Variations in the germinal center response revealed by genetically diverse mouse strains.

The humoral response is complex and involves multiple cellular populations and signaling pathways. Bacterial and viral infections, as well as immunization regimens, can trigger this type of response, promoting the formation of microanatomical cellular structures called germinal centers (GCs). GCs formed in secondary lymphoid organs support the differentiation of high-affinity plasma cells and memory B cells. There is growing evidence that the quality of the humoral response is influenced by genetic variants. Using 12 genetically divergent mouse strains, we assessed the impact of genetics on GC cellular traits. At steady state, in the spleen, lymph nodes and Peyer's patches, we quantified GC B cells, plasma cells and follicular helper T cells. These traits were also quantified in the spleen of mice following immunization with a foreign antigen, namely, sheep red blood cells, in addition to the number and size of GCs. We observed both strain- and organ-specific variations in cell type abundance, as well as for GC number and size. Moreover, we find that some of these traits are highly heritable. Importantly, the results of this study inform on the impact of genetic diversity in shaping the GC response and identify the traits that are the most impacted by genetic background.

Constructing the cGAMP-Aluminum Nanoparticles as a Vaccine Adjuvant-Delivery System (VADS) for Developing the Efficient Pulmonary COVID-19 Subunit Vaccines.

The cGAMP-aluminum nanoparticles (CAN) are engineered as a vaccine adjuvant-delivery system to carry mixed RBD (receptor-binding domain) of the original severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its new variant for developing bivalent pulmonary coronavirus disease 2019 (COVID-19) vaccines (biRBD-CAN). High phosphophilicity/adsorptivity made intrapulmonary CAN instantly form the pulmonary ingredient-coated CAN (piCAN) to possess biomimetic features enhancing biocompatibility. In vitro biRBD-CAN sparked APCs (antigen-presenting cells) to mature and make extra reactive oxygen species, engendered lysosome escape effects and enhanced proteasome activities. Through activating the intracellular stimulator of interferon genes (STING) and nucleotide-binding domain and leucine-rich repeat and pyrin domain containing proteins 3 (NALP3) inflammasome pathways to exert synergy between cGAMP and AN, biRBD-CAN stimulated APCs to secret cytokines favoring mixed Th1/Th2 immunoresponses. Mice bearing twice intrapulmonary biRBD-CAN produced high levels of mucosal antibodies, the long-lasting systemic antibodies, and potent cytotoxic T lymphocytes which efficiently erased cells displaying cognate epitopes. Notably, biRBD-CAN existed in mouse lungs and different lymph nodes for at least 48 h, unveiling their sustained immunostimulatory activity as the main mechanism underlying the long-lasting immunity and memory. Hamsters bearing twice intrapulmonary biRBD-CAN developed high resistance to pseudoviral challenges performed using different recombinant strains including the ones with distinct SARS-CoV-2-spike mutations. Thus, biRBD-CAN as a broad-spectrum pulmonary COVID-19 vaccine candidate may provide a tool for controlling the emerging SARS-CoV-2 variants.

A "gullwing sign" on magnetic resonance imaging of extradural spinal tumors in dogs and cats allows prioritization of round cell neoplasia.

Extradural neoplasms are the most common spinal tumors in small animals. A bilobed appearance of ventral extradural spinal lesions ("gullwing sign") on MRI has been described with various conditions. The objective of this retrospective study was to determine if a "gullwing sign" is more common with certain types of extradural tumors. MRI studies of dogs and cats with extradural spinal neoplasms were reviewed for the presence of a "gullwing sign". Statistical analysis was performed to evaluate a possible relationship between tumor class and the presence of a "gullwing sign". Sixty-six cases were included (5 epithelial, 31 mesenchymal, 4 neuroendocrine, and 26 round cell tumors). A "gullwing sign" was identified in 12 of 66 cases (18.2%) and was significantly more common with round cell neoplasia than other tumor types (P < .001; OR = 28.6, 95% CI [3.4, 241.1]). This information may aid radiologists in prioritizing differential diagnoses for extradural tumors in small animals.

