Evans, Michael D

BACKGROUND AND OBJECTIVES Some Minnesota clinicians perceive that the incidence of prophylactic vitamin K refusal is increasing, yet the actual incidence and which populations are most likely to refuse is unknown. Our objective is to identify the incidence of vitamin K refusal and to characterize the maternal-newborn dyads with increased refusal rates. METHODS This retrospective multi-institution study analyzed vitamin K refusal in newborns born from 2015 to 2019. Maternal-newborn dyad delivery and community characteristics (language, religion, population size) were collected and analyzed by univariable and multivariable logistic regression. RESULTS Among 102 451 term infants, 1.3% did not receive intramuscular vitamin K. Refusal increased from 0.9% in 2015 to 1.6% by 2019 (P < .0001). In multivariable analysis, factors associated with increased likelihood of refusal included female sex (odds ratio [OR] 1.22, 95% CI 1.09–1.36), exclusive human milk feeding at hospital discharge (OR 3.46, 95% CI 2.87–4.17), parity greater than 0 (OR ranging from 1.32 [95% CI 1.13–1.54] for parity of 1, to 3.70 [95% CI 2.80–4.90] for parity of 4), having a midwife at delivery (OR 1.70, 95% CI 1.45–2.01), public insurance (OR 1.84, 95% CI 1.60–2.12), and Russian language (OR 4.92, 95% CI 2.90–8.35). Some religious identities had higher refusal rates (ie, Pentecostal 7.0%, Baptist 3.3%). CONCLUSION In a cohort of Minnesota hospital-born infants, the incidence of vitamin K refusal increased between 2015 and 2019. We identified large populations (eg, public insurance, exclusive human milk feeding) and smaller discrete communities (eg, Russian, Pentecostal) with opportunities for increasing prophylactic vitamin K acceptance through targeted community conversations.

Abstract Immune thrombotic thrombocytopenic purpura (iTTP) is a chronically relapsing disorder caused by autoantibody-mediated deficiency of ADAMTS13. Rituximab is frequently administered to prevent relapses, but whether the durability of rituximab effect is maintained with subsequent treatment courses has not been studied. Using the United States Thrombotic Microangiopathy Consortium (USTMA) retrospective iTTP registry, we evaluated clinical relapse-free survival (RFS) with subsequent courses of rituximab treatment in multiply relapsing patients. Separately, we evaluated overall RFS (composite of time to clinical relapse, ADAMTS13 relapse, or preemptive rituximab) in a prospective iTTP cohort from the Johns Hopkins University and the University of Minnesota. In the USTMA registry, median clinical RFS was shorter after the second or subsequent rituximab-treated episode than the first (2.1 vs 6.0 years; P = .04). White patients’ clinical relapse risk after the second and subsequent rituximab courses was not significantly different compared with the first (hazard ratio [HR], 1.86; 95% confidence interval [CI], 0.22-15.80; P = .57), whereas for Black patients, clinical relapse risk was significantly higher after the second or subsequent courses (HR, 2.82; 95% CI, 1.52-5.24; P = .001). In the prospective cohort, overall RFS progressively shortened after each episode of rituximab treatment with the first episode having the longest RFS (2.8 years; interquartile range, 2.0-6.0) and this loss of response durability was most pronounced in Black patients. The durability of rituximab’s effect declines with subsequent treatments, which is more pronounced in Black patients, who may benefit from closer monitoring and alternative immunomodulatory approaches such as maintenance rituximab and consideration of other agents.

Abstract Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is characterized by recurring episodes of thrombotic microangiopathy, causing ischemic organ impairment. Black patients are overrepresented in iTTP cohorts in the United States, but racial disparities in iTTP outcome and response to therapy have not been studied. Using the United States Thrombotic Microangiopathies Consortium iTTP Registry, we evaluated the impact of race on mortality and relapse-free survival (RFS) in confirmed iTTP in the United States from 1995 to 2020. We separately examined the impact of rituximab therapy and presentation with newly diagnosed (de novo) or relapsed iTTP on RFS by race. A total of 645 participants with 1308 iTTP episodes were available for analysis. Acute iTTP mortality did not differ by race. When all episodes of iTTP were included, Black race was associated with shorter RFS (hazard ratio [HR], 1.60; 95% CI, 1.16-2.21); the addition of rituximab to corticosteroids improved RFS in White (HR, 0.37; 95% CI, 0.18-0.73) but not Black patients (HR, 0.96; 95% CI, 0.71-1.31). In de novo iTTP, rituximab delayed relapse, but Black patients had shorter RFS than White patients, regardless of treatment. In relapsed iTTP, rituximab significantly improved RFS in White but not Black patients. Race affects overall relapse risk and response to rituximab in iTTP. Black patients may require closer monitoring, earlier retreatment, and alternative immunosuppression after rituximab treatment. How race, racism, and social determinants of health contribute to the disparity in relapse risk in iTTP deserves further study.