Long-term outcomes and renal responses following autologous hematopoietic stem cell transplantation for light chain deposition disease: a retrospective study on behalf of the Chronic Malignancies Working Party of the European Society for Blood and Marrow Transplantation.

There is little long-term outcome data on the efficacy of autologous hematopoietic stem cell transplantation (ASCT) in light chain deposition disease (LCDD). We identified 51 LCDD patients in the EBMT registry who had undergone upfront ASCT between 1995 and 2021. The median serum creatinine was 280 µmol/L and 45% required renal replacement therapy (RRT) at time of transplant. The melphalan dose was 100mg/m2 in 23%, 140mg/m2 in 55% and 200 mg/m2 in 21%. The rate of very good partial response or better improved from 41% pre-transplant to 66% at Day +100 post-ASCT. In RRT-independent patients, there was a modest improvement in renal function within the first 3 months; the median eGFR increased from 44 to 51 ml/min/1.73 m2. There was no further change between 3 and 12 months post- ASCT. No patient who was RRT-independent at ASCT became RRT dependent by Day + 100 post-ASCT. Median follow-up post-ASCT was 84 months (IQR: 46-122). At 6-years post ASCT, overall survival (OS) was 88% (95% CI: 78-98%) and PFS was 44% (95% CI: 28-60%). The 2-year cumulative incidence of relapse and non-relapse mortality (NRM) was 17% (95% CI: 6-27%) and 2% (95% CI: 0-6%), respectively. The cumulative incidence of renal transplantation at 4 years after ASCT was 27% (95% CI 13-41) with renal transplantation performed between 6.3 and 52.9 months post-ASCT (median 24.7 months). ASCT represents a feasible option for LCDD patients even if RRT dependent at time of transplant. Outcomes are favourable with low NRM and good long-term OS.

Screening for multidrug-resistant organisms in high-risk hospitalized patients with hematologic diseases.

OBJECTIVES: Patients treated for hematologic malignancies are at higher risk for blood stream infections (BSI) and multidrug-resistant organisms (MDRO) are increasingly involved. Studies showed a significant association between rectal colonization status and a higher risk of subsequent MDRO BSI. The objective of our study was to probe the practice of surveillance cultures in Belgian hematology centers. METHODS: A questionnaire was sent to the 13 hematology centers participating in the acute leukemia board of the Belgian Hematology Society. 21 questions probed for the method of surveillance cultures, MDRO screened, antimicrobial prophylaxis, and empirical therapy and their relationship with colonization status. RESULTS: All centers completed the questionnaire in full. Routine gastrointestinal surveillance cultures in hematologic patients are taken in 10 hospitals. Organisms tested for included mostly ESBL (n = 9) and carbapenem-resistant (n = 8) Enterobacterales. All centers with a screening strategy adapt empiric antibiotic therapy based on MDRO colonization. Prophylaxis strategies are variable, only two centers adapt prophylaxis upon documentation of fluoroquinolone resistance. CONCLUSIONS: The majority of the Belgian centers perform routine surveillance cultures and adapt empiric therapy for neutropenic fever accordingly. Other reasons for testing include to gain insight into local epidemiology and to prevent in-hospital transmission. In general, there was significant variability in surveillance dimensions.

The world apheresis association registry, 2023 update.

