Differences in thyroid-infiltrating B lymphocytes in patients with Graves' disease: relationship to autoantibody detection.
OBJECTIVE
Thyroid-infiltrating B (Thyr-B) lymphocytes are thought to play an important role in the pathogenic mechanisms underlying Graves' disease.


METHODS
In this study, a broad phenotypic analysis of these cells has been performed in 15 consecutive patients who underwent thyroidectomy.


RESULTS
Data reveal the occurrence of two distinct types of Thyr-B cell infiltrates. Type 1 was present in most of the cases (10/15) and consisted of a combination of IgM+ IgD(low to-) B lymphocytes showing features of marginal zone B cells, and IgG+ classic memory B cells. In contrast, in 5 of the 15 cases, a second type of Thyr-B cell infiltrate occurred, exhibiting the profile IgM- IgD- CD44(low to-) CD38++ CD71+ CD95+. This phenotype is highly suggestive of germinal center (GC) B cells, a finding not always anticipated from routine histologic examination. The presence of these ectopic GC was closely associated with the elevated serum level of anti-thyroid peroxidase (TPO), but not with anti-thyrotropin receptor (TSHR), autoantibodies. Moreover, local active anti-thyroglobulin (Tg) antibody secretion was only detected in cultures of type 2 Thyr-B cells.


CONCLUSIONS
These findings indicate that high titers of anti-TPO, but not anti-TSHR antibody, might be associated with intrathyroidal GC development.
Segundo
Carmen
C
Servico de Inmunología, Hospital Universitario Puerta del Mar, Cádiz, Spain.
Rodríguez
Carmen
C
Aguilar
Manuel
M
García-Poley
Antonio
A
Gavilán
Inmaculada
I
Bellas
Carmen
C
Brieva
José A
JA
D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000097:blood; D001323:Autoantibodies / Q000032:analysis*; D001402:B-Lymphocytes / Q000276:immunology* / Q000473:pathology; D005260:Female; D006111:Graves Disease / Q000276:immunology* / Q000473:pathology* / Q000601:surgery; D006684:HLA-DR Antigens; D006801:Humans; D007072:Immunoglobulin D / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008875:Middle Aged; D013954:Thyroglobulin / Q000276:immunology*; D013961:Thyroid Gland / Q000276:immunology* / Q000473:pathology; D013965:Thyroidectomy
D015703:Antigens, CD; D001323:Autoantibodies; D006684:HLA-DR Antigens; D007072:Immunoglobulin D; D007075:Immunoglobulin M; D013954:Thyroglobulin