Anti-neutrophil cytoplasmic antibody-associated (ANCA-associated) small vessel necrotizing vasculitis is caused by immune-mediated inflammation of the vessel wall and is diagnosed in some cases by the presence of myeloperoxidase-specific antibodies (MPO-ANCA). This multicenter study sought to determine whether differences in ANCA epitope specificity explain why, in some cases, conventional serologic assays do not correlate with disease activity, why naturally occurring anti-MPO autoantibodies can exist in disease-free individuals, and why ANCA are undetected in patients with ANCA-negative disease. Autoantibodies from human and murine samples were epitope mapped using a highly sensitive epitope excision/mass spectrometry approach. Data indicated that MPO autoantibodies from healthy individuals had epitope specificities different from those present in ANCA disease. Importantly, this methodology led to the discovery of MPO-ANCA in ANCAnegative disease that reacted against a sole linear sequence. Autoantibodies against this epitope had pathogenic properties, as demonstrated by their capacity to activate neutrophils in vitro and to induce nephritis in mice. The confounder for serological detection of these autoantibodies was the presence of a fragment of ceruloplasmin in serum, which was eliminated in purified IgG, allowing detection. These findings implicate immunodominant epitopes in the pathology of ANCA-associated vasculitis and suggest that autoantibody diversity may be common to other autoimmune diseases.

SummaryBackground and objectives B cell significance in ANCA disease pathogenesis is underscored by the finding that ANCA alone can cause disease in mouse models and by the effectiveness of rituximab as therapy in ANCA-small vessel vasculitis (ANCA-SVV). To avoid infections and adverse events from therapy, clinicians require improved markers of disease activity and impending relapse to guide immunosuppression strategies after rituximab treatment.Design, setting, participants, & measurements The B cell phenotype was investigated in patients with active ANCA-SVV and in remission. From 2003 to 2009, 54 patients were followed longitudinally for 4-99 months and compared with 68 healthy controls. In a subset of 19 patients, the B cell immunophenotype was examined in samples after rituximab therapy.Results Patients with active ANCA-SVV had lower %CD5 + B cells, whereas %CD5 + B cells from patients in remission were indistinguishable from healthy controls. After rituximab, median time to relapse was 31 months in patients maintaining normalized %CD5 + B cells, with or without maintenance immunosuppression. Among patients whose B cells repopulated with low %CD5 + B cells or had a sharply declining %CD5 + B cells, those who were on low or no maintenance immunosuppression relapsed sooner (median 17 months) than patients who were maintained on high levels of oral maintenance immunosuppression (29 months; P=0.002). Conclusions The %CD5+ B cells, as a component of the human B regulatory cell phenotype, is a useful indicator of disease activity, remission, and future relapse, and thus may guide remission maintenance therapy after rituximab treatment.

We examined adults with untreated Burkitt lymphoma (BL) from 2009 to 2018 across 30 US cancer centers. Factors associated with progression-free survival (PFS) and overall survival (OS) were evaluated in univariate and multivariate Cox models. Among 641 BL patients, baseline features included the following: median age, 47 years; HIV+, 22%; Eastern Cooperative Oncology Group (ECOG) performance status (PS) 2 to 4, 23%; >1 extranodal site, 43%; advanced stage, 78%; and central nervous system (CNS) involvement, 19%. Treatment-related mortality was 10%, with most common causes being sepsis, gastrointestinal bleed/perforation, and respiratory failure. With 45-month median follow-up, 3-year PFS and OS rates were 64% and 70%, respectively, without differences by HIV status. Survival was better for patients who received rituximab vs not (3-year PFS, 67% vs 38%; OS, 72% vs 44%; P < .001) and without difference based on setting of administration (ie, inpatient vs outpatient). Outcomes were also improved at an academic vs community cancer center (3-year PFS, 67% vs 46%, P = .006; OS, 72% vs 53%, P = .01). In multivariate models, age ≥ 40 years (PFS, hazard ratio [HR] = 1.70, P = .001; OS, HR = 2.09, P < .001), ECOG PS 2 to 4 (PFS, HR = 1.60, P < .001; OS, HR = 1.74, P = .003), lactate dehydrogenase > 3× normal (PFS, HR = 1.83, P < .001; OS, HR = 1.63, P = .009), and CNS involvement (PFS, HR = 1.52, P = .017; OS, HR = 1.67, P = .014) predicted inferior survival. Furthermore, survival varied based on number of factors present (0, 1, 2 to 4 factors) yielding 3-year PFS rates of 91%, 73%, and 50%, respectively; and 3-year OS rates of 95%, 77%, and 56%, respectively. Collectively, outcomes for adult BL in this real-world analysis appeared more modest compared with results of clinical trials and smaller series. In addition, clinical prognostic factors at diagnosis identified patients with divergent survival rates.

