Minimal Residual Disease Detection and Evolved IGH Clones Analysis in Acute B Lymphoblastic Leukemia Using IGH Deep Sequencing

High-throughput sequencing of archival cerebrospinal fluid specimens defines B-lymphoblastic leukemia clonal composition

Detailed characterization of the B-lymphoblastic leukemia (B-ALL) cells which invade the central nervous system (CNS) has been limited by practical challenges. To test whether the clonal composition of the cerebrospinal fluid (CSF) reflects the primary B-ALL tissue, we applied immunoglobulin (Ig) high-throughput sequencing (HTS) of archival CSF cytospin preparations from six patients with morphologically defined CNS involvement. We discovered that most CSF clones are detectable at some timepoint in the primary tissue, but that shifting clonal abundance is prevalent across tissue sites between diagnosis and relapse. Ig HTS of CSF cytospins may improve understanding of sanctuary site dissemination in B-ALL.

Monitoring measurable residual disease in paediatric acute lymphoblastic leukaemia using immunoglobulin gene clonality based on next-generation sequencing

BACKGROUND

Assessment of measurable residual disease (MRD) is an essential prognostic tool for B-lymphoblastic leukaemia (B-ALL). In this study, we evaluated the utility of next-generation sequencing (NGS)-based MRD assessment in real-world clinical practice.

METHOD

The study included 93 paediatric patients with B-ALL treated at our institution between January 2017 and June 2022. Clonality for IGH or IGK rearrangements was identified in most bone marrow samples (91/93, 97.8%) obtained at diagnosis.

RESULTS

In 421 monitoring samples, concordance was 74.8% between NGS and multiparameter flow cytometry and 70.7% between NGS and reverse transcription-PCR. Elevated quantities of clones of IGH alone (P < 0.001; hazard ratio [HR], 22.2; 95% confidence interval [CI], 7.1-69.1), IGK alone (P = 0.011; HR, 5.8; 95% CI, 1.5-22.5), and IGH or IGK (P < 0.001; HR, 7.2; 95% CI, 2.6-20.0) were associated with an increased risk of relapse. Detection of new clone(s) in NGS was also associated with inferior relapse-free survival (P < 0.001; HR, 18.1; 95% CI, 3.0-108.6). Multivariable analysis confirmed age at diagnosis, BCR::ABL1-like mutation, TCF3::PBX1 mutation, and increased quantity of IGH or IGK clones during monitoring as unfavourable factors.

CONCLUSION

In conclusion, this study highlights the usefulness of NGS-based MRD as a routine assessment tool for prognostication of paediatric patients with B-ALL.

Self-supervised learning of T cell receptor sequences exposes core properties for T cell membership

The T cell receptor (TCR) repertoire is an extraordinarily diverse collection of TCRs essential for maintaining the body's homeostasis and response to threats. In this study, we compiled an extensive dataset of more than 4200 bulk TCR repertoire samples, encompassing 221,176,713 sequences, alongside 6,159,652 single-cell TCR sequences from over 400 samples. From this dataset, we then selected a representative subset of 5 million bulk sequences and 4.2 million single-cell sequences to train two specialized Transformer-based language models for bulk (CVC) and single-cell (scCVC) TCR repertoires, respectively. We show that these models successfully capture TCR core qualities, such as sharing, gene composition, and single-cell properties. These qualities are emergent in the encoded TCR latent space and enable classification into TCR-based qualities such as public sequences. These models demonstrate the potential of Transformer-based language models in TCR downstream applications.

Using Measurable Residual Disease to Optimize Management of AML, ALL, and Chronic Myeloid Leukemia

In this review, we discuss the use of measurable residual disease (MRD) in AML, ALL, and chronic myeloid leukemia (CML). Our aims were to review the different methodologies for MRD assessment; describe the clinical relevance and medical decision making on the basis of MRD; compare and contrast the usage of MRD across AML, ALL, and CML; and discuss what patients need to know about MRD as it relates to their disease status and treatment. Finally, we discuss ongoing challenges and future directions with the goal of optimizing MRD usage in leukemia management.

