Improvement of angiographic and clinical outcomes of percutaneous coronary intervention for chronic total occlusion after implementation of a dedicated team: a single-centre experience.

INTRODUCTION: In a Dutch heart centre, a dedicated chronic total occlusion (CTO) team was implemented in June 2017. The aim of this study was to the evaluate treatment success and clinical outcomes before and after this implementation. METHODS: A total of 662 patients who underwent percutaneous coronary intervention (PCI) for a CTO between January 2013 and June 2020 were included and divided into pre- and post-CTO team groups. The primary endpoint was the angiographic success rate of CTO-PCI. Secondary endpoints included angiographic success stratified by complexity using the J­CTO score and the following clinical outcomes: in-hospital complications and myocardial infarction, target vessel revascularisation, all-cause mortality, quality of life (QoL) and major adverse cardiac events (MACE) at 30-day and 1­year follow-up. RESULTS: Compared with the pre-CTO team group, the success rate in the post-CTO team group was higher after the first attempt (81.4% vs 62.7%; p < 0.001) and final attempt (86.7% vs 73.8%; p = 0.001). This was mainly driven by higher success rates for difficult and very difficult CTO lesions according to the J­CTO score. The MACE rate at 1 year was lower in the post-CTO team group than in the pre-CTO team group (6.4% vs 16.0%; p < 0.01), while it was comparable at 30-day follow-up (0.1% vs 1.7%; p = 0.74). Angina symptoms were significantly reduced at 30-day and 1­year follow-up, and QoL scores were higher after 1 year. CONCLUSION: This study demonstrated higher success rates of CTO-PCI and improved clinical outcomes and QoL at 1­year follow-up after implementation of a dedicated CTO team using the hybrid algorithm.

Neoadjuvant FOLFOXIRI prior to chemoradiotherapy for high-risk ("ugly") locally advanced rectal cancer: study protocol of a single-arm, multicentre, open-label, phase II trial (MEND-IT).

BACKGROUND: The presence of mesorectal fascia (MRF) invasion, grade 4 extramural venous invasion (EMVI), tumour deposits (TD) or extensive or bilateral extramesorectal (lateral) lymph nodes (LLN) on MRI has been suggested to identify patients with indisputable, extensive locally advanced rectal cancer (LARC), at high risk of treatment failure. The aim of this study is to evaluate whether or not intensified chemotherapy prior to neoadjuvant chemoradiotherapy improves the complete response (CR) rate in these patients. METHODS: This multicentre, single-arm, open-label, phase II trial will include 128 patients with non-metastatic high-risk LARC (hr-LARC), fit for triplet chemotherapy. To ensure a study population with indisputable, unfavourable prognostic characteristics, hr-LARC is defined as LARC with on baseline MRI at least one of the following characteristics; MRF invasion, EMVI grade 4, enlarged bilateral or extensive LLN at high risk of an incomplete resection, or TD. Exclusion criteria are the presence of a homozygous DPD deficiency, distant metastases, any chemotherapy within the past 6 months, previous radiotherapy within the pelvic area precluding standard chemoradiotherapy, and any contraindication for the planned treatment. All patients will be planned for six two-weekly cycles of FOLFOXIRI (5-fluorouracil, leucovorin, oxaliplatin and irinotecan) prior to chemoradiotherapy (25 × 2 Gy or 28 × 1.8 Gy with concomitant capecitabine). A resection will be performed following radiological confirmation of resectable disease after the completion of chemoradiotherapy. A watch and wait strategy is allowed in case of a clinical complete response. The primary endpoint is the CR rate, described as a pathological CR or a sustained clinical CR one year after chemoradiotherapy. The main secondary objectives are long-term oncological outcomes, radiological and pathological response, the number of resections with clear margins, treatment-related toxicity, perioperative complications, health-related costs, and quality of life. DISCUSSION: This trial protocol describes the MEND-IT study. The MEND-IT study aims to evaluate the CR rate after intensified chemotherapy prior to concomitant chemoradiotherapy in a homogeneous group of patients with locally advanced rectal cancer and indisputably unfavourable characteristics, defined as hr-LARC, in order to improve their prognosis. TRIAL REGISTRATION: Clinicaltrials.gov: NCT04838496 , registered on 02-04-2021 Netherlands Trial Register: NL9790. PROTOCOL VERSION: Version 3 dd 11-4-2022.

