Vergidis, Paschalis

Abstract Background Despite advances in clinical microbiology, the diagnosis of invasive fungal infections remains challenging. Giant magnetoresistance (GMR) is a novel technology that enables the detection of trace amounts of cell-free DNA (cfDNA). We evaluated a high-multiplex molecular diagnostic assay coupled with GMR-enabled lab-on-a-chip technology that can detect 18 different fungal species. Methods Analytical performance was evaluated in spiked plasma samples. After amplification, cfDNA was digested. Residual single-stranded DNA was flowed over a GMR sensor that was surface-coated with probes specific to different fungal species. After hybridization, magnetic beads bound to the probe complexes produced a GMR signal that was detected by the sensors. Clinical performance was determined using residual serum samples collected before the initiation of antifungal treatment from 20 patients with infection. Results The limit of detection of the assay ranged from 5 to 50 copies per polymerase chain reaction (PCR) reaction. Nonspecific signals were not observed in the spiked samples. Fungal cfDNA was detected in 80% of patients with invasive candidiasis (3/4 with candidemia, 5/6 with invasive candidiasis without candidemia), all 3 cases of invasive pulmonary aspergillosis, and all 3 cases of disseminated histoplasmosis. cfDNA was not detected in 2 patients with cryptococcosis (both had negative blood cultures) and 2 patients with Pneumocystis pneumonia. Conclusions We developed a novel GMR-enabled multiplex PCR assay detecting fungal pathogens that have been prioritized for public health action. Clinical sensitivity was highest in cases of presumed angioinvasion and dissemination. This technology has the potential for use in the clinical microbiology laboratory setting.

Abstract Background Invasive mold infections (IMI) lead to significant morbidity and mortality in patients with hematologic malignancies. We provide patients deemed at higher risk mold active prophylaxis but still observe breakthrough IMIs. The purpose of this study was to evaluate risk factors associated with these breakthrough infections. Methods We conducted a retrospective cohort study of adult hematologic patients at 3 tertiary care medical centers from November 19, 2011 - August 6, 2021. Only IMI cases defined as proven or probable per EORTC/MSG criteria were included. Patients with IMIs who received a minimum of 7 days of mold active prophylaxis were classified as breakthrough infection. We performed logistical regression analysis to identify risk factors associated with breakthrough IMI. Results Majority of cases were probable IMIs, with 16 (28.6%) and 25 (15.7%) proven cases amongst breakthrough and non-breakthrough IMIs, respectively. Many variables indicative of weakened host immune system, including neutropenia and hypogammaglobulinemia, were associated with breakthrough IMIs, albeit not statistically significant (Table 1). Multivariate analysis revealed history of AML (OR 4.20, 95% CI 2.03-8.88; p < 0.001) and receipt of HCT (OR 3.37, 95% CI 1.46-8.11; p = 0.003) to be independent host risk factors for breakthrough IMI. Of all the pathogens, Fusarium (OR 4.38, 95% CI 1.56-12.56; p = 0.005) and Mucorales (OR 5.59, 95% CI 2.11-15.61; p < 0.001) were significantly likely to lead to breakthrough IMIs. 26 (47.3%) of the breakthrough IMIs were on appropriately dosed prophylaxis at the time of infection, with only 9 (16.4%) found to be subtherapeutic (Table 2). Overall, mortality was slightly higher amongst the breakthrough IMIs (51.8% vs 45.9%) but not significantly different (Figure 1). Conclusion In our cohort of probable/proven IMIs, we did not observe any significant difference in mortality between patients with breakthrough IMIs and those not on mold active prophylaxis. Even with appropriate prophylactic dosing, breakthrough infections occurred, irrespective of agent. Our study demonstrates that host risk factors and the causative pathogen are clinically more pertinent than the prophylaxis regimen in breakthrough IMIs. Disclosures Paschalis Vergidis, MD, MSc, AbbVie: Advisor/Consultant|Ansun Biopharma: Grant/Research Support|Cidara Therapeutics: Grant/Research Support|F2G: Grant/Research Support|Scynexis: Advisor/Consultant|Scynexis: Grant/Research Support

