Diagnostic accuracy of pelvic magnetic resonance imaging for the assessment of bone marrow involvement in diffuse large B-cell lymphoma

Purpose

We investigated the efficacy of pelvic magnetic resonance imaging (MRI) in the diagnosis of bone marrow involvement (BMinv) in diffuse large B-cell lymphoma (DLBCL) patients.

Patients and methods

This was a retrospective study of data from a previous study (NCT02733887). We included 171 patients who underwent bone marrow biopsy (BMB) and bone marrow smear (BMS), pelvic MRI, and whole-body positron emission tomography-computed tomography (PET/CT) from January 2016 to December 2019 at a single center. BMB/BMS and whole-body PET/CT results were used as reference standards against which we calculated the diagnostic value of pelvic MRI for BMinv in DLBCL patients. A chi-square test was used to compare detection rates, and a receiver operating characteristic curve was used to evaluate diagnostic value of pelvic MRI. Propensity-score matching was performed according to clinical information, and Kaplan-Meier curves were constructed to compare progression-free survival (PFS) and overall survival (OS) of patients.

Results

The BMinv detection rate of pelvic MRI (42/171) was higher (P = 0.029) than that of BMB/BMS (25/171), and similar to that of PET/CT (44/171; P = 0.901). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of pelvic MRI were 83.33%, 98.37%, 94.15%, 95.24%, and 93.80%, respectively. Median PFS values were as follows: BMB/BMS-positive, 17.8 months vs. BMB/BMS-negative, 26.9 months (P = 0.092); PET/CT-positive, 24.8 months vs. PET/CT-negative, 33.0 months (P = 0.086); pelvic MRI-positive, 24.9 months vs. pelvic MRI-negative, 33.1 months (P<0.001). Median OS values were as follows: BMB/BMS-positive, 22.3 months vs. BMB/BMS-negative, 29.8 months (P = 0.240); PET/CT-positive, 27.9 months vs. PET/CT-negative, 33.9 months (P = 0.365); pelvic MRI-positive, 27.3 months vs. pelvic MRI-negative, 35.8 months (P = 0.062).

Conclusion

Pelvic MRI is effective for detecting BMinv in DLBCL patients, providing a more accurate indication of PFS than BMB/BMS and PET/CT do. It may ultimately be used to improve the accuracy of clinical staging, guide patient treatment, and evaluate prognosis.

A novel prognostic model for angioimmunoblastic T-cell lymphoma: A retrospective study of 55 cases

Objective

To explore prognostic factors and develop an accurate prognostic prediction model for angioimmunoblastic T-cell lymphoma (AITL).

Methods

Clinical data from Chinese patients with newly diagnosed AITL were retrospectively analysed. Overall survival (OS) and progression-free survival (PFS) were estimated using Kaplan-Meier method survival curves; prognostic factors were determined using a Cox proportional hazards model. The sensitivity and specificity of the predicted survival rates were compared using area under the curve (AUC) of receiver operating characteristic (ROC) curves.

Results

The estimated 5-year OS and PFS of 55 eligible patients with AITL were 22% and 3%, respectively. Multivariate analysis showed that the presence of pneumonia, and serous cavity effusions at initial diagnosis were significant prognostic factors for OS. Based on AUC ROC values, our novel prognostic model was superior to IPI and PIT based models and suggested better diagnostic accuracy.

Conclusions

Our prognostic model based on pneumonia, and serous cavity effusions at initial diagnosis enabled a balanced classification of AITL patients into different risk groups.

Exploration of intrinsic and extrinsic apoptotic pathways in zearalenone-treated rat sertoli cells

Zearalenone (ZEA) is a nonsteroidal estrogenic mycotoxin produced mainly by Fusarium. ZEA causes reproductive disorders and is both cytotoxic and genotoxic in animals; however, little is known regarding the molecular mechanism(s) leading to ZEA toxicity. Sertoli cells are somatic cells that support the development of spermatogenic cells. The objective of this study was to explore the effects of ZEA on the proliferation, apoptosis, and necrosis of rat Sertoli cells to uncover signaling pathways underlying ZEA cytotoxicity. ZEA reduced the proliferation of rat Sertoli cells in a dose-dependent manner, as indicated by a CCK8 assay, while flow cytometry revealed that ZEA caused both apoptosis and necrosis. Immunoblotting revealed that ZEA treatment increased the ratio of Bax/Bcl-2, as well as the expression of FasL and caspases-3, -8, and -9, in a dose-dependent manner. Collectively, these data suggest that ZEA induced apoptosis and necrosis in rat Sertoli cells via extrinsic and intrinsic apoptotic pathways. This study provides new insights into the molecular mechanisms by which ZEA exhibits cytotoxicity. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1731-1739, 2016.

