Techniques to improve flow cytometric detection of light chain restriction.
OBJECTIVE
To compare 3-color flow cytometry (using a permeabilization step to detect cytoplasmic immunoglobulin in selected cases) with 2-color flow cytometry in the detection of light chain restriction (LCR).


METHODS
Analysis of clinical specimens submitted for lymphocyte immunophenotyping using both methods.


METHODS
Marshfield Laboratories serving Saint Joseph's Hospital (525 beds) and the Marshfield Health Care Network.


METHODS
Sensitivity and specificity for detecting LCR in B-cell neoplasms. Final diagnosis based on review of clinical, laboratory and histologic data.


RESULTS
Of 61 specimens, the 3-color method yielded better sensitivity, detecting LCR in 30 of 39 cases of B-cell neoplasms (77%) versus 16 of 39 (41%) for the 2-color method (P < 0.001). Both methods had comparable specificity (95-100%). The 3-color cytoplasmic technique identified another 4 cases yielding an overall sensitivity of 87% for a 2-tiered testing strategy.


CONCLUSIONS
A 3-color surface technique, backed up by a permeabilization step in selected cases, provides a cost-effective and sensitive technique for detecting LCR.
Shaw
G R
GR
Marshfield Clinic, WI 54449, USA.
Gonering
E
E
Koller
S
S
D003362:Cost-Benefit Analysis; D005434:Flow Cytometry / Q000191:economics / Q000379:methods*; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000032:analysis*; D016130:Immunophenotyping / Q000191:economics / Q000379:methods*; D016393:Lymphoma, B-Cell / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity