Increase In Plasma Cells Research Articles

Leptin accelerates B cell dysfunctions via activating JAK/STAT3/5 and ERK1/2 pathways in patients with systemic lupus erythematosus.

Our previous studies found that serum leptin was increased significantly in SLE, characterised by dysregulated autoreactive B cells producing excessive inflammatory cytokines and autoantibodies. The aim of this study was to explore the effects of leptin on B cell functions in SLE and clarify the key pathways in leptin dysregulated B cells. Peripheral blood samples were obtained from 86 SLE patients and 28 normal controls. Purified B cells were stimulated with leptin or SLE serum and with or without anti-leptin antibody. The frequencies of CD19-CD138+ plasma cells and the expression of leptin receptor (LEPR) on B cells were determined with flow cytometry. The levels of antibodies and cytokines were assayed by ELISA. Classic signalling pathways were detected with western blotting method. Increased plasma cells and the levels of IgG and anti-dsDNA antibodies were positively correlated with serum leptin in SLE patients. LEPR+CD19+B cells were increased in SLE patients. Leptin up-regulated LEPR on B cells and activated B cells to produce higher levels of IL-6, IL-10 and TNF-α, and induced B cells to differentiated into plasma cells secreting more IgG and IgM. More importantly, anti-leptin neutralising antibody could partially restore increased cytokines, antibodies and plasma cells induced by SLE serum. Mechanistically, both leptin and SLE serum activated JAK/STAT3/5 and ERK1/2 signalling pathways in B cells, and the secretion-enhancing effects were restored by their inhibitors. Leptin may be a key factor leading to B cell dysfunction by activating JAK/STAT3/5 and ERK1/2 signalling pathways in SLE.

Activated PI3Kδ signals compromise plasma cell survival via limiting autophagy and increasing ER stress.

While phosphatidylinositide 3-kinase delta (PI3Kδ) plays a critical role in humoral immunity, the requirement for PI3Kδ signaling in plasma cells remains poorly understood. Here, we used a conditional mouse model of activated PI3Kδ syndrome (APDS), to interrogate the function of PI3Kδ in plasma cell biology. Mice expressing a PIK3CD gain-of-function mutation (aPIK3CD) in B cells generated increased numbers of memory B cells and mounted an enhanced secondary response but exhibited a rapid decay of antibody levels over time. Consistent with these findings, aPIK3CD expression markedly impaired plasma cell generation, and expression of aPIK3CD intrinsically in plasma cells was sufficient to diminish humoral responses. Mechanistically, aPIK3CD disrupted ER proteostasis and autophagy, which led to increased plasma cell death. Notably, this defect was driven primarily by elevated mTORC1 signaling and modulated by treatment with PI3Kδ-specific inhibitors. Our findings establish an essential role for PI3Kδ in plasma cell homeostasis and suggest that modulating PI3Kδ activity may be useful for promoting and/or thwarting specific immune responses.

A Case Study on Multiple Myeloma

Introduction: Multiple myeloma (MM), also known as plasma cell myeloma and simply myeloma, is a cancer of plasma cells, a type of white blood cell that normally produces antibodies. Often, no symptoms are noticed initially. As it progresses, bone pain, anemia, kidney dysfunction, and infections may occur. Multiple myeloma is a hematologic disease characterized by an increase in plasma cells in the bone marrow and, more commonly, the presence of monoclonal immunoglobulin in the blood and / or urine. It is the second major hematologic attack found to have an annual occurrence with an increase in the United States of nearly 15,000 and approximately 45,000, respectively. The condition is higher with age (age between acquisitions of 67 yr). This case report describes a multiple myeloma patient presented with muscle sclerosis and was suspected of having myotonic dystrophy type 2 and illustrates the aspects of differential diagnosis, the use of laboratory and imaging for diagnosis.
 Conclusion: Despite the fact that periodontal illness has a detrimental impact on one's quality of life, those benefits are often ignored. As a consequence, periodontal consultation can be a key component of MM care. Treatment for periodontal disease should begin as soon as possible.

Endometrial polyps with increased plasma cells are associated with chronic endometritis in infertility patients: Hysteroscopic findings and post-polypectomy pregnancy rates.