Activation of fibroblasts by plasma cells via PDGF/PDGFR signaling in IgG4-related sialadenitis.

IgG4-related sialadenitis (IgG4-SA) is one of the IgG4-related disease. The histological features of IgG4-SA include dense lymphoplasmacytic infiltrates and fibrosis. This study aimed to reveal the involvement of plasma cells in the development of fibrosis and the mechanism underlying fibrosis in IgG4-SA. Hematoxylin-eosin staining, Azan staining, silver staining, and immunohistochemistry (IHC) were performed on IgG4-SA and chronic sialadenitis specimens, and theses samples were analyzed by image analysis software. Histological spatial analysis was used to analyze the localization of IHC-positive cells and the distances between these cells. In the IgG4-SA group, many secondary lymphoid follicles with germinal centers were found, and many collagen fibers developed around these germinal centers. Collagen fibers composed mainly of type I collagen was abundant at sites away from secondary lymphoid follicles, and reticular fibers composed of type III collagen was abundant near secondary lymphoid follicles. Many FAP+ fibroblasts and MUM1+ plasma cells were localized near secondary lymphoid follicles. Histological spatial analysis demonstrated that 90.4% of MUM1+ plasma cells accumulated within 20 µm of FAP+ fibroblasts. Multiple immunofluorescence assays revealed that MUM1+ plasma cells expressed platelet-derived growth factor (PDGF) ß, and FAP+ fibroblasts expressed PDGF receptor (PDGFR) ß and pSTAT3 in IgG4-SA. We have shown that fibrosis is localized around secondary lymphoid follicles and that fibroblasts are activated by plasma cells via PDGF/PDGFR signaling in IgG4-SA.

[Analysis of the prognostic factors in primary plasma cell leukemia in the era of novel agents].

Objective: To explore the prognostic factors of primary plasma cell leukemia (pPCL) in the era of novel agents. Methods: The clinical data of 66 patients with pPCL treated at the Department of Haematology, Beijing Chao-Yang Hospital, Capital Medical University from 2011 to 2022 were retrospectively collected to analyze their prognostic factors. Results: Among the 66 patients with pPCL, the median age was 59 (range: 29-79) years. The median overall survival (OS) duration was 19.0 (95% CI 10.4-27.6) months, and the median progression-free survival (PFS) duration was 11.0 (95% CI 6.5-15.6) months. The median OS and PFS were significantly longer in patients with the best post-treatment response of very good partial remission (VGPR) or better than in patients with a response of partial remission (PR) or worse (median OS: 33.0 months vs 6.0 months, P<0.001; median PFS: 16.0 months vs 3.0 months, P<0.001). OS was significantly longer in patients who underwent autologous hematopoietic stem cell transplantation than in those who did not undergo transplantation (49.0 months vs 6.0 months, P=0.002), and there was a trend toward a longer PFS in patients who underwent transplantation than in those who did not undergo transplantation (19.0 months vs 8.0 months, P=0.299). The median OS and PFS were significantly longer in patients who received maintenance therapy than in those who did not receive maintenance therapy (median OS: 56.0 months vs 4.0 months, P<0.001; median PFS: 20.0 months vs 2.0 months, P<0.001). Multivariate analysis showed that hypercalcemia was an independent risk factor (HR=3.204, 95% CI 1.068-9.610, P=0.038) for patients with pPCL, while receiving maintenance therapy (HR=0.075, 95% CI 0.022-0.253, P<0.001) and post-treatment response of VGPR or better (HR=0.175, 95% CI 0.048-0.638, P=0.008) were independent protective factors for patients with pPCL. Conclusions: In the era of novel agents, hypercalcemia, receiving maintenance therapy, and post-treatment response of VGPR or better are independent prognostic factors for pPCL.

Current and Emerging Immunotherapies for Systemic AL Amyloidosis.

