Health-related quality of life in transplant ineligible newly diagnosed multiple myeloma patients treated with either thalidomide or lenalidomide-based regimen until progression: a prospective, open-label, multicenter, randomized, phase 3 study.

Data on the impact of long term treatment with immunomodulatory drugs (IMiD) on health-related quality of life (HRQoL) is limited. The HOVON-87/NMSG18 study was a randomized, phase 3 study in newly diagnosed transplant ineligible patients with multiple myeloma, comparing melphalan-prednisolone in combination with thalidomide or lenalidomide, followed by maintenance therapy until progression (MPT-T or MPR-R). The EORTC QLQ-C30 and MY20 questionnaires were completed at baseline, after three and nine induction cycles and six and 12 months of maintenance therapy. Linear mixed models and minimal important differences were used for evaluation. 596 patients participated in HRQoL reporting. Patients reported clinically relevant improvement in global quality of life (QoL), future perspective and role and emotional functioning, and less fatigue and pain in both arms. The latter being of large effect size. In general, improvement occurred after 6-12 months of maintenance only and was independent of the World Health Organisation performance at baseline. Patients treated with MPR-R reported clinically relevant worsening of diarrhea, and patients treated with MPT-T reported a higher incidence of neuropathy. Patients who remained on lenalidomide maintenance therapy for at least three months reported clinically meaningful improvement in global QoL and role functioning at six months, remaining stable thereafter. There were no clinically meaningful deteriorations, but patients on thalidomide reported clinically relevant worsening in neuropathy. In general, HRQoL improves both during induction and maintenance therapy with immunomodulatory drugs. The side effect profile of treatment did not negatively affect global QoL, but it was, however, clinically relevant for the patients. (Clinicaltrials.gov identifier: NTR1630).

Rituximab-PECC induction followed by 90 Y-ibritumomab tiuxetan consolidation in relapsed or refractory DLBCL patients who are ineligible for or have failed ASCT: results from a phase II HOVON study.

Patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) after, or ineligible for, autologous stem cell transplantation (ASCT) have a dismal prognosis. This phase II study evaluated treatment with R-PECC (rituximab, prednisolone, etoposide, chlorambucil, lomustine), every 28 days for 4 cycles in 62 patients, followed by radio-immunotherapy consolidation with 90 Y-ibritumomab tiuxetan in responsive patients. Primary endpoints were failure-free survival (FFS) and incidence of grade ≥3 adverse events from start of 90 Y-ibritumomab tiuxetan. The overall response rate after R-PECC was 50%. Twenty-nine of 31 responsive patients proceeded to 90 Y-ibritumomab tiuxetan. Five out of 15 partial remission patients converted to complete remission after 90 Y-ibritumomab tiuxetan. One-year FFS and overall survival (OS) from start of 90 Y-ibritumomab tiuxetan was 52% (95% confidence interval [CI], 33-68%) and 62% (95% CI, 42-77%), respectively. One-year FFS and OS from start of R-PECC was 28% (95% CI, 17-39%) and 49% (95% CI, 36-61%), respectively. Toxicities of R-PECC and 90 Y-ibritumomab tiuxetan were mainly haematological. In conclusion, for relapsed DLBCL patients the largely oral R-PECC regimen achieves promising response rates, combined with an acceptable safety profile. Consolidation with 90 Y-ibritumomab tiuxetan resulted in long-term response durations in approximately one third of the patients that received it.

Melphalan, prednisone, and lenalidomide versus melphalan, prednisone, and thalidomide in untreated multiple myeloma.