The WAA apheresis registry contains data on more than 140,000 apheresis procedures conducted in 12 different countries. The aim is to give an update of indications, type and number of procedures and adverse events (AEs). MATERIAL AND METHODS: The WAA-registry is used for registration of apheresis procedures and is free of charge. The responsible person for a center can apply at the site www.waa-registry.org RESULTS: Data includes reported AEs from 2012 and various procedures and diagnoses during the years 2018-2022; the latter in total from 27 centers registered a total of 9500 patients (41% women) that began therapeutic apheresis (TA) during the period. A total of 58,355 apheresis procedures were performed. The mean age was 50 years (range 0-94). The most common apheresis procedure was stem cell collection for which multiple myeloma was the most frequent diagnosis (51%). Donor cell collection was done in 14% and plasma exchange (PEX) in 28% of patients; In relation to all performed procedures PEX, using a centrifuge (35%) and LDL-apheresis (20%) were the most common. The main indication for PEX was TTP (17%). Peripheral veins were used in 56% as the vascular access. The preferred anticoagulant was ACD. AEs occurred in 2.7% of all procedures and were mostly mild (1%) and moderate 1.5% (needed supportive medication) and, only rarely, severe (0.15%). CONCLUSION: The data showed a wide range of indications and variability in apheresis procedures with low AE frequency.

Shallow-depth sequencing of cell-free DNA for Hodgkin and diffuse large B-cell lymphoma (differential) diagnosis: a standardized approach with underappreciated potential.

Shallow-depth sequencing of cell-free DNA, a cheap and standardized approach to obtain molecular information on tumors non-invasively, is insufficiently explored for lymphoma diagnosis and disease follow-up. This study collected 318 samples, including longitudinal liquid and paired solid biopsies, from a prospectively recruited cohort of 38 Hodgkin lymphoma (HL) and 85 aggressive B-cell non- HL patients, represented by 81 diffuse large B-cell lymphoma (DLBCL) cases. Following sequencing, copy number alterations and viral read fractions were derived and analyzed. At diagnosis, liquid biopsies showed detectable copy number alterations in 84.2% of HL (88.6% for classical HL) and 74.1% of DLBCL patients. Copy number profiles between liquid-solid pairs were highly concordant within DLBCL (r=0.815±0.043); and, compared to tissue, HL liquid biopsies had abnormalities with higher amplitudes (P=.010), implying that tumor DNA is more abundant in plasma. Additionally, 39.5% of HL and 13.6% of DLBCL cases had a significantly elevated number of plasmatic Epstein-Barr virus DNA fragments, achieving a sensitivity of 100% compared to current standard. Longitudinal analysis determined that, when detectable, copy number patterns were similar across (re)staging moments in refractory/relapsed patients. Moreover, the overall profile anomaly highly correlated with the total metabolic tumor volume (P.

Serum free light chain analysis: persisting limitations with new kids on the block.

OBJECTIVES: Serum free light chain (sFLC) measurements have inherent analytical limitations impacting sFLC clinical interpretation. We evaluated analytical and diagnostic performance of three polyclonal sFLC assays on four analytical platforms. METHODS: sFLC concentration was measured using Diazyme FLC assays (Diazyme) on cobas c501/c503 analyzer (Roche); Freelite assays (The Binding Site) on Optilite analyzer (The Binding Site) and cobas c501 analyzer and Sebia FLC ELISA assays (Sebia) on AP22 ELITE analyzer (DAS). Imprecision, linearity, method comparison vs. Freelite/Optilite, antigen excess detection and reference value verification were assessed. Diagnostic performance was compared on 120 serum samples and on follow-up samples of five patients with κ and λ monoclonal gammopathy. RESULTS: Method comparison showed excellent correlation with Freelite/Optilite method for all assays. A large proportional negative bias was shown for both Sebia κ and λ ELISA and a significant positive proportional bias for λ in the low (<10 mg/L) Freelite/cobas c501 method. Clinically relevant underestimation of κ sFLC levels due to antigen excess was shown for 7% of each Diazyme/cobas application and for 11 and 32.1% of λ sFLC assay of respectively Diazyme/cobas and Sebia/AP22. sFLC reference values revealed application specific. Cohen's κ values were (very) good for κ sFLC but only moderate to good for λ sFLC. In 4/10 follow-up patients, significant differences in clinical interpretation between sFLC assays were noticed. CONCLUSIONS: Important analytical limitations remain for all sFLC applications. Differences in reference values and diagnostic performance hamper interchangeability of sFLC assays. Assay specific sFLC decision guidelines are warranted.

