AIMS: In order to clarify the differentiation and proliferation status of the 
Reed-Sternberg and Hodgkin cells we studied A and B-type lamin expression with 
specific monoclonal antibodies in nodular sclerosing Hodgkin's disease. Its 
normal counterpart, the reactive lymph node, was also examined for lamin subtype 
expression.
METHODS AND RESULTS: The CD20 positive centrocytes and centroblasts of the 
follicle centre in the reactive lymph nodes expressed lamin B1, but were not or 
only very weakly positive for lamin B2 or A-type lamin antibodies. Mantle zone 
lymphocytes displayed lamins B1 and B2, but were negative for A-type lamins. 
Furthermore, CD3- and CD20-positive lymphocytes in the medulla and paracortex 
lacked A-type lamins, but were positive for both B-type lamins. Finally, the 
proliferation marker Ki67 was mainly detected in the centroblasts, but also in a 
fraction of the A-type lamin negative cells in the paracortex and medulla. In 
Hodgkin's disease, all cells expressed lamins B1 and B2, whereas A-type lamins 
were primarily observed in CD30-positive Reed-Sternberg and Hodgkin cells. About 
20% of the Reed-Sternberg and Hodgkin cells expressed Ki67, with co-expression 
of lamin A in most of these cells.
CONCLUSIONS: Ki67 and A-type lamin staining were in general mutually exclusive 
in lymph nodes, indicating that A-type lamin positive cells are not 
proliferative. This suggests also that the A-type lamin expression in 
Reed-Sternberg and Hodgkin cells is correlated with a relatively mature 
phenotype of these malignant cells. However, some of these differentiated 
malignant cells still have a capacity to proliferate as indicated by Ki67 
positivity. Our observation that lamin B2 expression in the follicle centre 
cells of the reactive lymph node is low or absent indicates that this lamin 
subtype is not always expressed in nucleated cells, which is in clear contrast 
to the results obtained in previous studies in other diseases and in normal 
tissues. Absence of lamin B2 expression may be associated with the follicle 
centre stage of B-cells.