Screening bone marrow samples for abnormal lymphoid populations and myelodysplasia-related features with one 10-color 14-antibody screening tube

Background: We have designed one-tube 14-antibody 10-color flow cytometry (FCM) panel that would provide maximum information on lymphoid and myeloid cell subsets in bone marrow aspirates (BMA) from patients with cytopenia(s).

Samples and methods: BMA from 8 normal donors, from 286 non-malignant hospital controls, 92 myelodysplastic syndromes (MDS), 47 myeloproliferative neoplasms (MPN), and from 14 MDS/MPN patients were investigated. One tube 14-monoclonal antibody (MAb) 10-fluorochrome panel included: kappa+CD4 FITC, Lambda+CD8 PE, CD3 + CD14 ECD, CD34 APC, CD20+CD56 PC7, CD10 APC-A750, CD19 APC-A700, CD33 PC5.5, CD5 PB, and CD45 KO. Kappa/lambda expression was evaluated separately in CD19+, CD10+ and CD5+ B-cells. CD4+CD3+, CD8+CD3+, CD5+CD3+ T-lymphocyte subsets were enumerated. Blasts were evaluated using CD45/SSC and CD34 gating. The FCM score for MDS (sc. Ogata score) included CD34+ myeloblast and B-progenitor cluster size, myeloblast/lymphocyte CD45 expression, and granulocyte/lymphocyte SSC ratio.

Results: Abnormal lymphoid populations or increased plasma cells were found in 18 patients (4%). A 43/92 BMA from MDS and 7/14 from MDS/MPN patients had score >2. Score >2 had 92.5% positive predictive value for MDS/MDS-MPN diagnosis. Negative predictive value for MDS/MDS-MPN was 83% for scores under 3 and 88% for scores under 2. All but two of normal/hospital control samples had FCM score <3 (99%). Differences in scores between MDS & MDS/MPN and the control groups were statistically significant (P < 0.0001).

Conclusions: Our one-tube FCM panel can be easily applied to screening for aberrant lymphoid populations and myelodysplasia-related features. MDS scores >2 are highly indicative of MDS or MDS-MPN.