Immunophenotypic profiles for distinguishing orbital mucosa-associated lymphoid tissue lymphoma from benign lymphoproliferative tumors

Characteristics of orbital lymphoproliferative disorders: a retrospective study of 84 cases

OBJECTIVE

To investigate the variations in clinical presentation, imaging characteristics, and immunohistochemical features between benign and malignant orbital lymphoproliferative disorders (OLPDs).

METHODS

At the Eye Center of the First Affiliated Hospital, Zhejiang University School of Medicine, a retrospective analysis was performed on the clinical records of all patients diagnosed with OLPDs from 2014 to 2022. This study included a comparative analysis between patients diagnosed with benign and malignant OLPDs.

RESULTS

A total of 84 patients were included in this research, with a mean age of 62.24 ± 14.52 years and male-to-female ratio of 43:41. The pathological types comprised benign orbital lymphoproliferative tumours (26/84, 31%, mean age 59.31 ± 10.4 years, male-to-female ratio of 16:10) and malignant orbital lymphomas (58/84, 69%, mean age 63.55 ± 15.93 years, male-to-female ratio of 27:31). The most common symptoms in benign and malignant OLPDs were palpable mass and eyelid swelling. Typically, malignant orbital lymphoma masses exhibited low signal intensity on T1-weighted imaging (T1WI), whereas benign lymphoproliferative tumours commonly demonstrated iso-intensity on T1WI. Notably, the expression of cluster of differentiation 3, 5, 10, 23, 43, and human immunoglobulin light chain lambda demonstrated statistically significant differences between the benign and malignant OLPD groups.

CONCLUSION

Benign and malignant OLPDs exhibit similar clinical presentations and imaging characteristics. Currently, distinguishing between benign and malignant OLPDs still requires pathological biopsy. Research on specialized imaging techniques and specific biomarkers for malignant orbital lymphomas is underway, showing potential for enhancing the accuracy of non-invasive diagnoses for benign and malignant OLPDs.

Single-cell RNA-sequencing reveals cellular heterogeneity and immune microenvironment characteristics between ocular adnexal mucosa-associated lymphoid lymphoma and IgG4-related ophthalmic disease

Introduction

The molecular pathogenesis of ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma and IgG4-related ophthalmic disease (IgG4-ROD) remains incompletely understood. Differentiating between the two diseases is vital given that the diagnostic evaluation and treatment approaches can vary significantly; this difficulty in distinction is exacerbated by the absence of specific biomarkers. This study aimed to investigate the differences between these two diseases based on their cellular composition, transcriptional heterogeneity, and the immune microenvironment using single-cell RNA transcriptional sequencing (scRNA-seq) technology.

Methods

We collected orbital lacrimal gland region tissue samples from three patients with MALT lymphoma and another three with IgG4-ROD and performed single-cell sequencing experiments. Subsequently, we conducted bioinformatics analyses, including cell subpopulation segmentation and inter-group comparison, tumor cell identification, functional enrichment analysis, and pseudotime trajectory analysis. Furthermore, we analyzed the cellular communication between tumor B-cell and T-cell subsets within the immune microenvironment of MALT lymphoma tissues. We performed immunofluorescence assays to verify the co-expression of receptor-ligand pairs.

Results

A total of six major cell subpopulations were identified, with B-cells and T-cells being the predominant cell types. All B-cell subpopulations in MALT lymphomas are malignant, exhibiting significant intratumoral and intertumoral heterogeneity. Reclustering of the T-cell subpopulation identified five major T-cell subpopulations. Pseudotime analysis revealed that CD4+ naive T-cells in MALT lymphoma patients were highly likely to differentiate into follicular helper T-cells, whereas, in IgG4-ROD patients, CD4+ naive T-cells were highly likely to differentiate into regulatory T-cells. Intercellular communication analysis revealed that the CD27-CD70 immune checkpoint receptor-ligand pair and CXCL13-CXCR5 chemokine receptor-ligand pair were significantly upregulated between malignant B-cells and T-cells subpopulations.

Conclusion

This study is the first to conduct a comparative single-cell transcriptome sequencing analysis of ocular adnexal MALT lymphoma and IgG4-ROD. Our results reveal the cellular composition, key pathways, and critical immune microenvironment implicated in the development of these two diseases. These findings provide important insights into the pathogenesis of these two diseases and highlight the differences between them.

Diffuse large b-cell lymphoma of the ocular adnexa with flow cytometry analysis and review of the literature

PURPOSE

The aim of this study was to evaluate the clinicopathological features and flow cytometry (FCM) of tumor tissues in ocular adnexal diffuse large B-cell lymphoma (DLBCL).

METHODS

This retrospective, multicenter case study was designed to evaluate the clinical and immunohistochemical features of tumors. DLBCL was diagnosed based on histopathology, immunoglobulin (Ig) heavy chain gene rearrangement, and FCM in all surgically removed periocular tumor tissues. This study involved assessing percentages (%) of B-cell/T-cell markers, a natural killer cell marker, and cell-surface Ig kappa/lambda (κ/λ) expression measured by FCM analysis in tumor tissues.

