No abstract

Objectives: Early initiation of antifungal treatment for invasive candidiasis is associated with significant reduction of morality. The process of blood culture is timeconsuming and sensitivity is low for the deep-seated infection. Blood culture-guided treatment is mostly delayed. 1,3-beta-D-glucan (BDG) is one of the components in fungal cell wall and BDG assay is recommended for diagnosis of invasive candidiasis. The objective of this study was to evaluate the potential cost-effectiveness of active BDG surveillance for invasive candidiasis in patients admitted to ICU from the perspective of Hong Kong healthcare provider. MethOds: A Markov model was designed to simulate outcomes of active BDG surveillance with preemptive antifungal therapy (surveillance group) and no surveillance (standard care group). Candidiasis-associated outcome measures were mortality rate, quality-adjusted life year (QALY) loss, and direct medical cost. Sensitivity analyses evaluated robustness of model results. Results: In base-case analysis, the surveillance group was more costly (USD1,387 versus USD664) (USD1= HKD7.8) with lower candidiasis-associated mortality rate (0.653 versus 1.426 per 100 ICU admissions) and QALY loss (0.116 versus 0.254) than standard care group. The incremental cost per QALY saved by surveillance group versus standard care group was 5,239 USD/QALY. One-way sensitivity analyses found base-case results to be robust to variation of all model inputs.In probabilistic sensitivity analysis, the probability of surveillance group to be costeffective was 100% at willingness-to-pay (WTP) threshold of ≥ 27,800 USD/QALY (gross domestic product per capita in Hong Kong 2015= USD40,596). cOnclusiOns: Active BDG surveillance in ICU setting appears to be a highly cost-effective strategy to reduce candidiasis-associated mortality rate and save QALY in Hong Kong.

2063 Background: Immunity plays an important role in PCNSL development. PCNSL predictive factors need to be improved. Objective: to evaluate the characteristics and predictive value of blood LIP in PCNSL patients. Methods: we prospectively analyzed blood LIP in all newly PCNSL referred to our institution between December 2013 and January 2020. LIP analysis was performed before rituximab and chemotherapy administration. The clinical, radiological, histological, biological and treatment data were retrospectively collected. Results: fifty-three patients were included with a median age of 69.7 (range 21.7-87.5). Median KPS was 60 (range 30-100). All patients presented with cerebral involvement, 13 (25%) with cerebrospinal fluid extension and 8 (15%) with ocular extension. Thirty-four patients (62%) benefited of steroid treatment at the time of LIP. Patients characteristics did not differ depending on steroid intake. Forty-eight patients (95%) benefited of polychemotherapy with high-dose methotrexate as first line treatment. We observed three (6%) lymphoproliferative syndromes on the LIP and 33 patients (64%) presented with one or several lymphopenias: 21 (40%), 24 (46%) and 9 (17%) NK, T and B lymphopenias respectively. Only 11 patients (21%) had normal LIP. Median CD4/CD8 ratio was 2.11 (range 0.54-9.11). This ratio was normal, low or high in 27%, 28% and 44% of patients respectively. The presence of steroids did not impact LIP results, including CD4 (p = 0.475) or CD8 (p = 0.726) rates and CD4/CD8 ratio (p = 0.727). Complete or partial responses, stable and progressive disease (PD) were observed in 24 (50%), 10 (21%), 4 (8%), and 10 (21%) patients respectively. CD4/CD8 ratio tended to be different between refractory (PD patients) and non-refractory patients (p = 0.077). A ROC curve analysis was performed with an AUC of 0.684 allowing the selection of a CD4/CD8 ratio cutoff of 1.97 with a sensibility, specificity, positive predictive value, and negative predictive value to identify refractory patients of 90%, 55%, 35% and 95% respectively. Median progression-free survival (PFS) and overall survival (OS) were 14.7 (95%CI: 6.5-22.9) and 43.2 (95%CI: 21.6-64.9) months, respectively. In multivariate analyses, adjusted by KPS, a CD4/CD8 ratio > 1.97 was associated with poor PFS (p = 0.043, HR = 3.32 [1.02-4.88]) and tended to be associated with worse OS (p = 0.064). Conclusions: LIP at baseline may predict refractory disease and exhibits a prognostic value in PCNSL patients.