Immunoglobulin light chain restriction and clonal rearrangement in nodular paragranuloma.
B-cell clonality was demonstrated in a typical nodular paragranuloma case (NP) by both immunoglobulin (Ig) surface analysis and Ig genes rearrangement studies. On frozen sections, immunostaining for Ig light chain expression revealed a clear-cut predominance of Ig lambda-expressing cells, recognizable as both small lymphocytes and lympho-histiocytic (L&H) cells. Accordingly, molecular analysis of the Ig genes showed a monoclonal rearrangement of the lambda chain gene, although no specific pattern of heavy chain gene rearrangement could be detected by JH analysis. The C lambda rearranged band was identified with two different restriction enzymes, excluding the hypothesis of a genomic polymorphism. Furthermore, the C kappa gene was almost completely deleted, indicating that the developmental hierarchy of Ig genes rearrangement has been respected. The molecular pattern of the C lambda hybridizing band was consistent with monoallelic rearrangement of almost the entire DNA sample, indicating that clonal proliferation was not limited to L&H cells, but also involved surrounding lymphocytes. This finding is in keeping with the immunohistochemical evidence of a lambda light chain restriction on both L&H cells and small lymphocytes, pointing to a close relationship between these two cell types. Our results as a whole suggest that L&H cells and B lymphocytes share a common origin and may both be involved in clonal proliferation in NP.
Kerim
S
S
Department of Biomedical Sciences and Human Oncology, University of Turin, Italy.
Reato
G
G
Abele
C
C
Di Celle
P F
PF
Valente
G
G
Foà
R
R
Palestro
G
G
D015703:Antigens, CD / Q000032:analysis; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D006689:Hodgkin Disease / Q000276:immunology*; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000235:genetics*; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged
D015703:Antigens, CD; D007147:Immunoglobulin Light Chains