Comparison between laser sheaths, femoral approach and rotating mechanical sheaths for lead extraction.

INTRODUCTION: Efficiency and safety are important features in the selection of lead extraction tools. We report our experience with different endovascular techniques to extract individual pacing and defibrillator leads. METHODS: This is a single-centre study of consecutive lead extraction procedures from 1997 until 2019. A total of 1725 leads were extracted in 775 patients. Direct traction sufficed for 588 leads, and 22 leads were primarily removed by surgery. The endovascular techniques used in the remainder were a laser sheath (190 leads), the femoral approach (717 leads) and rotating mechanical sheaths (208 leads). RESULTS: The three approaches were comparably effective in completely removing the leads (p = 0.088). However, there were more major complications with the laser sheath than with the femoral approach or rotating mechanical sheaths (8.4%, 0.5% and 1.2%, respectively). Therefore, the procedural result-extraction without major complications-was significantly better with both the femoral approach and rotating mechanical sheaths than with the laser sheath (p < 0.001). This result was confirmed after propensity score matching to compensate for differences between lead cohorts (p = 0.007). Cross-over to another endovascular tool was necessary in 7.9%, 7.1% and 8.2% of laser, femoral and rotating mechanical attempts, respectively. CONCLUSION: All three endovascular lead extraction techniques showed comparable efficacy. However, there were significantly more major complications using the laser sheath compared to the femoral approach or rotating mechanical sheaths, leading us to abandon the laser technique. Importantly, no single endovascular technique sufficed to successfully extract all leads.

Evaluation of bifurcation stenting techniques at Catharina Hospital, Eindhoven in 2013.

AIMS: Percutaneous coronary intervention (PCI) of bifurcation lesions can be performed using various techniques. The aim of this study was to analyse the outcome of various techniques of bifurcation stenting in all patients undergoing bifurcation stenting at one large intervention centre in 2013, taking into account that more complex lesions might more often warrant a two-stent technique. METHODS AND RESULTS: This retrospective study included 260 consecutive patients who underwent non-primary PCI of a bifurcation lesion at the Catharina Hospital, Eindhoven, in 2013. Patients were classified into two groups: one-stent technique (provisional stenting), and two-stent techniques (culotte, crush and T­stenting). The primary endpoint was the rate of restenosis at 1 year. The secondary endpoints were procedural complications (side branch occlusion, periprocedural infarction, and death) and major adverse cardiac events (MACE) at 1 year. Periprocedural complications occurred in 15 patients (5.8 %) with no difference between the groups (p = 0.27). After 1 year, restenosis occurred in 3.2 % of the patients in the one-stent technique group and 7.3 % in the two-stent technique group (p = 0.20). MACE at 1 year did not differ between the groups at 11.9 % and 12.2 % respectively (p = 1.00). CONCLUSIONS: This study shows that there is no significant difference between restenosis rate, or any other outcome parameter, with the different techniques of bifurcation stenting. Since provisional stenting is the simplest, most straightforward and cheapest approach, if technically feasible this technique has our preference as the initial approach, and an upgrade can be considered if the result is insufficient.

Screening for coronary artery disease after mediastinal irradiation in Hodgkin lymphoma survivors: phase II study of indication and acceptance†.