Systemic light-chain (AL) amyloidosis is a rare and complex clonal plasma cell neoplasm characterized by the production of misfolded and unstable immunoglobulin light-chains leading to multisystem amyloid deposition, which progresses to organ dysfunction and eventual failure. The importance and urgency of AL amyloidosis depends on its potential to induce significant organ impairment, progressive course, risk of life-threatening complications, and the limited treatment options available. Treatment options and prognosis depend on the number and severity of organ involvement at the time of diagnosis with cardiac involvement carrying the worst outcomes. The treatments aim to target eliminating the underlying clonal plasma cell neoplasm and prevent the production and deposition of amyloid precursor immunoglobulin light-chain protein in the affected vital organs. Strategies for treating systemic AL amyloidosis have incorporated anti-plasma cell therapies approved in the management of multiple myeloma due to their shared cellular derivation. Quadruplet therapy of cyclophosphamide, bortezomib, dexamethasone and daratumumab (DaraCyborD) is the currently approved first-line induction therapy for systemic AL amyloidosis. Some patients need upfront autologous hematopoietic stem cell transplantation (HSCT) after high-dose melphalan conditioning particularly if DaraCyborD is not able to achieve complete hematologic response (CHR). Additionally, a promising treatment option involves disassembling amyloid deposits from the vital organs using monoclonal antibodies such as CAEL 101 or Birtamimab with the expectation of restoring damaged tissues of the vital organs affected thereby improving or reversing patients' symptoms. Both CAEL 101 and Birtamimab are currently being tested in phase 3 clinical trials for systemic AL amyloidosis patients with advanced cardiac involvement. This comprehensive review provides an up-to-date overview of AL amyloidosis therapy, with a particular focus on recent advances and future directions of immunotherapeutic strategies.

Absolute quantification of BACH1 and BACH2 transcription factors in B and plasma cells reveals their dynamic changes and unique roles.

Changes in the absolute protein amounts of transcription factors are important for regulating gene expression during cell differentiation and in responses to changes in the cellular and extracellular environment. However, few studies have focused on the absolute quantification of mammalian transcription factors. In this study, we established an absolute quantification method for the transcription factors BACH1 and BACH2, which are expressed in B cells and regulated by direct heme binding. The method used purified recombinant proteins as controls in Western blotting and was applied to mouse naïve B cells in the spleen, as well as activated B cells and plasma cells. BACH1 was present in naïve B cells at approximately half the levels of BACH2. In activated B cells, BACH1 decreased compared to naïve B cells, while BACH2 increased. In plasma cells, BACH1 increased back to the same extent as in naïve B cells, while BACH2 was not detected. Their target genes Prdm1 and Hmox1 were highly induced in plasma cells. BACH1 was found to undergo degradation with lower concentrations of heme than BACH2. Therefore, BACH1 and BACH2 are similarly abundant in B cells but differ in heme sensitivity, potentially regulating gene expression differently depending on their heme responsiveness.

A clinically effective model based on cell-free DNA methylation and low-dose CT for risk stratification of pulmonary nodules.

Accurate, non-invasive, and cost-effective tools are needed to assist pulmonary nodule diagnosis and management due to increasing detection by low-dose computed tomography (LDCT). We perform genome-wide methylation sequencing on malignant and non-malignant lung tissues and designed a panel of 263 differential DNA methylation regions, which is used for targeted methylation sequencing on blood cell-free DNA (cfDNA) in two prospectively collected and retrospectively analyzed multicenter cohorts. We develop and optimize an integrative model for risk stratification of pulmonary nodules based on 40 cfDNA methylation biomarkers, age, and five simple computed tomography (CT) imaging features using machine learning approaches and validate its good performance in two cohorts. Using the two-threshold strategy can effectively reduce unnecessary invasive surgeries, overtreatment costs, and injury for patients with benign nodules while advising immediate treatment for patients with lung cancer, which can potentially improve the overall diagnosis of lung cancer following LDCT/CT screening.

A Case of Solitary Amyloid Lung Nodule Treated With Surgery.