Enfermedad mínima residual por citometría de flujo en pacientes con leucemia linfoblástica aguda

Antecedentes. La citometría de flujo (CMF) es una técnica que permite el análisis multiparamétrico de poblaciones celulares, siendo esencial en la investigación biomédica y como herramienta diagnóstica. Esta técnica rápida tiene una alta sensibilidad, evaluandocaracterísticas en la población de interés como es el caso del tamaño, granularidad, complejidad del citoplasma celular y proteínas de que permiten la clasificación fenotípica y funcional de un gran número de células. Por estas razones, esta técnica ha adquiridoimportancia en el diagnóstico y seguimiento de enfermedades y anomalías hematológicas, como leucemias, síndromes mielodisplásicos y síndromes mieloproliferativos, entre otras. Objetivo. La presente revisión se enfoca en los avances en la implementación de la CMF en la Enfermedad Mínima Residual (EMR) presente en la Leucemia Linfoblástica Aguda (LLA), la cual es una población mínima leucémica que se detecta en un paciente después de suministrar un tratamiento oncológico, donde se evalúa su eficacia, el riesgo de una recaída y el proceso de remisión completa. Metodología. Se realiza una revisión no sistemática deliteratura en bases de datos, de los últimos 15 años, donde evalúen las implicaciones del uso de citometría de flujo en la EMR, de esta revisión se extraen aspectos relevantes al momento de emplear la CMF para el diagnóstico y seguimiento de pacientes con leucemias. Resultados. La CMF es una técnica muy versátil e importante para el diagnóstico y seguimiento de la EMR por su alta sensibilidad para la detección de bajos números de células resistentes a la terapia. Adicionalmente se muestra la importancia de la estandarización de protocolos como EUROFLOW para un adecuado procesamiento y análisis clínico de las muestras de pacientes.

Measurable residual disease in acute lymphoblastic leukemia: methods and clinical context in adult patients

Measurable residual disease (MRD) is the most powerful independent predictor of risk of relapse and long-term survival in adults and children with acute lymphoblastic leukemia (ALL). For almost all patients with ALL there is a reliable method to evaluate MRD, which can be done using multi-color flow cytometry, quantitative polymerase chain reaction to detect specific fusion transcripts or immunoglobulin/T-cell receptor gene rearrangements, and high-throughput next-generation sequencing. While next-generation sequencing-based MRD detection has been increasingly utilized in clinical practice due to its high sensitivity, the clinical significance of very low MRD levels (<10-4) is not fully characterized. Several new immunotherapy approaches including blinatumomab, inotuzumab ozogamicin, and chimeric antigen receptor T-cell therapies have demonstrated efficacy in eradicating MRD in patients with B-ALL. However, new approaches to target MRD in patients with T-ALL remain an unmet need. As our MRD detection assays become more sensitive and expanding novel therapeutics enter clinical development, the future of ALL therapy will increasingly utilize MRD as a criterion to either intensify or modify therapy to prevent relapse or de-escalate therapy to reduce treatment-related morbidity and mortality.

The Diagnostic and Prognostic Potential of the B-Cell Repertoire in Membranous Nephropathy

Membranous nephropathy (MN), an autoimmune glomerular disease, is one of the most common causes of nephrotic syndrome in adults. In current clinical practice, the diagnosis is dependent on renal tissue biopsy. A new method for diagnosis and prognosis surveillance is urgently needed for patients. In the present study, we recruited 66 MN patients before any treatment and 11 healthy control (HC) and analyzed multiple aspects of the immunoglobulin heavy chain (IGH) repertoire of these samples using high-throughput sequencing. We found that the abnormalities of CDR-H3 length, hydrophobicity, somatic hypermutation (SHM), and germ line index were progressively more prominent in patients with MN, and the frequency of IGHV3-66 in post-therapy patients was significantly lower than that in pre-therapy patients. Moreover, we found that the IGHV3-38 gene was significantly related to PLA2R, which is the most commonly used biomarker. The most important discovery was that several IGHV, IGHD transcripts, CDR-H3 length, and SHM rate in pre-therapy patients had the potential to predict the therapeutic effect. Our study further demonstrated that the IGH repertoire could be a potential biomarker for prognosis prediction of MN. The landscape of circulating B-lymphocyte repertoires sheds new light on the detection and surveillance of MN.

