Common occurrence of monoclonal B-cell lymphocytosis among members of high-risk CLL families.
Monoclonal B-cell lymphocytosis (MBL) is an asymptomatic haematological condition characterized by low absolute levels of B-cell clones with a surface immunophenotype similar to that of chronic lymphocytic leukaemia (CLL). In the general population, MBL increases with age with a prevalence of 5-9% in individuals over age 60 years. It has been reported to be higher among first-degree relatives from CLL families. We report results of multi-parameter flow cytometry among 505 first-degree relatives with no personal history of lymphoproliferative disease from 140 families having at least two cases of CLL. Seventeen percent of relatives had MBL. Age was the most important determinant where the probability for developing MBL by age 90 years was 61%. MBL clustered in certain families but clustering was independent of the number of known CLL cases in a family. As is the case with CLL, males had a significantly higher risk for MBL than did females (P = 0·04). MBL patients had significantly higher mean absolute lymphocyte counts (2·4 × 10(9) /l) and B-cell counts (0·53 × 10(9) /l) than those with a normal B-cell immuno-phenotype. Our findings show that MBL occurs at a very high rate in high risk CLL families. Both the age and gender distribution of MBL are parallel to CLL, implying a shared inherited risk.
Goldin
Lynn R
LR
Genetic Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892-7236, USA. goldinl@mail.nih.gov
Lanasa
Mark C
MC
Slager
Susan L
SL
Cerhan
James R
JR
Vachon
Celine M
CM
Strom
Sara S
SS
Camp
Nicola J
NJ
Spector
Logan G
LG
Leis
Jose F
JF
Morrison
Vicki A
VA
Glenn
Martha
M
Rabe
Kari G
KG
Achenbach
Sara J
SJ
Algood
Sallie D
SD
Abbasi
Fatima
F
Fontaine
Laura
L
Yau
Michelle
M
Rassenti
Laura Z
LZ
Kay
Neil E
NE
Call
Timothy G
TG
Hanson
Curtis A
CA
Weinberg
J Brice
JB
Marti
Gerald E
GE
Caporaso
Neil E
NE
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D016130:Immunophenotyping; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000453:epidemiology / Q000235:genetics*; D008218:Lymphocytosis / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D017678:Sex Distribution; D014481:United States / Q000453:epidemiology