(1,3)-β-D-glucan as a prognostic marker of treatment response in invasive candidiasis

Prognostic value of serial (1,3)-β-D-glucan measurements in ICU patients with invasive candidiasis

BACKGROUND

To determine whether a decrease in serum (1,3)-β-D-glucan (BDG) was associated with reduced mortality and to investigate the performance of BDG downslope in predicting clinical outcome in invasive candidiasis.

METHODS

Observational cohort study in ICU patients over a ten-year period (2012-2022) in Italy. Proven invasive candidiasis with at least 2 BDG determinations were considered.

RESULTS

In the study population of 103 patients (age 47 [35-62] years, SAPS II score 67 [52-77]) 68 bloodstream and 35 intrabdominal infections were recorded. Serial measurements showed that in 54 patients BDG decreased over time (BDG downslope group) while in 49 did not (N-BDG downslope group). Candida albicans was the pathogen most frequently isolated (61%) followed by C. parapsilosis (17%) and C. glabrata (12%), in absence of any inter-group difference. Invasive candidiasis related mortality was lower in BDG downslope than in N-BDG downslope group (17% vs 53%, p < 0.01). The multivariate Cox regression analysis showed the association of septic shock at infection occurrence and chronic liver disease with invasive candidiasis mortality (HR [95% CI] 3.24 [1.25-8.44] p = 0.02 and 7.27 [2.33-22.66] p < 0.01, respectively) while a BDG downslope was the only predictor of survival (HR [95% CI] 0.19 [0.09-0.43] p < 0.01). The area under the receiver operator characteristic curve for the performance of BDG downslope as predictor of good clinical outcome was 0.74 (p = 0.02) and our model showed that a BDG downslope > 70% predicted survival with both specificity and positive predictive value of 100%.

CONCLUSIONS

A decrease in serum BDG was associated with reduced mortality and a steep downslope predicted survival with high specificity in invasive candidiasis.

Exploring European Consensus About the Remaining Treatment Challenges and Subsequent Opportunities to Improve the Management of Invasive Fungal Infection (IFI) in the Intensive Care Unit

BACKGROUND

The global prevalence of invasive fungal infections (IFI) is increasing, particularly within Intensive Care Units (ICU), where Candida spp. and Aspergillus spp. represent the most important pathogens. Diagnosis and management of IFIs becomes progressively challenging, with increasing antifungal resistance and the emergence of rare fungal species. Through a consensus survey focused on assessing current views on how IFI should be managed, the aim of this project was to identify challenges around diagnosing and managing IFIs in the ICU. The current status in different countries and perceived challenges to date amongst a multidisciplinary cohort of healthcare professionals involved in the care of IFI in the ICU was assessed.

METHODS

Using a modified Delphi approach, an expert panel developed 44 Likert-scale statements across 6 key domains concerning patient screening and minimal standards for diagnosis of IFIs in ICU; initiation and termination of antifungal treatments and how to minimise their side effects and insights for future research on this topic. These were used to develop an online survey which was distributed on a convenience sampling basis utilising the subscriber list held by an independent provider (M3 Global). This survey was distributed to intensivists, infectious disease specialists, microbiologists and antimicrobial/ICU pharmacists within the UK, Germany, Spain, France and Italy. The threshold for consensus was set at 75%.

RESULTS

A total of 335 responses were received during the five-month collection period. From these, 29/44 (66%) statements attained very high agreement (≥ 90%), 11/44 (25%) high agreement (< 90% and ≥ 75%), and 4/44 (9%) did not meet threshold for consensus (< 75%).

CONCLUSION

The results outline the need for physicians to be aware of the local incidence of IFI and the associated rate of azole resistance in their ICUs. Where high clinical suspicion exists, treatment should start immediately and prior to receiving the results from any diagnostic test. Beta-D-glucan testing should be available to all ICU centres, with results available within 48 h to inform the cessation of empirical antifungal therapy. These consensus statements and proposed measures may guide future areas for further research to optimise the management of IFIs in the ICU.

Utility of incorporation of beta-D-glucan and T2Candida testing for diagnosis and treatment of candidemia

The additive role of non-culture-based methods for the diagnosis of candidemia remains unknown. We evaluated 2 clinical practices followed in our hospitals for the diagnosis of candidemia, namely practice#1 including a combination of blood cultures and T2Candida, and practice#2 that also included Beta-D-glucan (BDG). Three out of 96 patients testing positive with practice#1 received a complete antifungal course. Of the 120 patients evaluated with practice#2, 29 were positive. Only 55.2% of those received a complete course. We observed significant differences in antifungal utilization, with 268.5 antifungal days/1000 patient-days for practice#1, as opposed to 371.9 days for practice#2, a nearly 40% difference. However, we found similar rates of antifungal discontinuation among negative patients at 3 days of testing (36.8% and 37.0% respectively). No differences were detected in death and/or subsequent diagnosis of candidemia. In summary, addition of BDG was interpreted variably by clinicians, was associated with an increase in antifungal utilization, and did not correlate with measurable clinical benefits for patients.

Using (1,3)-β-D-glucan concentrations in serum to monitor the response of azole therapy in patients with eumycetoma caused by Madurella mycetomatis

INTRODUCTION

(1,3)-β-D-glucan is a panfungal biomarker secreted by many fungi, including Madurella mycetomatis, the main causative agent of eumycetoma. Previously we demonstrated that (1,3)-β-D-glucan was present in serum of patients with eumycetoma. However, the use of (1,3)-β-D-glucan to monitor treatment responses in patients with eumycetoma has not been evaluated.

MATERIALS AND METHODS

In this study, we measured (1,3)-β-D-glucan concentrations in serum with the WAKO (1,3)-β-D-glucan assay in 104 patients with eumycetoma treated with either 400 mg itraconazole daily, or 200 mg or 300 mg fosravuconazole weekly. Serial serum (1,3)-β-D-glucan concentrations were measured at seven different timepoints. Any correlation between initial and final (1,3)-β-D-glucan concentrations and clinical outcome was evaluated.

RESULTS

The concentration of (1,3)-β-D-glucan was obtained in a total of 654 serum samples. Before treatment, the average (1,3)-β-D-glucan concentration was 22.86 pg/mL. During the first 6 months of treatment, this concentration remained stable. (1,3)-β-D-glucan concentrations significantly dropped after surgery to 8.56 pg/mL. After treatment was stopped, there was clinical evidence of recurrence in 18 patients. Seven of these 18 patients had a (1,3)-β-D-glucan concentration above the 5.5 pg/mL cut-off value for positivity, while in the remaining 11 patients, (1,3)-β-D-glucan concentrations were below the cut-off value. This resulted in a sensitivity of 38.9% and specificity of 75.0%. A correlation between lesion size and (1,3)-β-D-glucan concentration was noted.