Abstract Background Optimizing antimicrobial prescribing for urinary tract infections (UTI) represents an area of opportunity for ambulatory antimicrobial stewardship programs. A pre-populated, ambulatory antibiotic order panel for UTI was implemented in the Mayo Clinic Enterprise on 5/16/2022. The order panel provides antimicrobial regimens which align with both institutional and national treatment guidelines based on patient comorbidities, complicating factors, and beta-lactam allergy status. We aimed to assess the impact of panel use on antibiotic prescribing for complicated and uncomplicated cystitis in the ambulatory setting. Methods This retrospective review included ambulatory encounters from the Mayo Clinic Enterprise in 2022 and 2023. Eligible encounters were randomly selected and included those with a primary ICD-10 code of cystitis performed by primary care or urgent care clinicians. Encounters were excluded if patients had symptoms indicative of pyelonephritis, underwent urinary instrumentation within 30 days, or had a urinary pathogen isolated within 90 days. The primary outcome was concordance with institutional guidelines. Secondary outcomes included repeat healthcare contact and therapy duration. Outcomes were analyzed with Pearson's chi-squared and Wilcoxon rank sum tests (α level = 0.05). Results 793 encounters (397 panel vs. 396 non-panel) were included. Prescribing was guideline concordant in 79.3% and 64.9% (p< 0.001) of panel and non-panel encounters, respectively. Inappropriate duration was the most common reason for non-concordance in the panel use cohort. There was no difference between groups for repeat healthcare contact incidence. Antimicrobials prescribed differed between panel and no-panel groups (Table 1), with higher use of sulfamethoxazole/trimethoprim and lower use of cefdinir in the panel cohort. Numerically shorter durations were seen in the panel group, with more 3- and 5-day regimens than the no-panel group. Conclusion Use of a pre-populated antimicrobial order panel for outpatient cystitis encounters resulted in greater adherence to institutional guideline recommendations, particularly in terms of antimicrobial selection, without adversely impacting repeat healthcare contact. Disclosures Paschalis Vergidis, MD, MSc, AbbVie: Advisor/Consultant|Ansun Biopharma: Grant/Research Support|Cidara Therapeutics: Grant/Research Support|F2G: Grant/Research Support|Scynexis: Advisor/Consultant|Scynexis: Grant/Research Support

ABSTRACT Introduction With reports of expanding epidemiology of blastomycosis across the United States, the purpose of this study was to evaluate the incidence and outcomes associated with blastomycosis in solid organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients. Methods We conducted a retrospective case series of adult SOT and HCT recipients at a tertiary care medical center between January 1, 2005 and September 30, 2023. Cases were defined as culture‐proven blastomycosis. We performed descriptive statistical analysis to evaluate diagnosis, management, and outcomes (mortality) of blastomycosis in SOT. Results The cumulative incidence of blastomycosis was 0.11% with a median time to infection following transplant of 743 days. Of the 19 cases, the majority of patients were SOT recipients (90%). Supratherapeutic immunosuppression within 30 days of diagnosis was observed in 42% of cases with documented drug monitoring. Urine antigen testing was highly sensitive (100%). Fourteen (73.7%) patients received induction therapy with liposomal amphotericin B followed by azole therapy for a minimum of 12 months. Despite appropriate treatment, 1‐year mortality was high at 26.3%, with attributable mortality of 21.1%. Conclusions While rates of blastomycosis remain low among SOT and HCT recipients, infection is associated with poor posttransplant outcomes. Antigen testing can aid in timely assessment of disease severity and initiation of appropriate therapy. Among survivors, no relapses were observed while on lifelong secondary suppression. Future studies should aim to better define risk factors associated with developing blastomycosis and establish effective strategies for prevention.