PurposeThe relationship between endometrial polyps (EPs), chronic endometritis (CE), hysteroscopic findings, and antimicrobial in infertility patients was determined.MethodsWe retrospectively enrolled 115 infertility patients with suspected EPs who underwent office hysteroscopy. Patients were divided into 3 groups: 38 with increased plasma cells in EPs (group 1); 31 without increased plasma cells in EPs (group 2); and 46 without EPs (group 3). The 3 groups underwent hysteroscopy with or without polypectomies, and immediately thereafter, an endometrial aspiration biopsy (EAB) was performed. CE was diagnosed based on plasma cell infiltration in the non‐polypoid endometrium obtained by EAB.ResultsThe percentage of CE was 68.4%, 32.2%, and 28.3% in groups 1, 2, and 3, respectively. CE was more frequent in group 1 than group 2 or 3 (P = .01 and P = .002, respectively). The number of polyps was higher in group 1 than group 2. After adjustment for age and assisted reproductive technology, antibiotic therapy was not associated with pregnancy (adjusted odds ratio, 0.44; 95% confidence interval, 0.05‐3.57) in patients with EPs and CE.ConclusionsGroup 1 was associated with CE, and hysteroscopic findings were different from group 2. Antibiotic therapy after polypectomy for EPs with CE may not always be necessary.

Signatures of B Cell Receptor Repertoire Following Pneumocystis Infection.

B cells play vital roles in host defense against Pneumocystis infection. However, the features of the B cell receptor (BCR) repertoire in disease progression remain unclear. Here, we integrated single-cell RNA sequencing and single-cell BCR sequencing of immune cells from mouse lungs in an uninfected state and 1–4 weeks post-infection in order to illustrate the dynamic nature of B cell responses during Pneumocystis infection. We identified continuously increased plasma cells and an elevated ratio of (IgA + IgG) to (IgD + IgM) after infection. Moreover, Pneumocystis infection was associated with an increasing naïve B subset characterized by elevated expression of the transcription factor ATF3. The proportion of clonal expanded cells progressively increased, while BCR diversity decreased. Plasma cells exhibited higher levels of somatic hypermutation than naïve B cells. Biased usage of V(D)J genes was observed, and the usage frequency of IGHV9-3 rose. Overall, these results present a detailed atlas of B cell transcriptional changes and BCR repertoire features in the context of Pneumocystis infection, which provides valuable information for finding diagnostic biomarkers and developing potential immunotherapeutic targets.

An unusual case of lymphoplasmacytic lymphoma/Waldenström macroglobulinemia presenting with intractable seizures and interference with automated testing

Lymphoplasmacytic lymphoma (LPL) is a B cell neoplasm composed of small lymphocytes, plasmacytoid lymphocytes, and plasma cells, which typically involves the bone marrow. Most cases of LPL present with Waldenstrom macroglobulinemia (WM) defined as the presence of monoclonal immunoglobulins of IgM type and LPL in the bone marrow. Herein, we present a case of LPL/WM presenting with intractable refractory seizures. A 71-year-old man with a 5-month history of seizures was brought to the emergency room after being found unresponsive. Automated hematology analysis revealed imprecise counts, wide variation, and multiple error flags. Peripheral smear review showed extracellular pale blue clumps of amorphous material. A marked cryoprecipitate of 7% was detected on a cryoglobulin screen. Serum protein electrophoresis (SPEP) detected a M-protein (1.58 g/dL) in the gamma region. Serum immunofixation revealed an IgM lambda monoclonal protein. A bone marrow biopsy showed hypercellularity with increased lymphocytes forming interstitial aggregates, admixed with plasmacytoid lymphocytes and plasma cells. Immunohistochemically, the lymphoma cells were positive for CD20 and negative for CD3, CD5, CD10, CD23, Cyclin D1 (Bcl-1), and Bcl-6. CD138 highlighted increased plasma cells. Flow cytometric analysis revealed 2.7% B cells with a predominance of lambda light chains, suggestive of a monoclonal B cell population. MYD88 mutational analysis revealed c.794T>C(p.L265P) mutation. A diagnosis of lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia was established. The patient underwent plasmapheresis leading to significant improvement in his symptoms. This case highlights a rare, unusual presentation of LPL/WM where the interference in automated testing led to identification of cryoglobulinemia and subsequent diagnosis of LPL/WM.

Multiple Myeloma with Suspected Non-Secretory Type

Multiple Myeloma (MM) is a hematological malignancy characterized by clonal plasma cell in bone marrow that produceabnormal globulin, which resulted in monoclonal gammopathy. Multiple Myeloma Non-Secretory (MMNS) is a very rareform of multiple myeloma with monoclonal plasmocytic proliferation in bone marrow supported by clinical manifestationand radiological findings. However, plasma cells fail to secrete immunoglobulin. A 44-year-old female came to SardjitoGeneral Hospital with main complaints of weakness and back pain. General weakness and pale palpebral conjunctiva were6 observed (+/+), liver and spleen were not palpable. Blood test results were as follows: Hb 3.0 g/dL, RBC 1.07 x 10 / μL, WBC3 3 562 x 10 /μL, PLT 114 x 10 /μL, A/G ratio 1.07, BUN 51.5 mg/dL, creatinine 4.62 mg/dL, and calcium 3.1 mmol/L. Skeletalsurvey suggested a multiple osteolytic. Protein electrophoresis revealed hypogammaglobulinemia with no M-spike. Therewere 66% of plasma cells in bone marrow. Patient was diagnosed by MMNS. Diagnosis MMNS can be established if clonalplasmacytes is accompanied with renal insufficiency and hypercalcemia. However, monoclonal gammopathy was not foundin serum protein electrophoresis. A case reported of 44-year-old female diagnosed as MMNS with 'punched out' multipleosteolytic, increased plasma cells in bone marrow without evidence of paraprotein in circulation proved by low A/G ratio andnegative M-spike.