CONCLUSION

Although in general (1,3)-β-D-glucan concentrations can be measured in the serum of patients with eumycetoma during treatment, a sharp decrease in β-glucan concentration was only noted after surgery and not during or after antimicrobial treatment. (1,3)-β-D-glucan concentrations were not predictive for recurrence and seem to have no value in determining treatment response to azoles in patients with eumycetoma.

Detailed β-(1→3)-D-glucan and mannan antigen kinetics in patients with candidemia

Fungal antigens such as β-(1→3)-D-glucan (BDG) or mannan (Mn) are useful for detection of candidemia. However, detailed data on serum levels before diagnosis and during treatment are scarce. We conducted a prospective study at two German tertiary care centers for 36 months. Sera from adult patients with candidemia were tested for BDG (Fungitell assay) and Mn (Platelia Candida Ag-Plus assay). For each patient, the clinical course and biomarker kinetics were closely followed and compared. 1,243 sera from 131 candidemia episodes and 15 relapses were tested. In 35% of episodes, empirical therapy included an antifungal drug. Before blood culture sampling, BDG and Mn levels were elevated in 62.4% and 30.8% of patients, respectively. Sensitivity at blood culture sampling was 78.6% (BDG) and 35.1% (Mn). BDG levels of non-survivors were significantly higher than those of survivors. During follow-up, a therapeutic response was associated with decreasing BDG and Mn levels in 84.3% or 70.5% of episodes, respectively. A median increase of 513 pg BDG/mL and 390 pg Mn/mL indicated a relapse of candidemia with a sensitivity of 80% or 46.7%, respectively. In 72.9% and 46.8% of patients, increasing BDG or Mn levels were associated with a fatal outcome. Prior to discharge, BDG and Mn levels had dropped or normalized in 65.7% or 82.1% of patients, respectively. Summarising, in patients with candidemia, biomarker positivity usually precedes culture positivity. Relapses are mostly accompanied by secondary biomarker increases. Rising concentrations of BDG and Mn predict lethality, whereas decreasing levels suggest a favorable outcome in the majority of patients.

Scedosporium apiospermum mediastinitis in an orthotopic heart transplant recipient

Scedosporiosis is an opportunistic mycosis that may cause disseminated disease in transplant recipients. This article reports a case of recurrent Scedosporium apiospermum mediastinitis without pneumonia in an orthotopic heart transplant recipient, with durable control achieved by long-term antifungal therapy and serial debridement. This case highlights the importance of an opportunistic scedosporium infection in immunocompromised hosts, given the challenges in microbiological identification and limited treatment options.

Noninvasive Testing and Surrogate Markers in Invasive Fungal Diseases

Invasive fungal infections continue to increase as at-risk populations expand. The high associated morbidity and mortality with fungal diseases mandate the continued investigation of novel antifungal agents and diagnostic strategies that include surrogate biomarkers. Biologic markers of disease are useful prognostic indicators during clinical care, and their use in place of traditional survival end points may allow for more rapid conduct of clinical trials requiring fewer participants, decreased trial expense, and limited need for long-term follow-up. A number of fungal biomarkers have been developed and extensively evaluated in prospective clinical trials and small series. We examine the evidence for these surrogate biomarkers in this review and provide recommendations for clinicians and regulatory authorities.

Is ß-d-glucan Relevant for the Diagnosis and Follow-Up of Intensive Care Patients with Yeast-Complicated Intra-Abdominal Infection?

The usefulness of (1,3)-ß-d-glucan (BDG) detection for the diagnosis of intra-abdominal candidiasis and treatment monitoring is unknown. A prospective, single-center study of consecutive patients admitted to an ICU with complicated intra-abdominal infection (IAI) over a 2-year period was conducted. BDG was measured in the peritoneal fluid and serum between day 1 (D1) and D10. Patients with a positive peritoneal fluid yeast culture (YP) were compared to those with a negative yeast culture (YN). The evolution of serum BDG was compared in the two groups. Seventy patients were included (sixty-five analyzed): YP group (n = 19) and YN group (n = 46). Median peritoneal BDG concentration during surgery was 2890 pg.mL⁻¹ [IQR: 942–12,326] in the YP group vs. 1202 pg.mL⁻¹ [IQR: 317–4223] in the YN group (p = 0.13). Initial serum BDG concentration was 130 pg.mL⁻¹ [IQR: 55–259] in the YP group vs. 88 pg.mL⁻¹ [IQR: 44–296] in the YN group (p = 0.78). No difference in evolution of serum BDG concentrations was observed between the groups (p = 0.18). In conclusion, neither peritoneal BDG nor serum BDG appear to be good discriminating markers for the diagnosis of yeast IAI. In addition, monitoring the evolution of serum BDG in yeast IAI did not appear to be of any diagnostic value.

Role of (1-3)-Β-D-Glucan Test in the Diagnosis of Invasive Fungal Infections among High-Risk Patients in a Tertiary Care Hospital

Background  Invasive fungal infections (IFI) are associated with high mortality. Serum fungal biomarkers offer an advantage over the traditional methods in early diagnosis and better clinical outcomes. The aim of the study was to evaluate the role of (1–3)-β-D-glucan (BDG) assay in the patients suspected of IFI.

Materials and Methods  This prospective study was conducted in the Department of Microbiology, Dayanand Medical College and Hospital, Ludhiana, over a period of 1 year. A total of 862 serum samples were received from patients suspected of IFI, for the BDG test (Fungitell, Associates of Cape Cod Inc., USA). The test was performed as per kit protocol. Appropriate samples were processed for KOH fungal smear and fungal culture. Blood culture was done by Bactec (Biomerieux).

Statistical Analysis  Results were analyzed using descriptive statistical methods. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated at different cutoffs. In addition, the receiver operating characteristic (ROC) curve using SPSS 21.00 software was calculated and the diagnostic accuracy was shown by the area under the ROC curve (AUC).