BACKGROUND: Cardiovascular diseases are the most common nonmalignant cause of death in Hodgkin lymphoma (HL) survivors, especially after mediastinal irradiation. We investigated the role of computed tomographic coronary angiography (CTA) as a screening tool for coronary artery disease (CAD) in asymptomatic HL survivors, and related CTA findings to exercise testing and subsequent interventions. PATIENTS AND METHODS: Patients were eligible for this phase II study if at least 10 years disease-free and treated with mediastinal radiotherapy. Screening consisted of electrocardiogram, exercise testing and CTA. Primary end point was significant CAD (stenosis >50%) on CTA. CTA screening was considered to be indicated for testing in a larger population if ≥6 of 50 CTA scanned patients (12%) would need revascularization. Screening was evaluated with a questionnaire before and after screening. RESULTS: Fifty-two patients were included, and 48 patients underwent CTA. Median age was 47 years, time since HL diagnosis 21 years. There were 45 evaluable scans. Significant CAD on CTA was found in 20% (N = 9), significantly increased compared with the 7% expected abnormalities (P = 0.01, 95% confidence interval 8.3% to 31.7%). In 11% (N = 5), significant stenosis was confirmed at coronary angiography, and revascularization was carried out. Additionally, two patients were treated with optimal medical therapy. Ninety percent of patients were content with screening, regardless whether the CTA showed abnormalities. CONCLUSIONS: Prevalence of significant CAD among HL survivors is high, while asymptomatic even in the presence of life-threatening CAD. This might justify screening by CTA in asymptomatic HL survivors who had mediastinal radiotherapy, but needs to be evaluated in a larger cohort. The trial protocol was approved by the Ethics Committee of the LUMC and registered with ClinicalTrials.gov, NCT01271127.

Intra-aortic balloon counterpulsation in acute myocardial infarction: old and emerging indications.

BACKGROUND: Recent evidence questions the role of intra-aortic balloon counterpulsation (IABP) in the treatment of acute myocardial infarction (AMI) complicated by cardiogenic shock (CS). An area of increasing interest is the use of IABP for persistent ischaemia (PI). We analysed the use of IABP in patients with AMI complicated by CS or PI. METHODS: From 2008 to 2010, a total of 4076 patients were admitted to our hospital for primary percutaneous coronary intervention (PCI) for AMI. Out of those, 239 patients received an IABP either because of CS or because of PI. Characteristics and outcome of those patients are investigated. RESULTS: The mean age of the study population was 64 ± 11 years; 75 % were male patients. Of the patients, 63 % had CS and 37 % had PI. Patients with CS had a 30-day mortality rate of 36 %; 1-year mortality was 41 %. Patients with PI had a 30-day mortality rate of 7 %; 1-year mortality was 11 %. CONCLUSIONS: Mortality in patients admitted for primary PCI because of AMI complicated by CS is high despite IABP use. Outcome in patients treated with IABP for PI is favourable and mandates further prospective studies.

Design and rationale of the efficacy of spinal cord stimulation in patients with refractory angina pectoris (SCRAP) trial.

BACKGROUND: The use of spinal cord stimulation (SCS) in patients with refractory angina pectoris (RAP) is still under debate. Studies up to date have shown a positive effect with an improvement in quality of life. However, no double blinded randomized controlled trials have been performed. HYPOTHESIS & METHODS: The objective of this trial is to investigate if high density SCS leads to a significant reduction in the amount of myocardial ischemia in patients with RAP. Eligible patients must meet the criteria for RAP, have proven ischemia and a positive transcutaneous electrical nerve stimulator treadmill test. Patients who meet the inclusion criteria will receive an implanted spinal cord stimulator. Patients receive 6 months of high density SCS and 6 months of no stimulation using a cross-over design. The order of the treatment options is determined using randomization. The primary endpoint is the effect of SCS measured by the change in percentage of myocardial ischemia using myocardial perfusion positron emission tomography scan. Key secondary endpoints are patient related outcome measures, major cardiac adverse events and safety endpoints. The follow-up period is 1 year for the primary and key secondary endpoints. RESULTS: The SCRAP trial began enrollment on December 21, 2021 and is set to complete the primary assessments in June 2025. To date, January 2, 2023, 18 patients have been enrolled in the study and 3 patients have completed the 1-year follow-up. CONCLUSIONS: The SCRAP trial is an investigator-initiated, single-center, double-blind, placebo-controlled, and cross-over randomized controlled trial investigating the efficacy of SCS in patients with RAP. (ClinicalTrials. gov Identifier: NCT04915157).

A phase II study of enzastaurin, a protein kinase C beta inhibitor, in patients with relapsed or refractory mantle cell lymphoma.