Primary or light-chain (AL) (lambda) amyloidosis is a rare systemic disorder that is characterized by the misfolding of autologous proteins and the extracellular deposition of abnormally folded proteins composed of immunoglobulin light chains, often caused by plasma cell dyscrasias. We present a unique case of a 57-year-old female with multiple comorbidities, including extensive smoking history and chronic kidney disease, who was incidentally discovered to have a left upper lobe lung nodule on a chest X-ray prompted by complaints of shortness of breath. The patient underwent biopsy of the lung nodule, and by utilizing the gold standard diagnostic technique of a Congo red stain, positive test results confirmed the diagnosis of AL amyloidosis. However, additional investigations, including bone marrow and fat pad biopsies, were negative for plasma cell dyscrasias. The patient subsequently underwent a wedge resection of the nodule, and a follow-up positron emission tomography-computed tomography (PET-CT) scan showed only post-surgical changes in the left upper lobe of the lung without evidence of disease progression or systemic involvement. Given the asymptomatic and multisystem symptomology of most cases, treatment options for AL amyloidosis are individualized. This case discusses pulmonary nodular AL amyloidosis and highlights the diagnostic and treatment options for this disorder.

Successful Treatment of Plasma Cell-Rich Acute Rejection Using Bortezomib: A Case Report.

Plasma cell-rich acute rejection (PCAR), a relatively rare subtype of acute allograft rejection, is usually associated with a significantly lower treatment response rate and a higher graft failure rate. PCAR is characterized by the presence of more than 10% of plasma cells out of all graft infiltrating cells, with approximately 40%-60% of PCAR resulting in graft failure within a year. Currently, there is no gold standard for the effective treatment of PCAR. This case report demonstrates the potential treatment effect of bortezomib in PCAR. A 37-year-old woman with reflux nephropathy received a kidney transplant from a brain-dead kidney donor. The patient presented with an acute kidney injury with a serum creatinine level over 4 mg/dL 4 months after the surgery. The allograft biopsy showed acute T cell-mediated rejection (TCMR), Grade IIA, plasma cell-rich variant. There were diffuse polyclonal plasma cells infiltrating the renal parenchyma with marked tubulitis and focal endarteritis. She received a methylprednisolone pulse of 500 mg daily x3, followed by thymoglobulin (rATG) at 4.2 mg/kg. However, a repeated biopsy after 2 months showed persistent plasma cells infiltrate with increased interstitial fibrosis with tubular atrophy. Then, the patient was given one cycle of bortezomib with a total of four subcutaneous injections and continued immunosuppressants of tacrolimus, mycophenolate mofetil, and prednisone. Following the treatment, the patient's serum creatinine level trended down to 2 mg/dL, and a second repeat biopsy after 4 months showed a significant treatment effect with complete resolution of interstitial inflammation and decreased chronicity. Bortezomib is a proteasome inhibitor that prevents cell proliferation by inducing apoptosis in plasma cells and has shown great promise as a therapeutic agent for multiple myeloma. Our case suggests that bortezomib can also be used as a potential therapeutic intervention for patients with PCAR.

The Evolving Role of Checkpoint Inhibitors in Multiple Myeloma.

Multiple myeloma (MM) is a plasma cell dyscrasia characterized by production of abnormal levels of a monoclonal immunoglobulin or plasma cell deposition that leads to end organ destruction. The disease remains incurable despite advances in combination treatments with classes of medications that include proteosome inhibitors, immunomodulating agents, monoclonal antibodies, small molecule inhibitors, alkylating agents, T-cell-based immunotherapies, and others. Checkpoint inhibitors (CKP-I), though showing robust efficacy in solid tumor and lymphoma, have had limited success as single agents in the treatment of MM. Furthermore, early FDA holds on trials involving CKP-I in myeloma led to diminished enrollment and data on its potential use. Nevertheless, clearer understanding of the mechanisms of immune dysregulation and unique bone marrow biology in the pathophysiology of MM have opened the opportunity for future uses of CKP-I in multiple myeloma. Herein we provide a comprehensive review of the immunologic basis of multiple myeloma, preclinical and published data from trials utilizing CKP-I in MM patients, and future targets in CKP-I development that may provide promising opportunities in the treatment of MM.