Results  Among 862 patients, 546 (63.3%) were males. The predominant age group (25.6%) was between 61 and 70 years. The most common risk factor (54.8%) was prolonged intensive care unit stay. Out of the total samples, 455 (52.8%) samples were found positive for BDG. Fungal elements were seen in 48 (10.5%) KOH smears and fungal growth was obtained in 81 (17.8%) cultures. Comparison of BDG assay and culture at different cutoffs yielded AUC—0.823. Sensitivity (100%), specificity (51.3%), accuracy (55.6%), PPV (15.8%), and NPV (100%) were observed at the kit cutoff of 80 pg/mL. Optimum sensitivity and specificity of 79.2% and 70.3%, respectively, were observed at a cutoff of 142.4pg/mL. A significant correlation was observed between BDG positivity and piperacillin–tazobactam use and dialysis. Among BDG positive patients, 38(8.4%) succumbed to death.

Conclusion  Detection of BDG helps in the early diagnosis of IFI in critically ill patients. As the assay has a high NPV, a negative test can be used to stop the empirical antifungal drugs. The use of a higher cutoff can be useful to avoid false-positive results.

Beta-D-Glucan in Patients with Haematological Malignancies

(1-3)-beta-D-glucan (BDG) is an almost panfungal marker (absent in zygomycetes and most cryptococci), which can be successfully used in screening and diagnostic testing in patients with haematological malignancies if its advantages and limitations are known. The aim of this review is to report the data, particularly from the last 5 years, on the use of BDG in haematological population. Published data report mainly on the performance of the Fungitell™ assay, although several others are currently available, and they vary in method and cut-off of positivity. The sensitivity of BDG for invasive fungal disease (IFD) in haematology patients seems lower than in other populations, possibly because of the type of IFD (lower sensitivity was found in case of aspergillosis compared to candidiasis and pneumocystosis) or the use of prophylaxis. The specificity of the test can be improved by using two consecutive positive assays and avoiding testing in the case of the concomitant presence of factors associated with false positive results. BDG should be used in combination with clinical assessment and other diagnostic tests, both radiological and mycological, to provide maximum information. Good performance of BDG in cerebrospinal fluid (CSF) has been reported. BDG is a useful diagnostic method in haematology patients, particularly for pneumocystosis or initial diagnosis of invasive fungal infections.

The Role of HMGB1 in Invasive Candida albicans Infection

INTRODUCTION

High mobility group box 1 (HMGB1) is an important "late" inflammatory mediator in bacterial sepsis. Ethyl pyruvate (EP), an inhibitor of HMGB1, can prevent bacterial sepsis by decreasing HMGB1 levels. However, the role of HMGB1 in fungal sepsis is still unclear. Therefore, we investigated the role of HMGB1 and EP in invasive C. albicans infection.

METHODS

We measured serum HMGB1 levels in patients with sepsis with C. albicans infection and without fungal infection, and control subjects. We collected clinical indices to estimate correlations between HMGB1 levels and disease severity. Furthermore, we experimentally stimulated mice with C. albicans and C. albicans + EP. Then, we examined HMGB1 levels from serum and tissue, investigated serum levels of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), determined pathological changes in tissues, and assessed mortality.

RESULTS

Serum HMGB1 levels in patients with severe sepsis with C. albicans infection were elevated. Increased HMGB1 levels were correlated with procalcitonin (PCT), C-reactive protein (CRP), 1,3-β-D-Glucan (BDG) and C. albicans sepsis severity. HMGB1 levels in serum and tissues were significantly increased within 7 days after mice were infected with C. albicans. The administration of EP inhibited HMGB1 levels, decreased tissue damage, increased survival rates and inhibited the release of TNF-α and IL-6.

CONCLUSIONS

HMGB1 levels were significantly increased in invasive C. albicans infections. EP prevented C. albicans lethality by decreasing HMGB1 expression and release. HMGB1 may provide an effective diagnostic and therapeutic target for invasive C. albicans infections.

Managing uncertainty in antifungal dosing: antibiograms, therapeutic drug monitoring and drug-drug interactions

PURPOSE OF REVIEW

A number of pharmacokinetic and pharmacodynamic factors in critically ill or severely immunosuppressed patients influence the effectiveness of antifungal therapy making dosing less certain. Recent position papers from infectious diseases societies and working groups have proposed methods for dosage individualization of antibiotics in critically ill patients using a combination of population pharmacokinetic models, Monte-Carlo simulation and therapeutic drug monitoring (TDM) to guide dosing. In this review, we examine the current limitations and practical issues of adapting a pharmacometrics-guided dosing approaches to dosing of antifungals in critically ill or severely immunosuppressed populations.

RECENT FINDINGS

We review the current status of antifungal susceptibility testing and challenges in incorporating TDM into Bayesian dose prediction models. We also discuss issues facing pharmacometrics dosage adjustment of newer targeted chemotherapies that exhibit severe pharmacokinetic drug-drug interactions with triazole antifungals.

SUMMARY

Although knowledge of antifungal pharmacokinetic/pharmacodynamic is maturing, the practical application of these concepts towards point-of-care dosage individualization is still limited. User-friendly pharmacometric models are needed to improve the utility of TDM and management of a growing number of severe pharmacokinetic antifungal drug-drug interactions with targeted chemotherapies.

Mind the gaps: challenges in the clinical management of invasive candidiasis in critically ill patients

PURPOSE OF REVIEW

Strict adherence to clinical practice guidelines is recognized to improve outcomes but the inconvenient truth is that only a small subset of what is done in medicine has been tested in appropriate, well designed studies. In this article, we aim to review controversial aspects of the clinical management of invasive candidiasis recommended by guidelines.

RECENT FINDINGS

Despite still being recommended by guidelines, we fail to identify a single randomized clinical trial documenting that the use of antifungal drugs in high-risk critically ill patients without microbiologic documentation of Candida infection decreases mortality. Regarding deep-seated Candida infections, most cohort studies of patients with candidemia found less than 5% of patients developed endophthalmitis and endocarditis. In this scenario, it is reasonable to reconsider routine universal screening of both complications in candidemic patients. Finally, a large number of studies have shown that critically ill patients usually have lower echinocandin exposure when compared with other populations. We need more data on the clinical relevance of this finding.

SUMMARY

We need robust studies to validate new strategies for the clinical management of candidemia in ICU, including: the use of fungal biomarkers in the early initiation or interruption of antifungal therapy in high-risk patients to replace the conventional empirical antifungal therapy driven by predictive rules; validation of targeted screening of eye infection and endocarditis with the aid of fungal biomarkers only in high-risk patients; we should clarify if higher doses of candins are necessary to treat invasive candidiasis in critically ill patients, especially in the case of intra-abdominal infections where drug penetration is suboptimal.