BACKGROUND: Protein kinase C beta (PKCbeta), a pivotal enzyme in B-cell signaling and survival, is overexpressed in most cases of mantle cell lymphoma (MCL). Activation of PI3K/AKT pathway is involved in pathogenesis of MCL. Enzastaurin, an oral serine/threonine kinase inhibitor, suppresses signaling through PKCbeta/PI3K/AKT pathways, induces apoptosis, reduces proliferation, and suppresses tumor-induced angiogenesis. PATIENTS AND METHODS: Patients with relapsed/refractory MCL, and no more than four regimens of prior therapy, received 500 mg enzastaurin, orally, once daily. RESULTS: Sixty patients, median age 66 years (range 45-85), Eastern Cooperative Oncology Group performance status of zero to two (48% had baseline International Prognostic Index of 3-5), were enrolled. Most patients had prior CHOP-like chemotherapy and/or rituximab (median = 2 regimens). No drug-related deaths occurred. There was one case each of grade 3 anemia, diarrhea, dyspnea, vomiting, hypotension, and syncope. Fatigue was the most common toxicity. Although no objective tumor responses occurred, 22 patients (37%, 95% CI 25% to 49%) were free from progression (FFP) for > or =3 cycles (one cycle = 28 days); 6 of 22 were FFP for >6 months. Two patients remain on treatment and FFP at >23 months. CONCLUSION: Freedom from progression for >6 months in six patients and a favorable toxicity profile with minimal hematological toxicity indicate that enzastaurin warrants evaluation as maintenance therapy and combination chemotherapy in MCL.

Incidence of central nervous system involvement in chronic lymphocytic leukemia and outcome to treatment.

Leptomeningeal involvement in patients with CLL is relatively rare and the prognosis is usually considered to be poor. The authors reviewed all CLL patients treated in a tertiary referral center to assess the incidence and outcome of leptomeningeal involvement (LI) in CLL. They found an incidence of 1-2% of LI. Most of the patients with LI had a longterm survival, despite failure to clear the cerebrospinal fluid from tumor cells.

Analysis of helper activity on pokeweed mitogen- and interleukin 2-driven immunoglobulin synthesis by neoplastic T4+ cells.

The neoplastic T cells of a series of seven patients with chronic T-cell neoplasia were tested for helper activity on pokeweed mitogen (PWM)-induced and interleukin 2 (IL-2)-induced Ig synthesis. The neoplastic T cells of all patients had a T3+4+8-11+I1- phenotype but differed in expression of the 3A1 antigen. The neoplastic T cells of three patients had helper activity on both PWM- and IL-2-driven Ig synthesis, and in addition produced IL-2 in response to PWM stimulation. Two of these patients had hypergammaglobulinemia. In contrast, the neoplastic T cells in the remaining four patients did not produce IL-2 and did not support PWM-driven Ig synthesis. The T4+ cells of these four patients, however, provided excellent helper activity on IL-2-driven Ig synthesis. These findings emphasize the role of IL-2 in T cell-dependent Ig synthesis and clearly show that IL-2 production is required for helper activity in the PWM-driven system. It is concluded that the combined use of PWM- and IL-2-driven Ig synthesis systems allows separate analysis of IL-2 production and T-helper activity in health and disease.

Short intensive sequential therapy followed by autologous stem cell transplantation in adult Burkitt, Burkitt-like and lymphoblastic lymphoma.

The feasibility and efficacy of up-front high-dose sequential chemotherapy followed by autologous stem cell transplantation (ASCT) in previously untreated adults (median age 33 years; range 15-64) with Burkitt lymphoma (BL), Burkitt-like lymphoma (BLL) or lymphoblastic lymphoma (LyLy), both without central nervous system or extensive bone marrow involvement was investigated in a multicenter phase II study. Treatment consisted of two sequential high-dose chemotherapy induction courses incorporating prednisone, cyclophosphamide, doxorubicin, etoposide and mitoxantrone, without high-dose methotrexate or high-dose cytarabine. Patients with at least PR went on with BEAM and ASCT. Protocol treatment was completed by 23/27 (85%) BL/BLL and 13/15 (87%) LyLy patients. Median treatment duration until BEAM was 70 (range: 50-116) days. No toxic deaths occurred. Response to treatment was complete response (CR) 81% and partial response (PR) 11% for BL/BLL, CR 73% and PR 20% for LyLy. At a median follow-up of 61 months of patients still alive, six BL/BLL and eight LyLy patients have died. The actuarial 5-year overall and event-free survival estimates are 81 and 73% for BL/BLL vs 46 and 40% for LyLy patients. In conclusion, this short up-front high-dose sequential chemotherapy regimen, followed by ASCT is highly effective in adults with BL/BLL with limited bone marrow involvement, but less so in patients with LyLy.

