Pre-Emptive Use of Rituximab in Epstein-Barr Virus Reactivation: Incidence, Predictive Factors, Monitoring, and Outcomes.

Post-transplant lymphoproliferative disease (PTLD) is a fatal complication of hematopoietic cell transplantation (HCT) associated with the Epstein-Barr virus (EBV). Multiple factors such as transplant type, graft-versus-host disease (GVHD), human leukocyte antigens (HLA) mismatch, patient age, and T-lymphocyte-depleting treatments increase the risk of PTLD. EBV reactivation in hematopoietic cell transplant recipients is monitored through periodic quantitative polymerase chain reaction (Q-PCR) tests. However, substantial uncertainty persists regarding the clinically significant EBV levels for these patients. Guidelines recommend initiating EBV monitoring no later than four weeks post-HCT and conducting it weekly. Pre-emptive therapies, such as the reduction of immunosuppressive therapy and the administration of rituximab to treat EBV viral loads are also suggested. In this study, we investigated the occurrence of EBV-PTLD in 546 HCT recipients, focusing on the clinical manifestations and risk factors associated with the disease. We managed to identify 67,150 viral genomic copies/mL as the cutoff point for predicting PTLD, with 80% sensitivity and specificity. Among our cohort, only 1% of the patients presented PTLD. Anti-thymocyte globulin (ATG) and GVHD were independently associated with lower survival rates and higher treatment-related mortality. According to our findings, prophylactic measures including regular monitoring, pre-emptive therapy, and supportive treatment against infections can be effective in preventing EBV-related complications. This study also recommends conducting EBV monitoring at regular intervals, initiating pre-emptive therapy when viral load increases, and identifying factors that increase the risk of PTLD. Our study stresses the importance of frequent and careful follow-ups of post-transplant complications and early intervention in order to improve survival rates and reduce mortality.

Intestinal thrombotic microangiopathy: a distinct entity in the spectrum of graft-versus-host disease.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a severe complication of allogeneic hematopoietic cell transplantation (allo-HCT) with multisystem involvement. Cases of TMA in the intestinal vasculature (intestinal TMA/iTMA) have been reported. We hypothesized that iTMA is a distinct entity from TA-TMA. To test this hypothesis, we prospectively recruited allo-HCT recipients with an indication for endoscopy. Among 20 patients, histological features of iTMA, including loss of glands, total denudation of mucosa, apoptosis and detachment of endothelial cells, mucosal hemorrhage, intraluminal fibrin and microthrombi were found in six. Only 2/6 were classified as GVHD/TA-TMA, while the other 4 as GVHD/no TA-TMA. Gastro-intestinal symptoms were similar between the patients with or without iTMA. With a median follow-up of 11.1 (2.1-67.5) months, 1-year overall survival was 22.2% for iTMA, 55% for GVHD and 60% for TA-TMA. On multivariate analysis, independent unfavorable predictors of OS were iTMA (p = 0.048), HLA mismatched donors (p = 0.008) and gastro-intestinal bleeding (p = 0.021). In conclusion, iTMA emerges as a novel distinct entity in patients with GVHD and/or TA-TMA. Distinct histological features may be useful in differential diagnosis of these severe HCT complications. The higher mortality rates of iTMA than TA-TMA highlight the need for further investigation of this condition.

Isolated Extramedullary Relapse as a Poor Predictor of Survival after Allogeneic Hematopoietic Cell Transplantation for Acute Leukemia.

Limited and conflicting data exist on outcomes of patients with extramedullary relapses (EMRs) after allogeneic hematopoietic cell transplantation (allo-HCT) for acute leukemias. We retrospectively reviewed charts of consecutive allo-HCT recipients who underwent transplantation in our center with the indication of acute leukemia (July 1990 to July 2018). Incidences of isolated EMR (iEMR) and bone marrow relapse (BMR) were calculated using cumulative incidence (CI) analysis, with each and treatment-related mortality considered a competing risk. We studied 554 allo-HCT recipients for 1.8 years (range, .04 to 27.75). Ten-year CI of 10.5% for iEMR was associated only with advanced disease phase at transplantation, whereas 10-year CI of 34.8% for BMR was independently associated with pretransplant disease phase, lines of treatment, and fungal infections. Most iEMR and BMR patients (75% and 81%, respectively) received systemic treatment combined with local radiation for iEMR (26%) and donor lymphocyte infusions (16% and 28%, respectively) when feasible. Extensive chronic graft-versus-host disease (GVHD) was recorded in 47% of iEMR and 48% of BMR patients. Outcomes were poor both in iEMR (10-year overall survival [OS], 18.3%) and BMR (10-year OS, 19.1%). Independent predictors of OS were disease phase, type of donor, acute and chronic GVHD, fungal infections, iEMR, and BMR. In a large population with long-term follow-up, incidence of iEMR was relatively high, developed at the late post-transplant period, and was associated only with disease phase at transplantation. Furthermore, iEMR and BMR conferred similarly poor outcomes despite systemic treatment or extensive chronic GVHD.