A 9-Year-Old Male with Barth Syndrome and a Cardiac Transplant Presenting with Hyperviscosity Syndrome Caused By EBV-Negative Plasmacytic PTLD

Posttransplant lymphoproliferative disorders (PTLD) are a spectrum of disorders characterized by lymphoid or plasmacytic proliferation secondary to extrinsic immunosuppression in solid organ transplant (SOT) or hematopoietic transplant recipients. According the 2016 revision of World Health Organization (WHO) classification, PTLD ranges from early lesion (mononucleosis-like) lymphoid hyperplasia or plasmacytic hyperplasia, polymorphic, monomorphic to classical Hodgkin lymphoma PTLD (Swerdlow et. al. Blood 2016). The incidence of PTLD in the pediatric population is closely associated with the type of transplanted organ, with the highest incidence in lung and small bowel transplant recipients due to chronic, iatrogenic immunosuppression. While Epstein-Barr Virus (EBV) is the key driver of abnormal lymphocytic proliferation in the majority of PTLDs, EBV-negative PTLD is a distinct subtype. We hereby report a 9-year-old boy with Barth syndrome, a rare genetic syndrome caused by a TAZ mutation, characterized by dilated cardiomyopathy, skeletal myopathy, neutropenia, and short stature. He required a heart transplant for left ventricular non-compaction cardiomyopathy at 11 months of age and presented with lower GI bleeding, acute-onset anemia, somnolence, retinal hemorrhages, and increased serum viscosity eight years post transplant. Workup was significant for hyperimmunoglobulinemia with elevated IgA and IgG, and serum protein electrophoresis (SPEP) showed two monoclonal bands (IgA Lambda and IgG Kappa) and an M spike. He was treated with plasmapheresis, and his symptoms improved significantly. Further workup with PET/CT scan showed diffuse lymphadenopathy of cervical, mediastinal, axillary, abdominal, and inguinal lymph nodes. Axillary lymph node biopsy was done, demonstrating a nondestructive morphology with an increase in plasma cells expressing excess lambda light chain and IgA; these abnormal cells were CD20 negative and CD138 positive, suggesting a clonal process. Cytogenetic fluorescence in situ hybridization (FISH) showed loss of TP53. Serum EBV detection by PCR and EBER staining by immunohistochemistry (IHC) on lymph node pathology were negative. Bone marrow biopsy showed a hypocellular marrow with trilineage hematopoiesis and 5-10% CD138 positive plasma cells. Combined, these studies were consistent with the diagnosis of early onset, nondestructive, plasmacytic PTLD. The patient was treated with a multiple myeloma-type therapy with dexamethasone and bortezomib (Short et. al. J Pediatr Hematol Oncol 2016), in addition to reduced immunosuppression consisting of low dose tacrolimus. Repeat PET/CT scan after 2 cycles of therapy showed resolution of previous PET-avid lesions. Stem cell collection was performed after 3 cycles in case of relapsed or recurrent disease. He completed 5 cycles of therapy with no complications. Unfortunately, the patient's end of treatment PET/CT scan was significant for a new mediastinal mass and multiple intraabdominal lymph nodes. Lymph node biopsy showed a lymphoplasmacytic infiltrate, which was IgA and lambda positive. The cells showed plasmacytoid features, but in contrast to the initial biopsy at diagnosis, there was marked CD20 positivity (image attached). This recurrence was most suggestive of a marginal zone lymphoma like PTLD (Galera et. al. Am J Surg Pathol 2020). He was initiated on therapy with rituximab and bendamustine. He is currently status post 2 treatment cycles and doing well. We continue to discuss the utility of autologous bone marrow transplant in this case, although the risks and benefits will have to be weighed carefully in a child who is prone to develop infections and complications from Barth Syndrome. We would like to share this case of EBV negative, plasmacytic PTLD with relapsed marginal zone lymphoma type PTLD to highlight the heterozygous pathologies of PTLD in children, and to share our experience of treating in the absence of standard protocol due to the rarity of this diagnosis. Figure Disclosures No relevant conflicts of interest to declare.

