Anne Marie Gonzales

Influence of infused cell dose and HLA match on engraftment after double-unit cord blood allografts

The influence of cell dose and human leukocyte antigen (HLA) match on double-unit cord blood (CB) engraftment is not established. Therefore, we analyzed the impact of cell dose and high-resolution HLA match on neutrophil engraftment in 84 double-unit CB transplant recipients. The 94% sustained engraftment rate was accounted for by 1 unit in nearly all patients. Higher CD3(+) cell doses (P = .04) and percentage of CD34(+) cell viability (P = .008) were associated with unit dominance. After myeloablative conditioning, higher dominant unit total nucleated cell (TNC), CD34(+) cell, and colony-forming unit doses were associated with higher sustained engraftment and faster neutrophil recovery (P = .07, P = .0008, and P < .0001, respectively). Total infused TNC (P = .0007) and CD3(+) cell doses (P = .001) also significantly influenced engraftment. At high-resolution extensive donor-recipient HLA disparity was frequent, but had no influence on engraftment (P = .66), or unit dominance (P = .13). Although the unit-unit HLA match also did not affect sustained engraftment (P = 1.0), recipients of units closely (7-10 to 10-10) HLA-matched to each other were more likely to demonstrate initial engraftment of both units (P < .0001). Our findings have important implications for unit selection and provide further insight into double-unit biology.

Quantitative assessment of T-cell repertoire recovery after hematopoietic stem cell transplantation

Delayed T cell recovery and restricted T cell receptor (TCR) diversity after allogeneic hematopoietic stem cell transplantation (allo-HSCT) are associated with increased risks of infection and cancer relapse. Technical challenges have limited faithful measurement of TCR diversity after allo-HSCT. Here we combined 5′ rapid amplification of complementary DNA ends PCR with deep sequencing to quantify TCR diversity in 28 recipients of allo-HSCT using a single oligonucleotide pair. Analysis of duplicate blood samples confirmed that we accurately determined the frequency of individual TCRs. After 6 months, cord blood–graft recipients approximated the TCR diversity of healthy individuals, whereas recipients of T cell–depleted peripheral-blood stem cell grafts had 28-fold and 14-fold lower CD4+ and CD8+ T cell diversities, respectively. After 12 months, these deficiencies had improved for the CD4+ but not the CD8+ T cell compartment. Overall, this method provides unprecedented views of T cell repertoire recovery after allo-HSCT and may identify patients at high risk of infection or relapse.

Reduced late mortality risk contributes to similar survival after double-unit cord blood transplantation compared with related and unrelated donor hematopoietic stem cell transplantation.

Cord blood transplantation (CB-T) is increasingly used as a treatment alternative for hematologic malignancies. However, how CB-T compares to related (RD-T) and unrelated donor transplantation (URD-T) is not established. We compared survival of 75 double-unit CB-T, 108 RD-T, and 184 URD-T recipients who received transplants over the same period for the treatment of hematologic malignancies. Patients had similar ages and disease risk, and a similar percentage had acute leukemia. The incidence of day 180 transplant-related mortality (TRM) of 21% (95% confidence interval [CI]: 12-31) after CB-T was higher than that of RD-T recipients. However, this was compensated for by a low risk of TRM after day 180, and a relatively low incidence of relapse. Hence, the 2-year progression-free survival (PFS) of 55% (95% CI: 45-68) after CB-T was similar to that after RD-T or URD-T (P = .573). In multivariate analysis, donor source had no influence on PFS, with the only significant factors being recipient age and disease risk. In a subanalysis of 201 patients with acute leukemia, CB-T, RD-T, and URD-T recipients also had similar 2-year disease-free survival (P = .482). These data provide strong support for the further investigation of double-unit CB grafts as an alternative hematopoietic stem cell source.

Characteristics and Outcomes of Breast Cancer in Women With and Without a History of Radiation for Hodgkin's Lymphoma: A Multi-Institutional, Matched Cohort Study

PURPOSE To compare characteristics and outcomes of breast cancer in women with and without a history of radiation therapy (RT) for Hodgkins lymphoma (HL). PATIENTS AND METHODS Women with breast cancer diagnosed from 1980 to 2006 after RT for HL were identified from eight North American hospitals and were matched three-to-one with patients with sporadic breast cancer by age, race, and year of breast cancer diagnosis. Information on patient, tumor and treatment characteristics, and clinical outcomes was abstracted from medical records. RESULTS A total of 253 patients with breast cancer with a history of RT for HL were matched with 741 patients with sporadic breast cancer. Median time from HL to breast cancer diagnosis was 18 years. Median age at breast cancer diagnosis was 42 years. Breast cancer after RT for HL was more likely to be detected by screening, was more likely to be diagnosed at an earlier stage, and was more likely to be bilateral at diagnosis. HL survivors had an increased risk of metachronous contralateral breast cancer (adjusted hazard ratio [HR], 4.3; 95% CI, 1.7 to 11.0) and death as a result of any cause (adjusted HR, 1.9; 95% CI, 1.1 to 3.3). Breast cancer-specific mortality was also elevated, but this difference was not statistically significant (adjusted HR, 1.6; 95% CI, 0.7 to 3.4). CONCLUSION In women with a history of RT for HL, breast cancer is diagnosed at an earlier stage, but these women are at greater risk for bilateral disease and are more likely to die as a result of causes other than breast cancer. Our findings support close follow-up for contralateral tumors in these patients and ongoing primary care to manage comorbid conditions.