The combination of melphalan, prednisone, and thalidomide (MPT) is considered standard therapy for newly diagnosed patients with multiple myeloma who are ineligible for stem cell transplantation. Long-term treatment with thalidomide is hampered by neurotoxicity. Melphalan, prednisone, and lenalidomide, followed by lenalidomide maintenance therapy, showed promising results without severe neuropathy emerging. We randomly assigned 668 patients between nine 4-week cycles of MPT followed by thalidomide maintenance until disease progression or unacceptable toxicity (MPT-T) and the same MP regimen with thalidomide being replaced by lenalidomide (MPR-R). This multicenter, open-label, randomized phase 3 trial was undertaken by Dutch-Belgium Cooperative Trial Group for Hematology Oncology and the Nordic Myeloma Study Group (the HOVON87/NMSG18 trial). The primary end point was progression-free survival (PFS). A total of 318 patients were randomly assigned to receive MPT-T, and 319 received MPR-R. After a median follow-up of 36 months, PFS with MPT-T was 20 months (95% confidence interval [CI], 18-23 months) vs 23 months (95% CI, 19-27 months) with MPR-R (hazard ratio, 0.87; 95% CI, 0.72-1.04; P = .12). Response rates were similar, with at least a very good partial response of 47% and 45%, respectively. Hematologic toxicity was more pronounced with MPR-R, especially grades 3 and 4 neutropenia: 64% vs 27%. Neuropathy of at least grade 3 was significantly higher in the MPT-T arm: 16% vs 2% in MPR-R, resulting in a significant shorter duration of maintenance therapy (5 vs 17 months in MPR-R), irrespective of age. MPR-R has no advantage over MPT-T concerning efficacy. The toxicity profile differed with clinically significant neuropathy during thalidomide maintenance vs myelosuppression with MPR.

Efficacy and Safety of Outpatient Treatment Based on the Hestia Clinical Decision Rule with or without N-Terminal Pro-Brain Natriuretic Peptide Testing in Patients with Acute Pulmonary Embolism. A Randomized Clinical Trial.

RATIONALE: Outpatient treatment of pulmonary embolism (PE) may lead to improved patient satisfaction and reduced healthcare costs. However, trials to assess its safety and the optimal method for patient selection are scarce. OBJECTIVES: To validate the utility and safety of selecting patients with PE for outpatient treatment by the Hestia criteria and to compare the safety of the Hestia criteria alone with the Hestia criteria combined with N-terminal pro-brain natriuretic peptide (NT-proBNP) testing. METHODS: We performed a randomized noninferiority trial in 17 Dutch hospitals. We randomized patients with PE without any of the Hestia criteria to direct discharge or additional NT-proBNP testing. We discharged the latter patients as well if NT-proBNP did not exceed 500 ng/L or admitted them if NT-proBNP was greater than 500 ng/L. The primary endpoint was 30-day adverse outcome defined as PE- or bleeding-related mortality, cardiopulmonary resuscitation, or intensive care unit admission. The noninferiority margin for the primary endpoint was 3.4%. MEASUREMENTS AND MAIN RESULTS: We randomized 550 patients. In the NT-proBNP group, 34 of 275 (12%) had elevated NT-proBNP values and were managed as inpatients. No patient (0 of 34) with an elevated NT-proBNP level treated in hospital (0%; 95% confidence interval [CI], 0-10.2%), versus no patient (0 of 23) with a post hoc-determined elevated NT-proBNP level from the direct discharge group (0%; 95% CI, 0-14.8%), experienced the primary endpoint. In both trial cohorts, the primary endpoint occurred in none of the 275 patients (0%; 95% CI, 0-1.3%) subjected to NT-proBNP testing, versus in 3 of 275 patients (1.1%; 95% CI, 0.2-3.2%) in the direct discharge group (P = 0.25). During the 3-month follow-up, recurrent venous thromboembolism occurred in two patients (0.73%; 95% CI, 0.1-2.6%) in the NT-proBNP group versus three patients (1.1%; 95% CI, 0.2-3.2%) in the direct discharge group (P = 0.65). CONCLUSIONS: Outpatient treatment of patients with PE selected on the basis of the Hestia criteria alone was associated with a low risk of adverse events. Given the low number of patients with elevated NT-proBNP levels, this trial was unable to draw definite conclusions regarding the incremental value of NT-proBNP testing in patients who fulfill the Hestia criteria. Clinical trial registered with www.trialregister.nl/trialreg/admin/rctview.asp?TC=2603 (NTR2603).