The Loss of Kdm6a in B-Cell Development Causes Germinal Center Hyperplasia and Impedes the B-Cell Immune Response in a Specific Manner

Putative loss-of-function mutations in KDM6A, an X-linked H3K27 demethylase, occur recurrently in B-cell malignancies, including B-cell non-Hodgkin lymphoma. How the KDM6A in normal B cell development and function, as well as the mechanism(s) by which its loss contributes lymphomagenesis has not been defined. To address this issue, we generated a conditional knockout mouse of the Kdm6a gene (with LoxP sites flanking the 3rd exon) and crossed these mice with Vav1-Cre transgenic mice to selectively inactivate Kdm6a in hematopoietic stem/progenitor cells. Our previous data have shown young Kdm6a-null mice have a myeloid skewing in the bone marrow, spleen and peripheral blood. These changes became more pronounced with age and were specific to the female, homozygous Kdm6a knockout mice. Early B-cell development is also altered in female Kdm6a-null mice. Flow cytometry showed a decrease in multipotent progenitor cells (MPPs) with a decrease in both common lymphoid progenitors (CLPs) and B cell-biased lymphoid progenitors (BLPs) in young, female Kdm6a-null mice bone marrow. B-cell progenitor analysis (Hardy profiles) showed an increase in Fraction A with a concomitant decrease in Fraction B/C and Fraction D. The GC B-cells are thought to be the cell-of-origin of diffuse large B-cell lymphoma (DLBCL). To determine if the loss of Kmd6a could impact the mature B cells undergo germinal center (GC) reaction, we immunized the young, female Kdm6a-null mcie and wildtype littermates with T cell-dependent antigen sheep red blood cell (SRBC). Mice were scrificed 14 days after immunization, spleen cells were examined by flow cytometry. As expected, we observed a significant increase in the percentage of GC B cells (B220+GL7+CD95+) from female Kdm6a-null mice compared to control mice. We also observed differences in the percentage of other B-cell subsets between these mice, including an increase in plasma cells (B220-CD138+) and memory B cells (B220+CD19+CD27+), concomitant with an increase trend towards the elevated marginal zone B cells (B220+CD23loCD21+) and transitional B cells (B220+CD23-CD21-). In contrast, there was a decrease in the follicular zone B cells (B220+CD23-CD21-) and plasmablast (B220+CD138+). To analyze the levels of SRBC-specific Abs from immunized mice, serum was collected from blood at day 14. A flow cytometry-based assay was performed to detect the fluorescent-labeled SRBC-specfic Abs for immunoglobulin. Results showed that the abundance of non-class-switched anti-SRBC IgM level was significantly increased in female Kdm6a-null mice serum compared with control mice. In contrast, these mice had significantly decreased anti-SRBC IgA, IgG, IgG1, IgG3 and IgE levels indicating a isotype class switch defect. The aberrant GC phenotype induced by SRBC indeicated that kdm6a loss results in expansion of GC B cells, which subsequently enhances the plasma cell generation. This finding prompted us to investigate if the Kdm6a impairs the immunoglobulin affinity maturation. Therefore, we analyzed the ability of female Kdm6a-null mice and wildtype littermates to generate specific Abs against another T cell-dependent antigen NP-Chicken Gamma Globulin (NP-CGG). Mice were immunized with NP-CGG (29) and serum were collected weekly up to 8 weeks total. ELISA analysis of serum revealed that NP-specfic total Ig level were similar for both groups of mice over time. However, consistent with the SRBC immunization results, we did observed a sinificant reduction in the titers of NP-specific IgA and IgG1 Abs in female Kdm6a-null mice compared with control mice at each time point, while these mice had a sinificant increase in NP-specific IgM Abs, which indicating the loss of Kdm6a disrupts the balance between non-class-switched and class-switched NP-specific Abs isotypes (Figure 1A-D). Likewise, we also observed an increase in the percentage of GC B cells and plasma cells 8 weeks after NP-CGG immunization by flow cytometry. Again, our findings indicate the loss of Kdm6a causes germinal center hyperplasia, enhances plasma cell differentiation, and likely impairs class switch recombination (CSR). Taken together, our data shows that Kdm6a plays an important, but complex, role in B-cell transiting in the GC reaction and that loss of Kdm6a causes germinal center hyperplasia and impedes the B-cell immune response in a specific manner that may contribute to infection and B-cell malignancies. Disclosures Wartman: Novartis: Consultancy; Incyte: Consultancy.