Azacitidine maintenance after intensive chemotherapy improves DFS in older AML patients.

The prevention of relapse is the major therapeutic challenge in older patients with acute myeloid leukemia (AML) who have obtained a complete remission (CR) on intensive chemotherapy. In this randomized phase 3 study (HOVON97) in older patients (≥60 years) with AML or myelodysplastic syndrome with refractory anemia with excess of blasts, in CR/CR with incomplete hematologic recovery (CRi) after at least 2 cycles of intensive chemotherapy, we assessed the value of azacitidine as postremission therapy with respect to disease-free survival (DFS; primary end point) and overall survival (OS; secondary end point). In total, 116 eligible patients were randomly (1:1) assigned to either observation (N = 60) or azacitidine maintenance (N = 56; 50 mg/m2, subcutaneously, days 1-5, every 4 weeks) until relapse, for a maximum of 12 cycles. Fifty-five patients received at least 1 cycle of azacitidine, 46 at least 4 cycles, and 35 at least 12 cycles. The maintenance treatment with azacitidine was feasible. DFS was significantly better for the azacitidine treatment group (logrank; P = .04), as well as after adjustment for poor-risk cytogenetic abnormalities at diagnosis and platelet count at randomization (as surrogate for CR vs CRi; Cox regression; hazard ratio, 0.62; 95% confidence interval, 0.41-0.95; P = .026). The 12-month DFS was estimated at 64% for the azacitidine group and 42% for the control group. OS did not differ between treatment groups, with and without censoring for allogeneic hematopoietic cell transplantation. Rescue treatment was used more often in the observation group (n = 32) than in the azacitidine maintenance group (n = 9). We conclude that azacitidine maintenance after CR/CRi after intensive chemotherapy is feasible and significantly improves DFS. The study is registered with The Netherlands Trial Registry (NTR1810) and EudraCT (2008-001290-15).

Clinical outcomes in patients with Philadelphia chromosome-positive leukemia treated with ponatinib in routine clinical practice-data from a Belgian registry.

Data on clinical use of ponatinib are limited. This prospective registry aimed to evaluate outcomes of ponatinib treatment in routine practice over 3 years (2016-2019) in Belgium (NCT03678454). Patients with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) were treated with ponatinib per current label. Fifty patients (33 CML and 17 Ph+ ALL) were enrolled. Fifty-five percent of CML and 29% of Ph+ ALL patients had received ≥3 prior tyrosine kinase inhibitors (TKIs). Reasons for starting ponatinib were intolerance (40%), relapse or refractoriness (28%) to previous TKIs, progression (16%), or T315I mutation (16%). Median follow-up was 15 months for CML and 4.5 months for Ph+ ALL patients. Best response was a major molecular response in 58% of CML and 41% of Ph+ ALL patients. Of 20 patients who started ponatinib due to intolerance to previous TKIs, 9 (64%) CML and 4 (67%) Ph+ ALL achieved a major molecular response. Three-year estimates of overall survival were 85.3% and 85.6%, respectively, in CML and Ph+ ALL patients; estimated progression-free survival was 81.6% and 48.9%. Adverse reactions were reported in 34 patients (68%); rash (26%) and dry skin (10%) were most common. Reported cardiovascular adverse reactions included vascular stenosis (3), arterial hypertension (2), chest pain (1), palpitations (1), and vascular occlusion (1). This Belgian registry confirms results from the PACE clinical trial and supports routine ponatinib use in CML and Ph+ ALL patients who are resistant or intolerant to previous TKIs or with the T315I mutation.

Using the World Apheresis Association Registry Helps to Improve the Treatment Quality of Therapeutic Apheresis.

