Clonal expansion of CD8+ BV8 T lymphocytes in bone marrow characterizes thymoma-associated B lymphopenia.
A subgroup of thymoma patients is affected by severe immunodeficiency clinically resembling an HIV infection (Good syndrome). These individuals are characterized by B lymphopenia with B-lymphopoiesis deficiency. To investigate the pathogenesis of this unique condition, we studied the T-cell repertoire in blood and bone marrow samples by heterogeneity length analysis of CDR3 beta variable regions of the T-cell receptor (spectratyping). While no alterations were found in the peripheral blood, we detected an oligoclonal population of beta variable 8 (BV8) CD8(+) T cells in 5 of 5 bone marrow samples. No lymphocyte expansions were found in the bone marrow of 2 thymoma patients with normal B-cell counts, 2 healthy donors, and 3 patients with diseases unrelated to thymoma. These data suggest that an immune response toward an unknown antigen is taking place in the bone marrow of B-lymphopenic thymoma patients. We propose that BV8 CD8(+) T cells may play a role in the pathogenesis of this immunodeficiency syndrome.
Masci
Anna Maria
AM
Dipartimento di Biologia e Patologia Cellulare e Molecolare, Federico II University of Naples, Italy.
Palmieri
Giovannella
G
Vitiello
Laura
L
Montella
Liliana
L
Perna
Francesco
F
Orlandi
Paola
P
Abbate
Gianfranco
G
Zappacosta
Serafino
S
De Palma
Raffaele
R
Racioppi
Luigi
L
D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D001402:B-Lymphocytes / Q000473:pathology*; D001853:Bone Marrow / Q000473:pathology*; D018414:CD8-Positive T-Lymphocytes / Q000473:pathology*; D002999:Clone Cells / Q000473:pathology; D005260:Female; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000209:etiology* / Q000473:pathology; D016130:Immunophenotyping; D018655:Lymphocyte Count; D008231:Lymphopenia / Q000209:etiology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D012141:Respiratory Tract Infections / Q000150:complications; D013577:Syndrome; D013945:Thymoma / Q000150:complications*; D013953:Thymus Neoplasms / Q000150:complications*