Adjusted estimates for time-to-event endpoints.

In the analysis of retrospective data or when interpreting results from a single-arm phase II clinical trial relative to historical data, it is often of interest to show plots summarizing time-to-event outcomes comparing treatment groups. If the groups being compared are imbalanced with respect to factors known to influence outcome, these plots can be misleading and seemingly incompatible with results obtained from a regression model that accounts for these imbalances. We consider ways in which covariate information can be used to obtain adjusted curves for time-to-event outcomes. We first review a common model-based method and then suggest another model-based approach that is not as reliant on model assumptions. Finally, an approach that is partially model free is suggested. Each method is applied to an example from hematopoietic cell transplantation

G-CSF-mobilized peripheral blood mononuclear cells added to marrow facilitates engraftment in nonmyeloablated canine recipients: CD3 cells are required

AbstractStable mixed donor/host hematopoietic chimerism can be uniformly established in dogs conditioned with 200 cGy TBI before dog leukocyte antigen (DLA)-identical marrow transplantation and immunosuppressed with a short course of mycophenolate mofetil (MMF) and cyclosporine (CSP) after the transplantation. A further decrease in the TBI dose to 100 cGy or the elimination of MMF in this model results in graft rejection. Here we asked whetherthe addition of G-CSF-mobilized peripheral blood mononuclear cells (G-PBMC) to marrow grafts would enhance donor engraftment in dogs conditioned with 100 cGy TBI and given postgrafting immunosuppression with CSP alone. Using this model, 7 of 9 dogs given only marrow cells rejected their grafts within 8 to 17 weeks after transplantation. In contrast, the addition of unmodified G-PBMC to marrow grafts resulted in stable mixed donor/host chimerism in 5 of 8 dogs studied (P = .06). However, addition of the CD3-depleted fraction of G-PBMC, which contained both CD34 cells and CD14 cells, resulted in engraftment in only 1 of 7 recipients. We conclude that adding G-PBMC to marrow grafts replaced the requirement of MMF and 100 cGy of TBI, and that CD3 cells were required to facilitate engraftment of marrow cells in DLA-identical recipients, whereas the additional CD34 cells present in G-PBMC were not sufficient for this effect.Biol Blood Marrow Transplant 2001;7(11):613-9

To My Daughter

<p>Equal numbers of macaque CD34⁺ cells were transduced in 3-d transduction cultures with either the HOXB4GFP or YFP vector and then cultured for an additional 9 d (T02266) or 6 d (K03290 and J02152) in the presence of SCF, TPO, Flt-3L, and G-CSF. All the transduced and expanded cells were infused into myeloablated animals. The percentage of HOXB4GFP⁺ and YFP⁺ granulocytes was assessed by flow cytometry. Shown is the engraftment of HOXB4GFP⁺ and YFP⁺ granulocytes after transplantation. (A) T02266, (B) K03290, and (C) J02152. </p

Pretransplant neutropenia is associated with poor-risk cytogenetic features and increased infection-related mortality in patients with myelodysplastic syndromes.

A retrospective cohort analysis was performed to determine the impact of neutropenia on the outcome of hematopoietic cell transplantation (HSCT) in patients with myelodysplasia (MDS). Among 291 consecutive patients, 178 (61%) had absolute neutrophil counts (ANCs) or =1500/microL within 2 weeks before HSCT. Neutropenic patients more often had poor-risk karyotypes (34% versus 12%, P < .0001) and high-risk International Prognostic Scoring System scores (37% versus 18%, P = .0006). After HSCT, the rate of infections caused by Gram-positive bacteria and invasive fungal infections was significantly increased among neutropenic patients (rate ratio [RR] 1.77, P = .02 and RR = 2.56, P = .03, respectively), whereas infections caused by Gram-negative bacteria were not affected (RR 1.33, P = .53). The hazards of nonrelapse mortality (NRM) (hazard ratio [HR] = 1.62 [1.1-2.4], P = .01), overall mortality (HR = 1.55 [1.1-2.1], P = 0.007), and infection-related mortality (HR = 2.22 [1.2-4.2], P = .01) were increased in neutropenic patients, whereas relapse, engraftment, and graft-versus-host-disease were not affected. After adjusting for cytogenetic risk and marrow myeloblast percentages, neutropenic patients remained at significant hazard for infection-related mortality (HR = 1.94 [1.0-3.8], P = .05), but not for overall mortality or NRM. We propose that intensified strategies to prevent infections should be implemented in MDS patients with preexisting neutropenia who undergo HSCT

Cytomegalovirus Viral Load and Virus-Specific Immune Reconstitution after Peripheral Blood Stem Cell versus Bone Marrow Transplantation

Peripheral blood stem cell (PBSC) products contain more T cells and monocytes when compared with bone marrow (BM), leading to fewer bacterial and fungal infections. Cytomegelovirus (CMV) viral load and disease as well as CMV-specific immune reconstitution were compared in patients enrolled in a randomized trial comparing PSBC and BM transplantation. There was a higher rate of CMV infection and disease during the first 100 days after transplantation among PBSC recipients (any antigenemia/DNAemia: PBSC, 63% vs BM, 42%, P = .04; CMV disease: PBSC, 17% vs BM, 4%, P = .03). By 2 years, CMV disease rates were similar. The early increase in CMV events correlated temporarily with lower CMV-specific CD4+ T helper and CD8+ cytotoxic T lymphocyte function at 30 days after transplantation in PBSC recipients. By 3 months after transplantation and thereafter, CMV-specific immune responses were similar between BM and PBSC recipients. In conclusion, higher CMV infection and disease rates occurred in PBSC transplant recipients early after transplantation. These differences may be because of a transient delay in CMV-specific immune reconstitution following PBSC transplantation

Overlap subtype of chronic graft-versus-host disease is associated with an adverse prognosis, functional impairment, and inferior patient-reported outcomes: A Chronic Graft-versus-Host Disease Consortium study

Background The National Institutes of Health Consensus Conference proposed the term “overlap” graft-versus-host disease to describe the situation when both acute and chronic graft-versus-host disease are present. Design and Methods We examined whether the overlap subtype of graft-versus-host disease was associated with a different prognosis, functional limitations, or patient-reported outcomes compared to “classic” chronic graft-versus-host disease without any acute features. Results Prospective data were collected from 427 patients from nine centers. Patients were classified as having overlap (n=352) or classic chronic (n=75) graft-versus-host disease based on reported organ involvement. Overlap cases had a significantly shorter median time from transplantation to cohort enrollment (P=0.01), were more likely to be incident cases (P\u3c0.001), and had a lower platelet count at onset of the graft-versus-host disease (P\u3c0.001). Patients with overlap graft-versus-host disease had significantly greater functional impairment measured by a 2-minute walk test, higher symptom burden and lower Human Activity Profile scores. Quality of life was similar, except patients with overlap graft-versus-host disease had worse social functioning, assessed by the Short Form-36. Multivariable analysis utilizing time-varying covariates demonstrated that the overlap subtype of graft-versus-host disease was associated with worse overall survival (HR 2.1, 95% CI 1.1–4.7; P=0.03) and higher non-relapse mortality (HR 2.8, 95% CI 1.2–8.3; P=0.02) than classic chronic graft-versus-host disease. Conclusions These findings suggest that the presence of acute features in patients with chronic graft-versus-host disease is a marker of adverse prognosis, greater functional impairment, and higher symptom burden