CD40 Agonist Combined with Radiation and PD-1 Blockade Enhances Development Of Systemic Tumor-Specific B-Cells And B-Cell Memory

Checkpoint blockade immunotherapy (CBI) is approved for head and neck squamous cell carcinoma; however, the majority of patients do not have objective responses and combinatorial therapies are needed to improve outcomes. Radiation therapy (RT) can enhance presentation of tumor antigens, and multiple studies have investigated the immunological effects of combined RT and CBI, particularly focusing on T-cells and myeloid populations. B-cells, however, have been relatively understudied, but their contributions in mounting a highly antigen-specific adaptive immune response are being further elucidated. Wild type C3H mice were injected subcutaneously with 5x105 cells of AT-84-E7-OVA into the right flank. Mice were then treated intravenously with 2 doses of 100 μg agonistic anti-CD40 antibody, 3 doses of 200 μg anti-PD-L1 antibody, and 12 Gy of focused RT. Tumors and spleens were dissected and analyzed by flow cytometry. An OVA-antigen biotinylated multimer was generated inhouse for tracking of tumor specific B-cells. Data were collected using a BD LSRII and analyzed using FlowJo. Mice treated with the combination of RT, PD-1 blockade, and CD40 activation had the highest frequency of tumor specific B-cells recognizing OVA, (from 3.3 +/-0.8 events per 50K live cells in untreated mice to 8.5 +/- 2.4; P = 0.01). We also observed a significant increase in plasma cells (from 11.9 +/- 8.0 events per 50K live cells in untreated mice to 235.5 +/- 131.2; P < 0.001). Additionally, mice treated with triple combination therapy had the highest proportion of plasma cells in the spleen (from 0.42 +/- 0.12% in untreated mice to 0.76 +/- 0.38% of all B220+ cells; P = 0.01), indicating augmented systemic B-cell immune responses induced by local radiation. Furthermore, mice treated with triple combination therapy demonstrated increased differentiation into PD-L2+ memory B cells (from 0.61 +/- 0.37% to 3.2 +/- 1.2% of all B220+ cells; P < 0.0001). Addition of CD40 agonist to RT and CBI significantly increases the frequency of systemic antigen-specific B-cells and B-cell memory. Continued investigation into the roles of distinct B-cell subpopulations and their responses to novel therapeutic combinations are ongoing and will help detail mechanisms combinatory activity.

MM-042: Case Report: Successful Management of an Unusual Metastatic Lesion Secondary to Multiple Myeloma

A case of a 50-year-old male presented with severe pain on the chest. CT scan done showed a bulky sternal mass, who was diagnosed after a biopsy in October 2010 with Sternal Plasmacytoma. Bone marrow biopsy and FNA of the mass consistent of MM, with no morphologic evidence of malignancy, and no increase in plasma cells. Patient received 25 sessions radiotherapy 45 Gy in 25 fractions till February 2011. In July 2011, a bone marrow biopsy showed a MM. Induction of chemotherapy with Bortezomib 1.3 mg/m2thalidomide 200 mg, steroids 40 mg, and zoledronic acid 4 mg IV was initiated with a very good response till January 2012. Patient refused to have an autologous stem cell transplant. Unfortunately, the patient found to be HBS-positive (HBV infection), so the chemotherapy was hold for a few months. Re-challenging the same treatment, with a good partial response. A new evaluation done in May 2013 showed a good partial response, the patient was maintained on thalidomide with zoledronic acid. In November 2016, bone marrow aspiration showed the level of plasma cells in the bone marrow was

IBCL-020: IgG4 Disease Presentation Mimicking Lymphoma

IgG4 -related disease (IgG4 -RD) is a fibro-inflammatory condition with unknown etiology that can affect any organ system. One of its characteristics is a diffuse or localized infiltration of the involved tissue by IgG4-positive plasma cells with association of lymphoplasma cellular inflammation, storiform fibrosis, and obliterative phlebitis. Elevated serum concentrations of IgG4 are present in many patients. The disease can sometimes be mistaken with lymphoma due to the presence of swelling and lymphadenopathy. Diagnosis is usually performed by the combination of radiologic and histopathologic data, in addition to a classic marked response to steroids. We report a 70-year-old man presenting with bulky generalized lymphadenopathy clinically and on CT scans, most strikingly in the right axillary and right inguinal area. He also had elevated ESR and CRP and anemia. Lymphoma was suspected, but a first biopsy of the right axillary lymph node interpreted by a general pathologist showed reactive lymphocytes. The patient left the hospital but came back a week later with near-syncope, fatigue, and generalized weakness. He underwent a new biopsy to the right inguinal lymph node, this time interpreted by a hematopathologist, showing reactive lymphocytes with increased plasma cells, without monoclonality or plasmacytoma, and the presence of necrotizing granulomas with fibrosis, HHV-8 negative, consistent with IgG-4 disease. Review of the initial biopsy of the right axillary lymph node showed the same. Serum IgG4 level was elevated (1.722 g/l), while VDRL and PPD were unremarkable. The diagnosis of IgG4-related disease was made and the patient was started on oral prednisone 1 mg/kg/day for 5 days than 40 mg daily tapered down over 2 months. He experienced a phenomenal clinical response with resolution of bulky lymphadenopathy, anemia, and generalized weakness and fatigue, and this was sustained after discontinuation of steroids and follow-up 6 months later.

