Abstract
multiple myeloma (MM) is currently an incurable hematological malignancy. Discovering molecular therapeutic targets is a new approach to improve the outcome in the treatment of the malignant disease. As CD200 is a type Ⅰmembrane glycoprotein expressed on myeloma cells, we asked if the expression of CD200 could serve as a prognostic marker for MM patients. Our data indicated that the expression level of CD200 is indeed correlated with the prognosis of the MM patients.
bone marrow samples from 96 newly diagnosed MM patients from April 2011 to July 2013 were evaluated by flow cytometry, using PE-conjugated anti-CD200 mAb, FITC-conjugated anti-CD138 mAb, and PE-Cy7-conjugated anti-CD45 mAb. PE-or FITC-conjugated normal mouse IgG was used as isotype-matched controls.
96 MM patients were investigated in the present study, including 60 men and 36 women, with a median age of 63 years (range 34–86 years). 81/96(84%) MM patients were CD200 positive with a median Mean Fluorescence Intensity (MFI) of 127 as analyzed by flow cytometry, which was consistent with the previous studies. While in 15 of 96 patients, CD200 expression was undetectable. Among the CD200 positive ones 7.40% patients were classified as stage Ⅰ, 12.35% were stage Ⅱ, and 80.25% were stage Ⅲ according to Durie–Salmon staging criteria. 40.74% patients were stageⅠ, 22.22% were stage Ⅱ, and 37.04% were stage Ⅲ, according to the International Staging System (ISS). Analysis of the CD200 positive patients revealed the MFI<127 group had a better progression free survival (PFS) (p=0.046) (Fig 1A) and overall survival (OS) (p=0.069) compared to those with MFI≥127. In the patients with age ≥65 years old, PFS (p=0.023) (Fig 1B) and OS (p=0.044) (Fig 1C) were much shorter in the MFI≥127 group, compared to the MFI<127 ones.
Kaplan-Meier survival curves for CD200 (+) patients 1A: PFS of patients with the MFI<127 was longer, compared to MFI>127 ones (p=0.046). 1B: In the patients with age ≥65 years old ,PFS of patients with MFI≥127 was much shorter, compared to MFI<127 group. (p=0.023). 1C: In the patients with age ≥65 years old ,OS of patients with MFI<127 years was better, compared to MFI≥127 group. (p=0.044).
Kaplan-Meier survival curves for CD200 (+) patients 1A: PFS of patients with the MFI<127 was longer, compared to MFI>127 ones (p=0.046). 1B: In the patients with age ≥65 years old ,PFS of patients with MFI≥127 was much shorter, compared to MFI<127 group. (p=0.023). 1C: In the patients with age ≥65 years old ,OS of patients with MFI<127 years was better, compared to MFI≥127 group. (p=0.044).
Our study demonstrated that the expression and MFI of CD200 on primary multiple myeloma cells is correlated with the prognosis of the MM patients. The better PFS and OS were observed in the MFI<127 group compared to the patients with MFI≥127, especially in the patients with age≥65 years old. Improved PFS in CD200 positive ones is likely due to the immune suppression mediated by CD200. Our study suggests that targeting therapy against CD200 may become a new approach to the treatment of MM in clinical practice.
No relevant conflicts of interest to declare.
