Continuous therapy in HHV-8 negative Multicentric Castleman Disease and prolonged progression-free survival.

The optimal treatment endpoints and duration of continuous therapy for multicentric Castleman disease (MCD) remain controversial. We retrospectively analyzed data from 123 patients with Human Herpesvirus (HHV)-8 negative MCD. We demonstrated that continuous therapy significantly enhanced progression-free survival (PFS) in patients who achieved an optimal response after initial treatment. These findings underscore the critical role of continuous therapy in HHV-8 negative MCD. Further studies with larger cohorts are required to validate these findings.

When idiopathic multicentric Castleman disease meets COVID-19: a multicenter retrospective study from China.

Idiopathic multicentric Castleman disease (iMCD) is a rare and cytokine storm-driven inflammatory disorder. The exact cause of iMCD is still unknown, although several hypotheses have been proposed. However, regardless of the underlying cause, the ultimate result is the activation of the inflammatory pathway, which can lead to damage in multiple organs. Currently, there have been several reports highlighting the intricate link between coronavirus disease 2019 (COVID-19) and iMCD. To better understand the impact of COVID-19-induced immune storm on iMCD, we conducted a multicenter retrospective study in three hospitals in China. A total of 28 patients with iMCD were included, among whom 25 had confirmed COVID-19 infection, and we presented 4 cases that showed different disease progression after the infection of COVID-19, including 2 who did not receive any treatment for Castleman disease before. Our findings underscore the necessity of carefully monitoring iMCD patients with COVID-19 and promptly intervening to address any changes in their condition. Besides, this study also summarized the shared cytokines between COVID-19 and iMCD. Recent studies have shown promising results in treating severe COVID-19 and iMCD using tocilizumab, an interleukin-6 receptor antagonist. Therefore, it suggests that other potential cytokine storm therapy targets that have been effective in COVID-19 may also be explored for the treatment of iMCD.

Upgraded Standardized Minimal Residual Disease Detection by Next-Generation Sequencing in Multiple Myeloma.

Minimal residual disease (MRD) is one of the most powerful prognostic factors in multiple myeloma. Therefore, standardization and easy operation of MRD testing are crucial. Previously, we validated the sensitivity of 10-5 with spike in of plasmid controls for a standardized next-generation sequencing (NGS) approach based on triplicate measurements of bone marrow by LymphoTrack-MiSeq platform. To improve the technique, we replaced spike-in plasmid controls by genomic DNA from myeloma cells. A spike-in control of 0.001% was consistently detected in all 19 samples tested, confirming a uniform sensitivity of 10-5 of this upgraded protocol. MRD was detected in 14 of 19 patients (78%), with a significant (P = 0.04) impact on progression-free survival based on high versus low MRD levels. Reproducibility of detection was confirmed by the extremely small interrun variation tested in three patients. In nine patients, MRD was tested in parallel by allele-specific oligonucleotide real-time quantitative PCR. NGS showed an improved sensitivity and provided quantification of MRD for cases assigned positive but not quantifiable by real-time quantitative PCR, obviating the need of patient-specific probes/primers. In summary, the use of genomic DNA as spike-in control simplifies NGS detection of MRD while preserving the sensitivity of 10-5. Validity and reproducibility of the standardized procedure were verified, and the prognostic impact of NGS-based MRD in myeloma was confirmed.

Minimal Residual Disease Detection by Next-Generation Sequencing in Multiple Myeloma: A Comparison With Real-Time Quantitative PCR.

Here we compared clonotype identification by allele-specific oligonucleotide real-time quantitative-PCR (ASO RQ-PCR) and next-generation sequencing (NGS) in 80 multiple myeloma patients. ASO RQ-PCR was applicable in 49/55 (89%) and NGS in 62/78 (80%). Clonotypes identified by both methods were identical in 33/35 (94%). Sensitivity of 10-5 was confirmed in 28/29 (96%) by NGS while sensitivity of RQ-PCR was 10-5 in 7 (24%), 5 × 10-5 in 15 (52%), and 10-4 in 7 (24%). Among 14 samples quantifiable by ASO RQ-PCR, NGS yielded comparable results in 12 (86%). Applicability of NGS can be improved if immunoglobulin heavy-chain incomplete DJ primers are included.

Standardized Minimal Residual Disease Detection by Next-Generation Sequencing in Multiple Myeloma.

