Notch1 in primary effusion lymphoma: a clinicopathological study

Targeting CD38 in Neoplasms and Non-Cancer Diseases

Simple Summary

CD38 remains an interesting target for anticancer therapy. Its relatively high abundance in neoplasms and crucial impact on NAD+/cADPR metabolism and the activity of T cells allows for changing the immune response in autoimmune diseases, neoplasms, and finally the induction of cell death. Antibody-dependent cell cytotoxicity is responsible for cell death induced by targeting the tumor with anti-CD38 antibodies, such as daratumumab. A wide range of laboratory experiments and clinical trials show an especially promising role of anti-CD38 therapy against multiple myeloma, NK cell lymphomas, and CD19- B-cell malignancies. More studies are required to include more diseases in the therapeutic protocols involving the modulation of CD38 activity.

Abstract

CD38 is a myeloid antigen present both on the cell membrane and in the intracellular compartment of the cell. Its occurrence is often enhanced in cancer cells, thus making it a potential target in anticancer therapy. Daratumumab and isatuximab already received FDA approval, and novel agents such as MOR202, TAK079 and TNB-738 undergo clinical trials. Also, novel therapeutics such as SAR442085 aim to outrank the older antibodies against CD38. Multiple myeloma and immunoglobulin light-chain amyloidosis may be effectively treated with anti-CD38 immunotherapy. Its role in other hematological malignancies is also important concerning both diagnostic process and potential treatment in the future. Aside from the hematological malignancies, CD38 remains a potential target in gastrointestinal, neurological and pulmonary system disorders. Due to the strong interaction of CD38 with TCR and CD16 on T cells, it may also serve as the biomarker in transplant rejection in renal transplant patients. Besides, CD38 finds its role outside oncology in systemic lupus erythematosus and collagen-induced arthritis. CD38 plays an important role in viral infections, including AIDS and COVID-19. Most of the undergoing clinical trials focus on the use of anti-CD38 antibodies in the therapy of multiple myeloma, CD19- B-cell malignancies, and NK cell lymphomas. This review focuses on targeting CD38 in cancer and non-cancerous diseases using antibodies, cell-based therapies and CD38 inhibitors. We also provide a summary of current clinical trials targeting CD38.

Lymphoid Neoplasms With Plasmablastic Differentiation: A Comprehensive Review and Diagnostic Approaches

Plasmablastic neoplasms encompass several entities including plasmablastic lymphoma, plasmablastic plasmacytoma/multiple myeloma, primary effusion lymphoma and its extracavitary variant, anaplastic lymphoma kinase-positive large B-cell lymphoma, and Kaposi sarcoma-associated herpesvirus/human herpesvirus 8 (HHV8)-positive diffuse large B-cell lymphoma, not otherwise specified. Morphologically, the tumor cells are large with eccentrically located nuclei, prominent nucleoli, and basophilic/amphophilic cytoplasm. Immunophenotypically, the tumor cells express plasma cell-related antigens including CD38, CD138, interferon regulatory factor-4 (IRF4)/MUM1, PR domain zinc finger protein-1 (PRDM1), and/or X-box binding protein-1 (XBP1), with frequent loss of CD20. These tumors are diagnostically challenging for general pathologists due to their overlapping morphology and immunophenotype, and due to their rarity, and particularly so when clinical and radiologic information is insufficient. We also discuss HHV8-negative effusion-based lymphoma due to its overlapping features with primary effusion lymphoma. In this review, we focus on the useful diagnostic markers and pertinent molecular findings in these distinct entities and propose a practical diagnostic algorithm using anaplastic lymphoma kinase, HHV8, in situ hybridization for Epstein-Barr virus-encoded small RNA, immunoglobulin M, light chain stains, and clinicoradiologic criteria to avoid misdiagnosis. At the molecular level, MYC protein overexpression with or without MYC rearrangement and PRDM1-inactivating mutations or deletions are noted in a subset of such tumors, especially in plasmablastic lymphoma. Prognosis in these entities is dismal with conventional CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy. Therefore, novel target therapies, such as anti-CD30 agents, and/or immune blockade therapy, are potential treatment options in the future.

