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Ninety-one serum samples from 51 hematology patients with bacteremia infections were tested for (1,3)-β-d-glucan (BG). Eleven samples (15%) from 7 patients (14%) were positive for BG. Of these 7 patients with positive BG results, 4 (8%) had invasive aspergillosis and 3 (6%) had no invasive fungal disease. Bacteremia was an unlikely cause of the false-positive BG results., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

Microbiological diagnosis of nosocomial candidemia is negatively affected by suboptimal culture yield. Alternative methods are not fully reliable as an aid in candidemia diagnosis. Recently, the detection of (1,3)-β-D-glucan (BG) has been shown to be very promising in this setting. We carried out a prospective study on the clinical usefulness of BG detection in early diagnosis of candidemia. BG detection was performed in patients with fever unresponsive to antibacterial agents and risk factors for candidemia. BG detection was done with the Fungitell test. A total of 152 patients were included in the study; 53 were proven to have candidemia, while in 52 patients candidemia was excluded on microbiological and clinical bases. The remaining 47 patients were considered to have possible candidemia. In summary, 41 of 53 candidemia patients (77.3%), 9 of 52 patients without candidemia (17.3%), and 38 of 47 patients with possible candidemia (80.8%) were positive in the BG assay. With these results, the sensitivity and the specificity of the assay were 77% and 83%, respectively. BG levels of >160 pg/ml were highly predictive of candidemia. In 36 of 41 patients with candidemia and positive BG testing, the BG assay was performed within 48 h from when the first Candida-positive blood sample for culture was drawn, thus allowing a possible earlier start of antifungal therapy. Based on these results, the BG assay may be used as an aid in the diagnosis of nosocomial candidemia. The timing of assay performance is critical for collecting clinically useful information. However, the test results should be associated with clinical data.

In 6 hematopoietic stem cell transplant (HSCT) recipients with candidemia, the (1,3)-β-d-glucan (BG) test was positive a median of 2.5 days after a positive blood culture. Only in 1 patient did BG positivity precede positive blood cultures. BG concentrations decreased in patients with clinical response, but positive BG results persisted long after blood cultures became sterile (median, 48 days).

(1,3)-beta-d-Glucan (BG) is a component of the Pneumocystis jiroveci cell wall. Thirty-one immunocompromised patients with pneumonia (16 with presumptive pneumocystis pneumonia [PCP] and 15 with non-PCP) were evaluated for serum BG levels. Serum from all 16 presumptive PCP patients and from 2/15 patients with non-PCP was positive for BG. Results indicate that BG is a reliable marker for diagnosing PCP.

The evaluation of antigen-specific T-cell responses is helpful for both research and clinical settings. Several techniques can enumerate antigen-responsive T cells or measure their products, but they require remarkable amounts of peripheral blood mononuclear cells (PBMCs). Since screening numerous antigens or testing samples from pediatric or lymphopenic patients is hampered in clinical practice, we refined a miniaturized, high-throughput assay for T-cell immunity. Antigens and cells in 10-microl volumes were dispensed into 1,536-well culture plates precoated with anti-gamma interferon (anti-IFN-gamma) antibodies. After being cultured, the wells were developed by enzyme-linked immunosorbent assay for bound cytokine. Miniaturization and automation allowed quantitation of antigen-specific responses on 10(4) PBMCs. This method was applied for epitope mapping of mycobacterial antigens and was used in the clinic to evaluate T-cell immunity to relevant opportunistic pathogens by using small blood samples. A comparison with conventional methods showed similar sensitivity. Therefore, current flow cytometric methods that provide information on frequency and phenotype of specific T cells can be complemented by this assay that provides extensive information on cytokine concentrations and profiles and requires 20- to 50-fold fewer PBMCs than other analytical methods.