Graft-versus-Host Disease after Double-Unit Cord Blood Transplantation Has Unique Features and an Association with Engrafting Unit-to-Recipient HLA Match

Manifestations of and risk factors for graft-versus-host disease (GVHD) after double-unit cord blood transplantation (DCBT) are not firmly established. We evaluated 115 DCBT recipients (median age, 37 years) who underwent transplantation for hematologic malignancies with myeloablative or nonmyeloablative conditioning and calcineurin inhibitor/mycophenolate mofetil immunosuppression. Incidence of day 180 grades II to IV and III to IV acute GVHD (aGVHD) were 53% (95% confidence interval, 44 to 62) and 23% (95% confidence interval, 15 to 31), respectively, with a median onset of 40 days (range, 14 to 169). Eighty percent of patients with grades II to IV aGVHD had gut involvement, and 79% and 85% had day 28 treatment responses to systemic corticosteroids or budesonide, respectively. Of 89 engrafted patients cancer-free at day 100, 54% subsequently had active GVHD, with 79% of those affected having persistent or recurrent aGVHD or overlap syndrome. Late GVHD in the form of classic chronic GVHD was uncommon. Notably, grades III to IV aGVHD incidence was lower if the engrafting unit human leukocyte antigen (HLA)-A, -B, -DRB1 allele match was >4/6 to the recipient (hazard ratio, 0.385; P = .031), whereas engrafting unit infused nucleated cell dose and unit-to-unit HLA match were not significant. GVHD after DCBT was common in our study, predominantly affected the gut, and had a high therapy response, and late GVHD frequently had acute features. Our findings support the consideration of HLA- A,-B,-DRB1 allele donor-recipient (but not unit-unit) HLA match in unit selection, a practice change in the field. Moreover, new prophylaxis strategies that target the gastrointestinal tract are needed.

[18F]FDG-positron emission tomography coregistration with computed tomography scans for radiation treatment planning of lymphoma and hematologic malignancies

PURPOSE Positron emission-tomography (PET) using 2-[(18)F]fluoro-2-deoxyglucose (FDG-PET) increases sensitivity and specificity of disease detection in lymphoma and thus is standard in lymphoma management. This study examines the effects of coregistering FDG-PET and computed tomography (CT) (PET/CT) scans on treatment planning for lymphoma patients. METHODS AND MATERIALS Twenty-nine patients (30 positive PET scans) underwent PET/CT treatment planning from July 2004 to February 2007 and were retrospectively studied. For each patient, gross tumor volume was blindly contoured on the CT-only and PET/CT studies by a radiation oncologist. Treatment plans were generated for both the CT-only and PET/CT planning target volumes (PTVs) for all patients. Normal tissue doses and PTV coverage were evaluated using dose--volume histograms for all sites. RESULTS Thirty-two treatment sites were evaluated. Twenty-one patients had non-Hodgkin lymphoma, 5 patients had Hodgkin lymphoma, and 3 patients had plasma cell neoplasms. Previously undetected FDG-avid sites were identified in 3 patients during PET/CT simulation, resulting in one additional treatment field. Due to unexpected PET/CT simulation findings, 2 patients did not proceed with radiation treatment. The addition of PET changed the volume of 23 sites (72%). The PTV was increased in 15 sites (47%) by a median of 11% (range, 6-40%) and reduced in 8 sites (25%) by a median of 20% (range, 6%-75%). In six (19%) replanned sites, the CT-based treatment plan would not have adequately covered the PTV defined by PET/CT. CONCLUSIONS Incorporation of FDG-PET into CT-based treatment planning for lymphoma patients resulted in considerable changes in management, volume definition, and normal tissue dosimetry for a significant number of patients.

Frequent human herpesvirus-6 viremia but low incidence of encephalitis in double-unit cord blood recipients transplanted without antithymocyte globulin.