Periodic Acid Schiff Staining to Detect Mott Cells, Aberrant Plasma Cells Containing Immunoglobulin Inclusions Called Russell Bodies.

Hematoxylin and eosin staining is widely used for routine histopathological analysis under light microscopic examination to determine alterations of tissue architecture and cellular components in animal studies. Aside from hematoxylin/eosin staining, periodic acid Schiff (PAS) staining is used to detect polysaccharides and carbohydrate-rich macromolecules, and is essential in immunological fields for evaluation of glomerular lesions of kidneys in autoimmune animals. Since erythrocytes are not stained by PAS, this stain is also helpful for identifying changes in immune cells in the red pulp of the spleen, which is filled with erythrocytes. This article describes a protocol to detect Mott cells, bizarre plasma cells containing immunoglobulin inclusion bodies (Russell bodies) in the cytoplasm. The protocol can be used for formalin-fixed, paraffin-embedded tissue sections, frozen tissue sections, tissue-touch preparations, blood films, and cytocentrifuged cell smears. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Detection of Mott cells by PAS staining in formalin-fixed, paraffin-embedded tissue sections Basic Protocol 2: Detection of Mott cells by PAS staining in frozen tissue sections, touch preparations, blood films, and cytocentrifuged cell smears.

Poor outcome despite modern treatments: A retrospective study of 99 patients with primary and secondary plasma cell leukemia.

BACKGROUND: Plasma cell leukemia (PCL) is a rare monoclonal gammopathy, associated with short survival. Because of its very low incidence, only a few cohorts have been reported and thus, information on this disease is scarce. The goal of this study was to better understand the clinical features, prognostic factors, and efficacy of modern treatments in both primary PCL (pPCL) and secondary PCL (sPCL). METHODS: We performed a retrospective, multicenter study of patients diagnosed with PCL, defined as circulating plasma cells ≥20% of total leukocytes and/or ≥2 × 109/L. RESULTS: We identified 99 eligible PCL patients, of whom 33 were pPCL and 66 were sPCL. The median progression-free survival (PFS) to frontline treatment and overall survival (OS) were, respectively, 4.8 (95% CI, 0.4-9.2) and 18.3 months (95% CI, 0.0-39.0) for pPCL and 0.8 (95% CI, 0.5-1.1) and 1.2 months (95% CI, 0.9-1.5) for sPCL (both p < 0.001). We observed no improvement in OS over time (2005-2012 vs. 2013-2020, p = 0.629 for pPCL and p = 0.329 for sPCL). Finally, our data suggested that sPCL originates from a high-risk multiple myeloma (MM) population with a short OS (median 30.2 months), early relapse after stem cell transplant (median 11.9 months) and a high proportion of patients with multiple cytogenetic abnormalities (36% with ≥2 abnormalities). CONCLUSIONS: This study is one of the largest PCL cohorts reported. We are also the first to investigate characteristics of MM before its transformation into sPCL and demonstrate that high-risk biologic features already present at the time of MM diagnosis. Moreover, our data highlights the lack of improvement in PCL survival in recent years and the urgent need for better treatment options.

ABO Discrepancy in a Patient With Plasma Cell Myeloma.

ABO discrepancies in plasma cell myeloma (PCM) present unique challenges in blood typing tests and transfusion management. We present the case of a 51-year-old male with PCM who exhibited discrepancies between forward and reverse blood grouping. Further investigation revealed that the patient's blood type was a variant of blood group B. While type III discrepancies, typically characterized by elevated globulin levels causing false-positive reactions in both forward and reverse blood grouping, are common in multiple myeloma, our case differed due to the loss of B antigens secondary to the malignant condition. This caused a discrepancy in forward blood grouping. The rarity of ABO discrepancies in multiple myeloma underscores the importance of thorough evaluation. Awareness of potential antigen alterations in such patients is crucial to ensure safe transfusion practices.

