Brentuximab vedotin and ESHAP is highly effective as second-line therapy for Hodgkin lymphoma patients (long-term results of a trial by the Spanish GELTAMO Group).

BACKGROUND: In this work, we assessed the efficacy and safety of brentuximab vedotin (BV) plus ESHAP (BRESHAP) as second-line therapy for Relapsed/Refractory Hodgkin lymphoma (RRHL) to improve the results before autologous stem-cell transplantation (ASCT). PATIENTS AND METHODS: This was a multicenter, open-label, phase I-II trial of patients with RRHL after first-line chemotherapy. Treatment had three 21-day cycles of etoposide, solumedrol, high-dose AraC, and cisplatin. BV was administered at three dose levels (0.9, 1.2, and 1.8 mg/kg) intravenous on day ‒1 to 3 + 3 cohorts of patients. Final BV dose was 1.8 mg/kg. Responding patients proceeded to ASCT, followed by three BV courses (1.8 mg/kg, every 21 days). Main end points for evaluation were maximum tolerable dose and overall and complete response (CR) before ASCT. RESULTS: A total of 66 patients were recruited (median age 36 years; range 18-66): 40 were primary refractory, 16 early relapse and 10 late relapse. There were 39 severe adverse events were reported in 22 patients, most frequently fever (n = 25, 35% neutropenic), including 3 deaths. Grade 3-4 hematological toxicity presented in 28 cases: neutropenia (n = 21), thrombocytopenia (n = 14), and anemia (n = 7). Grade ≥3-4 extrahematological adverse events (≥5%) were non-neutropenic fever (n = 13) and hypomagnesaemia (n = 3). Sixty-four patients underwent stem-cell mobilization; all collected >2×10e6/kg CD34+ cells (median 5.75; range 2.12-33.4). Overall response before transplant was 91% (CI 84% to 98%), including 70% (CRs 95% CI 59% to 81%). 60 patients were transplanted with no failure engraftments. Post-transplant response was CR in 49 patients (82% CI 73% to 91%) and partial responses in six (10% CI 5% to 15%). After a mean follow-up of 27 months, the 30-month time to treatment to failure was 74% (95% CI 68% to 80%), progression-free survival 71% (95% CI 65% to 77%), and overall survival 91% (CI 84% to 98%). CONCLUSION: BRESHAP looks a safe and effective pre-transplant induction regimen, does not jeopardize transplant and allows long-term remissions and survival.

Quantitative PCR: an alternative approach to detect common copy number alterations in multiple myeloma.

Chromosome 1q gains and 13q deletions are common cytogenetic aberrations in multiple myeloma (MM) that confer a poor prognosis. There are several techniques for the targeted study of these alterations, but interphase fluorescence in situ hybridization (FISH) is the current gold standard. The aim of the present study was to validate quantitative PCR (qPCR) as an alternative to FISH studies in CD138+-enriched plasma cells (PCs) from MM patients at diagnosis. We analyzed 1q gains and 13q deletions by qPCR in 57 and 60 MM patients, respectively. qPCR applicability was 84 and 88% for 1q and 13q, respectively. The qPCR and FISH methods had a sensitivity and specificity of 88 and 71% for 1q gains, and 79 and 100% for 13q deletions. A second qPCR assay for each region was carried out to confirm the previous results. Paired qPCR (two assays) and FISH results were available from 53 MM patients: 26 for 1q amplification and 27 for 13q deletion. qPCR assays gave concordant results (qPCR-consistent) in 20 of the 26 (77%) 1q gains and 25 of the 27 (93%) 13q deletions. Considering only the consistent data, the overall concordance among qPCR and FISH was 85 and 100% for 1q gains and 13q deletions, respectively. Our results show a substantial agreement between qPCR and the gold standard FISH technique, indicating the potential of qPCR as an alternative approach, particularly when the starting material is too scarce or cells are too damaged to obtain accurate results from FISH studies.