Background and Methods: IEC-HS is a hyperinflammatory state with high morbidity and mortality. Effective interventions to reverse the process early in the clinical course may be critical to improve outcomes. We previously examined cytokine differences between IEC-HS and other secondary hemophagocytic lymphohistiocytosis, and found significant differences in the patterns and outcomes.(1) This study examines cytokine profiles (CP) of patients treated with CAR-T from 9/2019 to 3/2024 who developed CRS, MAS-L and IEC-HS. Demographics and lab results were compared among the three groups and correlated with outcomes. Results: CP was tested in 113 of 366 CAR-T patients: 74 with CRS, 19 with MAS-L, and 20 with IEC-HS. The racial distribution was 93% White/Caucasian, 2% Black or African American, 1% Asian, 1% Native American and 3% other or unavailable. No differences were seen in demographics between groups except a higher percentage of patients with ECOG performance status ≥2 in IEC-HS (p=0.037). Incidence of IEC-HS by disease: 3.6% (7/193) in lymphoma, 5% (8/159) myeloma and 28.5% (4/14) B-acute lymphoblastic leukemia (p=0.0002). Incidence of IEC-HS by CAR-T product: 3% (4/150) in Axi-cel, 23% (6/26) in Brexu-cel, 8% (1/13) in Tisa-cel, 5% each (3/60) in Cilta-cel and Ide-cel, and 0/17 in Liso-cel (p=0.001). Prior to lymphodepletion, labs were already different among the CRS, MAS-L, and IEC-HS groups: hemoglobin (g/dL: 11.1, 9.6, 8.45); platelets (x109/L: 168, 116, 52.5); ferritin (µg/L: 115, 946, 1944). CP was started when patients needed a second dose of tocilizumab or concern for developing MAS-L/IEC-HS, and continued daily until clinical improvement or resolution of inflammatory state. Tocilizumab and dexamethasone use were similar across groups. Other therapies used were vasopressors (3%, 10.5%, 45%; p<0.0001), Methylprednisolone (20%, 31.6%, 50%; p=0.027), Anakinra (12%, 63%, 85%; p<0.0001), Siltuximab (9.5%, 16%, 30%; p=0.06), Basiliximab (30% of IEC-HS), and continuous veno-venous hemofiltration (30% of IEC-HS). Among the first CP, the CRS group had lower levels of cytokines (in pg/mL) compared to MAS-L and IEC-HS groups: TNF (31, 62.9, 47.7), IL-10 (29.3, 97.7, 169), IL-18 (794, 1353, 2011), IFN-gamma (74, 281, 250), MCP-1 (689, 2722, 2485.5), MIP-1 alpha (220, 234, 247.5), IL-6 (>315: 45%, 79%, 70%), soluble IL-2R alpha (>4000: 45%, 84%, 70%). The percentage of patients who received anakinra before CP1 were 4% (CRS), 21% (MAS-L) and 25% (IEC-HS) (p=0.007). IL-1 beta was below threshold among all patients who received anakinra in CRS and MAS-L and 75% in IEC-HS, suggesting rapid and effective IL-1 suppression by anakinra except in IEC-HS. Cytokines trends 24 hours and 48 hours after the first CP differed between MAS-L and IEC-HS. MAS-L had decreased TNF (62.9, 40.4, 18.5) and MCP-1 (2722, 355, 104) while these cytokines remained elevated or increased in IEC-HS (TNF: 47.7, 105.5, 62.6; MCP-1: 2486, 2276, 1585). IL-18 was minimally elevated in MAS-L (1353, 1955, 3068) and significantly increased in IEC-HS (2011, 2420, 4048). Notably, CP2 and CP3 levels of these cytokines in IEC-HS were statistically significantly higher than corresponding CPs among CRS and MAS-L. In addition, patients who died with persistent E. faecium bacteremia had higher IL-18 on CP3. Infections occurred in 43%, 58%, and 85% respectively (p=0.002), including E. faecium bacteremia (3%, 5%, 35%; p=0.0004), CMV viremia (30% of IEC-HS patients vs. 11% of non-IEC-HS; p=0.025), and invasive fungal infections (15% of IEC-HS patients; p=0.0001). Between the IEC-HS and non-IEC-HS groups, day 100 non-relapse mortality was 35% vs. 0 (p<0.0001), day 100 all-cause mortality was 45% vs. 3% (p<0.0001), and E. faecium bacteremia-related deaths were 50% vs. 1% (p<0.0001). Conclusions: CRS, MAS-L andIEC-HS are known complications of CAR-T. Cytokine-directed therapy can modify the cytokine milieu and control the inflammatory process. However, excess immunosuppression may result in life-threatening infections. Further studies are needed to identify optimal biomarker-guided immunosuppressive strategies to control the inflammatory cascade, while avoiding excess immunosuppression. References: 1. Leung, Nelson, et al. “Outcomes of patients who received CAR T cell therapy and developed IEC-HS treated with cytokine directed therapy.” (2024): 7516-7516.

