Frequent downregulation or loss of CD79a expression in plasma cell myelomas: Potential clue for diagnosis

Immunoglobulin D-Lambda Multiple Myeloma Initially Presenting in the Sphenoid Sinus, Orbital Apex, and Skull Base: A Systematic Review with a Case Report

Objectives  Multiple myeloma (MM) with initial manifestations in the sphenoid sinus, orbital apex, and skull base is exceedingly rare. A systematic review was conducted to investigate the epidemiology and advancements . Methods  Relevant cases were identified by searching CNKI, WanFang Data, CQVIP databases, PubMed, Embase, and Web of Science. Additionally, we present a case of IgD-λ (immunoglobulin D-lambda) MM with initial symptoms of dizziness, unilateral pain, blindness, and ophthalmoplegia, leading to a 4-month overall survival. Strictly based on PRISMA standards, we included and summarized existing cases and reflected our case. Results  Our systematic review includes 34 case reports, revealing 67.6% of patients initially presented with diplopia and 44.1% underwent endoscopic procedures, notably with only two cases of IgD-λ subtype. In our case, we performed an endoscopic wide trans-ethmoidal sphenoidotomy and biopsy of the skull base and orbital apex lesion. Postoperative pathology confirmed a highly active plasmacytoma, clinically diagnosed as IgD-λ MM with a TP53 deletion mutation and multiple extramedullary metastases. A range of diagnostic tools was employed, including hemoglobin, immunoglobulin, urinary protein analysis, positron emission tomography-computed tomography (CT), bone marrow cytology, and gene detection. Conclusion  The subtle clinical manifestations of IgD-λ MM in the paranasal sinuses and skull base hinder early diagnosis. There is a paucity of literature describing MM initially presenting in these locations. CT/magnetic resonance scans are necessary to identify characteristic bone destruction. An endoscopic approach is popular for tissue biopsy. Bone marrow biopsy with a smear, serum or urine protein electrophoresis, and immunofixation electrophoresis are crucial upon the appearance of target organ damage.

A case of multiple myeloma with pancreatic involvement diagnosed via endoscopic ultrasound-guided fine needle aspiration

This report highlights the importance of considering multiple myeloma in the differential diagnosis of a pancreatic tumor with bone lesions. sampling not only from the pancreatic lesion but also from bone lesions may reach an accurate diagnosis.

Case report: Suspected plasmablastic lymphoma in a dog resembling the clinical presentation in humans

Plasmablastic lymphoma (PBL) is a rare form of lymphoma in people. PBL originates from plasmablasts and usually presents with swelling/mass in the mouth/neck. A 7-year-old Mongrel dog was presented for a large oral and neck mass. Cytology and histopathology were suggestive of a round cell tumor that was suspected to be lymphoma. An immunohistochemical (IHC) stain panel showed positive for CD18, thus supporting the diagnosis of round cell tumor, but negative for T- and B-cell lymphomas, CD3, CD20, and PAX-5. Other markers including cytokeratin AE1/3 (for epithelial cell origin), CD31 (for endothelial cells), SOX10 (for melanoma), IBa-1 (for histiocytic sarcoma), and CD117 (for mast cell tumor) were all negative. MUM-1 (for plasma cell differentiation) was strongly positive and CD79a (B cell and plasma cells) was also scantly positive. Based on the histopathology and immunohistochemistry results in combination with the clinical presentation, a suspected diagnosis of PBL was made. As per available literature, this is perhaps the first highly suspected case of PBL in a dog.