Comorbidities, not age, are predictive of survival after autologous hematopoietic cell transplantation for relapsed/refractory Hodgkin's lymphoma in patients older than 50 years.

Autologous hematopoietic cell transplantation (AHCT) is the standard of care for young patients with relapsed/refractory (R/R) Hodgkin's lymphoma (HL). However, there is limited experience of its efficacy and feasibility in older patients. The characteristics and outcomes of 121 patients aged ≥50 years (42 of them are ≥60 years old) with R/R HL who underwent AHCT were reviewed. After a median follow-up of 3.1 years, overall survival (OS) and progression-free survival (PFS) at 5 years were 64 and 55 %, respectively, with no differences between 50-59-year-old and ≥60-year-old patients. Hematological and extra-hematological toxicities after AHCT were comparable between the two groups of age. In univariate analysis, poorer OS and PFS were associated with disease status other than complete remission, hematopoietic cell transplantation comorbidity index (HCT-CI) scores >1, and Charlson Comorbidity Index (CCI) scores >1. HCT-CI scores >1 were also associated with a higher risk of grade 3-4 extrahematologic toxicity. In multivariate analysis, HCT-CI and CCI remained significantly associated with OS and PFS after adjustment for disease status. Our data show that AHCT can be performed in selected patients with R/R HL ≥50 years with acceptable outcome and toxicity. Comorbidities appear to impact AHCT outcome more than age.

Design and application of a 23-gene panel by next-generation sequencing for inherited coagulation bleeding disorders.

INTRODUCTION: Molecular testing of Inherited bleeding coagulation disorders (IBCDs) not only offers confirmation of diagnosis but also aids in genetic counselling, prenatal diagnosis and in certain cases genotype-phenotype correlations are important for predicting the clinical course of the disease and to allow tailor-made follow-up of individuals. Until recently, genotyping has been mainly performed by Sanger sequencing, a technique known to be time consuming and expensive. Currently, next-generation sequencing (NGS) offers a new potential approach that enables the simultaneous investigation of multiple genes at manageable cost. AIM: The aim of this study was to design and to analyse the applicability of a 23-gene NGS panel in the molecular diagnosis of patients with IBCDs. METHODS: A custom target enrichment library was designed to capture 31 genes known to be associated with IBCDs. Probes were generated for 296 targets to cover 86.3 kb regions (all exons and flanking regions) of these genes. Twenty patients with an IBCDs phenotype were studied using NGS technology. RESULTS: In all patients, our NGS approach detected causative mutations. Twenty-one pathogenic variants were found; while most of them were missense (18), three deletions were also identified. Six novel mutations affecting F8, FGA, F11, F10 and VWF genes, and 15 previously reported variants were detected. NGS and Sanger sequencing were 100% concordant. CONCLUSION: Our results demonstrate that this approach could be an accurate, reproducible and reliable tool in the rapid genetic diagnosis of IBCDs.

The genomic profiling of high-risk smoldering myeloma patients treated with an intensive strategy unveils potential markers of resistance and progression.

Smoldering multiple myeloma (SMM) precedes multiple myeloma (MM). The risk of progression of SMM patients is not uniform, thus different progression-risk models have been developed, although they are mainly based on clinical parameters. Recently, genomic predictors of progression have been defined for untreated SMM. However, the usefulness of such markers in the context of clinical trials evaluating upfront treatment in high-risk SMM (HR SMM) has not been explored yet, precluding the identification of baseline genomic alterations leading to drug resistance. For this reason, we carried out next-generation sequencing and fluorescent in-situ hybridization studies on 57 HR and ultra-high risk (UHR) SMM patients treated in the phase II GEM-CESAR clinical trial (NCT02415413). DIS3, FAM46C, and FGFR3 mutations, as well as t(4;14) and 1q alterations, were enriched in HR SMM. TRAF3 mutations were specifically associated with UHR SMM but identified cases with improved outcomes. Importantly, novel potential predictors of treatment resistance were identified: NRAS mutations and the co-occurrence of t(4;14) plus FGFR3 mutations were associated with an increased risk of biological progression. In conclusion, we have carried out for the first time a molecular characterization of HR SMM patients treated with an intensive regimen, identifying genomic predictors of poor outcomes in this setting.