Perspective: sensitive detection of residual lymphoproliferative disease by NGS and clonal rearrangements-how low can you go?

Malignant lymphoproliferative disorders collectively constitute a large fraction of the hematological cancers, ranging from indolent to highly aggressive neoplasms. Being a diagnostically important hallmark, clonal gene rearrangements of the immunoglobulins enable the detection of residual disease in the clinical course of patients down to a minute fraction of malignant cells. The introduction of next-generation sequencing (NGS) has provided unprecedented assay specificity, with a sensitivity matching that of polymerase chain reaction-based measurable residual disease (MRD) detection down to the 10^-6 level. Although reaching 10^-6 to 10^-7 is theoretically feasible, employing a sufficient amount of DNA and sequencing coverage is placed in the perspective of the practical challenges when relying on clinical samples in contrast to controlled serial dilutions. As we discuss, the randomness of subsampling must be taken into account to accommodate the sensitivity threshold-in terms of both the required number of cells and sequencing coverage. As a substantial part of the reviewed studies do not state the depth of coverage or even amount of DNA in some cases, we call for increased transparency to enable critical assessment of the MRD assays for clinical implementation and feasibility.

How I investigate minimal residual disease in acute lymphoblastic leukemia

Minimal Residual Disease (MRD) is the most important independent prognostic factor in acute lymphoblastic leukemia (ALL) and refers to the deep level of measurable disease in cases with complete remission by conventional pathologic analysis, especially by cytomorphology. MRD can be detected by multiparametric flow cytometry, molecular approaches such as quantitative polymerase chain reaction for immunoglobulin and T-cell receptor (IG/TR) gene rearrangements or fusion genes transcript, and high-throughput sequencing for IG/TR. Despite the proven clinical usefulness in detecting MRD, these methods have differences in sensitivity, specificity, applicability, turnaround time and cost. Knowing and understanding these differences, as well as the principles and limitations of each technology, is essential to laboratory standardization and correct interpretation of MRD results in line with treatment time points, therapeutic settings, and clinical trials. Here, we review the methodological approaches to measure MRD in ALL and discuss the advantages and limitations of the most commonly used techniques.

High-throughput sequencing of immunoglobulin heavy chain for minimal residual disease detection in B-lymphoblastic leukemia

INTRODUCTION

Minimal residual disease (MRD) is a cornerstone for stratification of upfront B-lymphoblastic leukemia (B-ALL) treatment protocols to decrease relapse risk. Although its detection by flow cytometry (FC) and real-time quantitative polymerase has clinical usefulness, evidence suggests that methods with increased sensitivity could lead to improved outcomes. The aim of this study was to develop an amplicon-based assay followed by high-throughput sequencing of the immunoglobulin heavy chain variable region for MRD detection in B-ALL.

METHODS

We analyzed 84 samples, 27 from diagnosis, 5 from relapse, 40 from post-treatment samples, and 12 from healthy controls.

RESULTS

Our assay was able to identify more neoplastic clones at diagnosis than Sanger sequencing including incomplete DJ rearrangements. From the 40 MRD samples evaluated 21 were positive by our new approach on high-throughput sequencing assay, but only 15 of these were positive by FC. The remaining 19 were negative by the two techniques.

CONCLUSION

We have developed a novel approach on high-sensitive assay for MRD detection in B-ALL, which could add clinical value in the management of patients, especially in cases negative for MRD by FC.