Amplification of the c-myc and the pvt-like region in human multiple myeloma.

Genetic alterations that lead to the clonal expansion of differentiated cells in multiple myeloma have still to be elucidated. Many chromosomal aberrations have been found, but until now, none of them is typically associated with multiple myeloma. In search for genetic defects in multiple myeloma we studied the structure and expression of the c-myc oncogene and the pvt-like region because of their frequent association with other B-cell malignancies. Here we report co-amplification of the c-myc oncogene and the 5' part of the pvt-like region in two out of 26 cases of multiple myeloma. In both cases only kappa-light chains were produced. The amplification also manifested itself at the RNA level. Total RNA was analysed in one of these two cases showing abundant c-myc mRNA. In the same RNA sample we also detected a strong hybridizing band of about 7 kb, when the pSS.4 probe, representing the 5' part of the pvt-like region, was used. This band was not present in total RNA from normal bone marrow cells or bone marrow from multiple myeloma patients without the amplification of c-myc and the pvt-like region. Until now, transcripts of the pvt-like region were only found in a few human cell lines ranging in size from 1 to 11 kb. This is the first case in which a high expression of a +/- 7 kb transcript of the pvt-like region has been found in freshly obtained tumor material probably due to a pvt-amplification. The occurrence of abnormalities in the c-myc and the pvt-like region in multiple myeloma is a rare event and may be associated with the progression of this type of tumor.

Clinical significance of t(14; 18)-positive cells in the circulation of patients with stage III or IV follicular non-Hodgkin's lymphoma during first remission.

PURPOSE: To evaluate polymerase chain reaction (PCR) analysis as a method for the detection of circulating lymphoma cells in patients with stage III and IV t(14; 18)-positive follicular Non-Hodgkin's lymphoma (NHL) in first remission in a longitudinal prospective study. PATIENTS AND METHODS: Peripheral blood or bone marrow from eight patients with stage III and IV t(14; 18)-positive NHL was studied using PCR to detect the presence of t(14; 18)-positive cells in the circulation at different times during first remission. RESULTS: In four of six patients with no clinical evidence of disease (NCED), t(14; 18)-positive cells were detectable in the circulation. In one of two patients with clinical evidence of disease (CED), no t(14; 18)-positive cells were found at the four different occasions tested during first remission. First-remission duration ranged from 17 to 81+ months. The duration from the first PCR determination in remission until first relapse or the end of the observation period ranged from 10 to 37+ months. CONCLUSION: In patients with t(14; 18)-positive follicular NHL stage III and IV, treated with conventional remission induction therapy, the presence or absence of t(14; 18)-positive cells in the circulation shows no obvious correlation with the clinical remission status and the remission duration.

Second cancers among long-term survivors of Hodgkin's disease diagnosed in childhood and adolescence.

PURPOSE: To quantify the risk of second cancers among long-term survivors of Hodgkin's disease (HD) diagnosed before 21 years of age and to explore sex-, age-, and site-related differences. PATIENTS AND METHODS: We analyzed data from 5,925 pediatric HD patients, including 2,646 10-year and 755 20-year survivors, who were reported to 16 population-based cancer registries in North America and Europe between 1935 and 1994. RESULTS: A total of 157 solid tumors (observed/expected ratio [O/E] = 7.0; 95% confidence interval [CI], 5.9 to 8.2.) and 26 acute leukemias (O/E = 27.4; 95% CI, 17.9 to 40. 2) were reported. Risk of solid tumors remained significantly increased among 20-year survivors (O/E = 6.6, observed [O] = 40, cumulative risk = 6.5%) and persisted for 25 years (O/E = 4.6, O = 15, cumulative risk = 11.7%). Temporal trends for cancers of thyroid, female breast, bone/connective tissue, stomach, and esophagus were consistent with the late effects of radiotherapy. Greater than 50-fold increased risks were observed for tumors of the thyroid and respiratory tract (one lung and one pleura) among children treated before age 10. At older ages (10 to 16 years), the largest number of second cancers occurred in the digestive tract (O/E = 19.3) and breast (O/E = 22.9). Risk of solid tumors increased with decreasing age at HD on a relative but not absolute scale. CONCLUSION: Children and adolescents treated for HD experience significantly increased risks of second cancers at various sites for 2 to 3 decades. Although our results reflect the late effects of past therapeutic modalities, they underscore the importance of lifelong follow-up of pediatric HD patients given early, more aggressive treatments.

