables not only individualized voriconazole dosages but also individualized concentration targets to achieve suppression of galactomannan levels in a timely and optimally precise manner. Controlling galactomannan levels is a first critical step to maximizing clinical response and survival.

Galactomannan enzyme immunoassay and quantitative Real Time PCR as tools to evaluate the exposure and response in a rat model of aspergillosis after posaconazole prophylaxis

IntroductionA steroid-immunosuppressed rat model of invasive pulmonary aspergillosis was use to examine the usefulness of galactomannan enzyme immunoassay (GM) and quantitative real time PCR (RT-PCR) in evaluating the association between response and exposure after a high dose of prophylactic posaconazole. MethodsTwo different strains of Aspergillus fumigatus with different in vitro posaconazole susceptibility were used. ResultsSerum concentrations demonstrated similar posaconazole exposure for all treated animals. However, response to posaconazole relied on the in vitro susceptibility of the infecting strain. After prophylaxis, galactomannan index and fungal burden only decreased in those animals infected with the most susceptible strain. ConclusionThis study demonstrated that both biomarkers may be useful tools for predicting efficacy of antifungal compounds in prophylaxis.

Role of galactomannan assay in bronchoalveolar lavage fluid in the diagnosis of invasive aspergillosis in high risk patients with hematological disorders

Introduction: Invasive aspergillosis (IA) is the most frequent invasive fungal infection occurring in high risk patients with haematological disorders and also an important cause of morbidity and mortality in them. Lungs comprise the primary site of IA in the vast majority of cases, and the most frequently occurring form of IA. Early diagnosis followed by early initiation of therapy improves outcome. The current culture based diagnostic methods are insensitive and slow. Detection of Aspergillus galactomannan (GM) in serum using the platelia Aspergillus enzyme immunoassay (GM EIA) represents sensitive, non-culture-based tool for the early diagnosis of IA. Recent studies have shown that during IPA, GM is released earlier and in higher concentration in the BAL fluid than in serum. Thus, an early and accurate diagnosis of IPA can be reached by detecting antigen in BAL samples. Materials and Methods: Thirty consecutive high risk patients with haematological disorders satisfying the inclusion and exclusion criteria according to EORTC-MSG diagnostic criteria and undergoing indoor treatment were recruited between November 2013 and December 2014 into the study. In all the patients, bronchoalveolar lavage (BAL) fluid GM and serum GM assays were assayed. Results: The diagnostic accuracy of the two tests was measured by calculating the sensitivity, specificity, predictive values and receiver operating characteristic curve (ROC). The optimal BAL GM index for diagnosing probable and possible IPA was >1.00 OD, resulting in a sensitivity and specificity of 93.75% and 78.57% respectively. As per ROC curve, when the optimal BAL GM index for the diagnosis of probable and possible invasive pulmonary aspergillosis (IPA) was OD >0.5, it resulted in sensitivity and specificity of 50% and 71.43% respectively. BAL GM was thus found to have a significantly higher sensitivity as compared to serum GM. Conclusion: In all high-risk patients with haematological disorders where the clinical and radiological findings favour the possibility of invasive pulmonary aspergillosis, conducting a GM assay in BAL fluid sample is far more rewarding than carrying out the traditional serum GM assay. BAL GM has a high diagnostic accuracy when correlated with the EORTC/MSG diagnostic criteria, and this high diagnostic yield is useful in obviating the unnecessary widespread use and abuse of empirical antifungal therapy in patients with IPA.

Survey of Serum Aspergillus Antigen in Patients Undergoing Chemotherapy for Acute Myeloid Leukemia or Allogeneic Hematopoietic Stem Cell Transplantation: Role in Predicting Invasive Aspergillosis and in Modifying the Therapeutic Strategy

