He described IgG4-RD as "a continuous dance between T cells and B cells." The latest thinking regarding pathogenesis is that type 2 T follicular helper cells activate B cells, which become memory B cells or plasmablasts
. These activated B cells and plasmablasts
present antigen to CD4+ cytotoxic T cells at sites of disease.
In GLD, plasmablasts
may have an Hodgkin morphology and lesions can thus be misdiagnosed as lymphocyte-rich classical Hodgkin lymphoma or nodular lymphocyte predominant Hodgkin lymphoma, especially when germinotropism is not obvious (early forms).
Butcher, "A common mucosal chemokine (mucosae-associated epithelial chemokine/ CCL28) selectively attracts IgA plasmablasts
," The Journal of Immunology, vol.
Effect of CR1 Clustering on BCR-Induced Plasmablast
Formation and IgM Production.
T-dependent B cell activation leads to the emergence of memory B cells ([B.sub.mem]) as well as plasmablasts
In addition, IgG-positive plasmablasts
rapidly decline following treatment with rituximab in patients with IgG4-RD (74).
The investigators demonstrated that AD is accompanied by systemic expansion of transitional and chronically activated memory B cells, plasmablasts
, and IgE-expressing memory B cells in both skin and blood.
These studies decoded the global pattern of transcriptional response to TIV vaccination and independently reported that the extent of upregulation of a set of interferon-inducible genes, one to three days after vaccination, and of genes involved in plasmablasts
differentiation and activity, seven days after vaccination, correlates with the magnitude of serum functional antibody titers measured after one month.
However, it is suggested that EpsteinBarr virus infection and MYC dysregulation mediated by translocation or amplification  could allow plasmablasts
to escape apoptosis.
It has to be noted that CD20 is expressed on most types of B-lymphocytes (e.g., pre-B-cells, immature B-cells, naive B-cells, germinal-center B-cells, and memory B-cells) but not on pro-B-cells, plasmablasts
, and plasmacells .
Aspirates from multiple myeloma show numerous atypical plasmablasts
with binucleate and trinucleate atypical plasma cells with high nuclear/cytoplasmic ratio with prominent nucleoli (Figure D).
Numerous mott cells and occasional plasmablasts
were also noted (Figure 2).