Therapeutic apheresis (TA) is prescribed to patients that suffer from a severe progressive disease that is not sufficiently treated by conventional medications. A way to gain more knowledge about this treatment is usually by the local analysis of data. However, the use of large quality assessment registries enables analyses of even rare findings. Here, we report some of the recent data from the World Apheresis Association (WAA) registry. Data from >104,000 procedures were documented, and TA was performed on >15,000 patients. The main indication for TA was the collection of autologous stem cells (45% of patients) as part of therapy for therapy. Collection of stem cells from donors for allogeneic transplantation was performed in 11% of patients. Patients with indications such as neurological diseases underwent plasma exchange (28%). Extracorporeal photochemotherapy, lipid apheresis, and antibody removal were other indications. Side effects recorded in the registry have decreased significantly over the years, with approximately only 10/10,000 procedures being interrupted for medical reasons. CONCLUSION: Collection of data from TA procedures within a multinational and multicenter concept facilitates the improvement of treatment by enabling the analysis of and feedback on indications, procedures, effects, and side effects.

Lenalidomide maintenance for diffuse large B-cell lymphoma patients responding to R-CHOP: quality of life, dosing, and safety results from the randomised controlled REMARC study.

Lenalidomide maintenance therapy prolonged progression-free survival (PFS) versus placebo in elderly patients with diffuse large B-cell lymphoma (DLBCL) responding to induction chemotherapy in the phase 3 REMARC study. This subpopulation analysis assessed the impact of lenalidomide maintenance and treatment-emergent adverse events (TEAEs) on health-related quality of life (HRQOL). Global health status (GHS), and physical functioning and fatigue subscales were evaluated in patients who completed the European Organisation for Research and Treatment of Cancer quality-of-life questionnaire-C30 v3.0. The impact of TEAEs classified post hoc as subjective (patients can feel) or observable (only measurable by physicians) on dose reductions and discontinuations was assessed. Among 457 patients (lenalidomide, n = 229; placebo, n = 228), mean (standard deviation) GHS was similar between treatment arms [68·2 (20·7) Versus 72·0 (17·8)] at randomisation and remained similar during maintenance. Patients receiving lenalidomide experienced no meaningful changes in GHS, physical functioning, or fatigue. Observable TEAEs were more common (81·1% Versus 66·3%) and more likely to lead to dose reductions, than subjective TEAEs in both arms. PFS was superior in the lenalidomide arm regardless of dose reduction. Lenalidomide maintenance prolonged PFS and did not negatively impact HRQOL in patients with DLBCL despite TEAEs being more common, when compared with placebo.

Apheresis machines variably overestimate mononuclear cell collection volume.

INTRODUCTION: Calculation of the actual number of CD34+ cells in the collection product is based on the volume of the collected product and its concentration of CD34+ cells measured in the lab. The number of CD34+ cells infused correlates closely with the pace of hematopoietic reconstitution following autologous or allogeneic stem cell transplantation. METHODS: We studied peripheral blood stem cell collections in a single apheresis center with two Spectra Optia devices, using mononuclear cell collection or continuous mononuclear cell collection procedures. The collection volume displayed by the apheresis device was compared with the volume determined by a weight-based method. RESULTS: Fifty-two consecutive CD34 collections in 35 different donors (range 1-4 daily procedures per donor) were analyzed. The machines reported larger collection volumes (P < .001). The mean collection volume reported by the machine was 274.37 mL (range 162-396). The mean manually measured collection volume was 261.82 mL (range 155-371.40). Mean overestimation by machine was 12.53 mL (range -0.95 to 31.24; 95% confidence interval 10.94-14.11) or 4.88% (range -0.26 to 10.28). Median overestimation of the absolute number of CD34 was 10.29 × 106 (range -2.83 to 141.84 × 106 ). CONCLUSION: Both Spectra Optia machines overestimated the collection volume after peripheral blood stem cell collection. Although the mean variation falls within the expected range, in some cases, this overestimation may be clinically relevant if no other method of measurement is used.

Clinical characteristics and outcomes of invasive Lomentospora prolificans infections: Analysis of patients in the FungiScope® registry.

