There is evidence of a monoclonal B-cell population in the peripheral blood, both at baseline and at a second evaluation 3 or months later.
Findings - one or more of the following:
(1) presence of a monoclonal B-cell population with a disease-specific immunotype (see subclassification below; this would be CD5+ CD23+ or CD5+ CD23-)
(2) presence of a monoclonal B-cell population with an abnormal plasma kappa to lambda ratio (either > 3:1 or < 0.333:1
(3) presence of a monoclonal B-cell population with > 25% of B-cells with absent or reduced levels of surface immunoglobulin
Exclusion criteria - one or more of the following:
(1) presence of lymphadenopathy and organomegaly (hepatomegaly/splenomegaly)
(2) association with an autoimmune or infectious disease
(3) absolute B-lymphocyte count > 5,000 per µL
(4) presence of features diagnostic for a B-cell lymphoproliferative disorder (excluding the presence of a paraprotein)
Immunotypes for subclassification:
|
CD5
|
CD23
|
Immunotype
|
|
positive
|
positive
|
CLL
|
|
positive
|
negative
|
atypical CLL (evaluate CD20 and CD79b)
|
|
negative
|
NA
|
non-CLL lymphoproliferative disease
|
