More Prominent Inflammatory Response to Pachyman than to Whole-Glucan Particle and Oat-ß-Glucans in Dextran Sulfate-Induced Mucositis Mice and Mouse Injection through Proinflammatory Macrophages.

(1→3)-ß-D-glucans (BG) (the glucose polymers) are recognized as pathogen motifs, and different forms of BGs are reported to have various effects. Here, different BGs, including Pachyman (BG with very few (1→6)-linkages), whole-glucan particles (BG with many (1→6)-glycosidic bonds), and Oat-BG (BG with (1→4)-linkages), were tested. In comparison with dextran sulfate solution (DSS) alone in mice, DSS with each of these BGs did not alter the weight loss, stool consistency, colon injury (histology and cytokines), endotoxemia, serum BG, and fecal microbiome but Pachyman-DSS-treated mice demonstrated the highest serum cytokine elicitation (TNF-α and IL-6). Likewise, a tail vein injection of Pachyman together with intraperitoneal lipopolysaccharide (LPS) induced the highest levels of these cytokines at 3 h post-injection than LPS alone or LPS with other BGs. With bone marrow-derived macrophages, BG induced only TNF-α (most prominent with Pachyman), while LPS with BG additively increased several cytokines (TNF-α, IL-6, and IL-10); inflammatory genes (iNOS, IL-1ß, Syk, and NF-κB); and cell energy alterations (extracellular flux analysis). In conclusion, Pachyman induced the highest LPS proinflammatory synergistic effect on macrophages, followed by WGP, possibly through Syk-associated interactions between the Dectin-1 and TLR-4 signal transduction pathways. Selection of the proper form of BGs for specific clinical conditions might be beneficial.

Plasma 1,3-ß-d-glucan levels predict adverse clinical outcomes in critical illness.

BACKGROUNDThe fungal cell wall constituent 1,3-ß-d-glucan (BDG) is a pathogen-associated molecular pattern that can stimulate innate immunity. We hypothesized that BDG from colonizing fungi in critically ill patients may translocate into the systemic circulation and be associated with host inflammation and outcomes.METHODSWe enrolled 453 mechanically ventilated patients with acute respiratory failure (ARF) without invasive fungal infection and measured BDG, innate immunity, and epithelial permeability biomarkers in serially collected plasma samples.RESULTSCompared with healthy controls, patients with ARF had significantly higher BDG levels (median [IQR], 26 pg/mL [15-49 pg/mL], P < 0.001), whereas patients with ARF with high BDG levels (≥40 pg/mL, 31%) had higher odds for assignment to the prognostically adverse hyperinflammatory subphenotype (OR [CI], 2.88 [1.83-4.54], P < 0.001). Baseline BDG levels were predictive of fewer ventilator-free days and worse 30-day survival (adjusted P < 0.05). Integrative analyses of fungal colonization and epithelial barrier disruption suggested that BDG may translocate from either the lung or gut compartment. We validated the associations between plasma BDG and host inflammatory responses in 97 hospitalized patients with COVID-19.CONCLUSIONBDG measurements offered prognostic information in critically ill patients without fungal infections. Further research in the mechanisms of translocation and innate immunity recognition and stimulation may offer new therapeutic opportunities in critical illness.FUNDINGUniversity of Pittsburgh Clinical and Translational Science Institute, COVID-19 Pilot Award and NIH grants (K23 HL139987, U01 HL098962, P01 HL114453, R01 HL097376, K24 HL123342, U01 HL137159, R01 LM012087, K08HK144820, F32 HL142172, K23 GM122069).

Antifungal efficacy of isavuconazole and liposomal amphotericin B in a rabbit model of Exserohilum rostratum meningoencephalitis: A preclinical paradigm for management of CNS phaeohyphomycosis.

