Evaluation of Immunophenotypic Markers in Diagnosis and Prognosis of Atypical Chronic Lymphocytic Leukemia

Abstract

Abstract: BACKGROUND: Atypical chronic lymphocytic leukemia diagnosis (aCLL) constitutes of monoclonal B lymphocytes of more than 5000 with unique morphological and immunophenotypic features different from classical or typical CLL. By immunophenotyping, aCLL is differentiated from typical CLL in the negative expression of either one or two immunophenotypic markers, mostly CD23 and/or CD5, provided that the patient does not have the diagnostic criteria of any other lymphoid neoplasm. aCLL patients are usually presented clinically in an aggressive manner and have worse outcomes compared to classic CLL. MATERIALS AND METHODS: This cross-sectional study includes 36 patients diagnosed as aCLL compared to 36 patients diagnosed as typical CLL. Diagnosis depends on blood film morphology and immunophenotyping by 8-color flow cytometry, the markers that are used for diagnosis depend on Matutes scoring system of CLL with the addition of CD200 and CD43, in addition to prognostic markers CD38 and CD305. The clinical staging system was applied, and the patients were divided into low-, intermediate-, and high-risk groups. Follow-up program for 6–12 months with evaluation of their hematological and clinical response and assessment of their remission state as was instituted in the hematological center. RESULTS: CD5 and CD23 are negative in 16.6% and 33.3% of aCLL patients, respectively, whereas CD200 and CD43 are positively expressed in 100% and 83.33% of aCLL patients, respectively, co-expression percentage of both markers in 83.33%. aCLL cases were commonly presented with high-risk group and usually have markers that are linked to poor prognosis, including negative expression of CD305 in 83.3% and positive CD38 expression in 75% of cases and only 5.56% of patients achieved remission state. CONCLUSIONS: aCLL is characterized by immunophenotypic differences in comparison to typical CLL. A definitive diagnosis needs additional markers, mainly CD200 and CD43; the prognosis of aCLL is worse than classical CLL.