OBJECTIVES: Invasive fungal infections caused by Lomentospora prolificans are associated with very high mortality rates and can be challenging to treat given pan-drug resistance to available antifungal agents. The objective of this study was to describe the clinical presentation and outcomes in a cohort of patients with invasive L prolificans infections. METHODS: We performed a retrospective review of medical records of patients with invasive L prolificans infection in the FungiScope® registry of rare invasive fungal infections. Patients diagnosed between 01 January 2008 and 09 September 2019 were included in for analysis. RESULTS: The analysis included 41 patients with invasive L prolificans infection from eight different countries. Haematological/oncological malignancies were the most frequent underlying disease (66%), disseminated infection was frequent (61%), and the lung was the most commonly involved organ (44%). Most infections (59%) were breakthrough infections. Progression/deterioration/treatment failure was observed in 23/40 (58%) of patients receiving antifungal therapy. In total, 21/41 (51%) patients, and 77% of patients with underlying haematological/oncological malignancy, had a fatal outcome attributed to invasive fungal infection. Combination antifungal therapy was frequent (24/40) and associated with improved survival. In particular, treatment regimens including terbinafine were significantly associated with higher treatment success at final assessment (P = .012), with a positive trend observed for treatment regimens that included voriconazole (P = .054). CONCLUSIONS: Lomentospora prolificans infections were associated with mortality rates of 77% and above in patients with underlying haematological/oncological malignancies and those with disseminated infections. While combination therapy is the preferred option for now, the hope lies with novel antifungals currently under development.

Cutaneous mucormycosis.

Mucormycosis is an aggressive invasive fungal infection that occurs rarely in immunocompetent but frequently in immunocompromised patients. We present a case of a 68-year-old patient with cutaneous mucormycosis due to Rhizopus pusillus. He was initially hospitalized for invasive pulmonary aspergillosis and diabetes mellitus secondary to acute graft-versus-host treatment with glucocorticoids after allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia. Treatment with liposomal amphotericin B and posaconazole was initiated but the patient developed septic shock with multiple organ failure and died 5 days later. The risk factors, clinical presentation, treatment, and prognosis of cutaneous mucormycosis in hematopoietic stem cell and solid organ transplant patients are discussed.

Toxoplasma gondii-induced brachial plexus neuropathy after allogeneic hematopoietic stem cell transplantation.

Brachial plexus neuropathy is a rare, but underdiagnosed condition, characterized by intense analgesic-resistant shoulder pain, followed by brachial plexus paresis and sensory symptoms. We present a case of brachial plexus neuropathy, induced by Toxoplasma gondii (T. gondii) 17 days after allogeneic hematopoietic stem cell transplantation (alloHSCT) in a patient with acute myeloid leukemia. The diagnosis was made based on the clinical presentation, magnetic resonance imaging (MRI) of the brachial plexus, and positive T. gondii polymerase chain reaction (PCR) in cerebrospinal fluid. The patient was treated with pyrimethamine, sulfadiazine, and levofolinic acid during 6 weeks, with a positive outcome.

Diagnosis and management of PNH: Review and recommendations from a Belgian expert panel.

Despite its considerable morbidity and mortality, paroxysmal nocturnal haemoglobinuria (PNH) is still underdiagnosed. Patients with PNH can suffer from cardiovascular, gastrointestinal, neurological or haematological symptoms and refer to several specialists. The aim of this paper is to review the diagnosis and the management of PNH patients, with the primary focus on identifying high-risk groups. Additionally, the implementation and prognostic value of the defined high-risk groups will be commented on and the management of PNH patients is discussed from a Belgian perspective. Finally, based on the available data, recommendations are provided. Eculizumab is a potent C5 complement inhibitor and reduces intravascular haemolysis and thrombosis in PNH patients and improves their quality of life. As thrombosis is the main cause of death in PNH patients, identifying high-risk PNH patients in need of therapy is essential. Currently, novel complement inhibitors are in development and the first data seem promising. Another challenge in PNH is to identify new markers to assess the thrombotic risk to achieve a better risk-based prophylactic anti-thrombotic management. Finally, because of the low prevalence of the disease, PNH patients should be included in the prospective PNH registry, which will offer new insights on the natural course of the disease and the impact of treatment of PNH.

