An international multicenter study comparing COVID-19 omicron outcomes in patients with hematological malignancies treated with obinutuzumab versus rituximab.

OBJECTIVES: Hematological malignancy (HM) patients treated with anti-CD20 monoclonal antibodies are at higher risk for severe COVID-19. A previous single-center study showed worse outcomes in patients treated with obinutuzumab compared to rituximab. We examined this hypothesis in a large international multicenter cohort. METHODS: We included HM patients from 15 centers, from five countries treated with anti-CD20, comparing those treated with obinutuzumab (O-G) to rituximab (R-G) between December 2021 and June 2022, when Omicron lineage was dominant. RESULTS: We collected data on 1048 patients. Within the R-G (n = 762, 73%), 191 (25%) contracted COVID-19 compared to 103 (36%) in the O-G. COVID-19 patients in the O-G were younger (61 ± 11.7 vs. 64 ± 14.5, p = 0.039), had more indolent HM diagnosis (aggressive lymphoma: 3.9% vs. 67.0%, p < 0.001), and most were on maintenance therapy at COVID-19 diagnosis (63.0% vs. 16.8%, p < 0.001). Severe-critical COVID-19 occurred in 31.1% of patients in the O-G and 22.5% in the R-G. In multivariable analysis, O-G had a 2.08-fold increased risk for severe-critical COVID-19 compared to R-G (95% CI 1.13-3.84), adjusted for Charlson comorbidity index, sex, and tixagevimab/cilgavimab (T-C) prophylaxis. Further analysis comparing O-G to R-G demonstrated increased hospitalizations (51.5% vs. 35.6% p = 0.008), ICU admissions (12.6% vs. 5.8%, p = 0.042), but the nonsignificant difference in COVID-19-related mortality (n = 10, 9.7% vs. n = 12, 6.3%, p = 0.293). CONCLUSIONS: Despite younger age and a more indolent HM diagnosis, patients receiving obinutuzumab had more severe COVID-19 outcomes than those receiving rituximab. Our findings underscore the need to evaluate the risk-benefit balance when considering obinutuzumab therapy for HM patients during respiratory viral outbreaks.

The use of a diversion tube to reduce blood culture contamination: A "real-life" quality improvement intervention study.

BACKGROUND: Blood culture contamination is associated with health care costs and potential patient harm. Diversion of the initial blood specimen reduces blood culture contamination. We report results of the "real-life" clinical implementation of this technique. METHODS: Following an educational campaign, use of a dedicated diversion tube was recommended prior to all blood cultures. Blood culture sets taken from adults using a diversion tube were defined as "diversion sets," those without, "non-diversion" sets. Blood culture contamination and true positive rates were compared for diversion and nondiversion sets and to nondiversion historical controls. A secondary analysis investigated efficacy of diversion by patient age. RESULTS: Out of 20,107 blood culture sets drawn, the diversion group included 12,774 (60.5%) and the nondiversion group 8,333 (39.5%) sets. The historical control group included 32,472 sets. Comparing nondiversion to diversion, contamination decreased by 31% (5.5% [461/8333] to 3.8% [489/12744], P < .0001]. Contamination was also 12% lower in diversion than historical controls [3.8% (489/12744) vs 4.3% (1,396/33,174) P = .02)]. The rate of true bacteremia was similar. In older patients, contamination rate was higher, and the relative reduction associated with diversion decreased (54.3% amongst 20-40-year-olds vs 14.5% amongst >80-year-olds). CONCLUSIONS: Use of a diversion tube in the ED reduced blood culture contamination in this large real life observational study. Efficacy decreased with increasing age, which requires further investigation.