Treatment options for Exserohilum rostratum meningoencephalitis and other causes of phaeohyphomycosis of the central nervous system (CNS) are limited, while mortality and morbidity remain high. We therefore evaluated isavuconazole, a new antifungal triazole in comparison to liposomal amphotericin B (LAMB), in vitro and in the rabbit model of Exserohilum rostratum meningoencephalitis. We hypothesized that isavuconazole alone or in combination with LAMB or micafungin may be alternative options for treatment of CNS phaeohyphomycosis. We therefore investigated the in vitro antifungal activity of isavuconazole alone or in combination with amphotericin B deoxycholate (DAMB) or micafungin and efficacy of treatment with isavuconazole and LAMB in a rabbit model of experimental E. rostratum meningoencephalitis. Combination checkerboard plates were used to determine the minimum inhibitory concentrations, minimal lethal concentrations, fractional inhibitory concentration indices, and Bliss surface analysis of isavuconazole and amphotericin B deoxycholate (DAMB), either alone or in combination. As there were no in vitro synergistic or antagonistic interactions for either combination of antifungal agents against the E. rostratum isolates, in vivo studies were conducted with isavuconazole and LAMB as monotherapies. Rabbits were divided in following groups: treated with isavuconazole at 60 mg/kg/d (ISAV60), LAMB at 5.0 (LAMB5), 7.5 (LAMB7.5), and 10 mg/kg/d (LAMB10), and untreated controls (UC). In ISAV60-, LAMB5-, LAMB7.5-, and LAMB10-treated rabbits, significant reductions of fungal burden of E. rostratum in cerebral, cerebellar, and spinal cord tissues (P < 0.01) were demonstrated in comparison to those of UC. These antifungal effects correlated with significant reduction of CSF (1→3)-ß-D-glucan levels vs UC (P < 0.05). These data establish new translational insights into treatment of CNS phaeohyphomycosis.

Performance characteristics of Fungitell STAT™, a rapid (1→3)-ß-D-glucan single patient sample in vitro diagnostic assay.

Serum (1→3)-ß-D-glucan (BDG), is an adjunct test in the diagnosis of invasive fungal disease (IFD). Fungitell STAT™, a facile, rapid, single patient option, executable for one or more patient specimens in approximately an hour, has been developed to address a need for rapid in-house testing. This method presents qualitative information concerning serum BDG levels, using an index value that allows the rapid categorization of patients as positive, negative, or indeterminate relative to serum BDG titer. The categorical and analytical performance of Fungitell STAT was evaluated. The categorical agreement between methods was established by testing patient samples which had been previously categorized with Fungitell. Receiver Operating Characteristic curves were used to identify cut-offs using 93 de-identified patient specimens. Subsequently, using these cutoffs, an independent group of 488 patient specimens was analyzed. Positive percent agreement (PPA) with, and without, indeterminate results was 74% and 99%, respectively. Negative percent agreement (NPA) was 91% and 98% with, and without, indeterminate results, respectively. Additionally, commercially available normal off-the-clot sera were spiked with Saccharomyces cerevisiae-derived (1→3)-ß-D-glucan to produce analytical samples. Analytical reproducibility using spiked samples was excellent with 94% of the CV (coefficient of variation) values ≤10% among three independent laboratories. Good correlation with the predicate method was demonstrated with correlation coefficients of 0.90 or better with patient samples and 0.99 with spiked samples. The Fungitell STAT index assay provides a rapid and suitable method for serum BDG testing.

Efficacy and Pharmacokinetics of Fosmanogepix (APX001) in the Treatment of Candida Endophthalmitis and Hematogenous Meningoencephalitis in Nonneutropenic Rabbits.