PIRD: Pan Immune Repertoire Database

MOTIVATION

T and B cell receptors (TCRs and BCRs) play a pivotal role in the adaptive immune system by recognizing an enormous variety of external and internal antigens. Understanding these receptors is critical for exploring the process of immunoreaction and exploiting potential applications in immunotherapy and antibody drug design. Although a large number of samples have had their TCR and BCR repertoires sequenced using high-throughput sequencing in recent years, very few databases have been constructed to store these kinds of data. To resolve this issue, we developed a database.

RESULTS

We developed a database, the Pan Immune Repertoire Database (PIRD), located in China National GeneBank (CNGBdb), to collect and store annotated TCR and BCR sequencing data, including from Homo sapiens and other species. In addition to data storage, PIRD also provides functions of data visualization and interactive online analysis. Additionally, a manually curated database of TCRs and BCRs targeting known antigens (TBAdb) was also deposited in PIRD.

AVAILABILITY AND IMPLEMENTATION

PIRD can be freely accessed at https://db.cngb.org/pird.

Developing an Unbiased Multiplex PCR System to Enrich the TRB Repertoire Toward Accurate Detection in Leukemia

Accurate T cell receptor repertoire profiling has provided novel biological and clinical insights in widespread immunological settings; however, there is a lack of reference materials in the community that can be used to calibrate and optimize the various experimental systems in different laboratories. In this study, we designed and synthesized 611 T cell receptor (TCR) beta chain (TRB) templates and used them as reference materials to optimize the multiplex PCR experimental system to enrich the TRB repertoire. We assessed the stability of the optimized system by repeating the experiments in different batches and by remixing the TRB templates in different ratios. These TRB reference materials could be used as independent positive controls to assess the accuracy of the experimental system, and they can also be used as spike-in materials to calibrate the residual biases of the experimental system. We then used the optimized system to detect the minimal residual disease of T cell acute lymphoblastic leukemia and showed a higher sensitivity compared with flow cytometry. We also interrogated how chemotherapy affected the TCR repertoire of patients with B-cell acute lymphoblastic leukemia. Our result shows that high-avidity T cells, such as those targeting known pathogens, are largely selected during chemotherapy, despite the global immunosuppression. These T cells were stimulated and emerged at the time of induction treatment and further expanded during consolidation treatment, possibly to fight against infections. These data demonstrate that accurate immune repertoire information can improve our understanding of the adaptive immunity in leukemia and lead to better treatment management of the patients.

Minimal residual disease in acute lymphoblastic leukemia: technical aspects and implications for clinical interpretation

Minimal residual disease (MRD) monitoring has proven to be one of the fundamental independent prognostic factors for patients with acute lymphoblastic leukemia (ALL). Sequential monitoring of MRD using sensitive and specific methods, such as real-time quantitative polymerase chain reaction (qPCR) or flow cytometry (FCM), has improved the assessment of treatment response and is currently used for therapeutic stratification and early detection. Although both FCM and qPCR yield highly consistent results with sensitivities of 10^‒4, each method has several limitations. For example, qPCR is time-consuming and laborious: designing primers that correspond to the immunoglobulin (IG) and T-cell receptor (TCR) gene rearrangements at diagnosis can take 3‒4 weeks. In addition, the evolution of additional clones beyond the first or index clone during therapy cannot be detected, which might lead to false-negative results. FCM requires experienced technicians and sometimes does not achieve a sensitivity of 10^‒4. Accordingly, a next generation sequencing (NGS)-based method has been developed in an attempt to overcome these limitations. With the advent of high-throughput NGS technologies, a more in-depth analysis of IG and/or TCR gene rearrangements is now within reach, which impacts all applications of IG/TR analysis. However, standardization, quality control, and validation of this new technology are warranted prior to its incorporation into routine practice.