Update on Non-Culture-Based Diagnostics for Invasive Fungal Disease

Diagnostic tests for fungi provide the mycological evidence to strengthen diagnosis of invasive fungal disease. Conventional microbiology and histopathology have their limitations. Recognizing this, there have been attempts at developing new methods to improve yield of diagnosing invasive fungal disease (IFD). The recent focus has been on non-culture-based antigen detection and molecular methods. The use of antigen detection of IFD through 1,3-β-D-glucan and galactomannan assay have been expanded, followed by development of lateral flow assays, and in combination with other diagnostic modalities to further increase diagnostic yield. The molecular diagnostic front has seen initiatives to standardize polymerase chain reaction methodologies to detect fungi and anti-fungal resistance, new platforms such as the T2Candida Biosystems and foray into fungal metagenomics. As these newer assays undergo stringent validation before incorporation into the diagnostic algorithm, the clinician needs to be mindful of their bedside utility as well as their limitation.

Assessment of the Role of 1,3-β-d-Glucan Testing for the Diagnosis of Invasive Fungal Infections in Adults

Detection of 1,3-β-d-glucan (BDG) in serum has been evaluated for its inclusion as a mycological criterion of invasive fungal infections (IFI) according to EORTC and Mycoses Study Group (MSG) definitions. BDG testing may be useful for the diagnosis of both invasive aspergillosis and invasive candidiasis, when interpreted in conjunction with other clinical/radiological signs and microbiological markers of IFI. However, its performance and utility vary according to patient population (hematologic cancer patients, solid-organ transplant recipients, intensive care unit patients) and pretest likelihood of IFI. The objectives of this article are to provide a systematic review of the performance of BDG testing and to assess recommendations for its use and interpretation in different clinical settings.

Clinical Relevance and Prognostic Value of Persistently Negative (1,3)-β-D-Glucan in Adults With Candidemia: A 5-year Experience in a Tertiary Hospital

BACKGROUND

The clinical relevance and the potential prognostic role of persistently negative (1,3)-β-D-glucan (BDG) in adults with proven candidemia is unknown.

METHODS

This retrospective study included all adults diagnosed with candidemia our tertiary university hospital from 2012-2017 who had at least 2 serum BDG determinations throughout the episode of fungemia (Fungitell Assay; positive cut-off ≥80pg/mL). Epidemiology and clinical outcomes were compared between patients with all negative versus any positive BDG tests. Poor clinical outcomes included complications due to candidemia or 30-day all-cause mortality.

RESULTS

Overall, 26/148 (17.6%) candidemic adults had persistently negative BDG tests. These patients were less likely to present Candida growth in all 3 sets of blood cultures (15.4% vs 45.1%; P = .005) and had less severe clinical presentations (median Pitt score, 0 [interquartile range {IQR} 0-1] vs 1 [IQR 0-2] in patients with any positive BDG test; P = .039). Although adequate treatment was equally provided to both groups (96.2% in persistently negative group vs 93.4 in positive group; P = .599), the persistently negative group had a higher rate of microbiological clearance in the first follow-up blood cultures (92.3% vs 69.7% in positive group; P = .005), fewer complications due to candidemia (7.7% vs 33.6% in positive group; P = .008), a lower 30-day mortality rate (3.8% vs 23.8% in positive group; P = .004), and a shorter in-hospital stay (34 days [IQR 18-55] vs 51 days [IQR 35-91] in positive group; P = .003). In the multivariate analysis, persistently negative BDG tests were independently associated with better prognoses (odds ratio 0.12, 95% confidence interval 0.03-0.49; P = .003).

CONCLUSIONS

Candidemic patients with persistently negative BDG tests present a better prognosis than the comparative group, probably due to a lower systemic fungal burden. In this context, the appropriate use of persistently negative BDG results could be an aid to individualize therapeutic management in the near future.

Glucan rich nutrition does not increase gut translocation of beta-glucan

BACKGROUND

(1-3)-b-D-glucan (BDG) is a fungal cell wall component and, in the absence of invasive fungal infection, a novel biomarker for microbial translocation of endogenous fungal products from the gastrointestinal tract into systemic circulation. However, its value as a marker of fungal translocation is limited by a concern that plant BDG-rich food influences blood BDG levels.

METHODS

We conducted a pilot clinical trial to evaluate the impact of a standardised oral BDG challenge on blood BDG levels in participants with and without elevated microbial translocation. We enrolled 14 participants including 8 with HIV infection, 2 with advanced liver cirrhosis, and 4 healthy controls. After obtaining a baseline blood sample, participants received a standardised milkshake containing high levels of BDG followed by serial blood samples up to 8 hours after intake.

RESULTS

The standardised oral BDG challenge approach did not change the blood BDG levels over time in all participants. We found consistently elevated blood BDG levels in one participant with advanced liver cirrhosis and a single person with HIV with a low CD4 count of 201 cells/mm3 .

CONCLUSION

Our findings indicate that BDG blood levels were not influenced by plant origin BDG-rich nutrition in PWH, people with advanced liver cirrhosis, or healthy controls. Future studies are needed to analyse gut mycobiota populations in individuals with elevated blood BDG levels.

(1,3)-β-D-glucan is able to predict therapeutic failure of patients with candidemia and not only mortality

BACKGROUND

Candidemia is a major cause of bloodstream infection in tertiary hospitals worldwide and fungal biomarkers may provide early diagnosis.

OBJECTIVES

To evaluate the performance of (1-3)-β-D-glucan (BDG) in the diagnosis of candidemia and its ability to predict therapeutic failure.

PATIENTS AND METHODS

This was a prospective, multi-centre study conducted in 3 Brazilian hospitals. Clinical outcome was evaluated along 2 weeks of treatment, and therapeutic failure was defined as the occurrence of persistent candidemia, Candida deep-seated infection or death. Baseline BDG detection was performed with the Fungitell^® assay (Associates of Cape Cod, Falmouth-USA).

RESULTS

We enrolled a total of 71 patients with candidemia and a control group with 110 healthy volunteers. The sensitivity and specificity of BDG for diagnosing candidemia were as follows: 71.8% (95% confidence interval [95% CI] 59.7% - 81.5%) and 98.2% (95% CI 92.9% - 99.7%), respectively. The only predictor of therapeutic failure was a higher BDG value at diagnosis of candidemia; a value > 226 pg/mL predicted failure with sensitivity and specificity of 75% and 78%, respectively.

CONCLUSIONS

A high baseline serum BDG value was associated with therapeutic failure.