Candida endophthalmitis is a serious sight-threatening complication of candidemia that may occur before or during antifungal therapy. Hematogenous Candida meningoencephalitis (HCME) is also a serious manifestation of disseminated candidiasis in premature infants, immunosuppressed children, and immunocompromised adults. We evaluated the antifungal efficacy and pharmacokinetics of the prodrug fosmanogepix (APX001) in a rabbit model of endophthalmitis/HCME. Manogepix (APX001A), the active moiety of prodrug fosmanogepix, inhibits the fungal enzyme Gwt1 and is highly active in vitro and in vivo against Candida spp., Aspergillus spp., and other fungal pathogens. Plasma pharmacokinetics of manogepix after oral administration of fosmanogepix on day 6 at 25, 50, and 100 mg/kg resulted in maximum concentration of drug in plasma (Cmax) of 3.96 ± 0.41, 4.14 ± 1.1, and 11.5 ± 1.1 µg/ml, respectively, and area under the concentration-time curve from 0 to 12 h (AUC0-12) of 15.8 ± 3.1, 30.8 ± 5.0, 95.9 ± 14 µg·h/ml, respectively. Manogepix penetrated the aqueous humor, vitreous, and choroid with liquid-to-plasma ratios ranging from 0.19 to 0.52, 0.09 to 0.12, and 0.02 to 0.04, respectively. These concentrations correlated with a significant decrease in Candida albicans burden in vitreous (>101 to 103 log CFU/g) and choroid (>101 to 103 log CFU/g) (P ≤ 0.05 and P ≤ 0.001, respectively). The aqueous humor had no detectable C. albicans in treatment and control groups. The tissue/plasma concentration ratios of manogepix in meninges, cerebrum, cerebellum, and spinal cord were approximately 1:1, which correlated with a >102 to 104 decline of C. albicans in tissue versus control (P ≤ 0.05). Serum and cerebrospinal fluid (CSF) (1→3)-ß-d-glucan levels demonstrated significant declines in response to fosmanogepix treatment. These findings provide an experimental foundation for fosmanogepix in treatment of Candida endophthalmitis and HCME and derisk the clinical trials of candidemia and invasive candidiasis.

Specificity Influences in (1→3)-ß-d-Glucan-Supported Diagnosis of Invasive Fungal Disease.

(1→3)-ß-glucan (BDG) testing as an adjunct in the diagnosis of invasive fungal disease (IFD) has been in use for nearly three decades. While BDG has a very high negative predictive value in this setting, diagnostic false positives may occur, limiting specificity and positive predictive value. Although results may be diagnostically false positive, they are analytically correct, due to the presence of BDG in the circulation. This review surveys the non-IFD causes of elevated circulating BDG. These are in the main, iatrogenic patient contamination through the use of BDG-containing medical devices and parenterally-delivered materials as well as translocation of intestinal luminal BDG due to mucosal barrier injury. Additionally, infection with Nocardia sp. may also contribute to elevated circulating BDG. Knowledge of the factors which may contribute to such non-IFD-related test results can improve the planning and interpretation of BDG assays and permit investigational strategies, such as serial sampling and BDG clearance evaluation, to assess the likelihood of contamination and improve patient care.

(1,3) ß-D-Glucan in Bronchoalveolar Lavage of Lung Transplant Recipients for the Diagnosis of Invasive Pulmonary Aspergillosis.

(1,3) ß-D-Glucan (BDG) is present in the cell wall of most fungi. Its detection in serum has been useful in the diagnosis of invasive aspergillosis (IA) in patients with hematologic malignancies. However, assaying for BDG did not perform well in the serum of lung transplant recipients. We undertook to study the performance of BDG in the bronchoalveolar lavage (BAL) of lung transplant recipients for the diagnosis of invasive pulmonary aspergillosis (IPA). Available and stored BAL samples from lung transplant recipients at the Toronto General Hospital between October 2007 and April 2013 were tested for BDG using the Fungitell kit from the Associates of Cape Cod Inc, Falmouth, MA, USA : The International Society for Heart and Lung transplantation (ISHLT) criteria was used for the diagnosis of IA. Of 195 samples, there were ten episodes of IA. The sensitivity and specificity of the test were 80% and 53% and 60% and 70% at 41 pg/ml and 108 pg/ml cut-offs, respectively. On excluding 52 bronchoscopies due to receipt of anti-Aspergillus therapy during specimen collection, the sensitivity and specificity improved to 75% and 91%, respectively, at a 524 pg/ml cut-off. However, only four episodes of IA remained in this analysis. Using BDG in BAL of lung transplant recipients for the diagnosis of IA, our study demonstrated moderate sensitivity and specificity.