IntroductionInvasive aspergillosis (IA) remains an important cause of mortality in immunocompromised acute myeloid leukemia (AML) patients receiving induction chemotherapy and in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) for hematological malignancies. Early diagnostic is critical and challenging given the efficacy and availability of several new anti-fungal therapies. In this study, we evaluated the performance of different factors in predicting the occurrence of IA, including the Aspergillus antigen galactomannan (GM) detection in sera.MethodsWe included all AML patients receiving induction chemotherapy and patients undergoing allo-HSCT for any hematological malignancy at our center between April 2006 and April 2014 with available data on Aspergillus antigen GM. Serologic detection of circulating GM fungal biomarker was considered during the 100 days following the first day of induction chemotherapy in AML patients or from the day of allo-HSCT. Usual follow-up included two GM tests per week, only patients with at least three serum GM results were considered. The GM tests have been performed routinely using the ELISA kit (Platelia Aspergillus antigen ELISA, Biorad), giving the results in index values. Demographic, GM index results and diagnostic data were collected. IA cases were classified as proven or probable according to the EORTC criteria. The value of the first antigen test, the delay to positivity, and the slope of the progression of the index value between the first two antigens concentrations were considered as predictors of IA. ROC curves for each predictor and their combination were performed and prognostic scores were established.ResultsA total of 775 patients were included : i) 292 AML patients, 153 (52%) males with a median age of 62 years (range: 17-79), 15% were classified as favorable, 8% as intermediate I, 18% as intermediate II and 59% as unfavorable according to cytogenetics and molecular markers; ii) 483 allo-HSCT patients, 293 (61%) were males, median age was 48 years (range: 18-70), among them 234 (48%) AML, 66 (14%) multiple myeloma, 46 (10%) Myelodysplastic syndromes, 38 (8%) Non-Hodgkin Lymphoma and the rest of patients had other hematological disorders; 233 (48 %) patients received reduced intensity conditioning and 250 (52%) myeloablative conditioning. The disease status at allo-HSCT was complete remission (CR) in 366 (76%) patients and the rest of patients were in less than CR. HSC source was peripheral blood in 42.2% (90 identical siblings, 150 10/10 matched unrelated, 54 9/10 mismatched unrelated), bone marrow in 42.6% (105 identical siblings, 162 10/10 matched unrelated, 45 9/10 mismatched unrelated) and cord blood in 15.2%.A total of 877 episodes with 16121 GM serum antigen results was considered (median: 18 GM tests per patient). During the follow-up, we identified 121 episodes with at least one positive GM test with a cumulative incidence at day 100 of 13.8%. We also diagnosed 48 IA (2 proven, 46 probable), with a cumulative incidence at day 100 of 5.5% in total, 7.2% in AML and 4.3% in allo-HSCT, respectively. We then classified the GM positive episodes in 82 false-positive (68%) and 39 true-positive episodes (32%) for IA, respectively. A majority of IA events occurred during the first 30 days of follow up, GM positivity showing a positive predictive value of 41% versus a negative predictive value of 99%.The three IA predicting factors had similar independent effects and their combinations were performed, allowing the establishment of an area under ROC of 0.79 (95% CI: 0.70-0.89). Cut off values of the first positive GM serum and slope were equal or higher than 1.04 and 0.04, respectively, and delay to positivity equal or less than 15 days. To simplify the practical use in clinical practice, the prognostic score defining the IA risk probability was defined as the number of predictors present (values from 0 to 3). This score was tested on positive follow-up giving values of 0, 1, 2 or higher for 45 (37%), 39 (32%) and 37 episodes (31%), respectively. A score superior or equal to 2 was indicative of IA in 62% of the cases (figure 1).ConclusionAs IA has a significant impact on hematology patient's survival, this GM predictive score combining three predictors (value of the first antigen index, delay of positivity and slope of the index values) may help clinicians to conclude about starting an early preemptive IA treatment. [Display omitted] DisclosuresNicolini:Ariad Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.

Effects of host response and antifungal therapy on serum and BAL levels of galactomannan and (1→3)-β-D-glucan in experimental invasive pulmonary aspergillosis.

