Analysis of the levels of endotoxin and β-d-glucan in the synovial fluid of hemodialysis patients

The influence of continuous renal replacement therapy on 1,3-β-d-glucan levels in critically ill patients: a single-center retrospective propensity score study

1,3-β-d-Glucan (BDG) is commonly used for diagnosing invasive fungal infections (IFIs). While exposure to cellulose-based hemodialyzers is known to cause false-positive BDG results, the impact of modern hemofilters used in continuous renal replacement therapy (CRRT) remains unclear. This retrospective, single-center cohort study aimed to evaluate the effect of CRRT on BDG levels in critically ill patients. We included adult intensive care unit (ICU) patients with ≥1 BDG measurement between December 2019 and December 2020. The primary outcome was the rate of false-positive BDG results in patients exposed to CRRT compared to unexposed patients. Propensity score analysis was performed to control for confounding factors. A total of 103 ICU patients with ≥1 BDG level were identified. Most (72.8%) were medical ICU patients. Forty patients underwent CRRT using hemofilter membranes composed of sodium methallyl sulfonate copolymer (AN 69 HF) (82.5%) and of polyarylethersulfone (PAES) (17.5%). Among the 91 patients without proven IFI, 31 (34.1%) had false-positive BDG results. Univariable analysis showed an association between CRRT exposure and false-positive BDG results. However, the association between CRRT exposure and false-positive BDG results was no longer significant across three propensity score models employed: 1:1 match (n = 32) (odds ratio (OR) 1.65, p = .48), model-adjusted (n = 91) (OR 1.75, p = .38), quintile-adjusted (n = 91) (OR 1.78, p = .36). In this single-center retrospective analysis, exposure to synthetic CRRT membranes did not independently increase the risk of false-positive BDG results. Larger prospective studies are needed to further evaluate the association between CRRT exposure and false-positive BDG results in critically ill patients with suspected IFI.

Reliability of serum 1,3-beta-D-glucan assay in patients undergoing renal replacement therapy: a review of the literature

The serum 1,3-beta-D-glucan (BDG) test is a pan-fungal serum marker considered to detect the majority of pathogenic fungi, including Aspergillus spp. and Candida spp. For this review we searched for publications dealing with serum BDG levels in patients undergoing renal replacement therapy (RRT). The influence of various different membrane materials used for RRTs in these publications on serum BDG has been reviewed. We found that unmodified cellulose containing membranes increased the serum BDG levels highly, whereas conflicting results have been observed for modified cellulose containing materials. Synthetic materials (e.g. polysuflone) had no influence on serum BDG levels in the majority of the reviewed publications.