Identification of key genes in late-onset major depressive disorder through a co-expression network module

Late-onset major depressive disorder (LOD) increases the risk of disability and suicide in elderly patients. However, the complex pathological mechanism of LOD still remains unclear. We selected 10 LOD patients and 12 healthy control samples from the GSE76826 dataset for statistical analysis. Under the screening criteria, 811 differentially expressed genes (DEGs) were screened. We obtained a total of two most clinically significant modules through the weighted gene co-expression network analysis (WGCNA). Functional analysis of the genes in the most clinically significant modules was performed to explore the potential mechanism of LOD, followed by protein-protein interaction (PPI) analysis and hub gene identification in the core area of the PPI network. Furthermore, we identified immune infiltrating cells using the cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm between healthy subjects and LOD patients with the GSE98793 dataset. Next, six hub genes (CD27, IL7R, CXCL1, CCR7, IGLL5, and CD79A) were obtained by intersecting hub genes with DEGs, followed by verifying the diagnostic accuracy with the receiver operating characteristic curve (ROC). In addition, we constructed the least absolute shrinkage and selection operator (LASSO) regression model for hub gene cross-validation. Finally, we found that CD27 and IGLL5 were good diagnostic indicators of LOD, and CD27 may be the key gene of immune function change in LOD. In conclusion, our research shows that the changes in the immune function may be an important mechanism in the development of LOD, which can provide some guidance for the related research of LOD in the future.

Clinical Features, Phenotypic Markers and Outcomes of Diffuse Large B-Cell Lymphoma between HIV-Infected and HIV-Uninfected Chinese Patients

Background: The effect of HIV infection on the clinicopathological characteristics of diffuse large B-cell lymphoma (DLBCL) remains debatable. Methods: Fifty-three HIV-infected and ninety-three HIV-uninfected DLBCL patients were enrolled in the retrospective study by propensity score matching for sex, age, body mass index and international prognostic index (IPI) at a ratio of 1:2. The clinicopathological characteristics were compared between the two groups. Results: HIV-infected DLBCL patients had lower white blood cell counts [×109/L; 4.4 (3.4−5.6) vs. 6.1 (4.2−8.2), p < 0.001], platelet counts (×109/L; 184.7 ± 89.3 vs. 230.0 ± 113.9, p = 0.014) and serum albumin (g/L; 37.3 ± 6.9 vs. 41.3 ± 6.2, p < 0.001) but higher incidences of central nervous system (CNS) involvement (9.4% vs. 1.1%, p = 0.014), bone marrow involvement (24.5% vs. 11.5%, p = 0.044) and Epstein−Barr viremia (61.1% vs. 26.7%, p = 0.002) than HIV-uninfected patients. In terms of histopathology, HIV-infected patients had higher positivity of Epstein−Barr virus-encoded small RNA (EBER) (41.7% vs. 6.7%, p = 0.002), but lower CD20 (90.2% vs. 98.7%, p= 0.029) and CD79a (23.1% vs. 53.7%, p < 0.001) expression. The overall response rate (ORR) at the end of chemotherapy (70.2% vs. 87.8%, p= 0.012) and 1-year overall survival (OS) (61.7% vs. 84.2%, log-rank p = 0.006) in HIV-infected patients were significantly lower than those in HIV-uninfected patients. Multivariate analysis suggested IPI ≤2.0 [adjusted odds ratio (AOR) (95% confidence interval): 5.0 (1.2−21.2), p = 0.030] was associated with ORR, hypoalbuminemia [AOR: 3.3 (1.3−9.1), p = 0.018] and CNS involvement [AOR: 3.3 (1.0−10.5), p = 0.044] were associated with reduced 1-year OS in HIV-infected patients. Conclusion: HIV-infected DLBCL patients have unique blood profiles and phenotypic markers. Low ORR and 1-year OS were observed in HIV-infected DLBCL patients in our study, even in the HAART era.

Breast Plasmacytoma as Extra-Medullary Lesion of Multiple Myeloma: A Case Report

Breast plasmacytoma is relatively uncommon in which most of the recorded cases were related to disseminated multiple myeloma. However, many of these cases tend to be misdiagnosed with other breast lesions such as breast carcinoma. This article presents a case study on a Libyan female patient around the age of 55 who has a single breast lump, which was first diagnosed to be a malignant lesion. All the results of immunostaining for cytokeratins, GATA3, estrogen receptor, progesterone receptor, HER2, and E-cadherin were negative; hence, the possibility of a breast carcinoma was not considered. However, plasma cell tumors were indicated by the presence of CD138, MUM1, and kappa-light chain markers. In addition, the patient had multiple osteolytic bone lesions, plasma cell infiltration, a monoclonal gammopathy, and signs of renal failure, which considered to be an indication to an extra-medullary breast plasmacytoma secondary to advanced multiple myeloma. This case study emphasizes the necessity of complete histopathological and imaging evolution for proper diagnosis of breast plasmacytoma.