Galactomannan and (1→3)-β-D-glucan are useful biomarkers of invasive pulmonary aspergillosis (IPA). However, the effects of immunosuppression on levels of galactomannan or (1→3)-β-D-glucan in IPA are not well understood or quantified. We therefore studied the simultaneous levels of galactomannan and (1→3)-β-D-glucan in two rabbit models of experimental IPA: (1) AraC-induced neutropenia in untreated (UC-AraC) and liposomal amphotericin B-treated (LAMB-AraC) rabbits; and (2) nonneutropenic cyclosporine-methylprednisolone immunosuppression in untreated (UC-CsA+M) and LAMB-treated (LAMB-CsA+M) rabbits. Simultaneous levels of galactomannan and (1→3)-β-D-glucan were determined in bronchoalveolar lavage (BAL) fluid and serial serum specimens and correlated with pulmonary host response. Serum galactomannan index (GMI) and (1→3)-β-D-glucan concentration-time-curves were higher in UC-AraC vs. UC-CsA+M (Mann-Whitney U-test, P < .05). Serum galactomannan and (1→3)-β-D-glucan in treatment groups demonstrated therapeutic responses with similarly lower levels in comparison to UC (P < .01) in both models. Host differences did not affect BAL fluid GMI or (1→3)-β-D-glucan but did affect galactomannan and (1→3)-β-D-glucan levels in serum. The higher serum GMI and (1→3)-β-D-glucan concentration-time-curves in UC-AraC correlated with extensive pulmonary infiltration by angioinvasive hyphae and minimal inflammation, while the lower concentration-time-curves in UC-CsA+M were associated with shorter and fewer hyphae in lung tissue and an intensive neutrophil response to Aspergillus hyphae. Thus, serum levels of galactomannan and (1→3)-β-D-glucan in IPA depended upon immunosuppression, which also affected severity of infection and hyphal morphology, while BAL fluid galactomannan and (1→3)-β-D-glucan were sensitive biomarkers not affected by host response.

False-positive Aspergillus galactomannan and its kinetics in allogeneic hematopoietic stem cell transplantation

We evaluated the incidence of and risk factors for false-positive Aspergillus galactomannan (GM) antigenemia in allogeneic hematopoietic stem cell transplantation (HSCT). We also focused on the GM index value and its kinetics. Patients who underwent their first allogeneic HSCT at our center between June 2007 and December 2012 were included (n=172). Episodes of positive GM tests were classified as either "true-positive", which fulfilled the EORTC criteria for proven or probable invasive aspergillosis (IA), or "false-positive", which was not accompanied by clinical findings. The remaining cases were regarded as "inconclusive". The one-year cumulative incidences of IA and positive GM tests were 10.1% and 48.1%, respectively. Among 148 episodes of positive GM tests, 97(65.5%), 23(15.5%), and 28(19.0%) were classified as false-positive, true-positive and inconclusive, respectively. In the first episodes of positive GM tests in each patient (false-positive=67, others=30), an increase in the GM value in the first two measurements, neutropenia, and use of anti-mold agents at positive GM episode were associated with a significantly lower possibility of false-positive results according to a multivariate analysis. A false-positive GM test was frequently seen after allogeneic HSCT. An increase in the GM value may increase its positive predictive value.

Pharmacodynamics of amphotericin B deoxycholate, amphotericin B lipid complex, and liposomal amphotericin B against Aspergillus fumigatus.

Amphotericin B is a first-line agent for the treatment of invasive aspergillosis. However, relatively little is known about the pharmacodynamics of amphotericin B for invasive pulmonary aspergillosis. We studied the pharmacokinetics (PK) and pharmacodynamics (PD) of amphotericin B deoxycholate (DAMB), amphotericin B lipid complex (ABLC), and liposomal amphotericin B (LAMB) by using a neutropenic-rabbit model of invasive pulmonary aspergillosis. The study endpoints were lung weight, infarct score, and levels of circulating galactomannan and (1 → 3)-β-D-glucan. Mathematical models were used to describe PK-PD relationships. The experimental findings were bridged to humans by Monte Carlo simulation. Each amphotericin B formulation induced a dose-dependent decline in study endpoints. Near-maximal antifungal activity was evident with DAMB at 1 mg/kg/day and ABLC and LAMB at 5 mg/kg/day. The bridging study suggested that the "average" patient receiving LAMB at 3 mg/kg/day was predicted to have complete suppression of galactomannan and (1 → 3)-β-D-glucan levels, but 20 to 30% of the patients still had a galactomannan index of >1 and (1 → 3)-β-D-glucan levels of >60 pg/ml. All formulations of amphotericin B induce a dose-dependent reduction in markers of lung injury and circulating fungus-related biomarkers. A clinical dosage of liposomal amphotericin B of 3 mg/kg/day is predicted to cause complete suppression of galactomannan and (1 → 3)-β-D-glucan levels in the majority of patients.