Cytogenetic complexity in chronic lymphocytic leukemia: definitions, associations, and clinical impact.

Recent evidence suggests that complex karyotype (CK) defined by the presence of ≥3 chromosomal aberrations (structural and/or numerical) identified by using chromosome-banding analysis (CBA) may be relevant for treatment decision-making in chronic lymphocytic leukemia (CLL). However, many challenges toward the routine clinical application of CBA remain. In a retrospective study of 5290 patients with available CBA data, we explored both clinicobiological associations and the clinical impact of CK in CLL. We found that patients with ≥5 abnormalities, defined as high-CK, exhibit uniformly dismal clinical outcomes, independently of clinical stage, TP53 aberrations (deletion of chromosome 17p and/or TP53 mutations [TP53abs]), and the expression of somatically hypermutated (M-CLL) or unmutated immunoglobulin heavy variable genes. Thus, they contrasted with CK cases with 3 or 4 aberrations (low-CK and intermediate-CK, respectively) who followed aggressive disease courses only in the presence of TP53abs. At the other end of the spectrum, patients with CK and +12,+19 displayed an exceptionally indolent profile. Building upon CK, TP53abs, and immunoglobulin heavy variable gene somatic hypermutation status, we propose a novel hierarchical model in which patients with high-CK exhibit the worst prognosis, whereas those with mutated CLL lacking CK or TP53abs, as well as CK with +12,+19, show the longest overall survival. Thus, CK should not be axiomatically considered unfavorable in CLL, representing a heterogeneous group with variable clinical behavior. High-CK with ≥5 chromosomal aberrations emerges as prognostically adverse, independent of other biomarkers. Prospective clinical validation is warranted before ultimately incorporating high-CK in risk stratification of CLL.

Extramedullary relapse and discordant CD19 expression between bone marrow and extramedullary sites in relapsed acute lymphoblastic leukemia after blinatumomab treatment.

Blinatumomab, a bispecific T-cell engager antibody construct targeting CD19, has been shown to improve the outcome in patients with relapsed and/or refractory B-cell acute lymphoblastic leukemia. Treatment with blinatumomab demonstrated significant survival benefit over chemotherapy, supporting its use as a bridge therapy to allogeneic hematopoietic stem cell transplantation. Unfortunately, following initial response, approximately 50% of responding patients eventually relapse. At the time of failure, the majority of patients have CD19-positive blasts, yet a concerning number of CD19-negative relapses has been reported. In the data reported herein, we present an interesting case of a 42-year-old patient with primary refractory B-cell acute lymphoblastic leukemia who achieved complete morphologic remission after one cycle of blinatumomab as a single agent. Notably, and in the absence of extramedullary disease history, the response in marrow coincided with the emergence of CD19-positive extramedullary relapse including sites of previous punctures for blood and bone marrow samples, as confirmed by biopsy, as well as parenchymal organs (eg breast and lung). During the second cycle of blinatumomab, a CD19-negative morphological relapse emerged. The loss of CD19 was a transient event, as leukemic cells partially regained it after chemotherapy. This study illustrates a challenging situation of relapsed and refractory acute lymphoblastic leukemia complicated with extramedullary disease after exposure to a bispecific T-cell engager antibody, such as blinatumomab. Physicians should maintain a high level of suspicion for the evolution of extramedullary leukemia. This pattern of resistance and/or relapse to blinatumomab resembles the graft-versus-leukemia effect after allogeneic transplantation (stronger in blood and marrow than in other tissues). Mechanisms of resistance to blinatumomab are not yet clear. Combination treatments for refractory patients and those at high risk for exramedullary disease may warrant future assessment.

Long-term outcomes of total body irradiation plus cyclophosphamide versus busulfan plus cyclophosphamide as conditioning regimen for acute lymphoblastic leukemia: a comparative study.

The role of total body irradiation (TBI) in allogeneic hematopoietic stem cell transplantation (HCT) for adult acute lymphoblastic leukemia (ALL) remains controversial. Therefore, we investigated long-term treatment outcomes of transplanted ALL patients aiming to identify prognostic factors and the impact of conditioning. We enrolled consecutive ALL patients transplanted from 1990 to 2016, following TBI- or busulfan (Bu)-based conditioning regimen. We studied 151 ALL patients transplanted in first complete remission (CR) (60), other CR (33), or relapsed/refractory disease (58) from sibling (87), and HLA-matched (42) or mismatched (17) unrelated and alternative donors (5). High-dose fractionated TBI-based conditioning was administered in 84. No differences were observed in baseline characteristics, except for disease stage at transplant, donor type, and graft source. With a follow-up of 19.0 (0.5-170.5) in TBI and 14.5 (1.2-319.1) months in non-TBI patients, there was no difference in acute (grades II-IV) or chronic GVHD, thrombotic microangiopathy, and bacterial or fungal infections. Only viral infections were significantly increased in the non-TBI group. There was no significant difference in the cumulative incidence (CI) of treatment-related or relapse mortality and disease-free or overall survival (OS). In the multivariate analysis, unfavorable pre-transplant predictors of OS were age (p = 0.024), advanced disease stage (p = 0.007), and female-to-male donor (p = 0.006). Interestingly, TBI patients younger than 40 years had significantly higher OS (55.1%, p = 0.023) and DFS (48.6%, p = 0.020). In conclusion, high-dose TBI is feasible in younger patients providing better survival. The choice between TBI- or Bu-conditioning regimens remains challenging.

