The ISCCA flow protocol for the monitoring of anti‐CD20 therapies in autoimmune disorders

Abstract

Background: Anti-CD20 monoclonals (MoAbs) are used in a variety of autoimmune disorders. The aim is to eliminate memory B cells sustaining the tissue damage and the production of pathogenic autoantibodies, while preserving naïve cells. The disappearance of memory B cells and the repopulation by naïve cells correlate with good clinical response, while the reappearance of memory B cells and plasmablasts correlates with relapse or resistance to therapy. Anti-CD20 induce extremely low B cell levels, requiring high-resolution techniques. The immune monitoring protocol developed by ISCCA is described and validated, to provide a standardized method for the clinical decision-making process during anti-CD20 therapies in autoimmune diseases.

COVID-19-Associated Pneumonia in a B-Cell-Depleted Patient With Non-Hodgkin Lymphoma: Recovery With Hyperimmune Plasma

“…Another flow cytometric analysis of lymphocyte subsets was performed. The high-resolution peripheral lymphocyte immunophenotyping [ 6 ] confirmed the absence of B cells, at 0.0025% sensitivity level. The lymphocyte population (700/µL) was composed by T cells (580/µL), with low CD4/CD8 ratio (0.73) and natural killer (NK) cells (119/µL).…”

Immune Monitoring upon Treatment with Biologics in Sjögren’s Syndrome: The What, Where, When, and How

“…If B-cells are still present 3 months after treatment, especially in combination with the presence of memory cells (see Section 5 ), a new bolus or switching to another treatment strategy should be considered [ 58 ]. If B-cells are absent, patients should be monitored at a later time-point (after a couple of months when B-cell reconstitution is expected) to address B-cell maturation and differentiation.…”

“…The different B-cell subpopulations can be identified in the blood with the help of sIgD, CD27, and CD38 markers, making it possible to monitor B-cell maturation and differentiation ( Figure 3 ). Adding surface immunoglobulin (sIg) IgM (sIgM), IgA (sIgA), or IgG (sIgG) can provide additional information about isotype-switched subsets with different functions and, potentially, different roles in autoimmunity [ 58 ].…”

Comprehensive phenotyping of human peripheral blood B lymphocytes in pathological conditions

“…In both patients most B cells are of the transitional and mature-naïve B-cell type and the memory B cells are strongly reduced [Color figure can be viewed at wileyonlinelibrary.com]than 2 years from anti-CD20 administration[26][27][28][29]. Of note, the time of the B-cell subset reappearance is comparable following treatment with anti-CD20 monoclonal antibodies directed against different epitopes of CD20 such as rituximab and ofatumumab[30].In order to evaluate the duration of B-cell depletion and followup the reconstitution of the B-cell compartment in treated patients, a combined B and T cell staining has been proposed[31]. Our staining can be also used to monitor B cell depletion and regeneration (Figure1B).…”