Report of consensus panel 5 from the 11th international workshop on Waldenstrom's macroglobulinemia on COVID-19 prophylaxis and management.

Consensus Panel 5 (CP5) of the 11th International Workshop on Waldenstrom's Macroglobulinemia (IWWM-11; held in October 2022) was tasked with reviewing the current data on the coronavirus disease-2019 (COVID-19) prophylaxis and management in patients with Waldenstrom's Macroglobulinemia (WM). The key recommendations from IWWM-11 CP5 included the following: Booster vaccines for SARS-CoV-2 should be recommended to all patients with WM. Variant-specific booster vaccines, such as the bivalent vaccine for the ancestral Wuhan strain and the Omicron BA.4.5 strain, are important as novel mutants emerge and become dominant in the community. A temporary interruption in Bruton's Tyrosine Kinase-inhibitor (BTKi) or chemoimmunotherapy before vaccination might be considered. Patients under treatment with rituximab or BTK-inhibitors have lower antibody responses against SARS-CoV-2; thus, they should continue to follow preventive measures, including mask wearing and avoiding crowded places. Patients with WM are candidates for preexposure prophylaxis, if available and relevant to the dominant SARS-CoV-2 strains in a specific area. Oral antivirals should be offered to all symptomatic WM patients with mild to moderate COVID-19 regardless of vaccination, disease status or treatment, as soon as possible after the positive test and within 5 days of COVID-19-related symptom onset. Coadministration of ibrutinib or venetoclax with ritonavir should be avoided. In these patients, remdesivir offers an effective alternative. Patients with asymptomatic or oligosymptomatic COVID-19 should not interrupt treatment with a BTK inhibitor. Infection prophylaxis is essential in patients with WM and include general preventive measures, prophylaxis with antivirals and vaccination against common pathogens including SARS-CoV-2, influenza, and S. pneumoniae.

Impact of the COVID-19 pandemic on the diagnosis and treatment of onco-hematologic patients: a discussion paper.

We do not know the precise figure for solid organ tumors diagnosed each year in Spain and it is therefore difficult to calculate whether there has been a decrease in cancer diagnoses as a consequence of the pandemic. Some indirect data suggest that the pandemic has worsened the stage at which some non-hematological neoplasms are diagnosed. Despite the lack of robust evidence, oncology patients seem more likely to have a poor outcome when they contract COVID-19. The antibody response to infection in cancer patients will be fundamentally conditioned by the type of neoplasia present, the treatment received and the time of its administration. In patients with hematological malignancies, the incidence of infection is probably similar or lower than in the general population, due to the better protective measures adopted by the patients and their environment. The severity and mortality of COVID-19 in patients with hematologic malignancies is clearly higher than the general population. Since the immune response to vaccination in hematologic patients is generally worse than in comparable populations, alternative methods of prevention must be established in these patients, as well as actions for earlier diagnosis and treatment. Campaigns for the early diagnosis of malignant neoplasms must be urgently resumed, post-COVID manifestations should be monitored, collaboration with patient associations is indisputable and it is urgent to draw the right conclusions to improve our preparedness to fight against possible future catastrophes.

Report of consensus panel 7 from the 11th international workshop on Waldenström macroglobulinemia on priorities for novel clinical trials.

