Immunohistochemical expression of CD38,CD23 and serum beta 2 microglobulin in CLL and their correlation with Rai staging

Chronic lymphocytic leukemia (CLL) is a low-grade B-lineage lymphoid malignancy. It has a variable clinical course with a median survival ranging from two to twenty years and several biological markers were used to assess the disease activity. CD38 is a cell surface molecule frequently expressed on leukemic cells in patients who experienced relatively early CLL progression,CD38 appears to be a global molecular bridge to the environment, promoting survival/proliferation over apoptosis. CD23 is a functionally relevant molecule in B-cell chronic lymphocytic leukemia (CLL) which mediates growth and differentiation signals in B-cells. An intriguing feature of CD23 is its ability to be cleaved from the cell surface and released into the serum.
β2M is an extracellular protein component of the HLA Class I complex, its released constitutively by CLL cells and its level approximately correlates with tumor mass. Aims of the study: 1.To asses immunohistochemical expression of CD38,CD23, and beta 2 microglobulin( B2M) by Elisa method in CLL patients. 2. To study the possible correlation of CD38 and CD23 and other parameters( B2M) with Rai staging of CLL. Patients,materials and methods: Bone Marrow biopsies of fifty adult patients with CLL were collected from November 2011 to June 2012 ; forty of them were retrospectively collected from archive files of the Department of Hematology of the Medical City Teaching Laboratories while ten of them were prospectively collected from private laboratories. Clinical and laboratory information regarding age, gender, PCV, Hb, WBC count, platelet count, percentage of lymphocyte in the blood and bone marrow and the pattern of bone marrow infiltration were obtained from patients recording file at diagnosis For each case, one section was stained with hematoxylin and eosin and two other sections were stained immunohistochemically for CD23 , CD38 each section with 4 micron thickness. The slides were examined by light microscope and scanned on low and high powers. Used for beta 2 microglobulin. ELISA method
Results: 24 cases(48 %) were positive for CD38 , There was a significant association between CD38 score and age (p= 0. 023), with platelet count(p =0.013) , lymphocyte % in the bone marrow (p= 0.007) , lymph node enlargement (p=0.042 ) , splenomegaly ( p=0.033 ) , bone marrow pattern of involvment (P=0.026 ) and Modified Rai stage (p=0.036) . all CLL cases were positive for CD23. The result of β2-microglobulin was more than 3.0 μg/ml in nine of ten prospective cases, There was a significant correlation between β2M and WBC count( p<0.001) , bone marrow histology (P=0.049) , Modified Rai stage (p=0.043 ) and CD38 (p=0.029). Conclusions: 1. The proliferative marker CD38 expression was closely related to the clinical stage of the patient , thus it can be considered as informative and simple tool for assessing disease activity and it might predict the clinical course in CLL 2. This study revealed that CD23 expression in CLL is not related to the clinical stage of the patient. 3. No correlation was found between CD38 and CD23 score . 4. beta 2 microglobulin was closely related to the clinical stage of the patient , thus it can be considered as informative and simple tool for assessing disease activity . 5. There was a significant correlation between beta 2 microglobulin and CD38, so we can conclude that both of these markers can be used as simple tool for assessing disease activity and predict the clinical course in CLL.