Deficiency of β-arrestin2 exacerbates inflammatory arthritis by facilitating plasma cell formation.

β-arrestin2 (β-arr2) is, a key protein that mediates desensitization and internalization of G protein-coupled receptors and participates in inflammatory and immune responses. Deficiency of β-arr2 has been found to exacerbate collagen antibody-induced arthritis (CAIA) through unclear mechanisms. In this study we tried to elucidate the molecular mechanisms underlying β-arr2 depletion-induced exacerbation of CAIA. CAIA was induced in β-arr2-/- and wild-type (WT) mice by injection of collagen antibodies and LPS. The mice were sacrificed on d13 after the injection, spleen, thymus and left ankle joints were collected for analysis. Arthritis index (AI) was evaluated every day or every 2 days. We showed that β-arr2-/- mice with CAIA had a further increase in the percentage of plasma cells in spleen as compared with WT mice with CAIA, which was in accordance with elevated serum IgG1 and IgG2A expression and aggravating clinical performances, pathologic changes in joints and spleen, joint effusion, and joint blood flow. Both LPS stimulation of isolated B lymphocytes in vitro and TNP-LPS challenge in vivo led to significantly higher plasma cell formation and antibodies production in β-arr2-/- mice as compared with WT mice. LPS treatment induced membrane distribution of toll-like receptor 4 (TLR4) on B lymphocytes, accordingly promoted the nuclear translocation of NF-κB and the transcription of Blimp1. Immunofluorescence analysis confirmed that more TLR4 colocalized with β-arr2 in B lymphocytes in response to LPS stimulation. Depletion of β-arr2 restrained TLR4 on B lymphocyte membrane after LPS treatment and further enhanced downstream NF-κB signaling leading to additional increment in plasma cell formation. In summary, β-arr2 depletion exacerbates CAIA and further increases plasma cell differentiation and antibody production through inhibiting TLR4 endocytosis and aggravating NF-κB signaling.

Abstract 4635: Analysis of post-partum breast tissue to understand early onset breast cancer

Abstract Background: Parity reduces risk of late onset breast cancer (BC), but childbirth is associated with a transient rise in BC risk. In a prior analysis of normal breast tissues donated for research to the Komen Tissue Bank (KTB), we reported that numbers of lobules (the primary structures from which BCs arise) are increased among parous versus nulliparous women. To further define the histological features that may be related to the transient rise in post-partum BC risk, we performed an expanded histologic review of 757 breast tissues donated to the KTB by women ≤45 years of age and compared lobule number, acinar count per lobule, and abundance of immune cells, and specifically plasma cells, between nulliparous and parous women. Methods: We assessed digital scans of H&amp;E stained tissue sections of KTB tissues for total number of lobules, and evaluated acini / lobule (ordinal categories) and lobule span (um) for ≤10 lobules per section. Masked to epidemiologic data, we subjectively assessed images including ≥5 lobules for the presence of benign breast disease (BBD), ≥3 plasma cells per section and increased immune cells in lobules. We compared parous women according to time since last birth (≤5 years or &amp;gt;5 years) to nulliparas (referent) using age-adjusted regression models appropriate for data type (count, continuous, ordinal, or categorical). Results: Compared to nulliparous women, parous women ≤5 years of a birth had a 1.83-fold increase in lobule counts (95% confidence interval [CI]: 1.47-2.28, P&amp;lt;0.001), increased plasma cells in lobules (OR=1.86; 95% CI: 1.08-3.18, P&amp;lt;0.025), and subjectively, increased immune cells in lobules (OR=2.46, 95% CI: 1.39-4.36, P&amp;lt;0.002). Comparisons of parous women ≥5 years post-partum to nulliparas revealed a 1.83-fold increase in numbers of lobules (95% CI: 1.42-2.36, P&amp;lt;0.001); however, lobule span in parous women was 0.89 times that of nulliparous women (95% CI: 0.80-0.99, P=0.037) and other features assessed did not show statistically significant differences. Conclusion: Histologically, normal breast tissues reveal persistently increased lobule counts and increased plasma cells and inflammation for ≤5 years post-partum compared with nulliparous women, although other lobular features decrease between ≤5 and &amp;gt;5 years after a birth. Future molecular studies will define how these changes in the epithelium and microenvironment during the post-partum period may inform mechanisms that mediate the transient increase in BC risk after childbirth and the reduction in BC risk that occurs later in life. Citation Format: Joshua Ogony, DereK C. Radisky, Amy C. Degnim, Marlene Frost, Tanya L. Hoskin, Michael G. Heckman, Launia J. White, Mark E. Sherman. Analysis of post-partum breast tissue to understand early onset breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4635.