RESULTS

Eleven DLBCL patients (4 men and 7 women) with 11 tumors were enrolled in this study. The median age at the time of initial presentation was 73 years. The tumor cells were immunohistochemically positive for cluster of differentiation (CD) 20, while CD5 was negative in all 8 cases tested. At the time of ophthalmic diagnosis, two cases already showed systemic dissemination of DLBCL throughout the body. FCM of tumor tissues detected a high percentage of B-cell markers including CD19 and CD20 in all 11 tumors. One case with high CD10 levels in FCM was histologic transformation from follicular lymphoma. One case with a relatively low CD20 population involved a history of systemic treatments including intravenous rituximab.

CONCLUSION

Although caution should be exercised when interpreting the data, FCM is useful for not only supportive diagnosis complementary to immunohistochemistry, but also facilitates a better understanding of immunopathology including histologic transformation of follicular lymphoma to DLBCL in the ocular adnexa.

Evaluation of Orbital Lymphoproliferative and Inflammatory Disorders by Gene Expression Analysis

Non-specific orbital inflammation (NSOI) and IgG4-related orbital disease (IgG4-ROD) are often challenging to differentiate. Furthermore, it is still uncertain how chronic inflammation, such as IgG4-ROD, can lead to mucosa-associated lymphoid tissue (MALT) lymphoma. Therefore, we aimed to evaluate the diagnostic value of gene expression analysis to differentiate orbital autoimmune diseases and elucidate genetic overlaps. First, we established a database of NSOI, relapsing NSOI, IgG4-ROD and MALT lymphoma patients of our orbital center (2000−2019). In a consensus process, three typical patients of the above mentioned three groups (mean age 56.4 ± 17 years) at similar locations were selected. Afterwards, RNA was isolated using the RNeasy FFPE kit (Qiagen) from archived paraffin-embedded tissues. The RNA of these 12 patients were then subjected to gene expression analysis (NanoString nCounter®), including a total of 1364 target genes. The most significantly upregulated and downregulated genes were used for a machine learning algorithm to distinguish entities. This was possible with a high probability (p < 0.0001). Interestingly, gene expression patterns showed a characteristic overlap of lymphoma with IgG4-ROD and NSOI. In contrast, IgG4-ROD shared only altered expression of one gene regarding NSOI. To validate our potential biomarker genes, we isolated the RNA of a further 48 patients (24 NSOI, 11 IgG4-ROD, 13 lymphoma patients). Then, gene expression pattern analysis of the 35 identified target genes was performed using a custom-designed CodeSet to assess the prediction accuracy of the multi-parameter scoring algorithms. They showed high accuracy and good performance (AUC ROC: IgG4-ROD 0.81, MALT 0.82, NSOI 0.67). To conclude, genetic expression analysis has the potential for faster and more secure differentiation between NSOI and IgG4-ROD. MALT-lymphoma and IgG4-ROD showed more genetic similarities, which points towards progression to lymphoma.

Clinicopathologic Characteristics Associated with Prognosis in Ocular Extranodal Marginal Zone B Cell Lymphoma

Background and Objectives: Extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) type is the most common subtype of the ocular adnexal lymphoma. Despite its excellent prognosis, some patients experience partial remission or progressive disease. We aimed to evaluate clinicopathologic differences in the treatment responder group by comparing complete remission (CR) and non-complete remission (non-CR). Materials and Methods: This study retrospectively reviewed 48 patients who were diagnosed with ocular adnexal MALT lymphoma at Ulsan University Hospital between March 2002 and August 2018. Patients who were followed up for less than 6 months were excluded. Histologic and clinical features were analyzed. The patients were divided into two groups: CR and non-CR. Results: Among the 48 patients, 33 achieved CR and 15 achieved non-CR during the median follow-up period of 40.00 months (range, 7-109 months). In univariable analysis, more patients tend to undergo treatment in the CR group, and post-radiotherapy (post-RT) SUVmax, PET and serum lactate dehydrogenase (LDH) levels were higher in the non-CR group (p = 0.043, p = 0.016, and p = 0.042, respectively). In a multivariable analysis, only application of treatment, including radiotherapy or chemotherapy with immunotherapy, was related to CR (odd ratio 7.301, 95% confidence interval 1.273-41.862, p = 0.026). In subgroup analysis according to the site of involvement, none of the variables were significant except for the post-RT SUVmax of PET and level of serum LDH in the non-conjunctiva group (p = 0.026, and p = 0.037, respectively). Seven (14.6%) patients had a recurrence, and those with a recurring site other than the primary site had a higher Ki-67 labeling index, although it was not statistically significant (9.56% vs. 18.00%, p = 0.095). Conclusions: Although belonging to the early stages, the non-CR rate was high in patients with high serum LDH levels, and recurred patients had higher Ki-67. Thus, considering active treatment is recommended in this group of patients.

