Directionality of non-permissive HLA-DPB1 T-cell epitope group mismatches does not improve clinical risk stratification in 8/8 matched unrelated donor hematopoietic cell transplantation.

In 8/8 HLA-matched unrelated donor (UD) hematopoietic cell transplants (HCT), HLA-DPB1 mismatches between alleles from different T-cell epitope (TCE) groups (non-permissive mismatches) are associated with significantly higher risks of mortality compared with those between alleles from the same TCE group (permissive mismatches); however, the relevance of mismatch directionality, that is (host vs graft (uni-directional HvG), graft vs host (uni-directional GvH) or both (bi-directional) in the non-permissive setting is unknown. We show here significantly higher in vitro relative responses (RR) to bi-directional mismatches compared with uni-directional HvG or GvH mismatches in a total of 420 one-way mixed lymphocyte reactions between 10/10 matched pairs (RR 27.5 vs 7.5 vs 15.5, respectively, P<0.001). However, in 3281 8/8 matched UD HCT for leukemia or myelodysplastic syndrome, the hazards of transplant-related mortality (TRM) were similar for uni-directional HvG or GvH mismatches and bi-directional mismatches (hazard ratio (HR) 1.32, P=0.001 vs HR 1.28, P=0.005 and HR 1.34, P=0.046), compared with permissive mismatches. Similar results were observed for overall survival. No statistical differences between the uni- and the bi-directional non-permissive groups were detected in pairwise comparisons for any of the outcomes tested. We conclude that consideration of directionality does not improve risk stratification by non-permissive HLA-DPB1 TCE mismatches in UD searches.

Impact of early CMV reactivation in cord blood stem cell recipients in the current era.

Several studies have reported an association between CMV reactivation and a decreased incidence of relapse for AML after adult donor allogeneic hematopoietic cell transplantation (HCT). Limited data, however, are available on the impact of CMV reactivation on relapse after cord blood (CB) stem cell transplantation. The unique combination of higher incidence of CMV reactivation in the seropositive recipient and lower incidence of graft versus host disease (GvHD) in CB HCT permits a valuable design to analyze the impact of CMV reactivation. Data from 1684 patients transplanted with CB between 2003 and 2010 for AML and ALL were analyzed. The median time to CMV reactivation was 34 days (range: 2-287). CMV reactivation and positive CMV serology were associated with increased non-relapse mortality (NRM) among both AML and ALL CB recipients (reactivation, AML: relative risk (RR) 1.41 (1.07-1.85); ALL: 1.60 (1.14-2.23); Serology, AML: RR 1.39 (1.05-1.85), ALL: RR 1.61 (1.18-2.19)). For patients with ALL, but not those with AML, this yielded inferior overall survival (P<0.005). Risk of relapse was not influenced by CMV reactivation or positive CMV serostatus for either disease.

The incidence, mortality and timing of Pneumocystis jiroveci pneumonia after hematopoietic cell transplantation: a CIBMTR analysis.

Pneumocystis jiroveci pneumonia (PJP) is associated with high morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Little is known about PJP infections after HSCT because of the rarity of disease given routine prophylaxis. We report the results of a Center for International Blood and Marrow Transplant Research study evaluating the incidence, timing, prophylaxis agents, risk factors and mortality of PJP after autologous (auto) and allogeneic (allo) HSCT. Between 1995 and 2005, 0.63% allo recipients and 0.28% auto recipients of first HSCT developed PJP. Cases occurred as early as 30 days to beyond a year after allo HSCT. A nested case cohort analysis with supplemental data (n=68 allo cases, n=111 allo controls) revealed that risk factors for PJP infection included lymphopenia and mismatch after HSCT. After allo or auto HSCT, overall survival was significantly poorer among cases vs controls (P=0.0004). After controlling for significant variables, the proportional hazards model revealed that PJP cases were 6.87 times more likely to die vs matched controls (P<0.0001). We conclude PJP infection is rare after HSCT but is associated with high mortality. Factors associated with GVHD and with poor immune reconstitution are among the risk factors for PJP and suggest that protracted prophylaxis for PJP in high-risk HSCT recipients may improve outcomes.

Risk factors and impact of non-Aspergillus mold infections following allogeneic HCT: a CIBMTR infection and immune reconstitution analysis.

Risk factors for non-Aspergillus mold infection (NAMI) and the impact on transplant outcome are poorly assessed in the current era of antifungal agents. Outcomes of 124 patients receiving allogeneic hematopoietic cell transplantation (HCT) diagnosed with either mucormycosis (n=72) or fusariosis (n=52) between days 0 and 365 after HCT are described and compared with a control cohort (n=11 856). Patients with NAMI had more advanced disease (mucormycois: 25%, fusariosis: 23% and controls: 18%; P=0.004) and were more likely to have a Karnofsky performance status (KPS) <90% at HCT (mucormycosis: 42%, fusariosis: 38% and controls: 28%; P=0.048). The 1-year survival after HCT was 22% (15-29%) for cases and was significantly inferior compared with controls (65% (64-65%); P<0.001). Survival from infection was similarly dismal regardless of mucormycosis: 15% (8-25%) and fusariosis: 21% (11-33%). In multivariable analysis, NAMI was associated with a sixfold higher risk of death (P<0.0001) regardless of the site or timing of infection. Risk factors for mucormycosis include preceding acute GvHD, prior Aspergillus infection and older age. For fusariosis, increased risks including receipt of cord blood, prior CMV infection and transplant before May 2002. In conclusion, NAMI occurs infrequently, is associated with high mortality and appears with similar frequency in the current antifungal era.