Focal pancreatic lesions in autoimmune pancreatitis and weight loss

A 67-year-old male patient was admitted to hospital with upper abdominal pain, jaundice and pale stool for 2 weeks. Laboratory investigation showed highly elevated cholestatic parameters and transaminases but no...

027 Plasma Cell Mucositis of the Vagina and Cervix

In 1952, Professor Johannes Jacobus Zoon described Zoon’s balanitis, an inflammatory condition which causes increased plasmocytic infiltrate of the penis and prepuce (1,2). Zoon’s vulvitis, commonly referred to as plasma cell vulvitis (PCV) or vulvitis circumscripta plasmacellularis, was first documented by Garnier in 1954 (1,2,3). PCV is a rare, chronic inflammatory disease characterized by erythematous plaques with a red, orange hue and increased plasma cells affecting the vulva. PCV predominantly affects the vulvar vestibule, but may extend to the labia minora and majora.

SUBMICROSCOPIC CHANGES OF STRUCTURAL COMPONENTS OF THE SPLEEN DUE TO THE ACTION OF MONOSODIUM GLUTAMATE

The results of an experimental study conducted on white male rats and females of reproductive age were analyzed in order to detect submicroscopic changes in the structural components of the spleen under the action of monosodium glutamate in the dynamics. For two, four, six and eight weeks, the animals received monosodium glutamate at a dose of 0.07 g / kg body weight daily with food. Sections of the spleen were made on a UMTP-6M ultramicrotome with a diamond knife (DIATOM) and double contrast was performed according to Reynolds and uranyl acetate. Submicroscopic examinations of the organ were performed using an electron transmission microscope TEM-100. The investigated material was photodocuted using a SONY – H9 digital camera. The first violations of the structural components of the spleen are observed after two weeks, namely the expansion of intercellular spaces in both white and red pulp of the spleen, which contain vacuole-like structures, an increase in plasma cells, the cytoplasm of which is filled with dilated tubules. In dynamics with increase in duration of reception changes deepen, reaching a maximum in 8 weeks of experiment. Electron microscopy revealed that the signs of adaptive-compensatory processes by the end of the experiment lead to a loss of regenerative function.

A tissue level atlas of the healthy human virome

BackgroundHuman-resident microbes can influence both health and disease. Investigating the microbiome using next-generation sequencing technology has revealed examples of mutualism and conflict between microbes and humans. Comparing to bacteria, the viral component of the microbiome (i.e., the “virome”) is understudied. Somatic tissues of healthy individuals are usually inaccessible for the virome sampling; therefore, there is limited understanding of the presence and distribution of viruses in tissues in healthy individuals and how virus infection associates with human gene expression and perturbs immunological homeostasis.ResultsTo characterize the human virome in a tissue-specific manner, here we performed meta-transcriptomic analysis using the RNA-sequencing dataset from the Genotype-Tissue Expression (GTEx) Project. We analyzed the 8991 RNA-sequencing data obtained from 51 somatic tissues from 547 individuals and successfully detected 39 viral species in at least one tissue. We then investigated associations between virus infection and human gene expression and human disease onset. We detected some expected relationships; for instance, hepatitis C virus infection in the liver was strongly associated with interferon-stimulated gene upregulation and pathological findings of chronic hepatitis. The presence of herpes simplex virus type 1 in one subject’s brain strongly associated with immune gene expression. While torque teno virus was detected in a broad range of human tissues, it was not associated with interferon responses. Being notable in light of its association with lymphoproliferative disorders, Epstein-Barr virus infection in the spleen and blood was associated with an increase in plasma cells in healthy subjects. Human herpesvirus 7 was often detected in the stomach; intriguingly, it associated with the proportion of human leukocytes in the stomach as well as digestive gene expression. Moreover, virus infections in the local tissues associated with systemic immune responses in circulating blood.ConclusionsTo our knowledge, this study is the first comprehensive investigation of the human virome in a variety of tissues in healthy individuals through meta-transcriptomic analysis. Further investigation of the associations described here, and application of this analytical pipeline to additional datasets, will be useful to reveal the impact of viral infections on human health.