The ICF2 gene Zbtb24 specifically regulates the differentiation of B1 cells via promoting heme synthesis.

BACKGROUND: Loss-of-function mutations of ZBTB24 cause immunodeficiency, centromeric instability, and facial anomalies syndrome 2 (ICF2). ICF2 is a rare autosomal recessive disorder with immunological defects in serum antibodies and circulating memory B cells, resulting in recurrent and sometimes fatal respiratory and gastrointestinal infections. The genotype-phenotype correlation in patients with ICF2 indicates an essential role of ZBTB24 in the terminal differentiation of B cells. METHODS: We used the clustered regularly interspaced short palindromic repeats (CRISPER)/Cas9 technology to generate B cell specific Zbtb24-deficient mice and verified the deletion specificity and efficiency by quantitative polymerase chain reaction (Q-PCR) and western blotting analyses in fluorescence-activated cell sorting (FACS)-sorted cells. The development, phenotype of B cells and in vivo responses to T cell dependent or independent antigens post immunization were analyzed by flow cytometry and enzyme-linked immunosorbent assay (ELISA). Adoptive transfer experiment in combination with in vitro cultures of FACS-purified B cells and RNA-Seq analysis were utilized to specifically determine the impact of Zbtb24 on B cell biology as well as the underlying mechanisms. RESULTS: Zbtb24 is dispensable for B cell development and maintenance in naive mice. Surprisingly, B cell specific deletion of Zbtb24 does not evidently compromise germinal center reactions and the resulting primary and secondary antibody responses induced by T cell dependent antigens (TD-Ags), but significantly inhibits T cell independent antigen-elicited antibody productions in vivo. At the cellular level, Zbtb24-deficiency specifically impedes the plasma cell differentiation of B1 cells without impairing their survival, activation and proliferation in vitro. Mechanistically, Zbtb24-ablation attenuates heme biosynthesis partially through mTORC1 in B1 cells, and addition of exogenous hemin abrogates the differentiation defects of Zbtb24-null B1 cells. CONCLUSIONS: Zbtb24 seems to regulate antibody responses against TD-Ags B cell extrinsically, but it specifically promotes the plasma cell differentiation of B1 cells via heme synthesis in mice. Our study also suggests that defected B1 functions contribute to recurrent infections in patients with ICF2.

CCL19-producing fibroblasts promote tertiary lymphoid structure formation enhancing anti-tumor IgG response in colorectal cancer liver metastasis.

Tertiary lymphoid structures (TLSs) are associated with enhanced immunity in tumors. However, their formation and functions in colorectal cancer liver metastasis (CRLM) remain unclear. Here, we reveal that intra- and peri-tumor mature TLSs (TLS+) are associated with improved clinical outcomes than TLS- tumors. Using single-cell-RNA-sequencing and spatial-enhanced-resolution-omics-sequencing (Stereo-seq), we reveal that TLS+ tumors are enriched with IgG+ plasma cells (PCs), while TLS- tumors are characterized with IgA+ PCs. By generating TLS-associated PC-derived monoclonal antibodies in vitro, we show that TLS-PCs secrete tumor-targeting antibodies. As the proof-of-concept, we demonstrate the anti-tumor activities of TLS-PC-mAb6 antibody in humanized mouse model of colorectal cancer. We identify a fibroblast lineage secreting CCL19 that facilitates lymphocyte trafficking to TLSs. CCL19 treatment promotes TLS neogenesis and prevents tumor growth in mice. Our data uncover the central role of CCL19+ fibroblasts in TLS formation, which in turn generates therapeutic antibodies to restrict CRLM.

Pleural effusion, ascites, colon ulcers and hematochezia: What we can learn from the diagnostic process of a patient with plasma cell myeloma: A case report.

