Prognostic Influence of Marrow Hematogone Percentage and Cellularity in AML Patients Post Umbilical Cord Blood Transplant.
Theodore J Honebrink, Qing Cao, Michael R Verneris, Vanessa J Dayton. University of Minnesota, Minneapolis
Background: Increased percentages of hematogones (B-lymphocyte precursors) in bone marrow aspirates may be observed in a variety of settings including following umbilical cord blood transplantation (UCBT). Little is known about their prognostic significance in this setting and they are not routinely reported in marrow differential counts.
Design: The goal of this study was to determine whether several parameters available from the bone marrow aspirate and biopsy (percent hematogones, myeloid to erythroid (M/E) ratio, percent cellularity) at D+21 and D+100 were associated with post UCBT outcomes. Two independent reviewers (TH, VJD) blindly assessed these variables using Wright-Giemsa stained aspirate smears/touch preps and H&E stained trephine sections of 155 samples from 88 patients with AML undergoing UCBT. Placing all cases into two groups, those above and below the median, multivariate analysis (MVA) was performed to assess the impact of each variable at days 21 and 100 on overall survival (OS), disease free survival, transplant related mortality, relapse, neutrophil engraftment, platelet engraftment (PE), acute GVHD (AGVHD) grades 2-4 and 3-4, and chronic GVHD (CGVHD).
Results: In 147/155 cases (94.8%) the two observers reported hematogone percentages within +/-3.6%. Interobserver variability was calculated for all variables at days 21 and 100 with correlation coefficients ranging from 0.58 to 0.98 (p<0.01 in all cases). MVA showed a high percentage of hematogones at day 21 on the aspirate to be associated with PE at 100 days (p=0.03) and less AGVHD grade 3-4 (p=0.03). Day 100 hematogones were weakly associated with 1 year OS (p=0.08). Day 21 cellularity was weakly associated with increased AGVHD grade 2-4 (p=0.07). Day 100 cellularity was associated with less CGVHD (p=0.01). Day 21 M/E ratio was weakly associated with less 1-year relapse (p=0.06) and less CGVHD (p=0.09). Day 100 M/E ratio was associated with less CGVHD (p=0.03).
Conclusions: The current findings suggest that marrow hematogone percentage may be more useful than cellularity in AML patients post-UCBT for predicting transplant outcomes. These results suggest that the percent hematogones in bone marrow aspirates should be routinely reported. More importantly, they question whether trephine biopsies for assessment of cellularity are necessary in the evaluation of patients after UCBT.
Tuesday, March 1, 2011 1:00 PM
Poster Session IV # 175, Tuesday Afternoon