Primary effusion lymphoma in human immune deficiency (HIV)-negative non-organ transplant immunocompetent patients

Primary effusion lymphoma (PEL) is a rare non‐Hodgkin's lymphoma most commonly occurring in the context of human immune deficiency (HIV) infection. Herpes virus 8 (HHV‐8) has been associated with PEL and considered to be the etiologic agent. In addition, most cases (60%‐90%) also show evidence of Epstein‐Barr virus (EBV) infection. We describe here an elderly man who was HIV seronegative and immunocompetent, and presented with worsening weakness and ascites. The diagnosis of PEL was rendered cytologically and supported by the results of flow cytometry. The presence of HHV‐8 was demonstrated by immunohistochemistry, whereas EBV‐associated genetic material was absent by EBER ISH. No lymphadenopathy or organ involvement with lymphoma was found. Systemic chemotherapy with lenalidomide was started given the poor prognosis and commodities of severe coronary artery disease; however, the patient did not respond and succumbed to his disease in 4 months. We present detailed cytologic and clinical findings of this very rare occurrence, and review literature of all reported PEL cases of HIV‐negative, nontransplant, immunocompetent patients.

Primary effusion lymphoma in Taiwan shows two distinctive clinicopathological subtypes with rare human immunodeficiency virus association

AIMS

To investigate the clinicopathological and molecular features of primary effusion lymphoma (PEL) in Taiwan and the association with human immunodeficiency virus (HIV), human herpesvirus 8 (HHV8) and Epstein-Barr virus (EBV).

METHODS AND RESULTS

We investigated retrospectively 26 cases with a median age of 76.5. Only one (4%) patient was infected with HIV. Cytologically, all lymphoma cells revealed typical immunoblastic to plasmablastic morphology. Immunohistochemically, HHV8 was positive in eight (32%) tumours and negative in 17 (68%) cases. All 23 tested cases examined were of the non-germinal-centre B cell phenotype. MYC proto-oncogene (MYC) and Epstein-Barr encoding mRNA (EBER) were positive in 43% (nine of 21) and 17% (four of 23) cases, respectively. Immunoglobulin heavy chain (IGH), B cell lymphoma (BCL)2, BCL6 and MYC were rearranged in 71%, 11%, 12% and 18% cases, respectively. By univariate analysis, the overall survival (OS) was associated statistically with MYC expression (P = 0.012) and BCL2 rearrangement (P = 0.035), but not with the others. By multivariate analysis, no factor was statistically significant. Compared to the HHV8-negative cases, the HHV8-positive cases were mainly of the plasmablastic immunophenotype expressing CD30 and CD138, and with a less frequent expression of pan-B cell markers.

CONCLUSIONS

Apart from the phenotypical difference, our HHV8-positive neoplasms were not distinct from the HHV8-negative group. Literature review of 256 cases, including our cases, revealed that HHV8-positive cases were associated more frequently with HIV and EBV infection, with rare MYC rearrangement, and a poorer prognosis than HHV8-negative cases. We propose to name the HHV8-positive cases as 'classical' or 'type I PEL' and the HHV8-negative cases as 'type II PEL', stressing the similarities and the distinctive features between these two groups.

Human Herpesvirus 8-Unrelated Primary Effusion Lymphoma-Like Lymphoma in an Elderly Korean Patient with a Good Response to Rituximab Plus Cyclophosphamide, Doxorubicin, Vincristine, and Prednisolone

Primary effusion lymphoma (PEL) is a rare type of non-Hodgkin's lymphoma arising from a B-cell lineage characterized by the formation of malignant effusion in body cavities without evidence of a detectable tumor. The effusion contains tumor cells universally infected with human herpesvirus 8 (HHV8), which is the critical factor differentiating PEL from HHV8-unrelated PEL-like lymphoma (PEL-LL). This report describes a 77-year-old male patient with pleural effusion and ascites, containing lymphoma cells expressing a B-cell phenotype, but without markers of HHV8 in immunocytochemical analysis. The patient was diagnosed with PEL-LL and treated with six cycles of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP), which resulted in a complete remission. The patient is currently disease-free 15 months post-treatment. To the best of our knowledge, this is the first report on administration of R-CHOP in a PEL-LL patient in South Korea.