(1→3)-ß-d-Glucan: A Biomarker for Microbial Translocation in Individuals with Acute or Early HIV Infection?

BACKGROUND: The extent of gut microbial translocation, which plays roles in HIV disease progression and non-AIDS comorbidities, appears to vary with the composition of the gut microbiome, particularly the presence of Lactobacillales, which reduce mucosal injury. While low proportions of Lactobacillales in the distal gut microbiome are a very promising indicator of microbial translocation, measurement is expensive and complicated and not feasible for clinical routine. (1→3)-ß-d-Glucan (BDG) is a component of most fungal cell walls and might be a surrogate marker for Lactobacillales proportion in the gut and a useful indicator of HIV-associated gut injury. This study evaluated BDG as a biomarker of gut integrity in adults with acute or early HIV infection (AEH). METHODS: Study samples were collected longitudinally during study visits at weeks 0, 12, and 24 in a cohort of 11 HIV-infected men starting antiretroviral therapy during AEH. Blood plasma levels of BDG, soluble cluster of differentiation 14 (sCD14) and lipopolysaccharide (LPS) were measured and then correlated with the proportion of Lactobacillales in the distal gut microbiome, as measured by 16s rDNA sequencing by using mixed-effects models with random intercepts. RESULTS: Mean BDG and sCD14 levels across subjects were associated with Lactobacillales after controlling for time effects and within-subjects correlations (p-values < 0.05), while LPS levels were not. Specifically, each point increase in mean BDG and sCD14 levels across participants was associated with 0.31 ± 0.14 and 0.03 ± 0.01 percent decrease in mean Lactobacillales proportions, respectively. CONCLUSION: BDG and sCD14 may be indicators of low Lactobacillales in the gut in adults with acute or early HIV infection, and serve as biomarkers of gut integrity and microbial translocation in HIV infection. Larger studies are needed to confirm our findings.

Cerebrospinal Fluid (1,3)-Beta-d-Glucan Testing Is Useful in Diagnosis of Coccidioidal Meningitis.

Diagnosing coccidioidal meningitis (CM) can be problematic owing to its infrequency and/or a delay in the positivity of a cerebrospinal fluid (CSF) culture or CSF antibody, particularly if the primary coccidioidal infection is unrecognized. We tested 37 CSF specimens, 26 from patients with confirmed CM and 11 from patients with suspected microbial meningitis without fungal diagnosis, for (1,3)-beta-glucan (BG). BG in CM CSF specimens ranged from 18 to 3,300 pg/ml and in controls ranged from <3.9 to 103 pg/ml. Diagnostic performance was determined using a 31-pg/ml cutoff (the bottom of the serum range according to the directions for the commercial kit, although further serial dilutions of the standard indicated linearity to 3.9). Sensitivity was 96%, specificity was 82%, positive and negative predictive values were 93% and 90%, and the area under the receiver operating characteristic curve was 0.937. Fifteen of 15 samples of >103 pg/ml were CM. The one false-negative specimen was from a patient with a pseudosyrinx, without inflammatory evidence of meningitis activity. Serial samples from some patients were positive at ≤8 years, indicating no loss of positivity with chronicity. Samples stored frozen since 2000 included those with 2 of the 3 highest values, indicating that fresh samples not required. A previous study indicated serum sensitivities of 53% in acute, 50% in resolved, and 83% in disseminated and meningeal coccidioidomycosis. Three studies of other fungal meningitides ranged from 86 to 1,524 pg/ml CSF, with 37 controls of <4 to 115 pg/ml CSF. CSF BG analysis had good diagnostic performance in CM. CSF BG testing can be useful in CM, and a commercial kit is available. It will be of interest to correlate this with course, treatment, outcome, inflammation, and antigen. The only mycoses with common central nervous system (CNS) involvement are cryptococcal and coccidioidal, so CSF BG screening can be useful in meningitis diagnosis.