Expression characteristics of immune factors in the yak (Bos grunniens) testis

The goal of this study was to characterize and evaluate the main markers of macrophages, T lymphocytes, B lymphocytes and plasmocytes in the testis of juvenile and adult yaks by quantitative real-time polymerase chain reaction and immunohistochemistry. Within the same age group, the mRNA expression of CD68 was always highest, followed by that of CD3ε, CD79α, IgG and IgA. Moreover, CD68, CD3, CD79α, IgA and IgG positive cells were all located in the testicular interstitial tissues of juvenile and adult yaks. In the same age group, the frequency of CD68 positive macrophages was higher than that of CD3 positive T lymphocytes, which was followed by that of CD79α positive B lymphocytes and IgA and IgG positive plasmocytes. No significant difference was observed between the B lymphocyte and plasmocyte frequencies in yak testes. Furthermore, CD68, CD3ε, CD79α, IgA and IgG mRNA expression levels and the frequencies of CD68, CD3, CD79α, IgA and IgG positive cells increased from juveniles to adults. Similarly, the frequencies of CD68, CD3, CD79α, IgA and IgG positive cells also increased with age. These results suggest that in the yak testis, the immune defence system against pathogens might primarily comprise macrophages and T lymphocytes in the testicular interstitial tissue. Moreover, the testicular immune environment may mature and expand to a fully functional state in adult yaks. The low frequencies of B lymphocyte and plasmocyte in yaks, differing from those in rodents and humans, might be related to the fact that yaks live in low-oxygen plateaus.

Expression characteristics of immune factors in secondary lymphoid organs of newborn, juvenile and adult yaks (Bos grunniens)

Little is known about lymphoid organ development in yaks. In this study, we characterize and evaluate the main markers of T cell, B cell, plasma cell and antigen-presenting cell in the mesenteric lymph nodes, spleen and hemal node in newborn, juvenile and adult yaks by immunohistochemistry, real-time quantitative polymerase chain reaction and western blotting. The structures of all organs were not fully developed in newborn. The CD3⁺ cells were mainly located in the paracortex area of the mesenteric lymph node and the T cell dependent area in the hemal node and spleen. CD79a⁺ cells were mainly detected in the lymphoid follicles. The expression of CD3 and CD79a increased from newborn to juvenile and then decreased in adults. The expression of CD3 was always higher in the spleen and CD79a was higher in the mesenteric lymph node. IgG⁺ and IgA⁺ cells were observed in all examined samples, except in newborn yak hemal node. IgG and IgA were up-regulated with age and the highest expression was observed in the mesenteric lymph node. The SIRPα and CD68 were widely expressed. A significant feature was that the SIRPα expression in the spleen was lowest in newborns but highest in juvenile and adult yaks. The expression of CD68 in the hemal node was highest in all groups and increased from newborn to adult yaks. This study sheds light on the relationship between the morphology and function of these organs and provides useful references for normal yak lymphoid organ development.

Profiling the Atlantic Salmon IgM+ B Cell Surface Proteome: Novel Information on Teleost Fish B Cell Protein Repertoire and Identification of Potential B Cell Markers