Acute lymphoblastic leukemia clonal distribution between bone marrow and peripheral blood

Acute lymphoblastic leukemia (ALL) is often composed of numerous subclones. Here we test whether the clonal composition of the blood is representative of the bone marrow at leukemia onset. Using ultra-deep IGH sequencing, we detected 28 clones across 16 patients; 5/28 were only in the marrow. In four patients, the most abundant clones differed between sites, including three in which the dominant medullary clones were minimally detectable in the blood. These findings demonstrate that the peripheral blood often underrepresents the genetic heterogeneity in a B-ALL and highlight the potential impact of tissue site selection on the detection of minor subclones.

Selection of potential cytokeratin-18 monoclonal antibodies following IGH repertoire evaluation in mice

Cytokeratin 18 (CK18), the main scaffold protein of keratinocyte, is distributed in epithelial cells. This structural protein maintains the integrity and continuity of epithelial tissue. Cytokeratin is also frequently used as an immunohistochemical marker of tumor growth. In recent years, immune repertoire (IR) evaluation using next-generation sequencing (NGS) have become increasingly efficient. Here we deep sequenced the mouse IR of the immunoglobulin heavy chain (IGH) after CK18 immunization. We comprehensively analyzed the IR based on complementarity determining region 3 (CDR3) abundance, germline gene usage polarization, clone diversity, and lineage. We found many convergence characteristics after CK18 immunization. Convergence represents a phenomenon that antigen stimulation or pathogen exposure induces the antigen specific clone expansion and enrichment. The convergence could be used for the immune evaluation and antibody screen. After immunization, the IGHV5 gene clusters became preponderant. The abundance and length of the most frequent CDR3 both increased, nevertheless the IR diversity level decreased. From the convergent IGH repertoires, we selected and expressed six antibodies with the most frequent CDR3s and IGH V-J combinations. The ELISA results suggested all screened six antibodies bound CK18 specifically. The most potential antibody had 9.424E-10M M affinity for the interaction with the CK18. Therefore, this is the NGS platform has been first used for anti-CK18 monoclonal antibodies (MAbs) discovery. These analyses methods could also be used for vaccine evaluation.

Next-Generation Sequencing in Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer and accounts for about a quarter of adult acute leukemias, and features different outcomes depending on the age of onset. Improvements in ALL genomic analysis achieved thanks to the implementation of next-generation sequencing (NGS) have led to the recent discovery of several novel molecular entities and to a deeper understanding of the existing ones. The purpose of our review is to report the most recent discoveries obtained by NGS studies for ALL diagnosis, risk stratification, and treatment planning. We also report the first efforts at NGS use for minimal residual disease (MRD) assessment, and early studies on the application of third generation sequencing in cancer research. Lastly, we consider the need for the integration of NGS analyses in clinical practice for genomic patients profiling from the personalized medicine perspective.

The landscape and diagnostic potential of T and B cell repertoire in Immunoglobulin A Nephropathy

Immunoglobulin A Nephropathy (IgAN) is the most common glomerulonephritis worldwide. The pathologic hallmark of IgAN is immune complex deposited in glomerular mesangium, which induces inflammation and affects the kidney's normal functions. The exact pathogenesis of IgAN, however, remains obscure. Further, in current clinical practice, the diagnosis relies on needle biopsy of renal tissue. Therefore, a non-invasive method for diagnosis and prognosis surveillance of the disease is highly desirable. To this end, we investigated the T cell receptor beta chain (TCRB) and immunoglobulin heavy chain (IGH) repertoire in circulating lymphocytes and compared them with kidney infiltrating lymphocytes using immune repertoire high throughput sequencing. We found that some features of TCRB and IGH in renal tissues were remarkably different from that in the blood, including decreased repertoire diversity, increased IgA and IgG frequency, and more antigen-experienced B cells. The complementarity-determining region 3 (CDR3) length of circulating TCRB and IGH in IgAN patients was significantly shorter than that in healthy controls, which is the result of both VDJ rearrangement and clonal selection. The IgA1 frequency in the blood of IgAN patients is significantly higher than that in other Nephropathy (NIgAN) patients and healthy control. Importantly we identified a set of TCRB and IGH clones, which can be used to distinguish IgAN from NIgAN and healthy controls with high accuracy. These results indicated that the TCRB and IGH repertoire can potentially serve as non-invasive biomarkers for the diagnosis of IgAN. The characteristics of the kidney infiltrating and circulating lymphocytes repertoires shed light on IgAN detection, treatment and surveillance.

