Comparison of surface membrane phenotypes of IgM⁺ B-CLL cases grouped on the basis of immunoglobulin V gene mutation.

PBMCs from 51 IgM⁺ B-CLL cases were analyzed for the expression of CD38, CD39, CD40, CD62L, CD69, and CD71 on CD5⁺CD19⁺ cells. The B-CLL cases were segregated into 2 groups: unmutated, in which the expressed immunoglobulin V genes showed less than a 2.0% difference from the most similar germ line gene, and mutated, in which the expressed immunoglobulin V genes showed a 2.0% or greater difference from the most similar germ line. The mean ± SE of the percentages of CD5⁺CD19⁺ cells expressing these markers in the unmutated and mutated cases are represented. All differences were statistically significant (P < .001).