Follicular lymphoma of the ocular adnexa: Clinicopathological findings with flow cytometry analysis of eight cases

PURPOSE

Flow cytometry (FCM) is used to evaluate cell surface markers of various leukocyte populations quantitatively. However, little is known about the usefulness of FCM in follicular lymphoma (FL) of the ocular adnexa. The aim of this study was to evaluate the clinicopathological features and FCM results in ocular adnexal FL.

MATERIALS

This is a retrospective multicenter case study on clinical and immunohistochemical features. All tumors, surgically excised, were diagnosed based on histopathology, immunoglobulin heavy chain gene rearrangement, and FCM. The percentages (%) of B-cell markers, T-cell markers, a natural killer cell marker, and cell surface kappa/lambda measured by FCM analysis in tumor tissues were searched based on medical records.

RESULTS

This study enrolled nine tumors in eight FL patients (three men and five women). The median age at the time of initial presentation was 74 years. All the tumors surgically excised histologically exhibited cluster of differentiation (CD)10, CD20, and BCL2-positive cells. At the time of ophthalmic diagnosis, lymphomas were already disseminated throughout the body in five cases. FCM demonstrated high percentage of B-cell markers including CD10, CD19, CD20, and CD23 in all nine tumors. CD10 population was 73.5% ± 11.9% in seven out of nine tumors, while that in the other two tumors was particularly low being 11.7% ± 1.13%, which showed the relatively high T-cell lineages compared to the other seven tumors.

CONCLUSION

For ophthalmologists involving managements of ocular adnexal tumors, FCM can provide useful information for complementing the diagnosis and understanding pathophysiology of FL.

Comprehensive Gene Analysis of IgG4-Related Ophthalmic Disease Using RNA Sequencing

High-throughput RNA sequencing (RNA-seq) uses massive parallel sequencing technology, allowing the unbiased analysis of genome-wide transcription levels and tumor mutation status. Immunoglobulin G4-related ophthalmic disease (IgG4-ROD) is a fibroinflammatory disease characterized by the enlargement of the ocular adnexal tissues. We analyzed RNA expression levels via RNA-seq in the biopsy specimens of three patients diagnosed with IgG4-ROD. Mucosa-associated lymphoid tissue (MALT) lymphoma, reactive lymphoid hyperplasia (RLH), normal lacrimal gland tissue, and adjacent adipose tissue were used as the controls (n = 3 each). RNA-seq was performed using the NextSeq 500 system, and genes with |fold change| ≥ 2 and p < 0.05 relative to the controls were defined as differentially expressed genes (DEGs) in IgG4-ROD. To validate the results of RNA-seq, real-time polymerase chain reaction (PCR) was performed in 30 IgG4-ROD and 30 orbital MALT lymphoma tissue samples. RNA-seq identified 35 up-regulated genes, including matrix metallopeptidase 12 (MMP12) and secreted phosphoprotein 1 (SPP1), in IgG4-ROD tissues when compared to all the controls. Many pathways related to the immune system were included when compared to all the controls. Expressions of MMP12 and SPP1 in IgG4-ROD tissues were confirmed by real-time PCR and immunohistochemistry. In conclusion, we identified novel DEGs, including those associated with extracellular matrix degradation, fibrosis, and inflammation, in IgG4-ROD biopsy specimens. These data provide new insights into molecular pathogenetic mechanisms and may contribute to the development of new biomarkers for diagnosis and molecular targeted drugs.

Distinctive Tissue and Serum MicroRNA Profile of IgG4-Related Ophthalmic Disease and MALT Lymphoma

The molecular pathogenesis of orbital lymphoproliferative disorders, such as immunoglobulin G4-related ophthalmic disease (IgG4-ROD) and orbital mucosa-associated lymphoid tissue (MALT) lymphoma, remains essentially unknown. Differentiation between the two disorders, which is important since the work-up and treatment can vary greatly, is often challenging due to the lack of specific biomarkers. Although miRNAs play an important role in the regulation of carcinogenesis and inflammation, the relationship between miRNA and orbital lymphoproliferative diseases remains unknown. We performed a comprehensive analysis of 2565 miRNAs from biopsy and serum specimens of 17 cases with IgG4-ROD, where 21 cases with orbital MALT lymphoma were performed. We identified specific miRNA signatures and their miRNA target pathways, as well as the network analysis for IgG4-ROD and orbital MALT lymphoma. Machine-learning analysis identified miR-202-3p and miR-7112-3p as the best discriminators of IgG4-ROD and orbital MALT lymphoma, respectively. Enrichment analyses of biological pathways showed that the longevity-regulating pathway in IgG4-ROD and the mitogen-activated protein kinase (MAPK) signaling pathway in orbital MALT lymphoma was most enriched by target genes of downregulated miRNAs. This is the first evidence of miRNA profiles of biopsy and serum specimens of patients with IgG4-ROD and orbital MALT lymphoma. These data will be useful for developing diagnostic and therapeutic interventions, as well as elucidating the pathogenesis of these disorders.