Test

immunophenotypic diagnosis of CLL

Preamble:

file CD45CLL.jpg left 250px

typical CD45 ssc plot of CLL the cells generally lie close to the position of normal lymphocytes. however CLL cells may have lower expression of CD45 than typical B,T or NK cells and form a less tight group since the expression level of CD45 can be more variable compared with normal and many neoplastic lymphocytes

markers useful in diagnosis of CLL

• CD19 should be detected but intensity is generally low in CLL
• CD5 should be expressed at moderate intensity in CLL (note also on expressed on mcl and occasionally on other lpd)
• CD23 has expected expression in CLL often at low intensity, generally absent in mcl but variably present on other lpd
• CD79b similar to CD19 this marker is expected to be expressed but intensity is generally low in CLL
• immunoglobulin light chains sig expect either light chain restriction with low intensity or undetectable
• fmc7 a marker of b-cell activation that should have low or absent expression, high expression is particularly seen in pll and hairy cell-like disorders
• CD200 expressed on most CLL cases as well as other b-lpd but is most frequently absent in mcl optional markers extended panel for atypical cases
• CD20 a pan b-cell marker with expected expression in CLL but intensity is generally low
• CD43 a pan b-cell marker with expected expression in CLL; frequently but not always absent in mcl

note where markers are atypical consider alternative diagnoses use of panels in b-lpd click for summary ---- '),