A prognostic model predicting autologous transplantation outcomes in children, adolescents and young adults with Hodgkin lymphoma.

Autologous hematopoietic cell transplantation (AutoHCT) is a potentially curative treatment modality for relapsed/refractory Hodgkin lymphoma (HL). However, no large studies have evaluated pretransplant factors predictive of outcomes of AutoHCT in children, adolescents and young adults (CAYA, age <30 years). In a retrospective study, we analyzed 606 CAYA patients (median age 23 years) with relapsed/refractory HL who underwent AutoHCT between 1995 and 2010. The probabilities of PFS at 1, 5 and 10 years were 66% (95% confidence interval (CI): 62-70), 52% (95% CI: 48-57) and 47% (95% CI: 42-51), respectively. Multivariate analysis for PFS demonstrated that at the time of AutoHCT patients with Karnofsky/Lansky score ⩾90, no extranodal involvement and chemosensitive disease had significantly improved PFS. Patients with time from diagnosis to first relapse of <1 year had a significantly inferior PFS. A prognostic model for PFS was developed that stratified patients into low-, intermediate- and high-risk groups, predicting for 5-year PFS probabilities of 72% (95% CI: 64-80), 53% (95% CI: 47-59) and 23% (95% CI: 9-36), respectively. This large study identifies a group of CAYA patients with relapsed/refractory HL who are at high risk of progression after AutoHCT. Such patients should be targeted for novel therapeutic and/or maintenance approaches post-AutoHCT.

Allogeneic hematopoietic cell transplantation for neuroblastoma: the CIBMTR experience.

Although the role of autologous hematopoietic cell transplantation (auto-HCT) is well established in neuroblastoma (NBL), the role of allogeneic HCT (allo-HCT) is controversial. The Center for International Blood and Marrow Transplant Research conducted a retrospective review of 143 allo-HCT for NBL reported in 1990-2007. Patients were categorized into two different groups: those who had not (Group 1) and had (Group 2) undergone a prior auto-HCT (n=46 and 97, respectively). One-year and five-year OS were 59% and 29% for Group 1 and 50% and 7% for Group 2, respectively. Among donor types, disease-free survival (DFS) and OS were significantly lower for unrelated transplants at 1 and 3 years but not at 5 years post HCT. Patients in CR or very good partial response (VGPR) at transplant had lower relapse rates and better DFS and OS, compared with those not in CR or VGPR. Our analysis indicates that allo-HCT can cure some neuroblastoma patients, with lower relapse rates and improved survival in patients without a history of prior auto-HCT as compared with those patients who had previously undergone auto-HCT. Although the data do not address why either strategy was chosen for patients, allo-HCT after a prior auto-HCT appears to offer minimal benefit. Disease recurrence remains the most common cause of treatment failure.

Overexpression of p53 and rare genetic mutation in mesenchymal chondrosarcoma.

Mesenchymal chondrosarcoma is extremely rare and accounts for less than 2% of all chondrosarcomas. The pathogenesis and the molecular genetic events which contribute to the development of mesenchymal chondrosarcoma are not well elucidated, due in part to the lack of sufficient tumor tissue available. To characterize the involvement of the p53 gene abnormality in this disease, we analyzed expression and sequence alteration of p53 by immunohistochemical analysis of the protein expression and quantitative DNA/PCR and PCR-SSCP assays of the gene in 33 paraffin-embedded tissue specimens. Immunohistochemical analysis demonstrated that 19 (61.3%) of 31 had nuclear overexpression of p53 while 7 (22.6%) showed cytoplasmic expression. The remaining 5 (16.1%) were negative for p53 staining. The nuclear positivity of p53 was observed within a range of 22-64% (mean 37.3%) of tumor cells and showed a positive staining in mesenchymal components as well as chondroid components. Quantitative DNA/PCR analysis revealed that 6 (18.2%) of the 33 specimens carried significantly reduced or undetectably low levels of p53 indicating the genomic deletion of the gene in these tumors. In contrast, however, DNA/PCR-SSCP analysis failed to detect any types of mutations resulting in amino acid substitution within exons 5-9 regions of the gene. Taken together, our data suggests that genetic alteration of p53 is a relatively rare event in mesenchymal chondrosarcomas but substantial fraction of this type of tumors carries abnormal overexpression of p53, which might result from as yet unidentified epigenetic mechanism(s).

Identification of severe right ventricular dysfunction by technetium-99m-sestamibi gated SPECT imaging.

An 84-yr-old man with previous anterior wall myocardial infarction presented with shortness of breath and palpitations. His symptoms were attributed to myocardial ischemia, and he was referred for a stress 99mTc-sestamibi SPECT imaging study with gating. The images showed minimal left ventricular ischemia, but a dilated and hypokinetic right ventricle suggested pulmonary pathology as the probable etiology of his presenting symptoms. A subsequent ventilation perfusion study was consistent with the diagnosis of multiple pulmonary emboli. Thus, 99mTc-sestamibi SPECT imaging with gating provides information about right ventricular perfusion and function, enhancing the clinical utility of stress myocardial perfusion imaging.