Cord blood transplantation (CBT) is a known risk factor for human herpesvirus-6 (HHV-6) infection. We analyzed the nature of HHV-6 infections in 125 double-unit CBT recipients (median age, 42 years) transplanted for hematologic malignancies with calcineurin inhibitor/mycophenolate mofetil prophylaxis and no antithymocyte globulin. One hundred seventeen patients (94%) reactivated HHV-6 by quantitative plasma PCR (median peak, 7600 copies/mL; range, 100 to 160,000) at a median of 20 days (range, 10 to 59) after transplantation. HHV-6 encephalitis occurred in 2 patients (1.6%), of whom 1 died and 1 recovered with therapy. No association was found between high-level HHV-6 viremia (≥10,000 or ≥25,000 copies/mL) and age, diagnosis, conditioning intensity, or dominant unit characteristics or between high-level viremia and transplant outcomes (engraftment, cytomegalovirus reactivation, day 100 grades II to IV acute graft-versus-host disease, day 100 transplant-related mortality, or 1-year disease-free survival). HHV-6 therapy delayed the onset of cytomegalovirus reactivation. Interestingly, HHV-6 resolution was observed in untreated patients, and resolution of viremia correlated with absolute lymphocyte count recovery. We observed a low incidence of encephalitis and no association with CBT outcomes. Our data suggest therapy in uncomplicated viremia may not be warranted. However, further investigation of the risk-to-benefit of HHV-6 viremia treatment and standardization of PCR testing is required.

Incidence, nature and mortality of cytomegalovirus infection after double-unit cord blood transplant

Abstract Cord blood transplant (CBT) extends allograft access but is associated with a significant risk for cytomegalovirus (CMV) infection. We analyzed CMV infection in 157 CBT recipients transplanted for hematological malignancies. As compared with antigenemia testing, routine polymerase chain reaction (PCR) monitoring was associated with increased and earlier CMV infection detection (1-year incidence if seropositive 67% [median onset 41 days] vs. 100% at an earlier 33-day median [p < 0.001]) and decreased gastrointestinal disease. One-year CMV-related transplant-related mortality was 11% in CMV+ patients with 7/9 deaths associated with initial infection. Disease-free survival was lower in seropositive compared with seronegative patients (1-year: 55% vs. 73%, p = 0.02). However, in multivariate analysis adjusting for age, treatment failure risk in CMV+ patients was not significant (hazard ratio 1.52, p = 0.11). CMV infection is a major challenge in seropositive CBT recipients. While PCR surveillance permits early detection of viremia, new prophylaxis and therapeutic strategies are needed.

Donor-recipient allele-level HLA matching of unrelated cord blood units reveals high degrees of mismatch and alters graft selection.

The feasibility of selecting cord blood (CB) units at high-resolution HLA match has not been investigated. We analyzed the high-resolution donor–recipient HLA match of 100 double-unit 4–6/6 HLA-A,-B antigen, -DRB1 allele-matched CB grafts (units 1a and 1b) and their back-up units (n=377 units in total). The median cryopreserved graft dose was 2.9 × 107/kg/unit, and at high resolution these units had a median donor–recipient HLA-allele match of 5/8 (range 2–8/8) and 6/10 (range 2–9/10), respectively. We then evaluated how often use of high-resolution HLA-match criteria would change the original graft selection to substitute one or both of the back-up units for units 1a and/or 1b. On using a model in which both a higher eight-allele HLA match and a cell dose ⩾2.0 × 107/kg/unit were required, graft selection changed in 33% of transplants with minimal effect on cell dose (8.3% reduction). In summary, while units chosen based on HLA-A,-B antigen and -DRB1 allele match have substantial mismatch at higher resolution, CB selection based on high-resolution HLA match is possible in a significant proportion of patients without compromise in cell dose.

Importance of day 21 BM chimerism in sustained neutrophil engraftment following double-unit cord blood transplantation

Delayed or failed engraftment remains a concern after cord blood transplantation (CBT) even when using double-unit grafts. Therefore, we analyzed the association between BM assessment performed approximately 21 days after transplantation, and the speed and success of sustained donor-derived neutrophil engraftment in 56 myeloablative double-unit CBT (DCBT) recipients. Overall, the cumulative incidence of sustained neutrophil engraftment was 95% (95% confidence intervals (CI): 89–100). Of the percentage of myeloid precursors, the BM cellularity and the total donor chimerism the total donor chimerism percentage had the most critical association with the speed and success of engraftment. DCBT recipients who were 100% donor achieved a 98% engraftment rate at a median of 22 days. This compared with 100% engraftment in patients who were 90–99% donor, but at a delayed median of 29 days and only 68% engraftment in patients <90% donor at a median of 37 days (P=0.001). Multivariate analysis was performed in the subgroup of patients who had not engrafted at the time the BM analysis was performed, the subgroup of most clinical concern. This confirmed donor chimerism was predictive of subsequent neutrophil recovery (P=0.004). These findings demonstrate the importance of the day 21 BM chimerism determinations after DCBT.