Chronic Lymphocytic Leukaemia (CLL) is defined as being a clonal expansion of monomorphic, mature, immunologically incompetent CD5+ B cells in the peripheral blood, bone marrow and secondary lymphoid organs. An accurate diagnosis of B cell CLL is diagnostically important as the therapeutic regimes are different for other B Cell chronic lymphoproliferative disorders. The Matutes score uses immunotyping to identify the presence or expression of certain markers on the surface of the cell. Traditionally 5 markers were used – Surface Immunoglobulin, CD%, CD23, FMC7, and CD22, or CD79b. A scoring system is used for the diagnosis of CLL (see below). In CLL, scores are generally > 3, other B cell malignancies are < 3.
| Marker | Score = 1 | Score = 2 |
| Surface immunoglobulin | Weak | Strong |
| CD5 | Positive | Negative |
| CD23 | Positive | Negative |
| FMC7 | Negative | Positive |
| CD22 or CD79b | Weak | Strong |
Recently an additionally marker - CD200 - has been introduced to increase the accuracy and sensitivity of the score. CD200 is a glycoprotein on the surface membrane of normal B cells, B cell precursors, some T cells, dendritic cells, and neurons. CD200 was first described in 2009 for being always express in CLL but absent in Mantle Cell Lymphoma (MCL). A modified Matutes score was proposed by Jahal in 2021 which incorporates CD200 and also defines better the scoring criteria e.g. CD5 and CD23 score of 1 when the positive cells population <=30%, FMC7 and CD79b score of 1 when the positive cells population <30%. Using this additional marker increased the diagnostic accuracy of the Matutes score to 100%.
CD10 or common ALL antigen (CALLA) is almost always present on the surface of cells from patients with Follicular or Burkitt’s lymphoma. A panel of markers are used to fully diagnose Lymphoma e.g CD20, CD25, CD11c, CD103.
In addition to immunophenotyping, genetic mutation markers are used to assist in the diagnosis and choice of therapy. The genetic mutation BCL2/IGH t(14;18)(q32;q22) translocation is characteristic of Follicular Lymphoma.
The diagnosis of Lymphoproliferative disorders still requires a morphologist to be aware of abnormalities in the Lymphocyte population before any additional testing is performed.