Recent advances in the understanding of Waldenström macroglobulinemia (WM) biology have impacted the development of effective novel agents and improved our knowledge of how the genomic background of WM may influence selection of therapy. Consensus Panel 7 (CP7) of the 11th International Workshop on WM was convened to examine the current generation of completed and ongoing clinical trials involving novel agents, consider updated data on WM genomics, and make recommendations on the design and prioritization of future clinical trials. CP7 considers limited duration and novel-novel agent combinations to be the priority for the next generation of clinical trials. Evaluation of MYD88, CXCR4 and TP53 at baseline in the context of clinical trials is crucial. The common chemoimmunotherapy backbones, bendamustine-rituximab (BR) and dexamethasone, rituximab and cyclophosphamide (DRC), may be considered standard-of-care for the frontline comparative studies. Key unanswered questions include the definition of frailty in WM; the importance of attaining a very good partial response or better (≥VGPR), within stipulated time frame, in determining survival outcomes; and the optimal treatment of WM populations with special needs.

Report of consensus panel 2 from the 11th international workshop on Waldenström's macroglobulinemia on the management of relapsed or refractory WM patients.

The consensus panel 2 (CP2) of the 11th International Workshop on Waldenström's macroglobulinemia (IWWM-11) has reviewed and incorporated current data to update the recommendations for treatment approaches in patients with relapsed or refractory WM (RRWM). The key recommendations from IWWM-11 CP2 include: (1) Chemoimmunotherapy (CIT) and/or a covalent Bruton tyrosine kinase (cBTKi) strategies are important options; their use should reflect the prior upfront strategy and are subject to their availability. (2) In selecting treatment, biological age, co-morbidities and fitness are important; nature of relapse, disease phenotype and WM-related complications, patient preferences and hematopoietic reserve are also critical factors while the composition of the BM disease and mutational status (MYD88, CXCR4, TP53) should also be noted. (3) The trigger for initiating treatment in RRWM should utilize knowledge of patients' prior disease characteristics to avoid unnecessary delays. (4) Risk factors for cBTKi related toxicities (cardiovascular dysfunction, bleeding risk and concurrent medication) should be addressed when choosing cBTKi. Mutational status (MYD88, CXCR4) may influence the cBTKi efficacy, and the role of TP53 disruptions requires further study) in the event of cBTKi failure dose intensity could be up titrated subject to toxicities. Options after BTKi failure include CIT with a non-cross-reactive regimen to one previously used CIT, addition of anti-CD20 antibody to BTKi, switching to a newer cBTKi or non-covalent BTKi, proteasome inhibitors, BCL-2 inhibitors, and new anti-CD20 combinations are additional options. Clinical trial participation should be encouraged for all patients with RRWM.

A strategic reflection for the management and implementation of CAR-T therapy in Spain: an expert consensus paper.

CAR-T cell therapy represents a therapeutic revolution in the prognosis and treatment of patients with certain types of hematological cancer. However, they also pose new challenges in the healthcare, regulatory and financial fields. The aim of the RET-A project was to undertake a strategic reflection on the management of CAR-T therapies within the Spanish National Health System, to agree on recommendations that will help to better deal with the new context introduced by these cell therapies in the present and in the future. This think tank involved 40 key agents and opinion leaders. The experts identified three great challenges for implementing advanced therapies in Spain: therapeutic individualisation, with a multidisciplinary approach; acceleration of access times, by minimizing bureaucracy; and increase in the number of centers qualified to manage the CAR-T therapies in the NHS. The experts agreed on the ideal criteria for designating those qualified centers. They also agreed on a comprehensive CAR-T care pathway with the timings and roles which would ideally be involved in each part of the process.

Frequency of HLA-A, -B and -DRB1 specificities and haplotypic associations in the population of Castilla y León (northwest-central Spain).

