[1433] Diagnostic and Prognostic Significance of CD200 Expression in Plasma Cell Myeloma

Daniel Long, Annette Kim, Shaoying Li. Vanderbilt University School of Medicine, Nashville, TN

Background: CD200 is expressed in a large subset of plasma cell myelomas (PCM) but not in normal plasma cells. Previous studies have shown CD200 is a prognostic factor for PCM, but they are contradictory on the nature of the prognostic effect. In addition, little is know about the stability of CD200 expression in PCM.
Design: We studied CD200 expression in 77 cases of PCM by immunohistochemistry on paraffin sections from decalcified bone marrow biopsies. Clinical and laboratory data were obtained on each patient. A Fisher exact test was used to analyze the differences between the 2 groups. Patient survival was analyzed using the Kaplan-Meier method and compared using the log-rank test.
Results: The study cohort included 37 men and 17 women, with a median age of 62 years (range, 41–88 years). There were 13 newly diagnosed cases and 64 post treatment cases (chemotherapy and/or stem cell transplant) from 54 patients. CD200 demonstrated strong membrane expression in positive cases. Fifty-six of 77 cases (73%) or 38 of 54 patients (70%) show CD200 expression. Twenty of the 22 (91%) patients with serial specimens demonstrated stable CD200 expression (n=15) or lack of CD200 expression (n=5). The clinical, pathologic, and cytogenetic features between the CD200+ group and the CD200- group were similar in most instances. However, CD200 expression was associated with lower serum β2-microglobulin and lack of bony lesions (p=0.03, see Table 1). There was no significant difference in median overall survival between the CD200+ and CD200- patients (104 vs 95 months, p=0.32).

Table 1. Clinical, pathological, and cytogenetic features of CD200+ and CD200- plasma cell myelomas
 CD200+CD200+P
Cases73%27% 
Age: Median (range)62 (41-88)62 (50-74)>0.05
Age >=65yrs43%44.0%>0.05
Male68%75%>0.05
Kappa68%71%>0.05
IgA38%43%>0.05
IgG50%38%>0.05
B2-MG <=3.5 mg/L50%14%0.03
B2-MG > 5.5 mg/L25%36%>0.05
Albumin >3.5 g/dL80%62%>0.05
Hb <10.0 (g/L)39%43%>0.05
Creatinine >1.5 mg/dL14%24%>0.05
Calcium >10.5 mg/dL4%0>0.05
Bone lesion25%52%0.03
BM cellularity: Medain (range)60% (10-95%)60% (20-95%)>0.05
Plasma Cell%: Median (range)50% (20-100%)70% (30-95%)>0.05
CD56+56%38%>0.05
Abnormal Karyotype47%55%>0.05
FISH t(4;14)8%15%>0.05
FISH t(11;14)22%30%>0.05
FISH del(13q14/13q34)44%45%>0.05
FISH del (17p13)23%15%>0.05



Conclusions: CD200 was expressed in 73% of PCM and the expression was stable during the treatment process in majority of the cases. Therefore CD200 is a useful marker for diagnosis and follow up of PCM. However, our data suggests that CD200 expression does not correlate with outcome.
Category: Hematopathology

Wednesday, March 6, 2013 1:00 PM

Poster Session VI # 222, Wednesday Afternoon

 

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