Nodular alteration of the paracortical area. An in situ immunohistochemical analysis of primary, secondary, and tertiary T-nodules.
With the use of in situ immunohistochemical techniques on freshly frozen and paraffin-embedded material from 63 reactive lymph nodes, the cellular composition of T-nodules observed in 30 cases with nodular alteration of the paracortical area was analyzed. T-nodules were composed of S-100 beta + interdigitating reticulum cells (IDRCs), variable numbers of OKT6+ dendritic cells (DCs), high endothelial venules, and a very high T helper/T suppressor ratio because of an enrichment of OKT4+, Leu3a+ helper/inducer T cells in these nodules. According to their localization in the paracortical area, and the arrangement of IDRCs and high endothelial venules, T-nodules could be divided into "primary" and "secondary" T nodules. In all cases of dermatopathic lymphadenitis, very large aggregates of S-100 beta + and OKT6+ DCs, admixed with few high endothelial venules and variable numbers of OKT4+, Leu3a+ helper/inducer T cells, were observed and were termed "tertiary T-nodules." It is suggested that T-nodules represent the paracortical counterparts of B-lymphoid follicles and are the in vivo equivalents of DC/T-cell clusters observed in vitro. According to their cellular composition and localization in the lymph node, "primary" and "secondary" T-nodules probably represent subsequent maturation stages of distinctive nodular paracortical structures, which play an important role in the presentation of antigens to helper/inducer T cells and in the proliferation of antigen-responsive T cells. Their close topographic relationship to B-lymphoid follicles may indicate their role in the extrafollicular generation of antibody-forming cells.
J J
JJ
van den Oord
C
C
De Wolf-Peeters
V J
VJ
Desmet
K
K
Takahashi
Y
Y
Ohtsuki
T
T
Akagi
D000911:Antibodies, Monoclonal; D005615:Freezing; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D008198:Lymph Nodes / Q000166:cytology* / Q000276:immunology / Q000473:pathology; D008199:Lymphadenitis / Q000473:pathology; D010232:Paraffin; D009418:S100 Proteins / Q000032:analysis; D013194:Staining and Labeling; D013601:T-Lymphocytes / Q000145:classification / Q000166:cytology* / Q000276:immunology
D000911:Antibodies, Monoclonal; D009418:S100 Proteins; D010232:Paraffin