Remote Monitoring of Vital and Activity Parameters in Chronic Transfusion-Dependent Patients: A Feasibility Pilot Using Wearable Biosensors.

Introduction: Little is known if, and to what extent, outpatient red blood cell (RBC) transfusions benefit chronic transfusion-dependent patients. Costs, labour, and potential side effects of RBC transfusions cause a restrictive transfusion strategy to be the standard of care. However, effects on the actual performance and quality of life of patients who require RBCs on a regular basis are hardly studied. The aim of this study was to assess if new technologies and techniques like wearable biosensor devices and web-based testing can be used to measure physiological changes, functional activity, and hence eventually better assess quality of life in a cohort of transfusion-dependent patients. Methods: We monitored 5 patients who regularly receive transfusions during one transfusion cycle with the accelerateIQ biosensor platform, the Withings Steel HR, and web-based cognitive and quality of life testing. Results: Data collection by the deployed devices was shown to be feasible; the AccelerateIQ platform rendered data of which 97.8% was of high quality and usable; of the data the Withings Steel HR rendered, 98.9% was of high quality and usable. Furthermore, heart rate decreased and cognition improved significantly following RBC transfusions. Activity and quality of life measures did not show transfusion-induced changes. Conclusion: In a 5-patient cohort of transfusion-dependent patients, we found that the accelerateIQ, Withings Steel HR, and CANTAB platforms enable acquisition of high-quality data. The collected data suggest that RBC transfusions significantly and reversibly decrease heart rate and increase sustained attention in this cohort. This feasibility study justifies larger validation trials to confirm that these wearables can indeed help to determine personalized RBC transfusion strategies and thus optimization of each patient's quality of life.

Time trends in primary therapy and relative survival of diffuse large B-cell lymphoma by stage: a nationwide, population-based study in the Netherlands, 1989-2018.

It is unclear whether survival in diffuse large B-cell lymphoma (DLBCL) continues to increase in an era where rituximab-containing chemotherapy reigns for almost two decades. Therefore, we evaluated trends in primary therapy and relative survival (RS) among Dutch DLBCL patients diagnosed between 1989 and 2018. Analyses were performed separately according to the stage I (N = 6952) and stage II-IV disease (N = 20,676), stratified by calendar period and age (18-64, 65-74, and ≥75 years). The use of chemotherapy ± radiotherapy increased over time across all age and stage groups. As of the mid-2000s, >95% of chemotherapy-treated patients received chemoimmunotherapy, irrespective of age and stage. Overall, RS increased significantly over time across all age groups, especially after 2003 when rituximab-containing chemotherapy had become the standard of care. However, RS increased less pronounced between 2003-2010 and 2011-2018 than between 1989-2002 and 2003-2010. These findings were congruent across all studied stage groups. Five-year RS across the three age groups during 2011-2018 was 96%, 84%, and 67% for stage I DLBCL and 75%, 60%, and 46% for stage II-IV DLBCL. Collectively, survival in DLBCL increased modestly beyond the initial introduction of rituximab, with apparent survival differences across age and stage that warrant novel treatment approaches.

Platelet doubling after the first azacitidine cycle is a promising predictor for response in myelodysplastic syndromes (MDS), chronic myelomonocytic leukaemia (CMML) and acute myeloid leukaemia (AML) patients in the Dutch azacitidine compassionate named patient programme.

The efficacy of azacitidine in the treatment of high-risk myelodysplastic syndromes (MDS), chronic myelomonocytic leukaemia (CMML) and acute myeloid leukaemia (AML) (20-30% blasts) has been demonstrated. To investigate the efficacy of azacitidine in daily clinical practice and to identify predictors for response, we analysed a cohort of 90 MDS, CMML and AML patients who have been treated in a Dutch compassionate named patient programme. Patients received azacitidine for a median of five cycles (range 1-19). The overall response rate (complete/partial/haematological improvement) was 57% in low risk MDS, 53% in high risk MDS, 50% in CMML, and 39% in AML patients. Median overall survival (OS) was 13·0 (9·8-16·2) months. Multivariate analysis confirmed circulating blasts [Hazard Ratio (HR) 0·48, 95% confidence interval (CI) 0·24-0·99; P = 0·05] and poor risk cytogenetics (HR 0·45, 95% CI 0·22-0·91; P = 0·03) as independent predictors for OS. Interestingly, this analysis also identified platelet doubling after the first cycle of azacitidine as a simple and independent positive predictor for OS (HR 5·4, 95% CI 0·73-39·9; P = 0·10). In conclusion, routine administration of azacitidine to patients with variable risk groups of MDS, CMML and AML is feasible, and subgroups with distinct efficacy of azacitidine treatment can be identified.