Rupture of the stem cell bag before stem cell infusion: Evolving standard operating procedures.

The lives of recipients of peripheral blood progenitor cells (PBPC) depend upon the availability of PBPC. Rupture of stem cell bags does occur and can have devastating consequences. Each transplant center should agree on a rescue procedure and train its personnel to use it. We provide an example of such a procedure, and its update after the procedure was used for the first time.

Observational study of corrected count increments after transfusion of platelets treated with riboflavin pathogen reduction technology in additive solutions.

BACKGROUND: Mirasol pathogen reduction technology (PRT) treatment inactivates bacteria, viruses, and parasites in plasma products and platelets (PLTs) suspended in plasma and PLT additive solutions (PAS). Few clinical studies exist documenting transfusions with PAS. This study objective was to evaluate the count increments of PRT-treated PAS-C and PAS-E buffy coat (BC) PLTs in routine use observational settings. STUDY DESIGN AND METHODS: PLT pools of five or six BCs were collected, processed, and suspended in PAS-C or PAS-E, respectively. Products were exposed to ultraviolet light in the presence of riboflavin and then transfused into 19 patients with hematologic diseases. Patients were monitored for PLT corrected count increment (CCI) at 1 and 24 hours and for any adverse events in the 72 hours after transfusion. Sterility monitoring was performed with a microbial detection system (BacT/ALERT, bioMérieux). RESULTS: The PAS-E products had significantly higher PLT concentrations and counts than the PAS-C products. The mean CCIs of per-protocol (PP) units at 1 and 24 hours were 11,900 (n=27) and 5500 (n=30), respectively. Seventy-eight percent of PP transfusions classify as successful with CCIs at 1 hour of higher than 7500, and 63% higher than 4500 at 24 hours. One patient was excluded from all analyses as she was refractory to Mirasol-treated PLT transfusions and follow-up untreated transfusion products. No adverse events were observed and no contaminated products were detected by BacT/ALERT. CONCLUSION: PRT-treated BC PLTs in PAS-C or PAS-E demonstrate PLT transfusion success rates in hematology patients with thrombocytopenia that are comparable to previous studies examining PLTs stored in plasma.

Evaluation of AQUIOS STEM, a novel method for automated CD34+ stem cell enumeration using flow cytometry.

OBJECTIVES: Hematopoietic stem cell transplantation (HSCT) is a potentially curative treatment for various diseases. The measurement of CD34+ cells is crucial to schedule the peripheral blood stem cell collection and assess the engraftment potential of the apheresis product. The AQUIOS STEM system has been introduced as a novel application on the AQUIOS CL, a fully automated flow cytometer, for the enumeration of CD34+ hematopoietic progenitor cells (HPCs) in accordance with the The International Society for Hematotherapy and Graft Engineering guidelines. This study aimed to assess the potential of the novel AQUIOS STEM system versus currently used systems including the FACSCanto-II and the FACS Lyric flow cytometer in a multicenter study. METHODS: A total of 91 samples were used for the validation of the AQUOIS STEM system, including an analytical performance evaluation by means of assessing precision, sample stability, intersample carryover, and linearity and a method comparison with the present FACS systems in use to assess analytical and clinical decision agreement. RESULTS: Results showed excellent precision, with coefficient of variations <15% for dedicated quality control material and patient samples. There was no significant carry over. The fresh apheresis samples were stable when stored overnight at room temperature and at 4°C. Analytical comparison with the current systems demonstrated good correlation in peripheral blood, and minimal, clinically neglectable systematic and proportional bias in fresh apheresis products but a low correlation coefficient in cryopreserved products. CONCLUSIONS: The STEM system on AQUIOS CL allows automated enumeration of CD34+ stem cells, demonstrating good analytical performance and promising overall outcomes in peripheral blood and fresh apheresis products.