Intensive postremission chemotherapy without maintenance therapy in adults with acute lymphoblastic leukemia. Dutch Hemato-Oncology Research Group.

PURPOSE: To investigate the value of intensive consolidation chemotherapy not followed by maintenance therapy in adult acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: A multicenter phase II trial was conducted in 130 adult patients with ALL between 16 and 60 years of age. After standard induction therapy, postinduction chemotherapy was given: three courses of high-dose cytarabine (2,000 mg/m2 every 12 hours for four doses) in combination with amsacrine (course one), mitoxantrone (course two), and etoposide (course three). CNS prophylaxis consisted of 10 injections of intrathecal methotrexate (IT MTX). Patients younger than 50 years with an HLA-identical sibling were eligible to receive allogeneic bone marrow transplantation (BMT). RESULTS: Ninety-five patients (73%) achieved complete remission (CR); 82% were younger than 50 years and 41% were older than 50 years. Seventeen patients (13%) were resistant to chemotherapy, and 18 (14%) died during induction treatment. Only age and performance status were significantly associated with response (P<.001 and .03, respectively). Death during consolidation occurred in four patients. The estimated 5-year overall survival (OS) was 22% for the entire group and 26% for patients younger than 35 years. Disease-free survival (DFS) at 5 years was 28% +/- 6 for patients younger than 35 years, 25% +/- 9 for patients between 35 and 50 years, and 0% for patients older than 50 years. Increasing age (P<.01) and expression of CD34 (P<.01) were adverse factors. Only three patients (3%) developed an isolated CNS relapse. CONCLUSION: Intensive consolidation including high-dose cytarabine not followed by maintenance therapy provides an outcome for adult patients with ALL that may be worse or even inferior compared with studies using long-term maintenance therapy. High-dose cytarabine in combination with IT MTX was effective for CNS prophylaxis.

Proposals for the immunological classification of acute leukemias. European Group for the Immunological Characterization of Leukemias (EGIL).

Criteria for the immunological classification of acute leukemias are proposed by a recently established European group designated EGIL. The main aims of EGIL are to establish guidelines for the characterization of acute leukemias based on marker expression and provide a uniform basis for the diagnosis of the various types of these hemopoietic malignancies which should be helpful for future multinational clinical and laboratory investigations. Within the two major types (B and T cell lineage) of acute lymphoblastic leukemia (ALL), several groups are delineated according to the degree of cell differentiation. Within the acute myeloid leukemias (AML), only three subtypes as defined by the FAB classification: M0-AML, M6-AML and M7-AML, can be unequivocally defined by immunological markers; prospective studies are undertaken to see whether characteristic immunological profiles are associated with particular AML subtypes defined by specific cytogenetic abnormalities. Criteria for the definition of biphenotypic acute leukemia (BAL) are devised and a scoring system is outlined aimed to distinguish BAL from those acute leukemias with expression of a marker from another lineage. In addition, an uncommon subset of acute leukemias with no evidence of lymphoid or myeloid differentiation is recognized and the useful panel of markers to investigate and establish the cell nature of the acute leukemias is outlined. EGIL will focus in the future on testing the reproducibility of the proposed guidelines, particularly those for BAL, assessing their clinical value within a framework of multicentric trials and setting up uniform methodological criteria.

Characterization of the blast cells in acute leukemia with translocation (4;11): report of eight additional cases and of one case with a variant translocation.