Prognostic significance of Tet methylcytosine dioxygenase 2 (TET2) gene mutations in adult patients with acute myeloid leukemia: a meta-analysis

Tet methylcytosine dioxygenase 2 (TET2) gene mutations have recently been recognized in acute myeloid leukemia (AML). We performed a meta-analysis to evaluate the controversial prognostic significance of TET2 mutations in AML. Eight studies, covering 2552 patients with AML, were included in this analysis. Pooled hazard ratios (HRs) indicated that TET2 mutations had a poor prognostic impact on the survival of patients with AML. The combined HR for overall survival (OS) was 1.53 and the summary HR for event-free survival (EFS) was 1.64. Additionally, TET2 mutations appeared to be an adverse prognostic indicator in both patients with cytogenetically normal (CN)-AML (HR for OS: 1.43 and HR for EFS: 1.76) and subgroups of patients with favorable-risk genotypes (HR for EFS: 2.35) and intermediate-I-risk genotypes (HR for EFS: 1.57). These findings indicate that TET2 mutations have an adverse impact on prognosis and may help to justify risk-adapted therapeutic strategies for patients with AML.

Associations between RASSF1A promoter methylation and NSCLC: a meta-analysis of published data

BACKGROUND

RASSF1A has been reported to be a candidate tumor suppressor in non-small cell lung cancer (NSCLC). However, the association between RASSF1A promoter methylation and NSCLC remains unclear, particularly in regarding links to clinicopathologic features.

METHODS

Eligible studies were identified through searching PubMed, EMBASE, Cochrane Library and China National Knowledge Infrastructure (CNKI) databases. Studies were pooled and odds ratios (ORs) with corresponding confidence intervals (CIs) were calculated. Funnel plots were also performed to evaluate publication bias.

RESULTS

Nineteen studies involving 2,063 cases of NSCLC and 1,184 controls were included in this meta-analysis. A significant association was observed between RASSF1A methylation and NSCLC in the complete data set (OR = 19.42, 95% CI: 14.04- 26.85, P < 0.001). Pooling the control tissue subgroups (heterogeneous/autologous) gave pooled ORs of 32.4 (95% CI, 12.4-84.5) and 17.7 (95% CI, 12.5-25.0) respectively. Racial subgroup (Caucasian/Asian) analysis gave pooled ORs of 26.6 (95% CI, 10.9-64.9) and 20.9 (95% CI, 14.4-30.4) respectively. The OR for RASSF1A methylation in poorly-differentiated vs. moderately/well-differentiated NSCLC tissues was 1.88 (95% CI, 1.32- 2.68, P<0.001), whereas there were no significant differences in RASSF1A methylation in relation to gender, pathology, TNM stage and smoking behavior among NSCLC cases.

CONCLUSION

This meta-analysis suggests a significant association between RASSF1A methylation and NSCLC, confirming the role of RASSF1A as a tumor suppressor gene. Large-scale and well-designed case-control studies are needed to validate the associations identified in the present meta-analysis.

Resistance to Lyme disease in decorin-deficient mice

Microbial adhesion to the host tissue represents an early, critical step in the pathogenesis of most infectious diseases. BORRELIA: burgdorferi, the causative agent of Lyme disease (LD), expresses two surface-exposed decorin-binding adhesins, DbpA and DbpB. A decorin-deficient (Dcn(-/-)) mouse was recently developed and found to have a relatively mild phenotype. We have now examined the process of experimental LD in Dcn(-/-) mice using both needle inoculation and tick transmission of spirochetes. When exposed to low doses of the infective agent, Dcn(-/-) mice had fewer Borrelia-positive cultures from most tissues analyzed than did Dcn(+/+) or Dcn(+/-) mice. When the infection dose was increased, similar differences were not observed in most tissues but were seen in bacterial colonization of joints and the extent of Borreila-induced arthritis. Quantitative PCR demonstrated that joints harvested from Dcn(-/-) mice had diminished Borrelia numbers compared with issues harvested from Dcn(+/+) controls. Histological examination also revealed a low incidence and severity of arthritis in Dcn(-/-) mice. Conversely, no differences in the numbers of Borreila-positive skin cultures were observed among the different genotypes regardless of the infection dose. These differences, which were observed regardless of genetic background of the mice (BALB/c or C3H/HeN) or method of infection, demonstrate the importance of decorin in the pathogenesis of LD.

Helicobacter pylori mutagenesis by mariner in vitro transposition

We have developed a method for generating transposon insertion mutants using mariner in vitro mutagenesis. The gene of interest was PCR-amplified and cloned. A kanamycin-marked mariner transposon was randomly inserted into the purified plasmid in an in vitro transposition reaction. After repair and propagation in Escherichia coli, purified mutagenized plasmid was introduced into Helicobacter pylori by natural transformation. Transformants were selected by plating on kanamycin. Mutants were predominantly the result of double homologous recombination, and multiple mutants (with insertions in distinct positions) were often obtained. The site of insertion was determined by PCR or sequencing. We have made mutations in known or potential virulence genes, including ureA, hopZ, and vacA, using kanamycin- and kanamycin/lacZ-marked transposons. Colonies carrying a kanamycin/lacZ transposon appeared blue on medium containing the chromogenic agent X-gal, allowing discrimination of mutant and wild-type H. pylori in mixed competition experiments.

