Biggs, Megan D

ABSTRACT Background VEXAS is a relatively newly described immunocompromising condition with hematopoietic stem cell transplant increasingly being used. Little is known regarding infections in this high‐risk population. Methods We conducted a retrospective review of ten adult patients diagnosed with VEXAS who underwent HSCT in the Mayo Clinic Rochester and the Arizona medical record system. Results Nine out of ten individuals developed bacterial infection with bacteremia found in eight individuals despite being on prophylaxis at the time of infection. Six of the ten individuals were found to have viral infection; there were no documented invasive fungal infections and only one individual had a parasitic infection. Conclusion Providers should have a high suspicion for infection, especially bacterial, in this patient population, regardless of prophylaxis use. Patients should also be educated on signs and symptoms of infection.

Abstract Background Catheter related bloodstream infections (CRBSI) are associated with increased resource use, treatment costs, and mortality among patients with cancer. Coagulase-negative staphylococci (CoNS) are the most common cause of central venous catheter (CVC) infection in this population. While CVC removal remains the gold standard, CRBSI with CoNS is sometimes managed with CVC salvage, despite incomplete safety and efficacy data in patients with hematological malignancy.Table 1.Baseline Demographic and Clinical DataTable 2.Baseline Characteristics by Treatment Strategy Methods A retrospective review was conducted of adult patients at Mayo Clinic Rochester from 2013 to 2024 diagnosed with hematological malignancy and CRBSI with CoNS. Patients were included in a “CVC removed” group if the line was removed within 5 days of bacteremia onset, and all others were included in a “CVC retained” group. Electronic medical records were evaluated for relevant clinical comorbidities, risk factors, and management. The primary outcomes of interest were 90-day mortality and relapse. To control for baseline differences between groups, we employed a propensity weighted analysis based on inverse probability of treatment weighting using the propensity score.Weighted cumulative event rates for Relapse and Mortality Results A total of 140 cases were included, of whom 95 (67.9%) had undergone BMT and 111 (80.4%) were neutropenic at time of CRBSI. The predominant CoNS identified was Staphylococcus epidermidis (88.6%). 79 (56.4%) patients had the CVC retained and 61 (43.6%) underwent CVC removal. Those in whom the CVC was retained were more likely to be BMT recipients (p=0.007). However, line removal was more common with PICC lines (p< 0.001) and in those hospitalized for management of line-associated bacteremia (p=0.022). Within 90 days, there were 10 patients (cumulative incidence 8.2%) who had microbiological relapse (2 [4.3%] in the CVC removed group and 8 [11.1%] in the CVC retained group). Propensity weighted analysis demonstrated significantly higher rate of microbiologic relapse with CVC retention (p=0.043) but no difference in mortality (p=0.128), as shown by weighted cumulative event rate curves in Figure 1. Conclusion Despite the finding of increased risk of relapse associated with CVC retention, there was no significant difference in mortality between CVC removal and retention among individuals with CoNS CRBSI and hematological malignancy. Disclosures All Authors: No reported disclosures

Abstract Background Hematopoietic stem cell transplant (HSCT) recipients are susceptible to infections with respiratory viruses resulting in higher morbidity and mortality. Parainfluenza virus (PIV) infection in the setting of leukopenia is associated with higher risk of lower respiratory tract infection and mortality. Intravenous immunoglobulin (IVIG) has been used as adjunctive treatment in viral respiratory infections, although data guiding its use is limited.Table 1:Patient CharacteristicsTable 2:Clinical Outcomes Methods We conducted a retrospective cohort study of adult HSCT recipients diagnosed with PIV infection at our institution from January 2014 to September 2024. Diagnosis of PIV infection was made via BioFire® Respiratory Panel multiplex polymerase chain reaction (PCR) or viral culture from nasopharyngeal or bronchoalveolar lavage. Data on clinical characteristics and outcomes were collected and reviewed.Table 3:Clinical Outcomes for Patients with IgG <767 mg/dL Results A total of 110 HSCT recipients were diagnosed with PIV infection by PCR or viral culture within the study period. Patient characteristics and clinical outcomes are summarized in Tables 1 and 2. PIV type 3 was the most common, followed by PIV type 4 and type 1. Eighteen patients (16.36%) had co-infections with another virus. A total of 16 patients received IVIG at time of PIV infection. The mean cumulative IVIG dose was 28.75 grams. Patients who received IVIG were more likely to have been hospitalized due to symptoms related to the viral infection (p=0.03) and had a lower immunoglobulin G level (p< 0.001). Overall, there was no significant difference in rates of mechanical ventilation (12.5% vs 7.45%, p=0.616), development of secondary fungal or bacterial infection (12.5% vs 12.7%, p=1), or 90-day mortality (18.75% vs 6.38%, p=0.123) among patients treated with or without IVIG, respectively. Similarly, in a subset analysis of patients with IgG level < 767 mg/dL, there were no significant difference in outcomes for patients treated with or without IVIG (Table 3). Conclusion There were no significant differences in clinical outcomes, including rates of mechanical ventilation, secondary infections, or 90-day mortality, between HSCT patients who received IVIG and those who did not for PIV infection. Larger studies are needed to gain insight into efficacy of IVIG as adjunctive treatment in PIV infections in this population. Disclosures All Authors: No reported disclosures

Abstract Background Blastomyces is a dimorphic fungus found in the soil and is endemic to regions of the Ohio River basin and Southeastern United States. It can cause both local and systemic infections in several organs regardless of immunity status. Infection occurs through inhalation of aerosolized conidia. Blastomycoses most commonly affects the lungs and infection of the central nervous system (CNS) is rarely found representing approximately 5-10% of individuals with extra-pulmonary blastomycosis. Demographics of Patients with CNS Blastomycosis Methods Given the limited information on this rare form of blastomycoses, a retrospective review was conducted at a major tertiary center in Minnesota of adult inpatients diagnosed with proven or probable CNS blastomycoses between 2005 and 2020. Institutional Review Board approval at the Mayo Clinic was obtained. Data pertaining to diagnostic evaluation, treatment and outcomes were collected from eight medical charts found to meet criteria for proven or probable CNS Blastomycosis. Diagnosis, Treatment, and Outcomes in Patients with CNS Blastomycosis Results As seen in prior studies, most patients were male. The most common CNS related symptom on presentation was headache. Frequent comorbidities included diabetes, COPD, and alcohol use. Findings on MRI varied greatly. Blastomyces serum antibody was positive in only half of patients and urine antigen was frequently negative, however this test was not performed in one patient in this study. All but one patient survived to at least one year post diagnosis. All patients were treated with liposomal amphotericin B ranging from nine days to six weeks and voriconazole was the most frequently used azole. All patients treated with voriconazole survived at least one year following completion of treatment. Diagnosis, Treatment, and Outcomes in Patients with CNS Blastomycosis (continued) Conclusion This study emphasizes the importance of having a high suspicion when CNS symptoms are present in a patient with evidence of Blastomyces. Additionally, patients can have proven CNS blastomycoses without Blastomyces positive antibodies and/or antigen in blood or urine as well as variable MRI findings. Laboratory and Culture Results in Patients Found to Have CNS Blastomyces Disclosures All Authors: No reported disclosures