Fish immunology research is at a pivotal point with the increasing availability of functional immunoassays and major advances in omics approaches. However, studies on fish B cells and their distinct subsets remain a challenge due to the limited availability of differentially expressed surface markers. To address this constraint, cell surface proteome of Atlantic salmon IgM⁺ B cells were analyzed by mass spectrometry and compared to surface proteins detected from two adherent salmon head kidney cell lines, ASK and SSP-9. Out of 21 cluster of differentiation (CD) molecules identified on salmon IgM⁺ B cells, CD22 and CD79A were shortlisted as potential markers based on the reported B cell-specific surface expression of their mammalian homologs. Subsequent RT-qPCR analyses of flow cytometry-sorted subpopulations from head kidney leukocytes confirmed that both cd22 and cd79a genes were highly expressed in IgM⁺ lymphoid cells but were observed in barely detectable levels in IgM^- non-lymphoid suspension and adherent cells. Similarly, significantly high cd22 and cd79a mRNA levels were observed in IgM⁺ or IgT⁺ lymphoid cells from the spleen and peritoneal cavity, but not in their corresponding IgM^- IgT^- non-lymphoid fractions. This suggests that the B cell restrictive expression of CD22 and CD79A extend down to the transcription level, which was consistent across different lymphoid compartments and immunoglobulin isotypes, thus strongly supporting the potential of CD22 and CD79A as pan-B cell markers for salmon. In addition, this study provides novel information on the salmon B cell surface protein repertoire, as well as insights on B cell evolution. Further investigation of the identified salmon CD molecules, including development of immunological tools for detection, will help advance our understanding of the dynamics of salmon B cell responses such as during infection, vaccination, or immunostimulation.

CD24, CD27, CD36 and CD302 gene expression for outcome prediction in patients with multiple myeloma

Multiple myeloma (MM) is a B cell neoplasia characterized by clonal plasma cell (PC) proliferation. Minimal residual disease monitoring by multi-parameter flow cytometry is a powerful tool for predicting treatment efficacy and MM outcome. In this study, we compared CD antigens expression between normal and malignant plasma cells to identify new potential markers to discriminate normal from malignant plasma cells, new potential therapeutic targets for monoclonal-based treatments and new prognostic factors. Nine genes were significantly overexpressed and 16 were significantly downregulated in MMC compared with BMPC (ratio ≥2; FDR CD24, CD27, CD36 and CD302) was associated with a prognostic value in two independent cohorts of patients with MM (HM cohort and TT2 cohort, n=345). The expression level of these four genes was then used to develop a CD gene risk score that classified patients in two groups with different survival (P = 2.06E-6) in the HM training cohort. The prognostic value of the CD gene risk score was validated in two independent cohorts of patients with MM (TT2 cohort and HOVON65/GMMGHD4 cohort, n=282 patients). The CD gene risk score remained a prognostic factor that separated patients in two groups with significantly different overall survival also when using publicly available data from a cohort of relapsing patients treated with bortezomib (n=188). In conclusion, the CD gene risk score allows identifying high risk patients with MM based on CD24, CD27, CD36 and CD302 expression and could represent a powerful tool for simple outcome prediction in MM.

Variant morphology in multiple myeloma

A 45-year-old man presented to the clinic with the chief complaints of low back pain, marked weight loss, and pallor of 2 months duration. He was found to have severe normocytic anemia with leukoerythroblastosis. Bone marrow aspirate resulted in a dry tap. Marrow trephine biopsy showed findings initially interpreted as poorly differentiated carcinoma involving marrow. Immunohistochemistry and protein studies established a diagnosis of IgG Kappa multiple myeloma. Correlation of marrow biopsy findings with clinical, radiological and immunological data remain an essential part of the diagnostic evaluation of multiple myeloma.

Multiple myeloma in a captive lion (Panthera leo)

Multiple myeloma is a rare, systemic proliferation of neoplastic plasma cells. A case was reported in an 11-year-old male captive lion (Panthera leo) at the National Zoological Gardens of South Africa, Pretoria. The classic features of symptomatic multiple myeloma were all evident in this case; namely osteolytic lesions, monoclonal gammopathy in the serum with excretion of monoclonal proteins in the urine, neoplastic plasma cells in the bone marrow and associated renal failure and anaemia. In addition, similar to the common pattern of this disease in domestic felids, at least three extramedullary tumours were found and several organs were infiltrated by neoplastic plasma cells. The cytoplasm of approximately 50%of the neoplastic round cells, including a few giant myeloma cells, stained weakly to strongly using immunohistochemical stains for B-lymphocytes (CD79a). The normal haematological parameters and lack of any osteolytic lesions in the lion at the time of the first evaluation suggest that the primary neoplastic cells could have originated from one of the extramedullary tumour sites. Only two cases of multiple myeloma have previously been reported in captive wild felids. To the authors’ knowledge, there are no case reports of multiple myeloma in lions.

