Background Patients with cancer are particularly vulnerable to Clostridioides difficile infection (CDI). Guidelines recommend a two-step diagnostic algorithm to differentiate carriers from CDI; however, there is limited data for this approach while including other confounding risk factors for diarrhea such as radiation, cytotoxic chemotherapy and adoptive cell based therapies. Methods We conducted a prospective, non-interventional, single center, cohort study of cancer patients with acute diarrhea and C. difficile. Identified in stools by nucleic acid amplification tests (NAAT) and culture. Fecal toxin A/B was detected by enzyme immunoassay (EIA) and isolates were ribotyped using 16s rRNA fluorescent sequencing. Patients were followed for 90 days to compare outcomes according to malignancy type, infecting ribotype, and EIA status. Results We followed 227 patients with a positive NAAT. Of these, 87% were hospitalized and 83% had an active malignancy. EIA was confirmed positive in 80/227 (35%) of patients. Those with EIA+ were older (60 ± 18 yrs. vs. 54 ±1 9 yrs., p=0.01), more likely to fail therapy [24/80 (30%) vs. 26/147 (18%), p=0.04] and experience recurrence [20/80 (25%) vs. 21/147(14%), p<0.05]. We found a low prevalence (22%) of ribotypes historically associated with poor outcomes (002, 018, 027, 56, F078-126, 244) but their presence were associated with treatment failure [17/50 (34%) vs. 33/177 (19%), p=0.02]. Conclusions When compared to cancer patients with fecal NAAT+/EIA, patients with NAAT+/EIA+ CDI are less likely to respond to therapy and more likely to experience recurrence; particularly when due to ribotypes associated with poor outcomes.

INTRODUCTION: Data are scarce regarding the virologic impact and safety of immune checkpoint inhibitors (ICI) in patients with chronic hepatitis C virus (HCV) infection. We examined the virologic impact of ICI in HCV-infected patients with solid tumors and their safety. METHODS: HCV-infected patients with solid tumor treated with ICI at our institution between April 26, 2016, and January 5, 2022, were enrolled in a prospective observational study. The primary outcomes were ICI-induced changes in HCV viremia (HCV inhibition and HCV reactivation) and safety of ICI. RESULTS: We enrolled 52 consecutive patients with solid tumors treated with ICI. Most were men (41; 79%), White (31; 59%), without cirrhosis (34; 65%), and with HCV genotype 1 (40; 77%). Four patients (7.7%) experienced HCV inhibition while receiving ICI including 1 patient who developed undetectable viremia for 6 months in the absence of direct-acting antivirals (DAA). Two patients (4%) developed HCV reactivation, both while receiving immunosuppressive therapy for ICI-related toxic effects. Adverse events occurred in 36 patients (69%), and 39 of the 47 adverse events (83%) were grade 1–2. Grade 3–4 adverse events occurred in 8 patients (15%), and in all cases, they were related to ICI, not to HCV. No HCV-associated liver failure or death occurred. DISCUSSION: Inhibition of HCV replication with virologic cure can develop in patients receiving ICI without DAA. HCV reactivation occurs primarily in patients receiving immunosuppressants for ICI-related toxic effects. ICI are safe in HCV-infected patients with solid tumors. Chronic HCV infection should not be considered a contraindication for ICI therapy.

Introduction: Antibiotic use is a risk factor for Clostridioides difficile infection (CDI). Few studies have correlated use of prior antibiotic classes with CDI, microbiome composition, and disease severity in patients with cancer. We hypothesized that previous antibiotic exposure and fecal microbiome composition at time of presentation are risk factors for severe CDI in patients with cancer.Methods: This non-interventional, prospective, cohort study examined 200 patients with cancer who had their first episode or first recurrence of CDI. C. difficile was identified using nucleic acid amplification testing. Univariate analysis was used to determine significant risk factors for severe CDI. Fecal microbiome composition was determined by sequencing the V3/V4 region of 16 s rDNA encoding gene. Differential abundance analyses were used to single out significant microbial features which differed across severity levels.

Background An increasing number of observational studies have reported the persistence of symptoms following recovery from acute COVID-19 disease. The long-term consequences of COVID-19 are not fully understood and there is no clear consensus on the definition of post-acute sequelae of SARS-CoV-2 infection (PASC). The reported prevalence of PASC widely varies from 10% up to 87%. The purpose of this study is to assess PASC in cancer patients following acute COVID-19 recovery. Methods We assessed cancer patients at MD Anderson Cancer Center who were diagnosed with COVID-19 disease between March 1, 2020 and Sept 1, 2020. Using patient questionnaires and medical chart reviews we followed these patients from March 2020 till May 2021. Patient questionnaires were sent out remotely daily for 14 days after COVID-19 diagnosis then weekly for 3 months, and then monthly thereafter. Chart reviews were conducted for each patient hospital re-admission and emergency department visit. These admissions were classified as either COVID-19 related or non-related. The persistence or emergence of new COVID19-related symptoms were captured at each COVID-19 related admission. Results We included 312 cancer patients with a median age of 57 years (18-86). The majority of patients had solid tumors (75%). Of the 312 patients, 188 (60%) reported long COVID-19 symptoms with a median duration of 7 months and up to 14 months after COVID-19 diagnosis. The most common symptoms reported included fatigue (82%), sleep disturbances (78%), myalgias (67%) and gastrointestinal symptoms (61%), followed by headache, altered smell or taste, dyspnea (47%) and cough (46%). A higher number of females reported a persistence of symptoms compared to males (63% vs 37%; p=0.036). Cancer type, neutropenia, lymphocytopenia, and hospital admission during acute COVID-19 disease were comparable in both groups and did not seem to contribute to a higher number of long-COVID-19 patients in our study group. Conclusion Long-COVID occurs in 60% of cancer patients and may persist up to 14 months after acute illness. The most common symptoms are fatigue, sleep disturbance, myalgia and gastro-intestinal symptoms. Disclosures Fareed Khawaja, MBBS, Eurofins Viracor (Research Grant or Support)

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