[1377] CD34+ Progenitor-Based Flow Cytometric Immunophenotypic Analysis Is Sensitive and Specific in Assessment of Myelodysplastic Syndromes.

Guilin Tang, Yi Zhou, Jeffrey L Jorgensen, Ying Hu, Kersh Marian, L Jeffrey Medeiros, Guillermo Garcia-Manero, Sa A Wang. MD Anderson, Houston, TX

Background: Flow cytometric immunophenotypic (FCI) assays of bone marrow (BM) have shown diagnostic utility in MDS patients. Most MDS FCI assays, however, are based on recognition of altered myelomonocytic maturation patterns. These patterns often become less reliable in patients undergoing various therapies. A CD34+ progenitor-based multicolor FCI assay is tested in cytopenic patients with the goal of identifying alternations in CD34+ cells that distinguish MDS from reactive cytopenias.
Design: A 7-color FCI assay was performed consecutively in patients in whom “rule out MDS” was requested from 5/2009 through 5/2010. A total of 147 patients with a confirmed diagnosis of MDS, and 112 patients with non-MDS cytopenia were included. The later group included patients who received chemotherapy, growth factors, immunosuppressive agents, or stem cell transplant for various conditions.
Results: Compared with non-MDS cytopenic patients, MDS patients had a higher number of total CD34+ cells (2.7 ± 0.26% vs 1.1 ± 0.1%), lower number of stage I hematogones (5.5 ± 1.1% vs 25 ± 2.1%) and plasmacytoid dendritic precursors (PDP) (3.5 ± 0.14% vs 6.4 ± 0.46%), p<0.001. Other significant alterations (p<0.01) included altered CD45/side scatter, increased expression of CD13, CD33, CD34, CD117, and/or CD123, decreased CD38, aberrant lymphoid antigens (CD2, CD5, CD7, and/or CD56) or mature myelomonocytic antigens (CD10, CD11b, CD15, CD16, CD64, and/or CD65) expression (Table 1). By defining “positive” as ≥ 1 aberrant lymphoid antigen or ≥ 2 significant alterations of other markers, the FCI assay to assess for MDS we present has a sensitivity of 90.5%; specificity of 88%; PPV of 91%; NPV of 88%, and an accuracy of 90%.

Table 1

	Control (n=112)	MDS (n=147)	Sensi %	Speci %	Accu %
Stage 1 Hematogone (≤10%)	30	124	84	73	80
PDP (<5%)	35	104	71	69	70
Abn CD13/CD33	19	89	61	83	70
Inc CD117	10	75	51	91	68
Inc CD123	11	73	50	90	67
Abn CD45/SS	8	55	37	93	63
Inc CD34	2	45	31	98	60
Dec CD38	1	45	31	99	60
Inc CD184	6	39	27	95	56
CD34 (≥3%)	6	42	29	95	57
Lymphoid antigen	8	54	37	93	61
Mature myelomonocytic antigen	8	27	18	93	50

Conclusions: This CD34+ progenitor-based FCI assay we have developed is sensitive and specific for distinguishing MDS from reactive cytopenias. This assay is easy to interpret and score and has high diagnostic accuracy. We believe this assay is especially valuable in patients who have received various therapies in whom analyzing mature myelomonocytic antigens is less reliable.
Category: Hematopathology

Monday, February 28, 2011 1:00 PM

Poster Session II # 165, Monday Afternoon