Utilization of a Scoring System for Diagnosis of Chronic Lymphocytic Leukemia in Thai Patients
Orathai Promsuwicha MSc*, Wayuree Songmuang BSc*, Chirayu U Auewarakul MD, PhD*
Affiliation : * Division of Hematology, Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
Background : Chronic lymphocytic leukemia (CLL) is a rare B-lymphoid malignancy in Southeast Asia. We evaluated
whether a scoring system based on the expression of CD5, CD23, FMC7, CD79b and surface immunoglobulin (SIg) could
be utilized to distinguish CLL from other types of lymphoid neoplasms in the Thais.
Material and Method: One-hundred and forty-five samples with a clinical suspicion for CLL were analysed by flow
cytometry. A score of one was assigned if the following marker was identified: CD5+, CD23+, FMC7-, CD79b- and SIg-/weak.
A cut-off score of >3 was required for the definitive diagnosis of B-CLL.
Results : Only 50 cases (34.5%) were confirmed as B-CLL (scores >3). Cases with scores > 3 had significantly higher
leukocyte counts and marrow/blood lymphocytes than cases with scores < 2. Dual CD5/CD23 expression was found in
87.5% of CLL cases. In 81 cases with scores < 2, a variety of non-CLL disorders predominated, such as marginal zone
lymphoma, splenic lymphoma with villous lymphocytes, mantle cell lymphoma, and prolymphocytic leukemia.
Conclusion : A score of > 3 and dual CD5/CD23 expression are essential for the diagnosis of CLL while a score of < 2 mostly
indicative of non-CLL. The majority of clinical cases of CLL turned out to be non-CLL by flow cytometry. Increased utilization
of this scoring system should increase the accuracy of diagnosis of this rare type of leukemia in the Thai population.
Keywords : Chronic lymphocytic leukemia, Flow cytometry, Immunophenotyping, Scoring system, Leukemia