The frequencies of human leukocyte antigen (HLA) class I and class II specificities and haplotypic associations were determined in 1940 unrelated donors from Castilla y León and compared with other Iberian, Mediterranean and European populations. Specificities were determined using polymerase chain reaction reverse sequence-specific oligonucleotide or polymerase chain reaction sequence-specific primer techniques. In the analysis, 19, 29 and 13 specificities were found for HLA-A, -B and -DRB1, respectively, with HLA-A*02 (26%), -A*01 (11%), -B*44 (16%), -B*35 (10%), -DRB1*07 (16%) and -DRB1*13 (14%) showing the highest frequencies. In addition, 10 common HLA-A-B-DRB1 haplotypic associations were observed, A*01-B*08-DRB1*03 (3%) and A*29-B*44-DRB1*07 (3%) being the most frequent ones. These findings indicate that the population of Castilla y León is genetically equidistant from the Portuguese and other Spanish populations and shares a common origin with other Iberian populations, in which European, Mediterranean and North African genetic components are present; this is in agreement with the historical and genetic background of the population. These data contribute to a better understanding of the genetic structure of the Iberian Peninsula and provide a healthy control population from our region that should be useful for the study of disease associations.

Management of mixed acute rejection driven by a de novo donor-specific complement-binding anti-DQB1*03:01 antibody and intraepithelial CD8 T-cells in a kidney recipient: a case report.

Mixed acute rejection is a clinicopathological entity that is difficult to accurately diagnose, and so may be under-reported. Allografts are lost more often than in either humoral or cellular rejection. The diagnosis requires both histological and immunological studies on renal biopsy and blood specimens from the transplant recipient to provide the required rescue therapy to abolish the allogeneic response against the graft. We present a clinical case report of an active mixed acute rejection driven by a de novo donor-specific complement-binding anti-DQB1*03:01 antibody and intraepithelial CD8 T-cells in a patient with a kidney transplant. The patient was diagnosed, treated, and followed up as per the local institution's procedure with a full recovery of graft function. Our case emphasises the challenge of a mixed acute rejection and supports the need to improve the post-transplant outcome of recipients and their grafts.

Impact of the COVID-19 pandemic on the care of cancer patients in Spain.

BACKGROUND: Studies evaluating the effects of the COVID-19 pandemic on public healthcare systems are limited, particularly in cancer management. As no such studies have been carried out in Spain, our objective is to describe and quantify the impact of the COVID-19 pandemic on cancer patients in Spanish hospitals during the first wave of the pandemic. MATERIALS AND METHODS: This retrospective, multicenter, nationwide study collected information from hospital departments treating oncology patients. An electronic questionnaire comparing outcomes and management of oncohematological patients for the March-June 2019 and March-June 2020 periods was used. RESULTS: Information from 78 departments (36 tertiary hospitals) was analyzed. Forty-four departments implemented adapted protocols during March 2020. Most of these (n = 38/44; 86.4%) carried out COVID-19 triage, while 26 of 44 (59.1%) carried out onsite polymerase chain reaction tests for clinically suspected cases. A shift from in-person to telephone visits was observed in 43 of 44 (97.7%) departments. Comparing the March-June 2019 and March-June 2020 periods, the number of new patients decreased by 20.8% (from 160.2 to 126.4). Decreases were also seen in the mean number of total (2858.2 versus 1686.1) and cancer (465.5 versus 367.2) biopsies, as well as the mean number of bone marrow biopsies (30.5 versus 18.6). Concerning the number of patients visiting specific cancer care departments, a decrease from 2019 to 2020 was seen for mean number of chemotherapy treatments (712.7 versus 643.8) and radiation therapy (2169.9 versus 2139.9). Finally, a reduction from 2019 to 2020 of 12.9% (from 8.6 to 7.4) in the mean number of patients included in clinical trials was noted. CONCLUSIONS: This study provides the first comprehensive data concerning the impact of COVID-19 on cancer care in Spain. The pandemic caused a 20.8% decrease in newly diagnosed patients, which may impact future outcomes. Measures must be taken to ensure cancer management receives priority in times of healthcare emergencies.

