CD4 and Decreased total B cell count: ,70 As cognate CD4+ T cell help is critical for the differentiation of antigen-specific B cells (by extrafollicular responses or germinal center reactions) into memory B cells, antibody-secreting plasmablasts, and plasma cells,71, 72, 73, 74, 75, 76, 77, 78, 79, 80 the deleterious consequences of B cell lymphopenia in ESKD81 are compounded by impaired T-cell–dependent activity of B cells and are reflected in poor serologic responses to T-cell–dependent vaccines.63