CD200 is a useful marker in the diagnosis of chronic lymphocytic leukemia.

BACKGROUND: The diagnosis of CLL is supported by a typical morphology and immunophenotype and usually does not present difficulties. Nevertheless, some patients with CLL can show an atypical phenotype, this raising the possibility of a lymphoproliferative disorder other than CLL. It has been recently shown that the expression of CD200 could be a rather consistent marker for CLL. METHODS: The expression of CD200 was investigated in 120 consecutive patients with B-cell chronic lymphoproliferative disorders (B-CLPD) (65 cases diagnosed as typical CLL, 16 atypical CLL, and 39 non-CLL before entering the study) by using multiparametric flow cytometry with four color combinations. CD200 was analyzed as percentage of positive cells (≥30%) and MFIR expression. ROC curves were used to determine the cut-off for the CD200 MFIR. Matutes score (MS) was used as comparator. RESULTS: All 81 (100%) patients classified as CLL and 25 of 39 (64.1%) classified as non-CLL expressed high CD200 expression (≥30%). CD200 expression showed a high sensitivity (100%) and a low specificity (35.9%), and the accuracy was similar to that of Matutes score markers (range: 79.2%-86.7%); except SmIg that was 59.1%. The addition of CD200 to the Matutes score correctly identified 74 of 81 (91.4%) CLL cases including 9 of 16 atypical CLL cases. As per non CLL cases, 37 of 39 (94.9%) were correctly diagnosed by the modified system. Altogether, CD200 improved the diagnostic accuracy of Matutes score from 86.7% to 92.5% (P < .01). CONCLUSION: These results show that CD200 is a valuable, albeit not specific, CLL diagnostic marker. © 2018 International Clinical Cytometry Society.

Chronic Lymphocytic Leukemia: Clinical Stages Maintain Their Prognostic Significance Over the Course of the Disease and Are Surrogates for Response to Therapy.

BACKGROUND: To determine whether in patients with chronic lymphocytic leukemia (CLL), the clinical stage maintains prognostic significance over time and can be considered as a surrogate for the response to therapy. PATIENTS AND METHODS: The data from 229 CLL patients were retrospectively evaluated. The main aims of the study were to describe the changes in clinical stage during the course of CLL as a result of the response to treatment and to determine the time to next therapy (TTNT) and overall survival (OS) according to those changes, in particular, among the heterogeneous International Workshop on CLL (IWCLL) partial response (PR) category. RESULTS: Among the patients in the IWCLL PR category, differences were found in TTNT and OS according to the clinical stage at the response evaluation. With a median follow-up period of 91 months (range, 2-390 months), patients with a PR- Binet A at the response evaluation had significantly longer TTNT and OS compared with those with PR-Binet B/C (median TTNT, 26 vs. 11 months; P = .00; median OS, 63 vs. 43 months; P = .047). CONCLUSION: The results of the present study have shown that for patients with CLL, the Binet clinical stages are good outcome predictors throughout the disease course and also suggest that changes in Binet clinical stage could be useful as response surrogates and to divide the IWCLL PR category into different prognostic subgroups.

FcγRIIb expression in early stage chronic lymphocytic leukemia.

In normal B-cells, B-cell antigen receptor (BCR) signaling can be negatively regulated by the low-affinity receptor FcγRIIb (CD32b). To better understand the role of FcγRIIb in chronic lymphocytic leukemia (CLL), we correlated its expression on 155 samples from newly-diagnosed Binet A patients with clinical characteristics and outcome. FcγRIIb expression was similar in normal B-cells and leukemic cells, this being heterogenous among patients and within CLL clones. FcγRIIb expression did not correlate with well known prognostic markers [disease stage, serum beta-2 microglobulin (B2M), IGHV mutational status, expression of ZAP-70 and CD38, and cytogenetics] except for a weak concordance with CD49d. Moreover, patients with low FcγRIIb expression (69/155, 44.5%) required therapy earlier than those with high FcγRIIb expression (86/155, 55.5%) (median 151.4 months vs. not reached; p=.071). These results encourage further investigation on the role of FcγRIIb in CLL biology and prognostic significance in larger series of patients.