Non-Hispanic Black (NHB) and Hispanic patients with acute myeloid leukemia (AML) have higher mortality rates than non-Hispanic white (NHW) patients despite more favorable genetics and younger age. A discrete survival analysis was performed on 822 adult AML patients from six urban cancer centers and revealed inferior survival among NHB (HR=1.59, 95% CI: 1.15, 2.22) and Hispanic (HR=1.25, 95% CI: 0.88, 1.79) compared to NHW patients. A multilevel analysis of disparities was then conducted to investigate the contribution of neighborhood measures of structural racism on racial/ethnic differences in survival. Census tract disadvantage and affluence scores were individually calculated. Mediation analysis of hazard of leukemia death between groups was examined across six composite variables: structural racism (census tract disadvantage, affluence and segregation), tumor biology (ELN risk and secondary leukemia), health care access (insurance and clinical trial enrollment), comorbidities, treatment patterns (induction intensity and transplant utilization) and ICU admission during intensive chemotherapy. Strikingly, census tract measures accounted for nearly all of the NHB-NHW and Hispanic-NHW disparity in leukemia death. Treatment patterns, including induction intensity and allogeneic transplant, as well as treatment complications, as assessed by ICU admission during induction chemotherapy, were additional mediators of survival disparities in AML. This is the first study to formally test mediators for observed disparities in AML survival and highlights the need to investigate the mechanisms by which structural racism interacts with known prognostic and treatment factors to influence leukemia outcomes.

Data addressing prognostication in patients with HIV related Burkitt lymphoma (HIV-BL) currently treated remain scarce. We present an international analysis of 249 (United States: 140; United Kingdom: 109) patients with HIV-BL treated from 2008 to 2019 aiming to identify prognostic factors and outcomes. With a median follow up of 4.5 years, the 3-year progression-free survival (PFS) and overall survival (OS) were 61% (95% confidence interval [CI] 55% to 67%) and 66% (95%CI 59% to 71%), respectively, with similar results in both countries. Patients with baseline central nervous system (CNS) involvement had shorter 3-year PFS (36%) compared to patients without CNS involvement (69%; P < .001) independent of frontline treatment. The incidence of CNS recurrence at 3 years across all treatments was 11% with a higher incidence observed after dose-adjusted infusional etoposide, doxorubicin, vincristine, prednisone, cyclophosphamide (DA-EPOCH) (subdistribution hazard ratio: 2.52; P = .03 vs other regimens) without difference by CD4 count 100/mm3. In multivariate models, factors independently associated with inferior PFS were Eastern Cooperative Oncology Group (ECOG) performance status 2-4 (hazard ratio [HR] 1.87; P = .007), baseline CNS involvement (HR 1.70; P = .023), lactate dehydrogenase >5 upper limit of normal (HR 2.09; P < .001); and >1 extranodal sites (HR 1.58; P = .043). The same variables were significant in multivariate models for OS. Adjusting for these prognostic factors, treatment with cyclophosphamide, vincristine, doxorubicin, and high-dose methotrexate, ifosfamide, etoposide, and high-dose cytarabine (CODOX-M/IVAC) was associated with longer PFS (adjusted HR [aHR] 0.45; P = .005) and OS (aHR 0.44; P = .007). Remarkably, HIV features no longer influence prognosis in contemporaneously treated HIV-BL.