Invasive candidiasis in critical care: challenges and future directions

Invasive candidiasis is the most common critical care-associated fungal infection with a crude mortality of ~ 40-55%. Important factors contributing to risk of invasive candidiasis in ICU include use of broad-spectrum antimicrobials, immunosuppressive drugs, and total parenteral nutrition alongside iatrogenic interventions which breach natural barriers to infection [vascular catheters, renal replacement therapy, extracorporeal membrane oxygenation (ECMO), surgery]. This review discusses three key challenges in this field. The first is the shift in Candida epidemiology across the globe to more resistant non-albicans species, in particular, the emergence of multi-resistant Candida glabrata and Candida auris, which pose significant treatment and infection control challenges in critical care. The second challenge lies in the timely and appropriate initiation and discontinuation of antifungal therapy. Early antifungal strategies (prophylaxis, empirical and pre-emptive) using tools such as the Candida colonisation index, clinical prediction rules and fungal non-culture-based tests have been developed: we review the evidence on implementation of these tools in critical care to aid clinical decision-making around the prescribing and cessation of antifungal therapy. The third challenge is selection of the most appropriate antifungal to use in critical care patients. While guidelines exist to aid choice, this heterogenous and complex patient group require a more tailored approach, particularly in cases of acute kidney injury, liver impairment and for patients supported by extracorporeal membrane oxygenation. We highlight key research priorities to overcome these challenges in the future.

Colonic mucosa-associated candida assessed by biopsy culture is associated with disease severity in ulcerative colitis: A prospective study

OBJECTIVE

To evaluate the relationship of mucosa-associated candida (MAC) and disease severity in patients with ulcerative colitis (UC).

METHODS

We prospectively investigated the presence, nature, and quantification of MAC in patients with UC and its relationship with disease severity. Consecutive patients with UC were assessed for clinical, endoscopic, histological features and serum markers of disease severity. All patients underwent mucosal brushing cytology, brushing culture, and biopsy culture for candida growth. MAC was considered present if mucosal biopsy culture grew candida. Candida spp. identification was performed by matrix-assisted laser desorption/ionization. Serum β-D-glucan was measured with a Fungitell assay. Patients with irritable bowel syndrome who had undergone similar investigations were included as controls.

RESULTS

Ninety-six patients with UC showed evidence of MAC more often than the controls (n = 20) based on biopsy culture (33.3% vs 5.0%, P = 0.011), brush cytology (30.2% vs 5.0%, P = 0.019), and brush culture (36.5% vs 10.0%, P = 0.021). Patients with UC had higher candida colony counts (≥10³ CFU/mL) than controls (34.4% vs 5.0%, P = 0.007). Median β-D-glucan values were higher in patients with UC than in controls (103.26 pg/mL vs 66.51 pg/mL, P = 0.011). The UC group with MAC had a higher median total Mayo score, C-reactive protein, fecal calprotectin, β-D-glucan, and histological activity than those without MAC.

CONCLUSIONS

Patients with UC more often show evidence of MAC and a higher candida colony count than controls. The presence of MAC is associated with high disease severity in patients with UC.

Invasive mould infections in solid organ transplant patients: modifiers and indicators of disease and treatment response

PURPOSE

Invasive mould infections, in particular invasive aspergillosis (IA), are comparatively frequent complications of immunosuppression in patients undergoing solid organ transplantation (SOT). Guidelines provide recommendations as to the procedures to be carried out to diagnose and treat IA, but only limited advice for SOT recipients.

METHODS

Literature review and expert consensus summarising the existing evidence related to prophylaxis, diagnosis, treatment and assessment of response to IA and infections by Mucorales in SOT patients RESULTS: Response to therapy should be assessed early and at regular intervals. No indications of improvement should lead to a prompt change of the antifungal treatment, to account for possible infections by Mucorales or other moulds such as Scedosporium. Imaging techniques, especially CT scan and possibly angiography carried out at regular intervals during early and long-term follow-up and coupled with a careful clinical diagnostic workout, should be evaluated as diagnostic tools and outcome predictors, and standardised to improve therapy monitoring. The role of biomarkers such as the galactomannan test and PCR, as well as selected inflammation parameters, has not yet been definitively assessed in the SOT population and needs to be studied further. The therapeutic workup should consider a reduction of immunosuppressive therapy.

CONCLUSIONS

The role of immunosuppression and immune tolerance mechanisms in the response to invasive fungal infection treatment is an important factor in the SOT population and should not be underestimated. The choice of the antifungal should consider not only their toxicity but also their effects on the immune system, two features that are intertwined.

Federation of Infectious Diseases Societies of Southern Africa guideline: Recommendations for the detection, management and prevention of healthcare-associated Candida auris colonisation and disease in South Africa

Candida auris has been detected at almost 100 South African hospitals, causing large outbreaks in some facilities, and this pathogen now accounts for approximately 1 in 10 cases of candidaemia. The objective of this guideline is to provide updated, evidence-informed recommendations outlining a best-practice approach to prevent, diagnose and manage C. auris disease in public- and private-sector healthcare settings in South Africa. The 18 practical recommendations cover five focus areas: laboratory identification and antifungal susceptibility testing, surveillance and outbreak response, infection prevention and control, clinical management and antifungal stewardship.

Diagnostic work up to assess early response indicators in invasive pulmonary aspergillosis in adult patients with haematologic malignancies

In immunocompromised patients with acute leukaemia as well as in allogeneic hematopoietic stem cell transplant patients, pulmonary lesions are commonly seen. Existing guidelines provide useful algorithms for diagnostic procedures and treatment options, but they do not give recommendations on how to evaluate early success or failure and if or when it is best to change therapy. Here, we review the diagnostic techniques currently used in association with clinical findings and propose an approach using a combination of computer tomography, clinical and all available biomarkers and inflammation parameters, especially those positive at baseline, to assess early response in invasive pulmonary aspergillosis. Computed tomography scans should be carried out at regular intervals during early and long-term follow-up. Imaging on day seven, or even earlier in clinically unstable patients, combined with an additional testing of biomarkers and inflammatory markers in between, is needed for a reliable assessment at day 14. If no improvement is seen after 2 weeks of therapy or the clinical condition is deteriorating, a change of antifungal therapy should be considered. Alleged breakthrough infections or treatment failure should undergo early diagnostic workup, including tissue biopsies when possible, to retrieve fungal cultures for resistance testing.