Functions and uses of immunohistochemical stains in cutaneous infiltrates of hematopoietic origin: a review for the practicing dermatologist

BACKGROUND

Immunohistochemical stains, particularly those for cutaneous lymphomas, have similar-sounding names, which may lead to confusion among dermatologists who are not well versed in the terminology of the tools used for pathologic diagnosis. Also aiding in this is the fact that some familiar stains are constantly investigated for novel utility in different tumors, and a plethora of new stains regularly emerge in the peer-reviewed literature.

OBJECTIVE

To review the major stains encountered in dermatopathologic reports for cutaneous lymphomas. A select number of other stains are reviewed that are either new and under investigation in several cutaneous processes or have a new use described in recent reports.

METHODS

The peer-reviewed literature was searched and analyzed for the accepted purposes of using these markers.

RESULTS

All pertinent findings for these immunostains are reported with the purpose of educating the dermatology community.

CONCLUSION

This review serves as a reference to clarify potentially confusing immunohistochemical stains.

Downregulation of the B-cell receptor signaling component CD79b in plasma cell myeloma: a possible post transcriptional regulation

The CD79 molecule, encoded by the CD79a and CD79b genes, is a signaling unit of the B-cell receptor complex, which transmits signals of B-cell activation, growth, and differentiation. They are B-cell-specific and expressed at most stages of B-cell development. Although plasma cells have been believed to lack these gene products, the regulation of CD79 expression in plasma cells is still controversial. In particular, the regulation of CD79b expression remains unclear. We sought to examine CD79b expression in normal and neoplastic plasma cells by immunohistochemical analysis. Out of the 23 clinical samples and 11 cell lines of plasma cell myeloma (PCM), none of the clinical samples and only 1 of 11 cell lines expressed CD79b immunohistologically, whereas non-neoplastic plasma cells in reactive hyperplastic lymph nodes exhibited loss of CD79b protein expression. This finding is quite different from our previous report on CD79a. Not only immunocytochemistry, but also RT-PCR and Western blot analysis of PCM cell lines gave identical results. Interestingly, we detected mRNA transcripts of CD79b in PCM cell lines, although protein translation was lacking. These findings suggest that expression of CD79b is downregulated in both plasma cells and plasma cell myeloma, and this process is possibly under post transcriptional regulation.

Aberrant global methylation patterns affect the molecular pathogenesis and prognosis of multiple myeloma

We used genome-wide methylation microarrays to analyze differences in CpG methylation patterns in cells relevant to the pathogenesis of myeloma plasma cells (B cells, normal plasma cells, monoclonal gammopathy of undetermined significance [MGUS], presentation myeloma, and plasma cell leukemia). We show that methylation patterns in these cell types are capable of distinguishing nonmalignant from malignant cells and the main reason for this difference is hypomethylation of the genome at the transition from MGUS to presentation myeloma. In addition, gene-specific hypermethylation was evident at the myeloma stage. Differential methylation was also evident at the transition from myeloma to plasma cell leukemia with remethylation of the genome, particularly of genes involved in cell-cell signaling and cell adhesion, which may contribute to independence from the bone marrow microenvironment. There was a high degree of methylation variability within presentation myeloma samples, which was associated with cytogenetic differences between samples. More specifically, we found methylation subgroups were defined by translocations and hyperdiploidy, with t(4;14) myeloma having the greatest impact on DNA methylation. Two groups of hyperdiploid samples were identified, on the basis of unsupervised clustering, which had an impact on overall survival. Overall, DNA methylation changes significantly during disease progression and between cytogenetic subgroups.