Next-generation sequencing (NGS) has been applied to monitor minimal residual disease (MRD) in multiple myeloma (MM). Standardized DNA input and sequencing depth is essential for achieving a uniform sensitivity in NGS-based MRD study. Herein, the sensitivity of 10-5 was verified by a standardized experimental design based on triplicate measurements of 1 µg DNA input and 1 million sequencing reads using the LymphoTrack-MiSeq platform. MRD level was defined as the mean MRD burden of the triplicates. Two spike-in controls at concentrations of 0.001% tumor plasma cells (PC) for verifying the sensitivity of 10-5 and 0.01% (or 0.005%) for MRD normalization were systematically analyzed. The spike-in control of 0.001% MRD was consistently detected in all samples, confirming a sensitivity of 10-5. Moreover, this standardized NGS approach yielded MRD measurements concordant with serological response and comparable to allele-specific oligonucleotide (ASO) real-time quantitative (RQ)-PCR. Moreover, NGS showed an improved sensitivity and provided quantification of MRD for cases assigned "positive but not quantifiable" (PNQ) by ASO RQ-PCR, even without the use of patient-specific probes/primers. Issues regarding the specificity of myeloma-specific sequences as MRD target, optimal input for spike-in normalization, and interpretation of MRD from triplicates are discussed. Herein, the standardized LymphoTrack-MiSeq-based method is verified to carry a sensitivity of 10-5, hence an effective tool for MRD monitoring in MM. As only a small number of samples are tested here, further study with a larger number of patients is warranted.

Distinct promoter methylation profile reveals spatial epigenetic heterogeneity in 2 myeloma patients with multifocal extramedullary relapses.

Spatial and subclonal genetic heterogeneity in multiple myeloma (MM) have been demonstrated by sequencing of plasma cells from multi-focal regions, but studies of spatial epigenetic heterogeneity are scanty. Herein, promoter methylation status of genes implicated in disease progression (CDKN2A and SHP1) and marrow escape (CDH1, CD56, and CXCR4) was studied in two patients with multi-focal extramedullary relapses. Patient 1 developed simultaneous chest wall and duodenal plasmacytoma at relapse. While SHP1 and CDKN2A were hypermethylated in both plasmacytomas, CDH1 hypermethylation was detected only in the chest wall. In patient 2, SHP1 methylation was found in the extradural plasmacytoma but not bone marrow (BM) at diagnosis, and the circulating PCs but not the BM at relapse. As the clonality, based on sequence of the complementarity-determining region 3 (CDR3) of the immunoglobulin gene, was conserved in plasma cells at diagnosis and relapse, differential methylation of CDH1 in patient 1 and SHP1 in patient 2 was an illustration of spatial epigenetic heterogeneity. Furthermore, subclonal epigenetic heterogeneity was identified by the presence of subclonal SHP1 promoter methylation within the chest wall plasmacytoma of patient 1. In summary, our data showed distinct promoter methylation profile of plasma cells from multiple regions. This is the first report of spatial epigenetic heterogeneity in MM.

Synergistic antitumoral efficacy of a novel replicative adenovirus SG611-PDCD5 and daunorubicin in human leukemic cells.

BACKGROUND: Daunorubicin is a traditional chemotherapeutic agent that plays a pivotal role in leukemia therapy. However, the dose-related toxicity remains a considerable challenge. The apoptosis-regulating gene, PDCD5, is downregulated in various tumors, including leukemias, and may provide a potential target for the diagnosis and treatment of leukemia. The purpose of this study was to construct a triple-regulated oncolytic adenovirus carrying a PDCD5 gene expression cassette (SG611-PDCD5) and explore the combined antitumor efficacy of SG611-PDCD5 in combination with low dose daunorubicin on leukemic cells. MATERIALS AND METHODS: A variety of leukemic cell lines, including K562, MEG-01, KG-1a, HL-60, SUP-B15, and BV-173, were cultured according to the providers' instructions. The insertion and orientation of all recombined plasmids were confirmed by restriction enzyme digestion and PCR. The tumor-selective replication of the constructed conditionally replicating SG611-PDCD5 and its antitumor efficacy in combination with daunorubicin were characterized in leukemic cell lines in vitro and in a nude mouse xenograft model. Cell viability was detected using cell-counting kit-8. Apoptosis was detected in whole living cells using flow cytometry and in paraffin-embedded tumor tissues using a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. RESULTS: The triple-regulated CRAd carrying SG611-PDCD5 and nude mouse xenograft models of K562 cells were successfully constructed. In vitro treatment with SG611-PDCD5 in combination with low-dose daunorubicin elicited more potent anti-proliferative and proapoptotic effects in leukemic cells in a dose-dependent manner. The Chou-Talalay analysis revealed synergistic anti-proliferative effects in all of the above cell lines. In the nude mice xenograft model, the tumor size in the control, daunorubicin, SG611-PDCD5, and combined treatment groups on day 10 were 170.1±47.8, 111.9±81.1, 60.7±12.3, and 33.2±17.5 mm3, respectively (all P<0.05). The results of the TUNEL assay showed significantly more apoptotic cells in the SG611-PDCD5 plus daunorubicin group than in the SG611-PDCD5 or daunorubicin groups alone (25±0.82, 12.5±2.27, and 7.8±2.67 apoptotic cells/field, respectively) (P<0.05). CONCLUSION: The findings suggest that combined treatment with SG611-PDCD5 and daunorubicin may be a promising strategy for enhancing chemosensitivity and thus lowering the dose-related toxicity of daunorubicin in leukemia therapy.