Evaluation of Mass Spectrometry-Based Detection of Panfungal Serum Disaccharide for Diagnosis of Invasive Fungal Infections: Results from a Collaborative Study Involving Six European Clinical Centers

A mass spectrometry (MS) method that detects a serum disaccharide (DS) (MS-DS) was recently described for the diagnosis of invasive fungal infections (IFI). We carried out a European collaborative study to evaluate this assay. Patients with the following IFI were selected according to the availability of sera obtained at about the time that IFI was documented: invasive candidiasis (IC; n = 26 patients), invasive aspergillosis (IA; n = 19), and mucormycosis (MM; n = 23). Control sera originated from 20 neutropenic patients and 20 patients with bacteremia. MS-DS was carried out in blind manner for the diagnosis of IFI. A diagnosis of IC or IA was confirmed by detection of mannan (Man) or galactomannan (GM), respectively, associated with detection of (1,3)-β-d-glucan (BDG) in both infections. MM was detected by quantitative real-time PCR (qPCR). All tests discriminated sera from patients with IC from sera from control subjects with bacteremia (P ≤ 0.0009). For IC, the MS-DS sensitivity and specificity were 51% and 87%, respectively. MS-DS complemented the high specificity of Man monitoring. All tests discriminated sera from IA patients from sera from neutropenic controls (P ≤ 0.0009). For IA, MS-DS sensitivity and specificity were 64% and 95%, respectively. Only 13/36 serum samples from patients with MM were concordant by MS-DS and qPCR (6 were positive, and 7 were negative); 14 were positive by MS-DS alone. qPCR and MS-DS made a similar contribution to the diagnosis of MM. In patients undergoing long-term monitoring, the persistent circulation of serum disaccharide was observed, whereas DNA was detected only for a short period after initiation of treatment. MS-DS has an important role to play in the early diagnosis of IFI. Its panfungal nature and complementarity with other tests may justify its use in the management of IFI.

Candidemia in the cancer patient: diagnosis, treatment, and future directions

INTRODUCTION

The presence of Candida species in the blood is known as candidemia and may constitute a medical emergency for patients with cancer. Despite advances in diagnosis and treatment of this fungal infection, mortality remains unacceptably high. Areas covered: This paper reviews recent advances in molecular diagnostics to detect species of Candida as well as novel antifungal agents that have been developed to address candidiasis. We also review prophylaxis strategies to prevent candidiasis in high-risk cancer patients. Expert commentary: We draw from our own experiences treating candidemia in the cancer patient and review novel diagnostic strategies involving molecular resonance and mass spectroscopy. We also explore novel chemoprophylaxis and treatment options, including new drugs such as rezafungin and SCY-078. We also look ahead, to examine how this condition will be managed in the years ahead.

Pre-clinical Imaging of Invasive Candidiasis Using ImmunoPET/MR

The human commensal yeast Candida is the fourth most common cause of hospital-acquired bloodstream infections, with Candida albicans accounting for the majority of the >400,000 life-threatening infections annually. Diagnosis of invasive candidiasis (IC), a disease encompassing candidemia (blood-borne yeast infection) and deep-seated organ infections, is a major challenge since clinical manifestations of the disease are indistinguishable from viral, bacterial and other fungal diseases, and diagnostic tests for biomarkers in the bloodstream such as PCR, ELISA, and pan-fungal β-D-glucan lack either standardization, sensitivity, or specificity. Blood culture remains the gold standard for diagnosis, but test sensitivity is poor and turn-around time slow. Furthermore, cultures can only be obtained when the yeast resides in the bloodstream, with samples recovered from hematogenous infections often yielding negative results. Consequently, there is a pressing need for a diagnostic test that allows the identification of metastatic foci in deep-seated Candida infections, without the need for invasive biopsy. Here, we report the development of a highly specific mouse IgG3 monoclonal antibody (MC3) that binds to a putative β-1,2-mannan epitope present in high molecular weight mannoproteins and phospholipomannans on the surface of yeast and hyphal morphotypes of C. albicans, and its use as a [⁶⁴Cu]NODAGA-labeled tracer for whole-body pre-clinical imaging of deep-seated C. albicans infections using antibody-guided positron emission tomography and magnetic resonance imaging (immunoPET/MRI). When used in a mouse intravenous (i.v.) challenge model that faithfully mimics disseminated C. albicans infections in humans, the [⁶⁴Cu]NODAGA-MC3 tracer accurately detects infections of the kidney, the principal site of blood-borne candidiasis in this model. Using a strain of the emerging human pathogen Candida auris that reacts with MC3 in vitro, but which is non-infective in i.v. challenged mice, we demonstrate the accuracy of the tracer in diagnosing invasive infections in vivo. This pre-clinical study demonstrates the principle of using antibody-guided molecular imaging for detection of deep organ infections in IC, without the need for invasive tissue biopsy.

Prospective evaluation of a combination of fungal biomarkers for the diagnosis of invasive fungal disease in high-risk haematology patients

We prospectively evaluated a combination of fungal biomarkers in adult haematology patients with focus on their clinical utility at different time points during the course of infection. In total, 135 patients were monitored once to twice weekly for serum (1-3)-ß-d-glucan (BG), galactomannan (GM), bis-methyl-gliotoxin and urinary d-arabinitol/l-arabinitol ratio. In all, 13 cases with proven or probable invasive fungal disease (IFD) were identified. The sensitivity of BG and GM at the time of diagnosis (TOD) was low, but within 2 weeks from the TOD the sensitivity of BG was 92%. BG >800 pg/mL was highly specific for IFD. At a pre-test probability of 12%, both BG and GM had negative predictive values (NPV) >0.9 but low positive predictive values (PPV). In a subgroup analysis of patients with clinically suspected IFD (pre-test probability of 35%), the NPV was lower, but the PPV for BG was 0.86 at cut-off 160 pg/mL. Among IFD patients, 91% had patterns of consecutively positive and increasing BG levels. Bis-methyl-gliotoxin was undetectable in 15 patients with proven, probable and possible IA. To conclude, BG was the superior fungal marker for IFD diagnosis. Quantification above the limit of detection and graphical evaluation of the pattern of dynamics are warranted in the interpretation of BG results.

Empirical antimicrobial treatment in haemato-/oncological patients with neutropenic sepsis

Neutropenic sepsis in haemato-/oncological patients is a medical emergency, as infections may show a fulminant clinical course. Early differentiation between sepsis and febrile neutropenic response often proves to be challenging. To assess the severity of the illness, different tools, which are discussed in this article, are available. Once the diagnosis has been established, the correct use of early empirical antibiotic and antifungal treatment is key in improving patient survival. Therefore, profound knowledge of local resistance patterns is mandatory and carefully designed antibiotic regimens have to be established in cooperation with local microbiologists or infectious diseases specialists. In the following, identification, therapy and management of high-risk, neutropenic patients will be reviewed based on experimental and clinical studies, guidelines and reviews.

