Table 1.

Features of secondary lymphoid tissues in lymph nodes and tertiary lymphoid tissues in rheumatoid synovium

Tissue	Lymph node primary follicles	Lymph node secondary follicles	Synovial CD23-null T-cell–B-cell aggregates	Synovial CD23+ follicles
Organized T-cell zones	+	+	+	+
Follicular clustering of B cells	+	+	+	+
Proliferating B cells	-	+	-	+
Hypermutated immunoglobulin genes	-	+	?	+
Plasma cells with identical rearrangements	-	+	?	-
CD23+ FDC networks	+	-	-	+
CD8+CD40L+ cells	-	-	-	+