Frequent functional activation of RAS signalling not explained by RAS/RAF mutations in relapsed/refractory multiple myeloma.

RAS mutations are frequent in relapsed/refractory multiple myeloma (RRMM) but functional study in primary samples is scanty. Herein, in primary myeloma plasma cells of 17 suspected RRMM, functional activation of RAS signalling was studied by Western blot of phosphorylated ERK1/2 (phospho-ERK1/2). Moreover, activating mutations in KRAS, NRAS, BRAF, and ALK were studied by PCR and bidirectional direct sequencing. Furthermore, methylation of negative RAS signalling regulator genes, RASSF1A and RASD1, were analyzed by methylation-specific PCR. As evidenced by phospho-ERK1/2 over-expression, functional RAS activation was detected in 12 (75.0%) RRMM. Of patients with functional RAS activation, sequencing data showed only seven (58.3%) patients with one each had NRAS Q61H, NRAS Q61K, KRAS G12D, KRAS G12V, KRAS G13D, KRAS Q61P, or BRAF V600E mutation, whereas five (41.7%) patients had no RAS/RAF mutation. Conversely, patients without functional RAS activation had no RAS/RAF mutation. Moreover, none of the patients with functional RAS activation had ALK mutations, or methylation of RASSF1A and RASD1. Collectively, functional activation of RAS signalling was present in majority of RRMM but only about half (58.3%) accountable by RAS/RAF mutations. If verified in larger studies, clinical investigations of MEK inhibitors are warranted regardless of RAS/RAF mutations.

Synergistic antitumor activity of triple-regulated oncolytic adenovirus with VSTM1 and daunorubicin in leukemic cells.

V-set and transmembrane domain-containing 1 (VSTM1), which is downregulated in bone marrow cells from leukemia patients, may provide a diagnostic and treatment target. Here, a triple-regulated oncolytic adenovirus was constructed to carry a VSTM1 gene expression cassette, SG611-VSTM1, and contained the E1a gene with a 24-nucleotide deletion within the CR2 region under control of the human telomerase reverse transcriptase promoter, E1b gene directed by the hypoxia response element, and VSTM1 gene controlled by the cytomegalovirus promoter. Real-time quantitative PCR and Western blot analyses showed that SG611-VSTM1 expressed VSTM1 highly efficiently in the human leukemic cell line K562 compared with SG611. In Cell Counting Kit-8 and flow cytometric assays, SG611-VSTM1 exhibited more potent anti-proliferative and pro-apoptotic effects in leukemic cells compared with SG611 and exerted synergistic cytotoxicity with low-dose daunorubicin (DNR) in vitro. In xenograft models, SG611-VSTM1 intratumorally injected at a dose of 1 × 10(9) plaque forming units combined with intraperitoneally injected low-dose DNR displayed significantly stronger antitumor effects than either treatment alone. Histopathologic examination revealed that SG611-VSTM1 induced apoptosis of leukemic cells. These results implicate an important role for VSTM1 in the pathogenesis of leukemia, and SG611-VSTM1 may be a promising agent for enhancing chemosensitivity in leukemia therapy.

Prognostic impact of IKZF1 deletion in adults with common B-cell acute lymphoblastic leukemia.

BACKGROUND: Interrogate the impact of IKZF1 deletion on therapy-outcomes of adults with common B-cell acute lymphoblastic leukemia. METHODS: One hundred sixty-five consecutive adults with common B-cell ALL were tested for IKZF1 deletion and for BCR/ABL. Deletions in IKZF1 were detected using multiplex RQ-PCR, multiplex fluorescent PCR, sequence analysis and multiplex ligation-dependent probe amplification (MLPA). BCR/ABL was detected using RQ-PCR. All subjects received chemotherapy and some also received an allotransplant and tyrosine kinase-inhibitors. Multivariate analyses were done to identify associations between IKZF1 deletion and other variables on non-relapse mortality (NRM), cumulative incidence of relapse (CIR), leukemia-free survival (LFS) and survival. RESULTS: Amongst subjects achieving complete remission those with IKZF1 deletion had similar 5-year non-relapse mortality (NRM) (11% [2-20%] vs. 16% [4-28%]; P = 0.736), a higher 5-year cumulative incidence of relapse (CIR) (55% [35-76%] vs. 25% [12-38%]; P = 0.004), and worse 5-year leukemia-free survival (LFS) (33% [16-52%] vs. 59% [42-73%]; P = 0.012) and survival (48% [33-62%] vs. 75% [57-86%]; P = 0.002). In multivariate analyses IKZF1 deletion was associated with an increased relapse (relative risk [RR] =2.7, [1.4-5.2]; P = 0.002), a higher risk of treatment-failure (inverse of LFS; RR = 2.1, [1.2-3.6]; P = 0.007) and a higher risk of death (RR = 2.8, [1.5-5.5]; P = 0.002). The adverse impact of IKZF1 deletion on outcomes was stronger in subjects without vs. with BCR-ABL1 and in subjects receiving chemotherapy-only vs. an allotransplant. CONCLUSIONS: IKZF1 deletion was independently-associated with a higher relapse risk and worse LFS and survival in adults with common B-cell ALL after adjusting for other prognostic variables and differences in therapies. These data suggest IKZF1 deletion may be a useful prognostic variable in adults with common B-cell ALL, especially in persons without BCR-ABL1 and those receiving chemotherapy-only. Transplants appear to overcome the adverse impact of IKZF1 deletion on therapy-outcomes but confirmation in a randomized study is needed. The trial was registered in 2007 with the Beijing Municipal Government (Beijing Municipal Health Bureau Registration N: 2007-1007).