T2 Magnetic Resonance Assay: Overview of Available Data and Clinical Implications

Invasive candidiasis is a common healthcare-associated infection with a high mortality rate that can exceed 60% in cases of septic shock. Blood culture performance is far from ideal, due to the long time to positivity and suppression by antifungal agents. The T2 Magnetic Resonance (T2MR) assay is an FDA-approved qualitative molecular diagnostic method that can detect and speciate the 5 most common Candida spp.; namely, Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, and Candida krusei, in approximately 5 h. In a multicenter clinical trial that included both a prospective and a contrived arm to represent the full range of clinically relevant concentrations of Candida spp., T2MR demonstrated a sensitivity and specificity of 91.1% and 98.1%, respectively. The utility of T2MR in candidemia depends on the prevalence of disease in each clinical setting. In intensive care units and other high-prevalence settings, the incorporation of T2MR in diagnostic algorithms is very appealing. T2MR is expected to allow timely initiation of antifungal therapy and help with anti-fungal stewardship. In low-prevalence settings, the positive predictive value of T2MR might not be enough to justify initiation of antifungal treatment in itself. The performance of T2MR has not been studied in cases of deep-seated candidiasis. Despite some promising evidence in published clinical trials, further studies are needed to determine the performance of T2MR in invasive candidiasis without candidemia. Overall, experience with T2MR in everyday clinical practice is evolving but, in the right setting, this technology is expected to provide “actionable information” for the management of patients evaluated for candidemia.

What has changed in the treatment of invasive candidiasis? A look at the past 10 years and ahead

The treatment of invasive candidiasis has changed greatly in the past decade and must continue to evolve if we are to improve outcomes in this serious infection. A review of recent history may provide insights for the future. The morbidity and mortality of invasive candidiasis remain difficult to measure despite an obvious clinical burden. Current treatment guidelines now recommend echinocandins as first-line empirical treatment, with fluconazole as an acceptable alternative for selected patients, reflecting the efficacy demonstrated by echinocandins and increasing resistance observed with fluconazole. The selection of antifungal therapy now must consider not only resistance but also the shift in predominance from Candida albicans to non-albicans species, notably Candida glabrata. The recent emergence of Candida auris has been met with great interest, although the longer-term implications of this phenomenon remain unclear. The broad goal of treatment continues to be administration of safe, efficacious antifungal therapy as soon as possible. Diagnostic methods beyond traditional blood culture present an opportunity to shorten the time to an accurate diagnosis, and earlier treatment initiation based on prophylactic and empirical or pre-emptive strategies seeks to ensure timely therapeutic intervention. In addition, there are novel agents in the antifungal pipeline. These developments, as well as ongoing studies of dosing, toxicity and resistance development, are important items on the current research agenda and may play a role in future changes to the treatment of invasive candidiasis.

Use of 1,3-β-D-glucan in invasive fungal diseases in hematology patients

INTRODUCTION

Invasive fungal diseases (IFD) remain a leading cause of morbidity and mortality in hematology patients. Within a diagnostic-driven approach, the use of the serum (1,3)-ß-D-glucan (BDG) test represents a valid tool for the early diagnosis and treatment of IFD. Areas covered: The available literature on the use of BDG in hematology patients was systematically retrieved. Then, it was reviewed and discussed, to identify key issues pertaining to a clinically-oriented narrative presentation of the topic. Expert commentary: The use of BDG in hematology patients at risk for invasive aspergillosis (IA) is secondary to the use of galactomannan. However, since BDG is not specific for IA, it offers an advantage of diagnosing also other IFD, such as candidiasis and pneumocystosis. The limitations of BDG include high costs and lower sensitivity in hematology patients compared to other cohorts. The risk of false positive results is possibly lower in real life than in theory, since glucan-free equipment is available and modern dialysis membranes and blood products usually do not release BDG. Thus, in experienced hands and selected clinical situations, BDG is a useful diagnostic tool, particularly due to short turnover time to results and versatility in diagnosing different IFD.

Strategies to Reduce Mortality in Adult and Neonatal Candidemia in Developing Countries

Candidemia, the commonest invasive fungal infection, is associated with high morbidity and mortality in developing countries, though the exact prevalence is not known due to lack of systematic epidemiological data from those countries. The limited studies report a very high incidence of candidemia and unique epidemiology with a different spectrum of Candida species. The recent global emergence of multi-drug resistant Candida auris is looming large as an important threat in hospitalized patients of developing countries. While managing candidemia cases in those countries several challenges are faced, which include poor infrastructure; compromised healthcare and infection control practices; misuse and overuse of antibiotics and steroids; lack of awareness in fungal infections; non-availability of advance diagnostic tests and antifungal drugs in many areas; poor compliance to antifungal therapy and stewardship program. Considering the above limitations, innovative strategies are required to reduce mortality due to candidemia in adults and neonates. In the present review, we have unraveled the challenges of candidemia faced by low resource countries and propose a ten part strategy to reduce mortality due candidemia.

Invasive Fungal Infections in the Intensive Care Unit

Patients in the intensive care unit are exposed to multiple stressors that predispose them to invasive fungal infections (IFIs), which carry high morbidity and mortality. Getting acquainted with the diagnostic methods and therapies is imperative for patient safety and for providing high-quality health care. This article focuses on the most frequent IFIs: invasive candidiasis and invasive aspergillosis.

Yeasts

Yeasts are unicellular organisms that reproduce mostly by budding and less often by fission. Most medically important yeasts originate from Ascomycota or Basidiomycota. Here, we review taxonomy, epidemiology, disease spectrum, antifungal drug susceptibility patterns of medically important yeast, laboratory diagnosis, and diagnostic strategies.

Elevated Serum Beta-D-Glucan with Pseudomonas, Aspergillus, and a Partially Acid-Fast Organism in Respiratory Cultures: A Case of Hickam's Dictum Over Occam's Razor

We describe a case of a man with ectopic Cushing's syndrome, elevated serum beta-D-glucan, and respiratory cultures with Pseudomonas, Aspergillus, and a partially acid-fast organism. Our case highlights challenges in diagnosis and management of coinfection in an immunocompromised host.