Inferior Outcome of Addition of the Aminopeptidase Inhibitor Tosedostat to Standard Intensive Treatment for Elderly Patients with AML and High Risk MDS.

Treatment results of AML in elderly patients are unsatisfactory. We hypothesized that addition of tosedostat, an aminopeptidase inhibitor, to intensive chemotherapy may improve outcome in this population. After establishing a safe dose in a run-in phase of the study in 22 patients, 231 eligible patients with AML above 65 years of age (median 70, range 66-81) were randomly assigned in this open label randomized Phase II study to receive standard chemotherapy (3+7) with or without tosedostat at the selected daily dose of 120 mg (n = 116), days 1-21. In the second cycle, patients received cytarabine 1000 mg/m2 twice daily on days 1-6 with or without tosedostat. CR/CRi rates in the 2 arms were not significantly different (69% (95% C.I. 60-77%) vs 64% (55-73%), respectively). At 24 months, event-free survival (EFS) was 20% for the standard arm versus 12% for the tosedostat arm (Cox-p = 0.01) and overall survival (OS) 33% vs 18% respectively (p = 0.006). Infectious complications accounted for an increased early death rate in the tosedostat arm. Atrial fibrillation was more common in the tosedostat arm as well. The results of the present study show that the addition of tosedostat to standard chemotherapy does negatively affect the therapeutic outcome of elderly AML patients.

Peripheral Photopenia on Whole-Body PET/CT Imaging With 18F-FDG in Patients With Compartment Syndrome and Mesenteric Venous Thrombosis.

We present 2 cases that demonstrate photopenia in peripheral areas on whole-body PET/CT imaging with F-FDG as a sign of absent perfusion with severe short-term complications. The scan of the first patient shows photopenia in the right ankle and foot, resulting from compartment syndrome, caused by hemolytic group A streptococcus bacteremia with endocarditis and septic emboli, necessitating lower leg amputation. The scan of the second patient shows photopenia in the transverse colon, resulting from mesenteric venous thrombosis caused by polycythemia vera, leading to necrosis and perforation of the transverse colon, necessitating transverse and right hemicolectomy.

Effect of antithrombotic stewardship on the efficacy and safety of antithrombotic therapy during and after hospitalization.

BACKGROUND: Although the benefits of antithrombotic drugs are indisputable to reduce thrombotic events, they carry a high risk of compromising patient safety. No previous studies investigated the implementation and (cost-) effectiveness of a hospital-based multidisciplinary antithrombotic team on bleeding and thrombotic outcomes. The primary aim of this study was to compare the proportion of patients with a composite end point consisting of one or more bleeding episodes or one or more thrombotic event from hospitalization until three months after hospitalization. METHODS AND FINDINGS: A prospective, multicenter before-after intervention study was conducted in two Dutch hospitals. Adult patients hospitalized between October 2015 and December 2017 treated with anticoagulant therapy were included. The primary aim was to estimate the proportion of patients with a composite end point consisting of one or more bleeding episodes or one or more thrombotic event from hospitalization until three months after hospitalization. The intervention was the implementation of a multidisciplinary antithrombotic team focusing on education, medication reviews by pharmacists, implementing of local anticoagulant therapy guidelines based on national guidelines, patient counselling and medication reconciliation at admission and discharge. The primary endpoint was analysed using segmented linear regression. We obtained data for 1,886 patients: 941 patients were included in the usual care period and 945 patients in the intervention period. The S-team study showed that implementation of a multidisciplinary antithrombotic team over time significantly reduced the composite end point consisting of one or more bleeding episodes or one or more thrombotic event from hospitalization until three months after hospitalization in patients using anticoagulant drugs (-1.83% (-2.58% to -1.08%) per 2 month period). CONCLUSIONS: This study shows that implementation of a multidisciplinary antithrombotic team over time significantly reduces the composite end point consisting of one or more bleeding episodes or one or more thrombotic event from hospitalization until three months after hospitalization in patients using anticoagulant drugs. TRIAL REGISTRATION: Trialregister.nl NTR4887.