Eight new cases (five adults and three children) of acute leukemia characterized by the presence in bone marrow cells of a t(4;11)(q21;q23)and one similar case, a child, with a t(1;11)(p32;q23) are reported. All patients were diagnosed as having acute lymphoblastic leukemia (ALL) with high-risk features. Immunologically the blast cells of the nine cases showed a strikingly consistent immature lymphoid phenotype, i.e., TdT+, HLA-DR+, B4(CD19)+, CALLA(CD10)-, Smlg-, cmu-, BA-2(CD9)+ corresponding to a "null ALL." In addition, six of nine cases expressed the myeloid marker VIM-D5(CD15). By double immunofluorescence staining it was determined that the VIM-D5(CD15) antigen was expressed by terminal deoxynucleotidyl transferase-positive blast cells, excluding the possibility of double leukemia. In five cases investigation of the Ig heavy chain genes by Southern blot analysis showed clonal rearrangement of both Ig heavy chain gene alleles. These data suggest that the blast cells involved in t(4;11) leukemia represent early B-cell progenitors with "aberrant" expression of myelomonocytic features, possibly related to the 11q23 breakpoint.

Detection of minimal disease using rearranged immunoglobulin heavy chain genes from intermediate- and high-grade malignant B cell non-Hodgkins lymphoma.

Rearranged immunoglobulin heavy chain (IgH) genes provide unique clonal markers for B cells. Since amplification of the rearranged gene by polymerase chain reaction (PCR) and demonstrating that the amplified sequence is indeed derived from tumor cells is more problematic in non-Hodgkin's lymphoma (NHL) than in other B cell malignancies, we used a comprehensive PCR primer set and formulated stringent selection criteria to identify tumor-specific rearranged IgH genes. Rearranged IgH genes amplified from lymphoma DNA were considered to be of tumor origin if they were monoclonal, and if the same rearrangement was amplified with at least two independent VH-specific primers. From 11 of 13 (85%) intermediate- and high-grade malignant NHL, IgH rearrangements were isolated. Intraclonal IgH sequence heterogeneity was studied in four lymphomas, and detected in two of them. PCR using a lymphoma-specific primer followed by Southern hybridization of PCR product with a specific probe allowed detection of lymphoma DNA after 10,000-fold dilution. Circulating lymphoma cells were detected in patient blood and bone marrow samples which were negative by morphological and immunological criteria. Thus, also in intermediate- and high-grade malignant lymphoma, sensitive minimal disease detection using the rearranged IgH gene as a marker appears feasible.

Rearranged immunoglobulin light chain genes as minimal residual disease markers in intermediate- and high-grade malignant B cell non-Hodgkin's lymphoma.

Minimal residual disease (MRD) detection in B cell non-Hodgkin's lymphoma (NHL) patients has been shown to be possible using the rearranged heavy (IgH) chain gene as a tumor marker. To explore a second independent tumor marker, we used specific PCR primer sets to identify tumor-specific rearranged Ig light chain (IgL) genes. Rearranged IgL genes were amplified from lymphoma DNA by multiplex PCR using separate primer sets for the Igkappa and the Iglambda genes. They were considered to be of tumor origin if they were monoclonal, and if the same rearrangement was isolated from at least two independent PCR products. From 12 out of 13 intermediate- and high-grade malignant NHL, PCR products could be obtained with IgL specific primers. PCR products from five NHL were studied in detail by cloning and sequencing. The rearranged IgL genes showed 85-100% homology with their closest germ line counterparts. Intraclonal IgL sequence heterogeneity was studied in five lymphomas and detected in only one. Minimal disease was studied in three patients by PCR, followed by Southern hybridization of the PCR product with a lymphoma-specific oligonucleotide probe, which allowed for detection of lymphoma DNA following 1000-fold dilution. Blood samples from one patient, who is in long-term clinical remission, were negative for the lymphoma-specific rearranged Igkappa gene. In the second patient the rearranged Iglambda gene was detected during the first clinical remission, that was followed by a nodal relapse, but not during the second remission, that has been stable for almost 3 years now. The third patient was negative for the rearranged Iglambda gene in blood samples up to 102 months after diagnosis. Circulating lymphoma cells were detected in blood and bone marrow samples which were negative by morphological and immunological criteria. Our studies show that the rearranged IgL gene can be used as a second independent tumor marker in intermediate- and high-grade malignant NHL.