Detection of (1→3)-ß-d-Glucan in Eumycetoma Patients.

Mycetoma can be caused by bacteria (actinomycetoma) or fungi (eumycetoma). Here, we demonstrated in 45 eumycetoma patients, 30 actinomycetoma patients, and 30 healthy controls that (1→3)-ß-d-glucan detection in serum cannot reliably be used to discriminate between the two types of mycetoma.

(1→3)-ß-d-Glucan in Cerebrospinal Fluid as a Biomarker for Candida and Aspergillus Infections of the Central Nervous System in Pediatric Patients.

BACKGROUND: Fungal infections of the central nervous system (FICNS) are important causes of morbidity and mortality among immunocompromised pediatric patients. Standard diagnostic modalities lack the sensitivity for detecting and therapeutically monitoring these life-threatening diseases. Current molecular methods remain investigational. (1→3)-ß-d-glucan (BDG) is a cell wall component found in several fungal pathogens, including Candida and Aspergillus spp. Detecting BDG in cerebrospinal fluid (CSF) may be an important approach for detecting and therapeutically monitoring FICNS. To date, there has been no study that has investigated the effectiveness of CSF BDG as a diagnostic and therapeutic marker of FICNS in children. METHODS: Serial BDG levels were measured in serum and CSF samples obtained from pediatric patients (aged 0-18 years) with a diagnosis of probable or proven Candida or Aspergillus CNS infection. RESULTS: Nine cases of FICNS were identified in patients aged 1 month to 18 years. Two patients were infected with an Aspergillus species, and 7 patients were infected with a Candida species. All the patients at baseline had detectable BDG in their CSF. Among 7 patients who completed therapy for an FICNS, all elevated CSF BDG levels decreased to <31 pg/mL. At the time of this writing, 1 patient was still receiving therapy and continued to have elevated BDG levels. One patient died from overwhelming disseminated candidiasis. The lengths of therapy for these 9 children ranged from 2 weeks to 28 months. CONCLUSION: The BDG assay is useful in diagnosing and therapeutically monitoring Candida and Aspergillus CNS infections in pediatric patients.

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

Galactomannan and (1→3)-ß-D-glucan are useful biomarkers of invasive pulmonary aspergillosis (IPA). However, the effects of immunosuppression on levels of galactomannan or (1→3)-ß-D-glucan in IPA are not well understood or quantified. We therefore studied the simultaneous levels of galactomannan and (1→3)-ß-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)-ß-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)-ß-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)-ß-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)-ß-D-glucan but did affect galactomannan and (1→3)-ß-D-glucan levels in serum. The higher serum GMI and (1→3)-ß-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)-ß-D-glucan in IPA depended upon immunosuppression, which also affected severity of infection and hyphal morphology, while BAL fluid galactomannan and (1→3)-ß-D-glucan were sensitive biomarkers not affected by host response.

Utility of measuring (1,3)-ß-d-glucan in cerebrospinal fluid for diagnosis of fungal central nervous system infection.

(1-3)-ß-d-Glucan (BDG) from cerebrospinal fluid (CSF) is a promising marker for diagnostic and prognostic aid of central nervous system (CNS) fungal infection, but its relationship to serum values has not been studied. Herein, we detected BDG from CSF at levels 2-fold lower than those in serum in patients without evidence of fungal disease but 25-fold higher than those in in serum in noncryptococcal CNS fungal infections. CSF BDG may be a useful biomarker in the evaluation of fungal CNS disease.

Test performance of blood beta-glucan for Pneumocystis jirovecii pneumonia in patients with AIDS and respiratory symptoms.