Reasons for Hospitalization of Patients with Acute Pulmonary Embolism Based on the Hestia Decision Rule.

BACKGROUND: The Hestia criteria can be used to select pulmonary embolism (PE) patients for outpatient treatment. The subjective Hestia criterion "medical/social reason for admission" allows the treating physician to consider any patient-specific circumstances in the final management decision. It is unknown how often and why this criterion is scored. METHODS: This is a patient-level post hoc analysis of the combined Hestia and Vesta studies. The main outcomes were the frequency of all scored Hestia items in hospitalized patients and the explicit reason for scoring the subjective criterion. Hemodynamic parameters and computed tomography-assessed right ventricular (RV)/left ventricular (LV) ratio of those only awarded with the subjective criterion were compared with patients treated at home. RESULTS: From the 1,166 patients screened, data were available for all 600 who were hospitalized. Most were hospitalized to receive oxygen therapy (45%); 227 (38%) were only awarded with the subjective criterion, of whom 51 because of "intermediate to intermediate-high risk PE." Compared with patients with intermediate risk PE (RV/LV ratio > 1.0) treated at home (179/566, 32%), hospitalized patients with only the subjective criterion had a higher mean RV/LV ratio (mean difference +0.30, 95% confidence interval [CI] 0.19-0.41) and a higher heart rate (+18/min, 95% CI 10-25). No relevant differences were observed for other hemodynamic parameters. CONCLUSION: The most frequent reason for hospital admission was oxygen therapy. In the decision to award the subjective criterion as sole argument for admission, the severity of the RV overload and resulting hemodynamic response of the patient was taken into account rather than just abnormal RV/LV ratio.

Rituximab-CHOP With Early Rituximab Intensification for Diffuse Large B-Cell Lymphoma: A Randomized Phase III Trial of the HOVON and the Nordic Lymphoma Group (HOVON-84).

PURPOSE: Immunochemotherapy with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) has become standard of care for patients with diffuse large B-cell lymphoma (DLBCL). This randomized trial assessed whether rituximab intensification during the first 4 cycles of R-CHOP could improve the outcome of these patients compared with standard R-CHOP. PATIENTS AND METHODS: A total of 574 patients with DLBCL age 18 to 80 years were randomly assigned to induction therapy with 6 or 8 cycles of R-CHOP-14 with (RR-CHOP-14) or without (R-CHOP-14) intensification of rituximab in the first 4 cycles. The primary end point was complete remission (CR) on induction. Analyses were performed by intention to treat. RESULTS: CR was achieved in 254 (89%) of 286 patients in the R-CHOP-14 arm and 249 (86%) of 288 patients in the RR-CHOP-14 arm (hazard ratio [HR], 0.82; 95% CI, 0.50 to 1.36; P = .44). After a median follow-up of 92 months (range, 1-131 months), 3-year failure-free survival was 74% (95% CI, 68% to 78%) in the R-CHOP-14 arm versus 69% (95% CI, 63% to 74%) in the RR-CHOP-14 arm (HR, 1.26; 95% CI, 0.98 to 1.61; P = .07). Progression-free survival at 3 years was 74% (95% CI, 69% to 79%) in the R-CHOP-14 arm versus 71% (95% CI, 66% to 76%) in the RR-CHOP-14 arm (HR, 1.20; 95% CI, 0.94 to 1.55; P = .15). Overall survival at 3 years was 81% (95% CI, 76% to 85%) in the R-CHOP-14 arm versus 76% (95% CI, 70% to 80%) in the RR-CHOP-14 arm (HR, 1.27; 95% CI, 0.97 to 1.67; P = .09). Patients between ages 66 and 80 years experienced significantly more toxicity during the first 4 cycles in the RR-CHOP-14 arm, especially neutropenia and infections. CONCLUSION: Early rituximab intensification during R-CHOP-14 does not improve outcome in patients with untreated DLBCL.

