TY - JOUR
T1 - Restricted κ/λ light chain ratio by flow cytometry in germinal center B cells in Hashimoto thyroiditis
AU - Chen, Henry I.
AU - Akpolat, Ikser
AU - Mody, Dina R.
AU - Lopez-Terrada, Dolores
AU - De Leon, Audrey Ponce
AU - Luo, Yamin
AU - Jorgensen, Jeffrey
AU - Schwartz, Mary R.
AU - Chang, Chung Che
PY - 2006/1
Y1 - 2006/1
N2 - To determine the diagnostic significance of the κ/λ ratio in germinal center (GC) B cells in Hashimoto thyroiditis (HT), we used 4-color flow cytometry to immunophenotype 27 samples (21 patients) of well-characterized HT. B-cell clonality was analyzed further by polymerase chain reaction (PCR) of the immunoglobulin heavy chain (IgH) and bcl-2/IgH fusion genes using DNA extracted from aspirate smears and/or paraffin-embedded tissues. By flow cytometric analysis, the CD10+ GC B cells had a higher mean ± SD κ/λ ratio than the CD10- B cells (5.1 ± 3.3 vs 2.0 ± 0.8; P < .0001, Student t test). In 18 samples (67%), CD10+ GC B cells had κ/λ ratio greater than 3.07 (the upper limit of κ/λ ratio reported in reactive nodes; range, 3.2-14.4 in the 18 cases). Cases tested by PCR showed no evidence of a clonal proliferation. None of 21 cases developed lymphoma during clinical follow-up of up to 3 years. The κ/λ ratio of CD10+ GC B cells in HT can be skewed markedly beyond that reported in reactive lymph nodes. This finding frequently is present in HT. Pathologists should be familiar with this phenomenon to prevent misdiagnosis of follicular lymphoma in patients with HT.
AB - To determine the diagnostic significance of the κ/λ ratio in germinal center (GC) B cells in Hashimoto thyroiditis (HT), we used 4-color flow cytometry to immunophenotype 27 samples (21 patients) of well-characterized HT. B-cell clonality was analyzed further by polymerase chain reaction (PCR) of the immunoglobulin heavy chain (IgH) and bcl-2/IgH fusion genes using DNA extracted from aspirate smears and/or paraffin-embedded tissues. By flow cytometric analysis, the CD10+ GC B cells had a higher mean ± SD κ/λ ratio than the CD10- B cells (5.1 ± 3.3 vs 2.0 ± 0.8; P < .0001, Student t test). In 18 samples (67%), CD10+ GC B cells had κ/λ ratio greater than 3.07 (the upper limit of κ/λ ratio reported in reactive nodes; range, 3.2-14.4 in the 18 cases). Cases tested by PCR showed no evidence of a clonal proliferation. None of 21 cases developed lymphoma during clinical follow-up of up to 3 years. The κ/λ ratio of CD10+ GC B cells in HT can be skewed markedly beyond that reported in reactive lymph nodes. This finding frequently is present in HT. Pathologists should be familiar with this phenomenon to prevent misdiagnosis of follicular lymphoma in patients with HT.
KW - Flow cytometry
KW - Hashimoto thyroiditis
KW - Light chain-restricted B cells
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U2 - 10.1309/1G5F902YE7DDUNMA
DO - 10.1309/1G5F902YE7DDUNMA
M3 - Article
C2 - 16482990
AN - SCOPUS:30644469112
SN - 0002-9173
VL - 125
SP - 42
EP - 48
JO - American Journal of Clinical Pathology
JF - American Journal of Clinical Pathology
IS - 1
ER -