Successful Multimodal Therapy with Intracerebral Liposomal Amphotericin B and Systemic High-Dose Isavuconazole in Proven Disseminated Aspergillosis.

We report the case of a 32-year-old man receiving chemotherapeutics for an acute B-lymphoblastic leukemia who developed proven cerebral and pulmonary aspergillosis with Aspergillus flavus. Because of progressive fungal disease with neurological deterioration despite adequate systemic antifungal therapy and surgical debridement, intracerebral administration of liposomal amphotericin B was initiated at 5 mg twice weekly. This led to improvement of the cerebral infection. Surgical debridement of a pleural Aspergillus empyema was necessary, and pleural trough level of isavuconazole was found to be subtherapeutic despite adequate blood trough levels, which led us to increase the dose of isavuconazole. We conclude that intralesional amphotericin B might be beneficial at 5 mg twice weekly in cerebral aspergillosis if systemic antifungals and surgical debridement fail. In Aspergillus empyema, measurement of pleural isavuconazole trough levels should be considered.

Exploring the cell-free total RNA transcriptome in diffuse large B-cell lymphoma and primary mediastinal B-cell lymphoma patients as biomarker source in blood plasma liquid biopsies.

Introduction: Diffuse large B-cell lymphoma (DLBCL) and primary mediastinal B-cell lymphoma (PMBCL) are aggressive histological subtypes of non-Hodgkin's lymphoma. Improved understanding of the underlying molecular pathogenesis has led to new classification and risk stratification tools, including the development of cell-free biomarkers through liquid biopsies. The goal of this study was to investigate cell-free RNA (cfRNA) biomarkers in DLBCL and PMBCL patients. Materials and methods: Blood plasma samples (n=168) and matched diagnostic formalin-fixed paraffin-embedded (FFPE) tissue samples (n=69) of DLBCL patients, PMBCL patients and healthy controls were collected between 2016-2021. Plasma samples were collected at diagnosis, at interim evaluation, after treatment, and in case of refractory or relapsed disease. RNA was extracted from 200 µl plasma using the miRNeasy serum/plasma kit and from FFPE tissue using the miRNeasy FFPE kit. RNA was subsequently sequenced on a NovaSeq 6000 instrument using the SMARTer Stranded Total RNA-seq pico v3 library preparation kit. Results: Higher cfRNA concentrations were demonstrated in lymphoma patients compared to healthy controls. A large number of differentially abundant genes were identified between the cell-free transcriptomes of DLBCL patients, PMBCL patients, and healthy controls. Overlap analyses with matched FFPE samples showed that blood plasma has a unique transcriptomic profile that significantly differs from that of the tumor tissue. As a good concordance between tissue-derived gene expression and the immunohistochemistry Hans algorithm for cell-of-origin (COO) classification was demonstrated in the FFPE samples, but not in the plasma samples, a 64-gene cfRNA classifier was developed that can accurately determine COO in plasma. High plasma levels of a 9-gene signature (BECN1, PRKCB, COPA, TSC22D3, MAP2K3, UQCRHL, PTMAP4, EHD1, NAP1L1 pseudogene) and a 5-gene signature (FTH1P7, PTMAP4, ATF4, FTH1P8, ARMC7) were significantly associated with inferior progression-free and overall survival in DLBCL patients, respectively, independent of the NCCN-IPI score. Conclusion: Total RNA sequencing of blood plasma samples allows the analysis of the cell-free transcriptome in DLBCL and PMBCL patients and demonstrates its unexplored potential in identifying diagnostic, cell-of-origin, and prognostic cfRNA biomarkers.