Consensus guidelines for the optimal management of adverse events in newly diagnosed, transplant-ineligible patients receiving melphalan and prednisone in combination with thalidomide (MPT) for the treatment of multiple myeloma.

Thalidomide has received approval from the European Agency for the Evaluation of Medicinal Products for the treatment of newly diagnosed multiple myeloma (MM) patients older than 65 years or ineligible for transplant. The results of five phase III trials assessing thalidomide in combination with melphalan and prednisone (MPT) have demonstrated significantly improved response rates compared with melphalan and prednisone (MP) alone. Additionally, two of these studies showed that survival was extended by approximately 18 months in patients treated with MPT compared with MP alone. Thalidomide, in combination with MP, is associated with adverse events (AEs) including peripheral neuropathy and venous thromboembolism. In order to optimize the efficacy of MPT, a good awareness of these AEs is imperative. This manuscript outlines both evidence- and consensus-based recommendations discussed by a panel of experts, to provide a practical guide for physicians addressing the effective management of newly diagnosed, transplant-ineligible MM patients receiving thalidomide therapy.

The combination of thalidomide, cyclophosphamide and dexamethasone is potentially useful in highly resistant Hodgkin's lymphoma.

Few diseases have a prognosis worse than Hodgkin's lymphoma (HL), patients relapsing after autologous or allogeneic stem cell transplantation. Here, we report two highly refractory patients with HL who successfully responded to a combination of thalidomide, cyclophosphamide and dexamethasone (ThaCyDex). Despite the use of a very large number of different drugs (>5 different schemes) including high-dose therapy and autologous and allogeneic stem cell transplantation, both patients proved to be suffering from a highly resistant disease. Fortunately, they finally responded to the ThaCyDex combination, achieving sustained complete remission that would support the running of a trial within this setting.

Current functioning of cardio-oncology units in Spain.

PURPOSE: The aim of the current survey was to describe the functioning of cardio-oncology (C-O) units in Spain. METHODS: All members of the Spanish Society of Cardiology pertaining to scientific communities related to C-O received questionnaires on the existence of specific programs at their institutions. A second, more extensive questionnaire was sent to the centers which reported C-O organization. RESULTS: We identified 56 centers with C-O programs of which 32 (62.5%) replied to the extended questionnaire. 28% of all centers reported having a multidisciplinary unit involving specialists in several areas. More than 80% of the centers developed surveillance protocols locally adapted which included advanced echocardiographic techniques (68%) or troponin (82%). CONCLUSIONS: The number of institutions with C-O programs is still limited but higher than reported in a survey in 2017. Development of multidisciplinary units of C-O should be promoted to improve the cardiovascular health of cancer patients.

The use of bisphosphonates in multiple myeloma: recommendations of an expert panel on behalf of the European Myeloma Network.

BACKGROUND: Bisphosphonates (BPs) prevent, reduce, and delay multiple myeloma (MM)-related skeletal complications. Intravenous pamidronate and zoledronic acid, and oral clodronate are used for the management of MM bone disease. The purpose of this paper is to review the current evidence for the use of BPs in MM and provide European Union-specific recommendations to support the clinical practice of treating myeloma bone disease. DESIGN AND METHODS: An interdisciplinary, expert panel of specialists on MM and myeloma-related bone disease convened for a face-to-face meeting to review and assess the evidence and develop the recommendations. The panel reviewed and graded the evidence available from randomized clinical trials, clinical practice guidelines, and the body of published literature. Where published data were weak or unavailable, the panel used their own clinical experience to put forward recommendations based solely on their expert opinions. RESULTS: The panel recommends the use of BPs in MM patients suffering from lytic bone disease or severe osteoporosis. Intravenous administration may be preferable; however, oral administration can be considered for patients unable to make hospital visits. Dosing should follow approved indications with adjustments if necessary. In general, BPs are well tolerated, but preventive steps should be taken to avoid renal impairment and osteonecrosis of the jaw (ONJ). The panel agrees that BPs should be given for 2 years, but this may be extended if there is evidence of active myeloma bone disease. Initial therapy of ONJ should include discontinuation of BPs until healing occurs. BPs should be restarted if there is disease progression. CONCLUSIONS: BPs are an essential component of MM therapy for minimizing skeletal morbidity. Recent retrospective data indicate that a modified dosing regimen and preventive measures can greatly reduce the incidence of ONJ.

