Disease status at transplant impacts lymphocyte and platelet recovery after allogeneic peripheral blood stem cell transplant (PBSCT) for patients with AML/MDS (2006)

Lymphocyte and platelet count have been correlated with outcomes of allogeneic SCT. We sought to test this hypothesis in a homogeneous group of patients with AML/MDS. Patients and Methods: 54 consecutive patients with high-risk AML/MDS received a matched-sibling PBSCT with fludarabine (100-180 mg/m2) and melphalan (100-180 mg/m2) conditioning and tacrolimus-based GVHD prophylaxis between 1996 and 2003. Median age was 55 years (23-68). Disease status at PBSCT was complete remission (CR, 15/54), No CR with (NoCR/CB, 15/54) or without circulating blasts (NoCR/NoCB, 24/54). Cytogenetics were high-risk in 45% of patients, intermediate in 46%, unknown in 9%. Cox’s regression analysis was used to evaluate predictors of outcome at landmarks starting at day 30 post-SCT. We evaluated day 30 lymphocyte and platelet count (categorized at the respective medians: 760 × 109/L and 80 × 109/L), age, cytogenetics, disease status at transplant, first remission duration, and grade II-IV acute GVHD (a-GVHD) and chronic GVHD as time-dependent variables. Results: 51/54 patients were alive by day 30, and 47/51 (92%) had achieved a CR; 40/44 patients tested achieved 100% donor chimerism. Actuarial survival for these 47 patients in CR was 51% and disease progression 36% at 3 years. Grade II-IV a-GVHD was the only significant predictor of mortality at 3 years (HR = 2.8, P = .02). Disease status of NoCR/CB at PBSCT (HR = 2.3, 95% CI 0.9-6), lymphocyte (HR = 1.8, 95% CI 0.8-4) and platelet count below the median (HR = 1.6, 95% CI 0.7-4) showed a trend for higher mortality. Disease status of NoCR/CB at PBSCT was the only significant predictor of disease progression (HR = 4.6, P = .003). Lymphocyte count below the median showed a trend for higher progression rate (HR = 2.8, 95% CI (0.96-8)), in contrast to low platelet count (HR = 1.1 (95% CI 0.4-3)). A stratified analysis showed that patients who were in CR at PBSCT achieved the highest count on average, followed by the NoCR/NoCB and the NoCR/CB groups (Table 1). A similar pattern was observed excluding patients diagnosed with a-GVHD by day 30, or stratifying by the dose of melphalan in the preparative regimen. Conclusion: Among patients in CR after PBSCT for AML/MDS, day 30 lymphocyte and platelet counts are highly correlated with disease status at PBSCT. This illustrates the limited usefulness of these variables as independent predictors of outcome and highlights theassociation of disease status at PBSCT and delayed early lymphoid reconstitution (Table 1).Table 1Lymphocyte and Platelet Count (109/L) on Day 30 post Transplant for Patients Who Were in CR at That Time According to Disease Status at the Time of TransplantCR (n = 15)⁎CR: complete remission, CB: circulating blast.No CR/No CB (n = 19)⁎CR: complete remission, CB: circulating blast.No CR/CB (n = 13)Test for Trend (P: Value)Median lymphocyte count (range)1010 (230–1770)760 (220–3500)470 (70–1820).10Median platelet count (range)114 (16–64)75 (21–189)61 (11–279).03Days to platelet count 20K (range)14 (10–24)15 (7–72)22 (10–72).01Excluding patients with a-GVHD by day 30n = 11n = 15n = 8Median lymphocyte count (range)1030 (380–1770)770 (260–3500)560 (70–119).03Median platelet count (range)114 (56–164)85 (21–189)53 (31–121).04 CR: complete remission, CB: circulating blast. Open table in a new tab