OBJECTIVE: The objective of this study was to define the test characteristics of plasma beta-glucan for diagnosis of Pneumocystis jirovecii pneumonia (PCP) in AIDS patients with respiratory symptoms. DESIGN: Analysis of baseline blood samples in a randomized strategy study of patients with acute opportunistic infections, limited to participants with respiratory symptoms. METHODS: Participants in the 282-person ACTG A5164 trial had baseline plasma samples assayed for beta-glucan testing. As part of A5164 trial, two study investigators independently adjudicated the diagnosis of PCP. Respiratory symptoms were identified by investigators from a list of all signs and symptoms with an onset or resolution in the 21 days prior to or 14 days following study entry. Beta-glucan was defined as positive if at least 80 pg/ml and negative if less than 80 pg/ml. RESULTS: Of 252 study participants with a beta-glucan result, 159 had at least one respiratory symptom, 139 of whom had a diagnosis of PCP. The sensitivity of beta-glucan for PCP in participants with respiratory symptoms was 92.8% [95% confidence interval (CI) 87.2-96.5], and specificity 75.0% (95% CI 50.9-91.3). Among 134 individuals with positive beta-glucan and respiratory symptoms, 129 had PCP, for a positive predictive value of 96.3% (95% CI 91.5-98.8). Fifteen of 25 patients with a normal beta-glucan did not have PCP, for a negative predictive value of 60% (95% CI 38.7-78.9). CONCLUSION: Elevated plasma beta-glucan has a high predictive value for diagnosis of PCP in AIDS patients with respiratory symptoms. We propose an algorithm for the use of beta-glucan as a diagnostic tool on the basis of the pretest probability of PCP in such patients.

Serum (1->3)-ß-D-glucan measurement in coccidioidomycosis.

The serum (1→3)-ß-d-glucan assay has emerged as an important diagnostic test for invasive fungal disease. The utility of this assay in coccidioidomycosis has not been previously studied. Using a cutoff value of ≥80 pg/ml, we found the sensitivity (43.9%), specificity (91.1%), positive predictive value (81.8%), and negative predictive value (64.1%) to be similar to those of the assay in diagnosing other invasive mycoses.

Serum galactomannan and (1->3)-ß-D-glucan assays for patients with multiple myeloma and Waldenstrom's macroglobulinemia.

We assessed the performance of galactomannan and (1→3)-ß-d-glucan in 29 serum samples from patients with multiple myeloma and Waldenstrom's macroglobulinemia without invasive fungal disease to address issues of false positivity and uninterpretable results previously reported among patients with these conditions. Galactomannan and (1→3)-ß-d-glucan assays were not falsely elevated in any patient. (1→3)-ß-d-glucan assay results were uninterpretable in 24% of patients. Patients with IgG levels of >2,000 mg/dl had higher odds of uninterpretable (1→3)-ß-d-glucan results.

Does ampicillin-sulbactam cause false positivity of (1,3)-beta-D-glucan assay? A prospective evaluation of 15 patients without invasive fungal infections.

The purpose of this study was to investigate the interaction between intravenous ampicillin-sulbactam treatment and (1,3)-beta-D-glucan (BDG) assay. Fifteen patients with a median age of 60 (16-81) without known risk factors for invasive fungal infections who received a daily dose of 3×2g ampicillin-sulbactam monotherapy from different batches were included in the study. Thirteen patients had soft tissue infections. The 5 of 13 patients who went under surgery had surgical dressings. Serum samples were obtained both before and after antibiotic infusion on the first, third, seventh and tenth days of an ampicillin-sulbactam treatment course. BDG was assayed using the Fungitell kit (Associates of Cape Cod, East Falmouth, MA, USA) according to manufacturers' specifications. All serum samples were also tested for galactomannan (GM) antigenemia by Platelia Aspergillus ELISA (Bio-Rad Laboratories, Marnes-la-Coquette, France). A total of 37 of 117 serum samples were positive for BDG at a threshold of 80pg ml(-1) . Seven of 37 BDG positive serum samples had a GM index ≥0.5. When a cutoff value of ≥0.5 was used for GM positivity, 16 (13.3%) serum samples were positive. For a cutoff value of ≥0.7, eight (6.6%) serum samples were positive. There were no statistically significant differences in the median BDG levels (P=0.47) or median GM indices (P =0.28) of the various sampling times. None of the SAM vials tested positive for BDG or GM. After ruling out fungal infections and all known potential causes of false BDG positivity, environmental contamination remained possible cause of BDG reactivity. We did not observe any significant association of ampicillin-sulbactam administration and positive assays for BDG or GM.