Investigating macrophage function as a mechanism of resistance to daratumumab in relapsed refractory multiple myeloma patients.

e20547 Background: Daratumumab (Dara), an anti-CD38 antibody, has a variety of Fc-dependent immune effector mechanisms of action including macrophage-mediated antibody-dependent cellular phagocytosis (ADCP). However, it remains unclear which mechanism, when disrupted, drives in vivo resistance. Given widespread use of this agent for treatment of multiple myeloma, identifying how to overcome Dara resistance has become an urgent clinical need. We hypothesized that inhibiting macrophage activity, via increased plasma cell surface expression of the CD47 “don’t eat me” signal, could be a mechanism of acquired Dara resistance. Methods: We retrospectively identified 11 patients with relapsed refractory multiple myeloma who progressed on Dara and had sequential bone marrow core biopsies before and after Dara with both samples containing &gt; 20% plasma cells. Nine patients had sufficient material for analysis. Core biopsy slides were stained and analyzed for expression of CD47 (H-scoring for total intensity on plasma cells, as well as annotation of membrane vs. cytosolic localization), CD68 (cell counts of macrophages), and CD4/CD8/FOXP3 triple stain (cell counts of CD4 and CD8 effector and regulatory T-cells). Results: Median age was 57 years. Median R-ISS stage was 2. Two patients had high-risk cytogenetics at diagnosis. Median time from diagnosis to progression on Dara was 56.3 months (95% CI 37.43 – 88.92). Median overall survival was 69.5 months (95% CI: 46.5 – 97.1). Plasma cells in all samples expressed CD47 (H-score median = 96, range 43 - 290). However, in contrast to our hypothesis, there was no significant change in CD47 H-score at progression on Dara (H-score median = 100, range 29 – 140). Furthermore, we observed no significant change in CD68+ macrophage counts nor CD68+ localization at Dara progression. We did note a trend toward CD47 expression shifting from membrane to cytosol at Dara resistance ( p = 0.14). Consistent with prior studies, in our cohort we observed no influx in Tregs but a markedly increased CD8/CD4 ratio at resistance ( p = 0.01). Conclusions: In vitro and murine studies have proposed ADCP as an important mechanism of Dara efficacy. However, we did not observe signatures of resistance in patients being driven by this pathway. Our work suggests that anti-CD47 therapy, leading to activation of macrophages to eliminate tumor cells, will potentially be efficacious for both the Dara-naïve and Dara-refractory settings.

Prognostic role of beta-2 microglobulin in patients with light chain amyloidosis treated with autologous stem cell transplantation.

e20506 Background: Autologous stem cell transplantation (ASCT) prolongs survival in patients with light chain (AL) amyloidosis. Mayo 2012 stage and increased plasma cell percentage (%PC) are known predictors for survival. Increased beta-2 microglobulin (B2M) predicts survival in patients with multiple myeloma. However, its prognostic effect in patients with AL amyloidosis undergoing ASCT is not known. Methods: We retrospectively reviewed patients who had a diagnosis of AL amyloidosis and were treated with ASCT between July-1996 and September-2017. Patients with creatinine &gt; 1.2 mg/dL were excluded, as that affects B2M levels. The receiver operator curve was used to determine the best cutoff for B2M in predicting survival and was 2.5 mcg/mL. Baseline characteristics were compared between patients with B2M &gt; 2.5 and ≤2.5. Progression-free survival (PFS) was defined as time from ASCT to relapse or death, whichever occurred first. Overall survival (OS) was calculated from ASCT to death of any cause. Univariate and multivariate analysis were done for OS. Results: Five-hundred patients were identified and 222 (44%) had a B2M &gt; 2.5. These patients were more likely to be &gt; 65 years old (32% vs. 17%, P = 0.0001), have Mayo 2012 stage III/IV (33% vs. 8%, P &lt; 0.0001), have ≥3 organs involved (25% vs. 14%, P = 0.001), and have ≥10% PCs (56% vs. 40%, P = 0.0002) compared to patients with B2M ≤2.5. The median PFS and OS were shorter in patients with B2M &gt; 2.5 (median PFS: 64 vs. 80 months, P = 0.03); (median OS: 104.9 vs. 175.5 months, P &lt; 0.0001). On univariate analysis, predictors for OS included age &gt; 65 (HR: 1.6, P = 0.001), Mayo 2012 stage III/IV (HR: 3.3, P &lt; 0.0001), ≥3 organs involved (HR: 1.3, P = 0.06), ≥10% PC (HR: 1.5, P = 0.004), melphalan conditioning 200mg/m2 (HR: 0.28, P &lt; 0.0001), and B2M &gt; 2.5 (HR: 1.8, P &lt; 0.0001). In a multivariate analysis, only Mayo 2012 stage III/IV (HR: 1.8, P = 0.006), melphalan conditioning 200mg/m2 (HR: 0.35, P &lt; 0.0001), and B2M &gt; 2.5 (HR: 1.7, P = 0.01) remained independent predictive of OS. Conclusions: Beta-2 microglobulin &gt; 2.5 is an independent predictor for OS in AL amyloidosis patients undergoing ASCT and should be routinely measured.