Bisphosphonate-related osteonecrosis: genetic and acquired risk factors.

The objectives of this study were to review epidemiological, clinical and biological aspects associated with the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in multiple myeloma (MM) patients, with special emphasis on the genetic aspects. A detailed review of previously described risk factors as well as recent genetic findings mostly comprises this work. The most recent meeting abstracts and relevant articles published in journals covered by the Science Citation Index and Medline are also examined. The review pays special attention to the genetic component of BRONJ. A total of 15 series and 14 guidelines or revisions were selected to fit the aims of the review. Gene variability was reviewed in depth to give a clinical illustration on the genetic aspects of BRONJ. Crude prevalence and 5-year cumulative incidence were considered as the most important end points for predictive purposes. Several acquired factors were recognized as predictors for BRONJ in MM, especially intravenous bisphosphonates, dental trauma and advanced age. Among genetic factors, polymorphisms on CYP2C8 gene arise as a promising risk factor. Bisphosphonate-related osteonecrosis of the jaw can be predicted with a conjunction of genetic and environmental risk factors.

Low expression of ZHX2, but not RCBTB2 or RAN, is associated with poor outcome in multiple myeloma.

RAN, ZHX2 and RCBTB2 (CHC1L) expression was evaluated by quantitative real time reverse transcription polymerase chain reaction in plasma cells from 85 monoclonal gammopathies: 58 symptomatic multiple myeloma (MM) (52 untreated, six relapsed), eight smouldering MM, five monoclonal gammopathy of undetermined significance, four plasma cell leukaemias and 10 myeloid cell lines. ZHX2 was weakly expressed in high-risk/proliferative disease compared to low-risk or indolent disease. High ZHX2 expression was associated with better response and longer survival after high-dose therapy. RCBTB2 expression was weaker in hyperdiploid versus non-hyperdiploid cases while RAN was more expressed in symptomatic MM and cell lines.

Powerful strategy for polymerase chain reaction-based clonality assessment in T-cell malignancies Report of the BIOMED-2 Concerted Action BHM4 CT98-3936.

Polymerase chain reaction (PCR) assessment of clonal T-cell receptor (TCR) and immunoglobulin (Ig) gene rearrangements is an important diagnostic tool in mature T-cell neoplasms. However, lack of standardized primers and PCR protocols has hampered comparability of data in previous clonality studies. To obtain reference values for Ig/TCR rearrangement patterns, 19 European laboratories investigated 188 T-cell malignancies belonging to five World Health Organization-defined entities. The TCR/Ig spectrum of each sample was analyzed in duplicate in two different laboratories using the standardized BIOMED-2 PCR multiplex tubes accompanied by international pathology panel review. TCR clonality was detected in 99% (143/145) of all definite cases of T-cell prolymphocytic leukemia, T-cell large granular lymphocytic leukemia, peripheral T-cell lymphoma (unspecified) and angioimmunoblastic T-cell lymphoma (AILT), whereas nine of 43 anaplastic large cell lymphomas did not show clonal TCR rearrangements. Combined use of TCRB and TCRG genes revealed two or more clonal signals in 95% of all TCR clonal cases. Ig clonality was mostly restricted to AILT. Our study indicates that the BIOMED-2 multiplex PCR tubes provide a powerful strategy for clonality assessment in T-cell malignancies assisting the firm diagnosis of T-cell neoplasms. The detected TCR gene rearrangements can also be used as PCR targets for monitoring of minimal residual disease.