Carmustine, etoposide, cytarabine and melphalan versus a newly designed intravenous busulfan-based Busulfex, etoposide and melphalan conditioning regimen for autologous hematopoietic cell transplant: a retrospective matched-pair analysis in advanced Hodgkin and non-Hodgkin lymphomas.

Optimal conditioning remains a challenge in lymphomas. We designed a regimen consisting of Busulfex, etoposide and melphalan (BuEM). We retrospectively analyzed the outcome of patients conditioned with carmustine, etoposide, cytarabine and melphalan (BEAM) or BuEM in matched-pair analysis on a planned 2:1 ratio. Eighty-seven patients treated with BEAM who fulfilled the matching criteria were randomly selected. Two-year progression-free survival/overall survival (PFS/OS) were 63.2%/76.7% for BEAM vs. 65.6%/79.8% for BuEM after 64.7 and 42.7 months, respectively. Furthermore, marginally better PFS and OS were noted in Hodgkin lymphoma (HL) after BuEM. In multivariate analysis, PFS was superior in HL, chemosensitive disease and complete remission post-transplant. BEAM correlated with faster engraftment, reduced infections, less mucositis and liver toxicity, and BuEM with less need for blood cell and platelet transfusions and granulocyte colony-stimulating factor administration. In conclusion, BuEM was well tolerated and equally highly efficacious as BEAM for non-Hodgkin lymphoma and offered marginally significantly improved PFS and OS in HL with acceptable toxicity and zero mortality.

Familial CD3+ T large granular lymphocyte leukemia: evidence that genetic predisposition and antigen selection promote clonal cytotoxic T-cell responses.

CD3+ T-large granular lymphocyte (T-LGL) proliferations often present with cytopenias and splenomegaly and are linked to autoimmunity, especially rheumatoid arthritis and Felty's syndrome. We report here the intra-family occurrence of T-LGL leukemia in a father and son, both presenting with cytopenias and splenomegaly. Both patients carried the HLA-DRB1*04 allele, strongly associated with rheumatoid arthritis and Felty's syndrome, exhibited distinctive histopathological features suggestive of immune-mediated suppression of hematopoiesis and expressed a remarkably skewed T-cell receptor beta chain gene repertoire with overtime evolution (clonal drift). Immunoinformatics analysis and comparisons with clonotype sequences from various entities revealed (quasi)identities between (i) father and son, and (ii) father or son and patients with autoimmune disorders, T-LGL leukemia or chronic idiopathic neutropenia. Altogether, our results further corroborate antigen selection in the ontogeny of T-LGL leukemia and point to the interplay between genetics and the (micro)environment in shaping the outcome of cytotoxic T cell responses.

Chromosomal translocations and karyotype complexity in chronic lymphocytic leukemia: a systematic reappraisal of classic cytogenetic data.

The significance of chromosomal translocations (CTRAs) and karyotype complexity (KC) in chronic lymphocytic leukemia (CLL) remains uncertain. To gain insight into these issues, we evaluated a series of 1001 CLL cases with reliable classic cytogenetic data obtained within 6 months from diagnosis before any treatment. Overall, 320 cases were found to carry ≥ 1 CTRAs. The most frequent chromosome breakpoints were 13q, followed by 14q, 18q, 17q, and 17p; notably, CTRAs involving chromosome 13q showed a wide spectrum of translocation partners. KC (≥ 3 aberrations) was detected in 157 cases and significantly (P < 0.005) associated with unmutated IGHV genes and aberrations of chromosome 17p. Furthermore, it was identified as an independent prognostic factor for shorter time-to-first-treatment. CTRAs were assigned to two categories (i) CTRAs present in the context of KC, often with involvement of chromosome 17p aberrations, occurring mostly in CLL with unmutated IGHV genes; in such cases, we found that KC rather than the presence of CTRAs per se negatively impacts on survival; (ii) CTRAs in cases without KC, having limited if any impact on survival. On this evidence, we propose that all CTRAs in CLL are not equivalent but rather develop by different processes and are associated with distinct clonal behavior.