Blood (1->3)-beta-D-glucan as a diagnostic test for HIV-related Pneumocystis jirovecii pneumonia.

UNLABELLED: (See the editorial commentary by Morris and Masur, on pages 203-204.) BACKGROUND: Improved noninvasive diagnostic tests for Pneumocystis jirovecii pneumonia (PCP) are needed. We evaluated the test characteristics of plasma (1 → 3)-ß-D-glucan (ß-glucan) for HIV-related PCP among a large group of patients presenting with diverse opportunistic infections (OIs). METHODS: The study population included all 282 participants in AIDS Clinical Trials Group A5164, a study of early versus deferred antiretroviral therapy in conjunction with initial therapy of acute OIs. Baseline plasma samples were assayed for ß-glucan, with standard assay reference values defining ≥ 80 pg/mL as positive. Before this analysis, diagnosis of PCP was independently adjudicated by 2 study investigators after reviewing reports from study sites. RESULTS: A total of 252 persons had a ß-glucan result that could be analyzed, 173 (69%) of whom had received a diagnosis of PCP. Median ß-glucan with PCP was 408 pg/mL (interquartile range [IQR], 209-500 pg/mL), compared with 37 pg/mL (IQR, 31-235 pg/mL) without PCP (P < .001). The sensitivity of ß-glucan dichotomized at 80 pg/mL for the diagnosis of PCP was 92% (95% confidence interval [CI], 87%-96%), and the specificity was 65% (95% CI, 53%-75%); positive and negative predictive values were 85% (95% CI, 79%-90%) and 80% (95% CI, 68%-89%) respectively, based on the study prevalence of 69% of patients with PCP. Rates of abnormal lactate dehyrogenase levels did not differ significantly between those with and without PCP. CONCLUSIONS: Blood (1 → 3)-ß-D-glucan is strongly correlated with HIV-related PCP. In some clinical centers, this may be a more sensitive test than the induced sputum examination and could reduce the need for both bronchoscopy and empirical therapy of PCP.

Prospective survey of (1→3)-beta-D-glucan and its relationship to invasive candidiasis in the surgical intensive care unit setting.

Non-culture-based diagnostic strategies are needed for diagnosing invasive candidiasis (IC). We evaluated serial serum (1→3)-ß-d-glucan (BG) levels in patients in the surgical trauma intensive care unit (SICU) patients with clinical evidence of IC. Serum samples from patients admitted to the SICU for a minimum of 3 days were collected twice weekly and analyzed for BG by using a Fungitell kit with a positive cutoff of ≥ 80 pg/ml. Diagnosis of IC was done using a set of predefined and validated clinical practice-based criteria. A total of 57 patients consented to participate and were enrolled. The median ICU stay was 16 days (range, 3 to 51). A total of 14 of 57 (25%) false positives were observed in the first sample (ICU day 3) and, overall, 73% of the day 3 samples had higher BG levels than subsequent samples. On the date of clinical diagnosis of IC, the sensitivity of a positive BG for identifying invasive candidiasis was 87%, with a 73% specificity. In patients with evidence of IC, the median BG value was significantly higher than those without evidence of IC (171 versus 48 pg/ml, P = 0.02), respectively. In the three patients with proven IC, BG was detected 4 to 8 days prior to diagnosis. BG serum detection may be a useful tool to aid in the early diagnosis of IC in SICU patients, particularly after day 3 and in patients with at least two positive samples drawn several days apart. Elevated BG levels within the first 3 days need to be further characterized.