Next-generation antigen receptor sequencing of paired diagnosis and relapse samples of B-cell acute lymphoblastic leukemia: Clonal evolution and implications for minimal residual disease target selection

Antigen receptor gene rearrangements are frequently applied as molecular targets for detection of minimal residual disease (MRD) in B-cell precursor acute lymphoblastic leukemia patients. Since such targets may be lost at relapse, appropriate selection of antigen receptor genes as MRD-PCR target is critical. Recently, next-generation sequencing (NGS) - much more sensitive and quantitative than classical PCR-heteroduplex approaches - has been introduced for identification of MRD-PCR targets. We evaluated 42 paired diagnosis-relapse samples by NGS (IGH, IGK, TRG, TRD, and TRB) to evaluate clonal evolution patterns and to design an algorithm for selection of antigen receptor gene rearrangements most likely to remain stable at relapse. Overall, only 393 out of 1446 (27%) clonal rearrangements were stable between diagnosis and relapse. If only index clones with a frequency >5% at diagnosis were taken into account, this number increased to 65%; including only index clones with an absolute read count >10,000, indicating truly major clones, further increased the stability to 84%. Over 90% of index clones at relapse were also present as index clone at diagnosis. Our data provide detailed information about the stability of antigen receptor gene rearrangements, based on which we propose an algorithm for selecting stable MRD-PCR targets, successful in >97% of patients.

A Comprehensive Analysis of the T and B Lymphocytes Repertoire Shaped by HIV Vaccines

The exploitation of various human immunodeficiency virus type-1 (HIV-1) vaccines has posed great challenges for the researchers in precisely evaluating the vaccine-induced immune responses, however, the understanding of vaccination response suffers from the lack of unbiased characterization of the immune landscape. The rapid development of high throughput sequencing (HTS) makes it possible to scrutinize the extremely complicated immunological responses during vaccination. In the current study, three vaccines, namely N36, N51, and 5-Helix based on the HIV-1 gp41 pre-hairpin fusion intermediate were applied in rhesus macaques. We assessed the longitudinal vaccine responses using HTS, which delineated the evolutionary features of both T cell and B cell receptor repertoires with extreme diversities. Upon vaccination, we unexpectedly found significant discrepancies in the landscapes of T-cell and B-cell repertoires, together with the detection of significant class switching and the lineage expansion of the B cell receptor or immunoglobulin heavy chain (IGH) repertoire. The vaccine-induced expansions of lineages were further evaluated for mutation rate, lineage abundance, and lineage size features in their IGH repertoires. Collectively, these findings conclude that the N51 vaccine displayed superior performance in inducing the class-switch of B cell isotypes and promoting mutations of IgM B cells. In addition, the systematic HTS analysis of the immune repertoires demonstrates its wide applicability in enhancing the understanding of immunologic changes during pathogen challenge, and will guide the development, evaluation, and exploitation of new generation of diagnostic markers, immunotherapies, and vaccine strategies.

Simple deep sequencing-based post-remission MRD surveillance predicts clinical relapse in B-ALL

Background

Next-generation sequencing (NGS) of the rearranged immunoglobulin heavy-chain gene has emerged as a highly sensitive method to detect minimal residual disease (MRD) in B acute lymphoblastic leukemia/lymphoma (B-ALL). However, a sensitive and easily implemented NGS methodology for routine clinical laboratories is lacking and clinical utility of NGS-MRD surveillance in a post-remission setting to predict clinical relapse has not been determined.