7516 Background: Immune effector cell hemophagocytic lymphohistiocytosis IEC-HS is a complication of CAR T cell therapy (CART). This study aims to look at the outcomes of CART patients who develop IEC-HS. Methods: Patients who developed IEC-HS after receiving CART and patients who developed IEC-HS without (nonCART) between December 2020 and March 2022 were included. Results: The 20 CART patients were older than the 25 nonCART patients. Peak ferritin, fibrinogen, CRP, serum creatinine and transaminases were similar between the 2 group. CART patients had lower white blood cell count and platelets and bilirubin than the nonCART patients. CART patients were more like to have markedly elevated IL-6 levels (> 315 mg/ml), higher IL-18, higher MCP-1, and suppressed IL-1β and GMCSF than nonCART patients (Table). Treatment of IEC-HS included tocilizumab (n = 19), anakinra (n = 18) siltuximab (n = 4) and basiliximab (n = 4), dexamethasone (n = 18) methylprednisolone (n = 6), etoposide (n = 1) and ruxolitinib (n = 1). A significant response defined by a 90% reduction or normalization of the cytokine was observed with IL-10 and IFN-ϒ in 92.3% and 84.6% of the CART patients respectively. An intermediate response was noted with TNF, IL-6, MCP-1 and MIP-1 in 38.4%, 30.8% and 61.6% and 38.5% of the patients respectively. No patient had a significant response in IL-2Rα or IL-1β and only 7.7% had a significant response in IL-18. Of the 5 patients who had a MIP-1 response, 4 were on basiliximab +/- high flow continuous venovenous hemofiltration and the only patient that had an IL-18 response was on both modalities. The 100-day mortality after IEC-HS in the CART patients was 40% and was associated with higher peak and lower best ferritin but not the percentage reduction (Table). Higher TNF (90.3 pg/ml vs 37.2 pg/ml, p = 0.05), markedly elevated levels of IL-6 (92% vs 50%, p = 0.03) and IL-10 (33% vs 0%) and an IL-6 response (44.4% vs 0%) were associated with survival at day 100. IL-6 responders had lower peak ferritin vs IL-6 nonresponders (14066 mcg/L vs 45051 mcg/L, p = 0.08). Enterococcus faecium bacteremia developed in 75% of the nonsurvivors vs 16.6% of the 100-day survivors (p = 0.009). Survivors cleared the enterococcus bacteremia within days while nonsurvivors had protracted bacteremia. Conclusions: IEC-HS is devastating complication of CART. Anti-cytokine therapy can reduce some cytokines and ferritin but overimmunosuppression may lead infectious complication, in particular with E. faecium. Better biomarkers are needed to finetune immunosuppressive therapy in order to avoid over-immunosuppression. [Table: see text]

Abstract We studied patients diagnosed with aspergillosis based on positive bronchoalveolar lavage (BAL) Aspergillus galactomannan (GM) who had follow-up BAL sampling within 180 days. GM trend and clinical outcome were concordant in only 60% (30/50). While useful for the initial diagnosis, BAL GM trending does not always correlate with treatment response.

