title: L-index as a novel index to evaluate both the intensity and duration of lymphopenia after allogeneic hematopoietic stem cell transplantation.
abstract: We retrospectively investigated L-index, which evaluates both the intensity and duration of lymphopenia after allogeneic hematopoietic stem cell transplantation (HSCT) (n = 50). L-index was defined as the area over the lymphocyte curve during lymphopenia (absolute lymphocyte count < 700/μL). We calculated the L-index from the start of conditioning to day 30 - L-index(30) - and to day 100 - L-index(100) - after HSCT. Multivariate analysis revealed that human leukocyte antigen mismatched donor, female gender, and non-lymphoid disease were significantly associated with high L-index(30). Grade III-IV acute graft-versus-host disease, alemtuzumab-containing regimen, and non-lymphoid disease were identified as independent significant factors for high L-index(100). Cytomegalovirus (CMV) antigenemia was detected > 3 cells/2 slides by C10/11 method in 30 patients (CMV-AG ≥ 3 group) and was not detected in 20 patients (CMV-AG < 3 group). Although no significant difference was seen in absolute lymphocyte count on day 30 between the 2 groups, the L-index(30) was significantly higher in the CMV-AG ≥ 3 group than in the CMV-AG < 3 group (P = 0.050). L-index(30) was identified as an independent factor on CMV reactivation in multivariate analysis, when it was treated as a dichotomous variable with a cut-off value of 22,318, determined by receiver operating characteristic curve analysis. In conclusion, both the intensity and duration of lymphopenia in early phase after HSCT evaluated on the basis of L-index(30) showed significant association with CMV reactivation.
authors.affiliation: Division of Hematology, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors.forename: S-I
authors.initials: SI
authors.lastname: Kimura
authors.forename: H
authors.initials: H
authors.lastname: Wada
authors.forename: K
authors.initials: K
authors.lastname: Sakamoto
authors.forename: M
authors.initials: M
authors.lastname: Ashizawa
authors.forename: M
authors.initials: M
authors.lastname: Sato
authors.forename: K
authors.initials: K
authors.lastname: Terasako
authors.forename: H
authors.initials: H
authors.lastname: Nakasone
authors.forename: M
authors.initials: M
authors.lastname: Kikuchi
authors.forename: S
authors.initials: S
authors.lastname: Okuda
authors.forename: S
authors.initials: S
authors.lastname: Kako
authors.forename: R
authors.initials: R
authors.lastname: Yamazaki
authors.forename: K
authors.initials: K
authors.lastname: Oshima
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: A
authors.initials: A
authors.lastname: Tanihara
authors.forename: J
authors.initials: J
authors.lastname: Nishida
authors.forename: Y
authors.initials: Y
authors.lastname: Kanda
mesh_terms: D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D003587:Cytomegalovirus / Q000502:physiology*; D003586:Cytomegalovirus Infections / Q000821:virology*; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006801:Humans; D018655:Lymphocyte Count / Q000592:standards*; D008231:Lymphopenia / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D019172:Transplantation Conditioning; D014184:Transplantation, Homologous / Q000009:adverse effects; D014775:Virus Activation; D055815:Young Adult