Methods

Here we described a simple and quantitative NGS platform and assessed its performance characteristics, quantified NGS-MRD levels in 122 B-ALL samples from 30 B-ALL patients, and explored the clinical merit of NGS-based MRD surveillance.

Results

The current NGS platform has an analytic sensitivity of 0.0001% with excellent specificity and reproducibility. Overall, it performs better than routine multi-color flow cytometry (MCF) in detecting MRD. Utilizing this assay in MRD surveillance in a post-remission setting showed that it detected conversion to positive MRD (CPMRD) in patients with NGS-based molecular remission much earlier than MCF, and that positive MRD conversion could be detected as early as 25.6 weeks prior to clinical relapse in closely surveilled patients. Post-remission CPMRD, but not NGS-based MRD positivity at end of induction, can accurately predict clinical relapse in our limited cohort of B-ALL patients.

Conclusions

This pilot proof-of-concept study illustrates the clinical utility of a simple, sensitive, and clinically feasible MRD detection platform in post-remission NGS-based MRD surveillance and early relapse detection in B-ALL patients.

Electronic supplementary material

The online version of this article (10.1186/s13045-018-0652-y) contains supplementary material, which is available to authorized users.

Reassessment of the Risk-stratified GD-2008 ALL Protocol

OBJECTIVE

To explore the clinical features and outcomes of relapsed childhood acute lymphoblastic leukemia (ALL) at our center, achieve the early detection of risk factors for recurrence and assess the risk-stratified Guangdong (GD)-2008 ALL protocol.

MATERIALS AND METHODS

In total, 59 Chinese childhood ALL patients treated with the GD-2008 ALL protocol who relapsed between July 2008 and March 2015 were enrolled in this study. Their clinical features and outcomes were retrospectively analyzed and compared with those of 218 patients who achieved continuous complete remission.

RESULTS

Of the 285 study participants, 8 died of treatment-related infections or other complications before remission, 218 achieved continuous complete remission, and 59 patients relapsed, yielding a relapse rate of 20.7%. The number of relapsed patients in the standard-risk, intermediate-risk, and high-risk groups were 15 (17.0%), 27 (19.7%), and 17 (32.7%), respectively. Risk factors included age 10 years and above at first diagnosis, white blood cell (WBC) count ≥50×10/L, poor prednisone response, failure to achieve bone marrow complete remission at day 15 of induction chemotherapy. High-risk stratification and a high level (≥0.1%) of minimal residual disease at day 33 were the risk factors for relapse. Multivariate analysis showed that a high WBC at first diagnosis was an independent risk factor for relapse (P=0.000).

CONCLUSION

For the GD-2008 ALL risk stratification based on age and initial WBC, 10 years of age and WBC 50×10/L can be used as cut-offs. Patients at high risk benefited from the GD-2008 ALL protocol. In addition, the impact of minimal residual disease on prognosis should be considered.

T Cell Receptor Profiling in Type 1 Diabetes

PURPOSE OF REVIEW

The genetic susceptibility and dominant protection for type 1 diabetes (T1D) associated with human leukocyte antigen (HLA) haplotypes, along with minor risk variants, have long been thought to shape the T cell receptor (TCR) repertoire and eventual phenotype of autoreactive T cells that mediate β-cell destruction. While autoantibodies provide robust markers of disease progression, early studies tracking autoreactive T cells largely failed to achieve clinical utility.

RECENT FINDINGS

Advances in acquisition of pancreata and islets from T1D organ donors have facilitated studies of T cells isolated from the target tissues. Immunosequencing of TCR α/β-chain complementarity determining regions, along with transcriptional profiling, offers the potential to transform biomarker discovery. Herein, we review recent studies characterizing the autoreactive TCR signature in T1D, emerging technologies, and the challenges and opportunities associated with tracking TCR molecular profiles during the natural history of T1D.