AbstractBackgroundThere are no established clinical breakpoints for antifungal agents against Cryptococcus species; however, epidemiological cut‐off values can help distinguish wild‐type (WT) isolates without any acquired resistance from non‐WT strains, which may harbour resistance mechanisms.Patients/MethodsWe describe the trends of antifungal MICs and percentages of WT C. neoformans species complex (CNSC) isolates processed in our reference laboratory from November 2011 to June 2021. There were only nine isolates in 2011, thus, we included them in the year 2012 for data analysis. Clinical data is also described when available.ResultsWe identified 632 CNSC, the majority collected from blood (n = 301), cerebrospinal fluid (n = 230), and respiratory (n = 71) sources. The overall percentage of WT isolates for amphotericin B (AMB), 5‐flucytosine, and fluconazole was 77%, 98%, and 91%, respectively. We noticed a statistically significant change in the percentage of AMB WT isolates over the years, with 98% of isolates being WT in 2012 compared to 79% in 2021 (p < .01). A similar change was not observed for other antifungal agents. Clinical data was available for 36 patients, primarily non‐HIV immunocompromised patients with disseminated cryptococcosis. There were no statistically significant differences in the clinical characteristics and outcomes between patients with WT (58.3%) versus non‐WT (41.7%) isolates, but we noticed higher mortality in patients infected with an AMB non‐WT CNSC isolate.ConclusionsWe observed an increase in the percentage of AMB non‐WT CNSC isolates in the past decade. The clinical implications of this finding warrant further evaluation in larger studies.

Abstract Background Optimizing antimicrobial regimens for outpatients with community-acquired pneumonia (CAP) represents an area of opportunity for ambulatory antimicrobial stewardship programs. A pre-populated, antibiotic order panel for outpatient respiratory syndromes was implemented in the Mayo Clinic Enterprise on 1/4/2021. For CAP, it provides national guideline adherent regimens (i.e., selection, dosing, and durations) by patient comorbidity and beta-lactam allergy status. We aimed to assess impacts of panel use on antibiotic prescribing in outpatients with CAP. Methods This retrospective review included Mayo Clinic outpatient encounters from Minnesota in 2021 and 2022. Eligible encounters used a CAP-related primary ICD-10 code, conveyed intention to treat CAP in encounter notes, and were performed by primary care, emergency department, or urgent care clinicians who managed ≥1 CAP patient with the panel and ≥1 without the panel during the study period. Encounters were excluded if patients were already receiving antibiotics at the time of encounter. The primary outcome was adherence (drug and duration) to guideline recommendations. Secondary outcomes included utilization rate by agent and therapy duration. Outcomes were analyzed with Kruskal-Wallis rank sum and Pearson’s chi-squared tests (α level = 0.05). Results 352 encounters (134 panel vs. 218 non-panel) were included. Prescribing was guideline adherent in 61.9% and 29.4% (p&lt; 0.01) of panel and non-panel encounters, respectively. The most common reason for guideline non-adherence during panel use was inappropriate drug selection (n = 45/51, 88.2%). This was predominantly driven by use of the incorrect section of the treatment panel based on patient comorbidity status (n = 30/45, 66.7%). Individual antibiotic utilization rates differed between panel and non-panel cohorts (Table 1), with higher rates of amoxicillin and amoxicillin/clavulanate use and lower rates of azithromycin and doxycycline use in the panel cohort. Durations &gt;5 days were more common in the non-panel as compared to the panel cohort (34.4% vs. 7.5%, p &lt; 0.01). Conclusion Use of a pre-populated antimicrobial order panel in outpatients with CAP resulted in greater adherence to national guideline recommendations. Disclosures Paschalis Vergidis, MD, MSc, AbbVie: Advisor/Consultant|Ansun: Grant/Research Support|Cidara: Grant/Research Support|Scynexis: Grant/Research Support