Elevated serum B-lymphocyte stimulator levels in patients with familial lymphoproliferative disorders.
OBJECTIVE
Serum B-lymphocyte stimulator (BLyS) levels have been found to be elevated in a number of immune disease models. Therefore, we sought to establish whether BLyS levels were elevated in patients with B-cell lymphoproliferative disorders and to determine whether elevated BLyS levels correlated with clinical characteristics of the disease.


METHODS
Specimens were collected from the peripheral blood of individuals diagnosed with B-cell chronic lymphocytic leukemia (B-CLL; n = 70) or from age- and sex-matched patients seen at the same institution (n = 41). Serum BLyS levels were determined by enzyme-linked immunosorbent assay, and sequencing of the BLyS promoter was performed by conventional methods and confirmed by restriction fragment length polymorphism analysis.


RESULTS
We found that elevated BLyS levels were more common in patients with familial B-CLL than individuals with sporadic B-CLL or normal controls. Because of this association, we sequenced the BLyS promoter in patients with B-CLL and normal controls and identified a polymorphic site, -871 C/T. We found that the wild-type sequence was significantly underrepresented in patients with familial B-CLL (4%) compared with patients with sporadic B-CLL (30%; P = .01) or controls (24%; P = .04). Furthermore, using a luciferase reporter under control of the BLyS promoter containing either a C or a T at position -871, we found that the reporter construct containing a T at -871 had a 2.6-fold increase in activity (P = .004).


CONCLUSIONS
Our data suggest serum BLyS levels are elevated in patients with familial B-CLL and that elevated BLyS levels correlate with the presence of a T at -871 in the BLyS promoter.
Novak
Anne J
AJ
Division of Hematology and Internal Medicine, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN 55905, USA.
Grote
Deanna M
DM
Ziesmer
Steven C
SC
Kline
Michael P
MP
Manske
Michelle K
MK
Slager
Susan
S
Witzig
Thomas E
TE
Shanafelt
Tait
T
Call
Timothy G
TG
Kay
Neil E
NE
Jelinek
Diane F
DF
Cerhan
James R
JR
Gross
Jane A
JA
Harder
Brandon
B
Dillon
Stacey R
SR
Ansell
Stephen M
SM
D000328:Adult; D000368:Aged; D053264:B-Cell Activating Factor; D014408:Biomarkers, Tumor / Q000097:blood* / Q000235:genetics; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D018922:HL-60 Cells; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000097:blood* / Q000235:genetics; D016393:Lymphoma, B-Cell / Q000097:blood* / Q000235:genetics; D008297:Male; D008565:Membrane Proteins / Q000097:blood* / Q000235:genetics; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D053264:B-Cell Activating Factor; D014408:Biomarkers, Tumor; D008565:Membrane Proteins; C505719:TNFSF13B protein, human; D014409:Tumor Necrosis Factor-alpha