Risk of bleeding in hospitalized patients on anticoagulant therapy: Prevalence and potential risk factors.

INTRODUCTION: Bleeding is the most important complication of treatment with anticoagulant therapy. Although several studies have identified risk factors of bleeding in outpatients, no studies have been performed that evaluated prevalence and potential risk factors of bleeding in hospitalized patients treated with anticoagulant therapy. METHODS: The primary objective of this study was to determine the prevalence of bleeding in anticoagulant users during hospitalization. The secondary objective was to identify potential risk factors of bleeding in hospitalized patients on anticoagulant therapy. A prospective, observational cohort study was conducted in two Dutch hospitals. Adult patients hospitalized between October 2015 and October 2016 treated with anticoagulant therapy were included. Bleeding was defined as a composite endpoint of major bleeding and non-major bleeding according to the International Society on Thrombosis and Heamostasis (ISTH) criteria. Data analysis was performed by multivariate logistic regression. RESULTS: The prevalence of in-hospital bleeding in patients using anticoagulant therapy was 7.2%; 95% confidence interval [95% CI] 5.5-9.1 (65 out of 906 patients). Multivariate logistic regression analysis indicated that female gender (adjusted odds ratio [ORadj] 2.1; 95% CI 1.2-3.7), high-bleeding-risk surgical procedure (ORadj 5.3; 95% CI 2.7-10.2), low-bleeding-risk surgical procedure (ORadj 4.9; 95% CI 1.9-12.6), and non-surgical interventions (ORadj 6.2; 95% CI 3.0-12.6) were associated with bleeding events in hospitalized patients treated with anticoagulants. CONCLUSIONS: The prevalence of bleeding in anticoagulant users during hospitalization was 7.2%. This study detected potential risk factors that can help to identify patients on anticoagulants who have an increased risk of bleeding during hospitalization.

Antithrombotic stewardship: a multidisciplinary team approach towards improving antithrombotic therapy outcomes during and after hospitalisation: a study protocol.

INTRODUCTION: Antithrombotic therapy carries high risks for patient safety. Antithrombotics belong to the top 5 medications involved in potentially preventable hospital admissions related to medication. To provide a standard for antithrombotic therapy and stress the importance of providing optimal care to patients on antithrombotic therapy, the Landelijke Standaard Ketenzorg Antistolling (LSKA; Dutch guideline on integrated antithrombotic care) was drafted. However, the mere publication of this guideline does not guarantee its implementation. This may require a multidisciplinary team effort. Therefore, we designed a study aiming to determine the influence of hospital-based antithrombotic stewardship on the effect and safety of antithrombotic therapy outcomes during and after hospitalisation. METHODS AND ANALYSIS: In this study, the effect of the implementation of a multidisciplinary antithrombotic team is compared with usual care using a pre-post study design. The study is performed at the Erasmus University Medical Center Rotterdam and the Reinier de Graaf Hospital Delft. Patients who are or will be treated with antithrombotics are included in the study. We aim to include 1900 patients, 950 in each hospital. Primary outcome is the proportion of patients with a composite end point consisting of ≥1 bleeding or ≥1 thrombotic event from the beginning of antithrombotic therapy (or hospitalisation) until 3 months after hospitalisation. Bleeding is defined according to the International Society of Thrombosis and Haemostasis (ISTH) classification. A thrombotic event is defined as any objectively confirmed arterial or venous thrombosis, including acute myocardial infarction or stroke for arterial thrombosis and deep venous thrombosis or pulmonary embolism or venous thrombosis. An economic evaluation is performed to determine whether the implementation of the multidisciplinary antithrombotic team will be cost-effective. ETHICS AND DISSEMINATION: This protocol was approved by the Medical Ethical Committee of the Erasmus University Medical Center. The findings of the study will be disseminated through peer-reviewed journals and presented at relevant conferences. TRIAL REGISTRATION NUMBER: NTR4887; pre-results.