BACKGROUND: Plasma cell myeloma (PCM) is characterized by hypercalcemia, renal impairment, anemia, and bone destruction. While pleural effusion, ascites, abdominal pain, and bloody stool are common manifestations of lung disease or gastrointestinal disorders, they are rarely observed in patients with PCM. CASE SUMMARY: A 66-year-old woman presented with complaints of recurrent chest tightness, wheezing, and abdominal bloating accompanied by bloody stools. Computed tomography revealed pleural effusion and ascites. Pleural effusion tests showed inflammation, but the T-cell spot test and carcinoembryonic antigen were negative. Endoscopy showed colonic mucosal edema with ulcer formation and local intestinal lumen stenosis. Echocardiography revealed enlarged atria and reduced left ventricular systolic function. The diagnosis remained unclear. Further testing revealed elevated blood light chain lambda and urine immunoglobulin levels. Blood immunofixation electrophoresis was positive for immunoglobulin G lambda type. Smear cytology of the bone marrow showed a high proportion of plasma cells, accounting for about 4.5%. Histopathological examination of the bone marrow suggested PCM. Flow cytometry showed abnormal plasma cells with strong expression of CD38, CD138, cLambda, CD28, CD200, and CD117. Fluorescence in situ hybridization gene testing of the bone marrow suggested 1q21 gene amplification, but cytogenetic testing showed no clonal abnormalities. Colonic mucosa and bone marrow biopsy tissues were negative for Highman Congo red staining. The patient was finally diagnosed with PCM. CONCLUSION: A diagnosis of PCM should be considered in older patients with pleural effusion, ascites, and multi-organ injury.

ciRS-7 circular RNA overexpression in plasma cells is a promising molecular biomarker of unfavorable prognosis in multiple myeloma.

Several non-coding RNAs are known to be associated with the pathobiology and progression of multiple myeloma (MM). ciRS-7 (also known as CDR1-AS), a key oncogenic circular RNA (circRNA) that sponges miR-7-5p and other cancer-related microRNAs, was recently found to be downregulated in malignant plasma cells resistant to immunomodulatory drugs. Considering that various circRNAs have a strong potential as molecular biomarkers, we aimed to investigate the expression of ciRS-7 in plasma cell disorders, assess its prognostic importance in MM, and compare these findings with those of individuals with smoldering MM (SMM) and monoclonal gammopathy of unknown significance (MGUS). This study included 171 patients (110 newly diagnosed MM, 34 SMM, and 27 MGUS cases), from which bone marrow aspirate samples were collected for CD138+ plasma cell selection. Total RNA was reversely transcribed using random hexamer primers, and the expression levels of ciRS-7 were quantified using an in-house-developed protocol that includes pre-amplification and real-time quantitative polymerase chain reaction. ciRS-7 levels were found to significantly differ among CD138+ plasma cells of MM, SMM, and MGUS patients. ROC analysis indicated that ciRS-7 expression effectively distinguishes between MM and SMM patients. Moreover, high levels of ciRS-7 were associated with unfavorable prognosis in MM, independently of MM patients' age and Revised International Staging System stage. Additionally, in silico analysis predicted the binding of 85 microRNAs to ciRS-7. In conclusion, this study provides novel insights into the role of ciRS-7 as a promising molecular marker able to distinguish MM from SMM and predict prognosis in MM.

Idiopathic Lympho-Plasma Cellular Mucositis; A Diagnostic Predicament.

The term "idiopathic lymphoplasmacellular mucositis" (ILPM) refers to a set of conditions marked by extensive lymphocyte and plasma cell infiltrates in the submucosa which can involve the oral cavity, upper respiratory tract and the genital epithelium. There is no recognized cause of ILPM, and the diagnosis is mostly done on an exclusion basis. Herein, we report a 32-year-old man presented with an erosive ulcerated lesion on the hard palate and review the literature regarding the possible differential diagnosis including squamous cell carcinoma. We also reviewed the previously reported cases of ILPM with palatal involvement to summarise clinical presentation, treatment, and outcome of the entity to date.