- CD19 is critically involved in establishing intrinsic B cell signaling thresholds through modulating both B cell receptor (= BCR)-dependent and independent signaling. - It plays roles in the antigen-independent development as well as the immunoglobulin-induced activation of B cells.

Nov 18, 2019 · Preinfusion dim CD19 expression and rare CD19 – events in B-ALL do not affect relapses or responses to CD19-directed CAR T-cells. Prior blinatumomab treatment increases the rate of failure to achieve MRD – remission and CD19 – MRD and relapse.

Nov 26, 2019 · Tisagenlecleucel, a chimeric antigen receptor (CAR) T-cell product targeting CD19 is approved for relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL).

Flow-cytometric demonstration of the typical chronic lymphocytic leukemia (CLL) immunophenotype is vital for diagnosis. CLL has a characteristic immunophenotype, expressing CD5, CD19, dim CD20, dim CD22, CD23, bright CD43, dim CD45, dim to negative CD79b, dim CD81, CD200, and dim monoclonal surface …

CD19 is classified as a type I transmembrane protein, with a single transmembrane domain, a cytoplasmic C-terminus, and extracellular N-terminus. CD19 is a biomarker for normal and neoplastic B cells, as well as follicular dendritic cells.

Dec 10, 2004 · Our results indicated that a visible decrease in CD19 expression is observed in many B-cell lymphomas and is particularly common in follicular lymphomas, regardless of grade. An example of the usefulness of a gating strategy that uses CD19-dim lymphocytes to identify minimal residual disease is presented.

Nov 12, 2021 · CD19 expression was stratified into four groups: positive (moderate-bright expression with > 90% blasts CD19+), dim (> 90% CD19+ blasts but less intensity than mature B cells), partial (population 50%-90% CD19+), and negative (> 50% of blasts CD19–).

We have presented our cohort of 14 de novo CD19 negative and dim B-ALLs and have highlighted the difficulties faced during diagnosis and MRD assessment of these patients. We have also discussed the need to identify alternative B-lineage gating markers and strategies to deal with such scenarios.

Sep 23, 2022 · Several mechanisms have been shown to mediate antigen escape by rendering CD19 dim or CD19 − leukemic blasts unrecognizable to CD19-targeting T cells 2, 3, including alternative CD19 mRNA...

Mar 22, 2022 · CD19 expression was quantified on B-lymphoblasts by the amount of anti-CD19 antibody bound per cell (ABC). “Dim” expression was defined as CD19-positive blasts expressing a CD19 site density between 200 and 2000, a delineation based on the lowest 10% of CD19 expression seen in our prior patients.