Translating the MDS flow cytometric score into clinical practice.

Myelodysplastic syndromes (MDS) are classified by the WHO as myeloid neoplasms, and are characterized by cytopenia and dysplasia in one or more myeloid cell lines. Recently, a flow cytometric score (FCM-score) was published capable of discriminating low-grade MDS from non-clonal cytopenias (Della Porta et al., 2012). We tested the applicability of the FCM-score in a patient population from a large peripheral teaching hospital in The Netherlands. The evaluation of the proposed FCM score in low-grade MDS showed a high sensitivity and specificity, and clinically significant positive and negative likelihood ratios. The use of CD10 and CD19 positivity to identify progenitor B-cell blasts provided a specific and precize method to separate progenitor B-cell blasts from myeloid blasts within the CD34+/low CD45+ population and may be more convenient compared to the published method using low SSC and CD45 expression. This study confirms the value of utilizing the FCM-score in our patient population.

Loss or downregulation of HLA class I expression at the allelic level in acute leukemia is infrequent but functionally relevant, and can be restored by interferon.

Human leukocyte antigen (HLA) class I expression at the allelic level was analyzed in 397 acute myeloid leukemia (AML) and 186 acute lymphoid leukemia (ALL) using a complement-dependent cytotoxicity assay. Impaired recognition possibly due to HLA downregulation was observed in 2% of the patients with AML and ALL in complete remission, and in 8%-15% in the groups with blasts. In 15 instances of diminished cytotoxicity, leukemic cells and control PHA blasts from the same patients were further analyzed using flow cytometry. In 4/6 ALL and 4/9 AML patients HLA downregulation or complete loss (2 patients) of cell surface expression could be confirmed. No genomic abnormalities were observed. In addition, 12 AML and 13 ALL patients were tested during relapse using flow cytometry. In 1/12 AML patients and 1/13 ALL patients allelic downregulation of cell surface expression was found. In two patients tested, downregulation or loss of cell surface expression of HLA class I antigens corresponded with impaired T cell mediated lysis by HLA restricted cytotoxic T lymphocyte.Treatment of the cells with alpha- or gamma-interferon could restore HLA class I expression and T-cell recognition. In conclusion, downregulation of cell surface expression of HLA class I expression at the allelic level in AML and ALL is infrequent but functionally relevant. HLA downregulation was reversible and T-cell recognition could be restored by alpha- or gamma-interferon.

Quantification of the HA-1 gene product at the RNA level; relevance for immunotherapy of hematological malignancies.

Minor histocompatibility antigens can induce cytotoxic T cells that play an important role in the graft-versus-leukemia and graft-versus-host-disease (GvHD) activity after stem cell transplantation. Minor histocompatibility antigens (mHags) with expression limited to the hematopoietic system may have a prominent role in the graft-versus-leukemia reaction. Earlier in vitro studies demonstrated that cytotoxic T cells specific for the minor histocompatibility antigen HA-1 only lysed cells of hematopoietic origin. Despite this limited expression, an HA-1 mismatch is associated with GvHD. Yet, the hematopoietic-restricted HA-1 membrane expression motivated us to develop an ex vivo HA-1-specific protocol for cellular immunotherapy of relapsed leukemia. To ensure the feasibility and safety of such cellular therapy, broad HA-1 RNA analysis is indispensable. Here we demonstrate the hematopoietic-restricted expression at the HA-1 gene transcriptional level with high RNA expression in normal and in malignant hematopoietic cells and background expression levels in nonhematopoietic cells. In tissues that showed low HA-1 RNA expression, hematopoietic cells were present as demonstrated by CD45 RNA expression analyzed in parallel. Thus, the mHag HA-1 can function as an excellent target antigen for immunotherapy of hematological malignancies with no or low risk of GvHD.