A rapid, highly accurate method for quantifying CALR mutant allele burden in persons with myeloproliferative neoplasms.

BACKGROUND: Calreticulin (CALR) mutations were recently identified in a substantial proportion of persons with essential thrombocythemia (ET) and with primary myelofibrosis (PMF) without JAK2(V617F). Consequently rapid, sensitive, and specific methods to detect and quantify these mutations are needed. METHODS: We studied samples from 1088 persons with myeloproliferative neoplasms (MPNs) including 421 JAK2(V617F) negative subjects with ET, PMF, polycythemia vera (PV), chronic myeloid leukemia (CML) and hyper-eosinophilic syndrome (HES). Detection of CALR exon 9 mutations was done by PCR amplification followed by fragment length analysis and direct sequencing. Dilution assays were used to determine CALR mutant allele burden. RESULTS: We detected CALR mutations in blood and bone marrow samples from 152 subjects with ET and with PMF but not in samples from normal or persons with PV, CML, or HES. CALR mutant peaks were distinct from wild-type peaks and dilution experiments indicated a sensitivity level of 0.5-5% for a CALR mutant allele in a wild-type background. Diverse types of mutations were detected including deletions, insertions, and complex indels. All mutations were confirmed by direct sequencing. We also used dilution experiments to quantify mutant allele burden. We were able to reproducibly detect mutant allele levels as low 5% (0.5-5%) in a wild-type background. CONCLUSIONS: PCR amplification followed by fragment length analysis is a rapid, sensitive, and specific method for screening persons with MPNs for CALR mutations, especially those with ET and PMF and for estimating mutant allele burden.

VSTM-v1, a potential myeloid differentiation antigen that is downregulated in bone marrow cells from myeloid leukemia patients.

Leukocyte differentiation antigens often represent important markers for the diagnosis, classification, prognosis, and therapeutic targeting of myeloid leukemia. Herein, we report a potential leukocyte differentiation antigen gene VSTM1 (V-set and transmembrane domain-containing 1) that was downregulated in bone marrow cells from leukemia patients and exhibited a higher degree of promoter methylation. The expression level of its predominant encoded product, VSTM1-v1, was positively correlated with myeloid cell maturation state. Restoration of VSTM1-v1 expression inhibited myeloid leukemia cells' growth. Therefore, VSTM1-v1 might represent an important myeloid leukocyte differentiation antigen and provide a potential target for the diagnosis and treatment of leukemia.

Frequency and allele burden of CALR mutations in Chinese with essential thrombocythemia and primary myelofibrosis without JAK2(V617F) or MPL mutations.

CALR mutations are detected in about 50% of persons of predominately European descent with essential thrombocythemia (ET) or primary myelofibrosis (PMF) with wild-type alleles of JAK2 and MPL. We studied 1088 Chinese with diverse myeloproliferative neoplasms including ET (N=234) and PMF (N=50) without JAK2(V617F) or MPL exon 10 mutations. CALR mutation was detected in 53% (95% CI, 46-60%) of subjects with ET and 56% (95% CI, 41-70%) of subjects with PMF. 152 CALR mutations were identified clustering into 15 types including deletions (N=8), insertions (N=3) and complex indels (N=4). We also identified 9 new mutations. Mean (±SD) mutant allele burden was 31±12% (range, 0.5-69%). Persons with PMF had higher CALR mutant allele burdens than those with ET (38±8% vs. 29±12%; P<0.001). Amongst persons with CALR mutations, those with PMF had different clinical features from those with ET. These data may be useful for diagnosing ET and PMF in Chinese who are about 40% of all persons with ET and PMF and for monitoring therapy-response. They also highlight similarities and differences in CALR mutations between Chinese and persons of predominately European descent with these diseases.