Adherence of Borrelia burgdorferi. Identification of critical lysine residues in DbpA required for decorin binding

Borrelia burgdorferi, the causative agent of Lyme disease, expresses on its surface two decorin binding adhesins, DbpA and DbpB. Previous studies have demonstrated that vaccination of mice with DbpA provided protection against challenge with heterologous Borrelia strains despite considerable sequence variability among DbpA in these strains. We have now examined the importance of individual amino acid residues in DbpA for decorin binding. We demonstrated that chemical modification of lysine residues resulted in loss of ligand binding activity. Of the 27 lysine residues in native DbpA from strain 297, 6 are present in most and 5 are conserved in all 30 DbpA sequences examined so far. Analysis of recombinant DbpA in which individual lysine residues have been mutated to alanine suggested that three of the conserved residues distributed throughout the DbpA sequence are required for decorin binding. These mutants lost their ability to bind decorin in Western ligand blot assay and bound reduced amounts of decorin in an ELISA. Furthermore, these mutant DbpA proteins did not inhibit the adherence of B. burgdorferi to a decorin substrata, and they did not recognize decorin in an extracellular matrix established by human fibroblast cultures. We conclude that the three lysine residues Lys-82, Lys-163, and Lys-170 are crucial for the binding of DbpA to decorin.

Decorin-binding adhesins from Borrelia burgdorferi

Lyme disease is a tick-transmitted infection caused by the spirochete Borrelia burgdorferi. Ticks deposit B. burgdorferi into the dermis of the host, where they eventually become associated with collagen fibres. We demonstrated previously that B. burgdorferi is unable to bind collagen, but can bind the collagen-associated proteoglycan decorin and expresses decorin-binding proteins (Dbps). We have now cloned and sequenced two genes encoding the proteins, DbpA and DbpB, which have a similar structure, as revealed by circular dichroism (CD) spectroscopy of recombinant proteins. Competition experiments revealed a difference in binding specificity between DbpA and DbpB. Western blot analysis of proteinase K-treated intact B. burgdorferi and transmission electron microscopy studies using antibodies raised against recombinant Dbps demonstrated that these proteins are surface exposed. DbpA effectively inhibits the attachment of B. burgdorferi to a decorin substrate, whereas DbpB had a marginal effect, suggesting a difference in substrate specificity between the two Dbps. Polystyrene beads coated with DbpA adhered to a decorin-containing extracellular matrix produced by cultured skin fibroblasts, whereas beads coated with OspC did not. Taken together, these data suggest that Dbps are adhesins of the MSCRAMM (microbial surface component-recognizing adhesive matrix molecule) family, which mediate B. burgdorferi attachment to the extracellular matrix of the host.

Active and passive immunity against Borrelia burgdorferi decorin binding protein A (DbpA) protects against infection

Borrelia burgdorferi, the spirochete that causes Lyme disease, binds decorin, a collagen-associated extracellular matrix proteoglycan found in the skin (the site of entry for the spirochete) and in many other tissues. Two borrelial adhesins that recognize this proteoglycan, decorin binding proteins A and B (DbpA and DbpB, respectively), have recently been identified. Infection of mice by low-dose B. burgdorferi challenge elicited antibodies against DbpA and DbpB that were sustained at high levels, suggesting that these antigens are expressed in vivo. Scanning immunoelectron microscopy showed that DbpA was surface accessible on intact borreliae. Passive administration of DbpA antiserum protected mice from infection following challenge with heterologous B. burgdorferi sensu stricto isolates, even when serum administration was delayed for up to 4 days after challenge. DbpA is the first antigen target identified that is capable of mediating immune resolution of early, localized B. burgdorferi infections. DbpA immunization also protected mice from B. burgdorferi challenge; DbpB immunization was much less effective. DbpA antiserum inhibited in vitro growth of many B. burgdorferi sensu lato isolates of diverse geographic, phylogenetic, and clinical origins. In combination, these findings support a role for DbpA in the immunoprophylaxis of Lyme disease and suggest that DbpA vaccines have the potential to eliminate early-stage B. burgdorferi infections.

Adherence of Borrelia burgdorferi to the proteoglycan decorin

Lyme disease is a tick-borne infection that can develop into a chronic, multisystemic disorder. The causative agent, Borrelia burgdorferi, is initially deposited by the tick into the host dermis, where it associates with collagen fibers, replicates, and eventually disseminates to other tissues. We have examined the adherence of the spirochete to different components of the collagen fiber and demonstrated that decorin, a proteoglycan which decorates collagen fibers, can support the attachment of B. burgdorferi. No significant direct attachment to isolated type I or III collagens could be detected. Attachment of the spirochetes to decorin was highly specific, and the process could be inhibited by soluble decorin but not by various unlabeled, unrelated components. B. burgdorferi also bound soluble 125I-labeled decorin in a time- and concentration-dependent manner. Spirochete binding of soluble 125I-labeled decorin required intact proteoglycan and could not be inhibited by either isolated core protein or glycosaminoglycan chain. B. burgdorferi expresses two decorin-binding proteins with apparent molecular masses of 19 and 20 kDa as revealed in a Western blot (immunoblot)-type assay. Our results indicate that decorin may mediate the adherence of B. burgdorferi to collagen fibers in skin and other tissues.