Invasive aspergillosis after kidney transplant: case-control study.

Transplant recipients are at risk for invasive aspergillosis (IA), associated with a significant mortality rate. Renal transplant-specific risk factors have not been established. Forty-one adult kidney transplant recipients diagnosed with proven or probable IA from 1995 through 2013 were identified by search of the computerized patient files in the University Hospitals Leuven. The control population in this 1:2 case-control study consisted of the 2 patients who received a kidney transplant immediately before and after each identified patient and did not develop IA (n = 82). Leukopenia after kidney transplant increased the risk of IA among all patients (odds ratio [OR], 2.345 [95% confidence interval {CI}, 1.084-5.071]). For early-onset infection (ie, occurred during the first 3 months after transplant), a longer duration of renal replacement therapy pretransplant and the occurrence of leukopenia were risk factors (OR per year, 1.192 [95% CI, 1.006-1.413] and OR, 3.346 [95% CI, 1.063-10.527], respectively), whereas donor cytomegalovirus seropositivity increased the risk for late-onset IA (ie, occurred >3 months after transplant) (OR, 3.677 [95% CI, 1.388-9.743]). Twelve-week mortality rate was 39%. Disseminated infection, leukopenia, and the height of the serum galactomannan index were associated with an increased risk of death (hazard ratio [HR], 5.080 [95% CI, 1.740-14.830]; HR, 3.198 [95% CI, 1.183-8.649]; and HR, 1.371 [95% CI, 1.123-1.674], respectively). Prolonged renal replacement therapy before kidney transplant increases the risk of IA early after transplant. The height of the serum galactomannan index predicts mortality.

Detection of galactomannan in bronchoalveolar lavage of the intensive care unit patients at risk for invasive aspergillosis.

Background and Purpose:Invasive aspergillosis (IA) is one of the most common life-threatening fungal infections among the critically ill patients including intensive care unit (ICU) patients. Delayed diagnosis and therapy may lead to poor outcomes. Diagnosis may be facilitated by a test for molecular biomarkers, i.e. detection of galactomannan (GM) antigen based on enzyme immunoassay, which is of increasing interest in the clinical settings for the diagnosis of IA. In the present study, we assessed GM testing of bronchoalveolar lavage (BAL) fluid as a tool for early diagnosis of IA among ICU patients who were at risk for developing IA.Material and Methods:A prospective study was performed in ICU patients with underlying predisposing conditions for IA between August 2010 and September 2011. BAL samples for direct microscopic examination, culture, and GM detection were obtained once or twice weekly. GM in BAL levels was measured using the Platellia Aspergillus EIA test kit. According to modified European Organization for the Research and Treatment of Cancer/ Mycoses Study Group (EORTC/MSG) criteria, patients were classified as having probable or possible IA.Results:Out of 43 suspected patients to IA, 13 (30.2%) cases showed IA. According to the criteria presented by EORTC/MSG, they were categorized as: 4 cases (30.8%) of possible IA and 9 (69.2%) of probable IA. Out of 21 BAL samples from patients with IA, 11 (52.4%) had at least one positive BAL GM index. Using a cutoff index of 0.5, the sensitivity and specificity, positive and negative predictive values of GM detection in BAL fluid were 100%, 85.7%, 65.7% and 96%, respectively. The sensitivity and specificity was 73% and 92.7% at cutoff ≥1.0, respectively. In 6 of 13 IA cases, BAL culture or direct microscopic examination remained negative, whereas GM in BAL was positive. Conclusion:Our data have revealed that the sensitivity of GM detection in BAL was better than that of conventional tests. It seems that GM detection in BAL is beneficial to establish or exclude the early diagnosis of IA in ICU patients.

Insufficient Demonstration of Long-Term Stability of Aspergillus Galactomannan

The report in the Journal of Clinical Microbiology by Wheat et al. ([1][1]) investigates the stability of the galactomannan index (GMI) (the ratio of the optical densities of patient samples to the mean optical density of control samples), following storage using the Platelia immunoassay to detect