First report of the unique expression of RECAF (receptor for alfa feto-protein) in adult B-NHL/CLL patients.

ABSTRACT

BACKGROUND: Lymphoproliferative disorders (LPDs) are a heterogeneous group of diseases characterized by an uncontrolled production of monoclonal lymphocytes. RECAF is the receptor for alpha-fetoprotein, which is re-expressed on malignant cells, thus serving as a broad-spectrum tumor marker. METHODS: The current study is a retrospective study carried out on 200 archival bone marrow trephine biopsy specimens [60 normal control (NC), 38 pathological control (PC) and 102 lymphoproliferative diseases (LPD) specimens]. RECAF expression was assessed using immunohistochemistry. RESULTS: The percentage of cells that are positive for RECAF was significantly higher in the LPD group than in the NC group (P=0.007), while there was no significant difference between non-Hodgkin lymphoma (NHL) patients and PC regarding the number of RECAF positive cells (P=0.1). RECAF showed a unique expression pattern among the different subtypes of LPD. None of the hairy cell leukemia (HCL) expressed RECAF, while the highest percentage was seen in follicular lymphoma (FL) and diffuse large B cell lymphoma (DLBCL) (P=0.001). Compared to routine histopathology, RECAF was more sensitive in detecting bone marrow (BM) infiltration in FL, mantle cell lymphoma (MCL), and DLBCL (P=0.01). CONCLUSION: RECAF is significantly expressed in the BM of NHL/chronic lymphocytic leukemia (CLL) patients. RECAF shows a unique expression pattern among the different subtypes of LPD. Furthermore, RECAF may help to detect bone marrow infiltration in lymphoma cells. This may help in the diagnosis, follow-up, and targeting of LPD.