Laboratory Diagnostics for Fungal Infections: A Review of Current and Future Diagnostic Assays

This article reviews the current diagnostic approaches, both serologic and molecular, for the detection of fungi associated with pulmonary disease. Classic serologic techniques, including immunodiffusion and complement fixation, both of which remain a cornerstone for fungal diagnostic testing, are reviewed and their performance characteristics presented. More recent advances in this field, including novel lateral-flow assays for fungal antigen detection, are also described. Molecular techniques for fungal identification both from culture and directly from patient specimens, including nucleic acid probes, mass spectrometry-based methods, nucleic acid amplification testing, and traditional and broad-range sequencing, are discussed and their performance evaluated.

Translational Development and Application of (1→3)-β-d-Glucan for Diagnosis and Therapeutic Monitoring of Invasive Mycoses

Early diagnosis and prompt initiation of appropriate antimicrobial therapy are crucial steps in the management of patients with invasive fungal infections. However, the diagnosis of invasive mycoses remains a major challenge in clinical practice, because presenting symptoms may be subtle and non-invasive diagnostic assays often lack sensitivity and specificity. Diagnosis is often expressed on a scale of probability (proven, probable and possible) based on a constellation of imaging findings, microbiological tools and histopathology, as there is no stand-alone assay for diagnosis. Recent data suggest that the carbohydrate biomarker (1→3)-β-d-glucan may be useful in both the diagnosis and therapeutic monitoring of invasive fungal infections due to some yeasts, molds, and dimorphic fungi. In this paper, we review recent advances in the use of (1→3)-β-d-glucan to monitor clinical response to antifungal therapy and explore how this assay may be used in the future.

Application of Mass Spectrometry Technology to Early Diagnosis of Invasive Fungal Infections

We recently developed a mass spectrometry (MS) procedure based on the detection of a serum disaccharide (MS-DS) in patients with invasive candidiasis (IC). Here, we compare the performance of MS-DS for the diagnosis of IC, invasive aspergillosis (IA), and mucormycosis (MM) with those of commercially available antigen detection tests. This retrospective study included 48 patients (23 IC patients [74 serum samples], 15 IA patients [40 serum samples], and 10 MM patients [15 serum samples]) and 49 appropriate controls (102 serum samples). MS-DS, mannan (Mnn), galactomannan (GM), and (1,3)-β-d-glucan (BDG) were detected by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) MS, Platelia, and Fungitell assays, respectively. For IC, the sensitivity and specificity of the MS-DS index, BDG detection, and Mnn detection were 62% and 84%, 82% and 60%, and 33% and 94% per serum sample and 83% and 69%, 96% and 31%, and 39% and 86% per patient, respectively. For IA, the corresponding values in comparison to BDG and GM detection were 83% and 81%, 62% and 95%, and 62% and 100% per serum sample and 93% and 76%, 87% and 90%, and 93% and 100% per patient, respectively. Nine of the 10 MM patients had a positive MS-DS result. MS-DS gave an early diagnosis in IC (73% positivity before blood culture), IA (positive before GM detection in six patients), and MM (positivity mainly preceded the date of diagnosis) patients. For IC, persisting MS-DS was associated with a poor prognosis. The different biomarkers were rarely detected simultaneously, suggesting different kinetics of release and clearance. For IA, MS-DS provided better complementation to GM monitoring than BDG monitoring. MS-DS detects panfungal molecules circulating during invasive fungal infections. The performance of MS-DS compared favorably with those of biological tests currently recommended for monitoring at-risk patients. Further validation of this test in multicenter studies is required.

Fungal infections in the ICU: advances in treatment and diagnosis

PURPOSE OF REVIEW

The aim of this review is to give an update on the available diagnostic approaches and currently adopted therapeutic management of severe fungal diseases in the ICU setting.

RECENT FINDINGS

In order to reduce the clinical impact of life-threatening Candida infections, prompt diagnosis and appropriate treatment are strictly required. Preemptive strategies, mainly based on serological markers [i.e., (1-3)-β-D-glucan assay] are progressively replacing prophylactic and empirical approaches, limiting inadequate antifungal use. For the diagnosis of aspergillosis new algorithm has been recently validated, supported by the better knowledge of galactomannan antigen kinetic as a clinical marker. Echinocandins and voriconazole are the first choice drugs for the treatment of invasive Candida and Aspergillus infections, respectively. Although rare, other fungal infections (i.e., Pneumocystis jirovecii, Cryptococcus spp., and Mucorales spp.) may be responsible for life-threatening diseases in ICU patients, and early diagnosis and appropriate treatment are also important.

SUMMARY

Critically ill patients may frequently experience severe invasive fungal infections. Biomarkers-based diagnostic approaches give, at the same time, the possibility to early detect the ongoing infection and reduce inappropriate antifungal therapy in nonconfirmed cases. Potent and well tolerated drugs are now available for the treatment of proven cases but clinicians should carefully consider the risk of treatment failure and the availability of new monitoring and therapeutic tools.

Prospective Evaluation of Serum β-Glucan Testing in Patients With Probable or Proven Fungal Diseases

We evaluated the positivity of (1-3)-β-D-glucan, a serum marker of invasive fungal diseases (IFD), at diagnosis and during treatment. (1-3)-β-D-Glucan may not be an early marker but could prove useful for diagnosis of chronic IFD.

Background. Early diagnosis and treatment are crucial in invasive fungal diseases (IFD). Serum (1-3)-β-d-glucan (BG) is believed to be an early IFD marker, but its diagnostic performance has been ambiguous, with insufficient data regarding sensitivity at the time of IFD diagnosis (TOD) and according to outcome. Whether its clinical utility is equivalent for all types of IFD remains unknown.

Methods. We included 143 patients with proven or probable IFD (49 invasive candidiasis, 45 invasive aspergillosis [IA], and 49 rare IFD) and analyzed serum BG (Fungitell) at TOD and during treatment.

Results. (1-3)-β-d-glucan was undetectable at TOD in 36% and 48% of patients with candidemia and IA, respectively; there was no correlation between negative BG results at TOD and patients' characteristics, localization of infection, or prior antifungal use. Nevertheless, patients with candidemia due to Candida albicans were more likely to test positive for BG at TOD (odds ratio = 25.4, P = .01) than patients infected with other Candida species. In 70% of the patients with a follow-up, BG negativation occurred in >1 month for candidemia and >3 months for IA. A slower BG decrease in patients with candidemia was associated with deep-seated localizations (P = .04). Thirty-nine percent of patients with rare IFD had undetectable BG at TOD; nonetheless, all patients with chronic subcutaneous IFD tested positive at TOD.

Conclusions. Undetectable serum BG does not rule out an early IFD, when the clinical suspicion is high. After IFD diagnostic, kinetics of serum BG are difficult to relate to clinical outcome.