Previous reports have shown a correlation between day 30 absolute lymphocyte count (ALC30) after allogeneic hematopoietic cell transplantation (alloHCT) and patient outcomes. These reports included patients with various conditioning regimens and reported decreased overall survival and increased acute Graft-versus-Host disease (aGVHD) in patients with lower ALC30. The objective of this study was to find correlation between ALC30 and outcomes after alloHCT using reduced intensity conditioning (RIC) of fludarabine (25mg/m2 IV/d d -5 to -1) and melphalan (70mg/m2 IV/d d -2 to -1) conditioning (Flu/Mel). A retrospective chart review of patients receiving RIC alloHCT from Jan 2012 to May 2015 was conducted. Patients received cyclosporine/mycophenolate mofetil (CSP/MMF) or tacrolimus/methotrexate (FK/MTX) for GVHD prophylaxis. The indications for alloHCT were AML (40), MDS (7), CML (2), ALL (3), NHL (1) and HL (1). Only patients who had one alloHCT using T cell-replete graft were included. Fifty four patients were analyzed; of these, 17 had ALC30 lower than 400x106/L. With a median follow-up of 11.8 months, the day 100 and 6 month survival were 65% and 53% for the low ALC30 group and 92% and 73% for the high ALC30 group. Of the 54 patients, 44 received CSP/MMF (median follow-up 17.5 months) and 10 had FK/MTX (median follow-up 9.8 months). None of the FK/MTX patients had low ALC30 while 17 of 44 (39%) CSP/MMF patients did. There were seven deaths before d100 in the low ALC30 group, all due to aGVHD. Of the three deaths before d100 in the high ALC30 group, two were due to aGVHD and one due to infection. Eleven patients (65%) in the low ALC30 group had Grade III-IV aGVHD compared to five (14%) in the high group. None of the FK/MTX patients had GIII-IV aGVHD compared to 36% of the CSP/MMF patients. Five patients relapsed, all of whom received CSP/MMF and had high ALC30. Overall survival at d100 and 6 months was 90% (9/10) and 80% (8/10) for the FK/MTX group compared to 82% (36/44) and 64% (28/44) for the CSP/MMF group, respectively. Post-transplant day 30 ALC over 400x106/L is predictive of lower incidence of Grade III-IV aGVHD and lower risk of early mortality, regardless of the GVHD prophylaxis in patients receiving RIC (Flu/Mel) allogeneic transplantation.Tabled 1Patient Outcomes, % (n)6-month survivalGraft sourceaGVHD, GradesI-IVaGVHD, GradesIII-IVDeaths by days 100(GVHD)∗Deaths by 6 months(GVHD)∗100-day survivalCSP/MMFLow ALC30(n = 17)PB sib: 1100% (17)65% (11)35% (6)47% (8)65% (11)53% (9)PB MUD: 8BM MUD: 8High ALC30 (n = 27)PB sib: 1367% (18)18% (5)7% (2)15% (4)92% (25)70% (19)PB MUD: 13BM MUD: 1FK/MTXLow ALC30 (n = 0)n/an/an/an/an/an/an/aHigh ALC30 (n = 10)PB sib: 330% (3)0% (0)0% (0)0% (0)90% (9)80% (8)PB MUD: 6BM MUD: 1Abbreviations: PB = peripheral blood. BM = bone marrow, MUD = matched unrelated donor, sib = sibling; *, deaths due to GVHD Open table in a new tab
