The diagnostic value of CD1d Expression in chronic lymphocytic leukemia and other B-cell chronic lymphoproliferative disorders

Abstract

he B-cell chronic lymphoproliferative disorders are a T heterogeneous group of B-cell malignancy of clonal origin with a highly variable clinical course. They are morphologically, immunologically and clinically heterogeneous. They refer to several conditions in which lymphocytes are produced in excessive quantities. The accurate discrimination of each separate B-CLPD is of paramount importance because the prognosis and treatment differ widely for the different types. The commonest B-CLPD is CLL, which characteristically expresses CD5 and CD19 on the cell surface. The differential diagnosis of a CD5/CD19 dual positive LPD lies mainly between CLL and MCL. MCL has a significantly poorer prognosis than CLL, often requiring more aggressive treatment; thus it is of clinical importance to discriminate between them. CD1d is a non-polymorphic HLA class I–like, B2M –associated glycoprotein that present lipids and glycolipids at the cell surface for recognition by T lymphocytes. CD1d is expressed widely in normal hematopoietic and non hematopoietic cells such as thymocytes, monocytes, macrophages, primitive hematopoietic stem cells, keratinocytes, and hepatocytes, whereas normal peripheral blood B cells exhibit constitutive expression of CD1d. As regards hematopoietic malignancies, myeloid and lymphoid acute leukemias variably express CD1d. This work aims to evaluate the diagnostic usefulness of CD1d in diagnosis of CLL and its value in differentiation of CLL from other B-CLPDs. The present study was conducted on forty three adult patients diagnosed as B-CLBDs; they were classified into twenty patients with CLL, ten patients with MCL and thirteen patients with other B-CLPDs including HCL, SMZL and FL who attended Ain Shams University Hospitals to be diagnosed in the clinical and chemical pathology department –Ain Shams University. As well as ten age and sex matched healthy subjects as a control group to evaluate CD1d expression on normal B-lymphocytes. Clinically, no statistical significant difference was detected between CLL and MCL cases and between B-NHL and MCL cases regarding; the presence of hepatomegaly and splenomegaly, however a statistical significant difference was observed regarding the presence of LN mainly in cases of MCL. Whereas no statistical significant difference between CLL and B-NHL cases was detected regarding; lymphadenopathy, hepatomegaly and splenomegaly.