Human Herpesvirus Type 8-associated Large B-cell Lymphoma: A Nonserous Extracavitary Variant of Primary Effusion Lymphoma in an HIV-infected Man: A Case Report and Review of the Literature

BACKGROUND

Primary effusion lymphoma (PEL) is a rare non-Hodgkin lymphoma subtype primarily seen in human immunodeficiency virus (HIV)-infected individuals with low CD4(+) cell counts and elevated HIV viral loads. It has always been associated with human herpesvirus type 8 (HHV-8) and in 80% of cases has also been associated with Epstein-Barr virus (EBV). Less commonly, PEL has presented in patients with advanced age and other conditions associated with an altered immunity, including malignancy, liver cirrhosis, and immunosuppressive medications. It is a tumor of B-cell lineage; however, it shows a "null" phenotype, rarely expressing pan-B cell surface antigens. It will usually express CD45, CD30, CD38, CD138, and MUM1 and is characterized by lymphomatous effusions in body cavities but not lymphadenopathy. It is an aggressive lymphoma, with an average median survival of < 1 year. HHV-8-associated large B-cell lymphoma (HHV-8-LBL) is a second variant of PEL that is both solid and extracavitary. It has immunoblastic and/or anaplastic morphologic features and a distinct immunohistochemical staining pattern. It could also have a different clinical presentation than that of classic PEL.

MATERIALS AND METHODS

We describe the case of a 57-year-old HIV-infected man who presented with a slow-growing and asymptomatic abdominal mass. Examination of an excisional biopsy specimen showed malignant large cells with prominent cytoplasm that were positive for pan-B cell antigen CD20, HHV-8, and EBV and negative for CD138, CD10, BCL-6, CD3, and CD30. The Ki-67 labeling index was 90%. The diagnosis was stage IIIA HHV-8-LBL, and he was treated with 6 cycles of R-EPOCH (rituximab, etoposide, vincristine, doxorubicin, cyclophosphamide, and prednisone) infusion chemotherapy. At 12 months after treatment, he was in complete remission. We also performed a Medline and Embase search to better understand the clinical findings of our patient and the unique attributes of HHV-8-LBL. Focusing our search on English language studies, we identified 83 cases of HHV-8-LBL without an effusion component. We compared these 83 cases with 118 reported cases of classic PEL.

RESULTS

The median age of the patients with HHV-8-LBL was 41 years (range, 24-77), and 96% of the cases were associated with HIV. The median age of the patients with classic PEL was 41 years (range, 26-86), and 96% of the cases were associated with HIV. Of those with HHV-8-LBL, 31 of 61 (51%) had a pre-existing diagnosis of acquired immunodeficiency syndrome (AIDS) and 47 of 63 (75%) were coinfected with EBV. In contrast, 69 of 96 patients (72%) with classic PEL had a pre-existing AIDS diagnosis and 40 of 49 (82%) were coinfected with EBV. The mean CD4(+) count of the HHV-8-LBL patients was 256 cells/μL (range, 18-1126 cells/μL) compared with 139 cells/μL (range, 2-557 cells/μL) in the classic PEL patients. The median survival time for both groups was similar at 5.5 months (range, 25 days to ≥ 25 months) for patients with HHV-8-LBL and 4 months (range, 2 days to ≥ 113 months) for those with classic PEL. More patients with HHV-8-LBL were alive at the last follow-up point (59% vs. 18%). The percentage of patients achieving complete remission was 54% (30 of 56) and 36% (32 of 89) for HHV-8-LBL and classic PEL, respectively.

CONCLUSION

Our patient's high CD4(+) cell count, the lack of a pre-existing AIDS diagnosis, and the excellent response to chemotherapy highlights that HHV-8-LBL might have distinct clinical features and possibly a better response to chemotherapy than classic PEL. HHV-8-LBL should be included in the differential diagnosis of HIV patients with solid lesions. It is essential that patients' Centers for Disease Control and Prevention HIV clinical status and HIV viral load at the diagnosis of PEL and HHV-8-LBL be reported and that the reported clinical results include longer term follow-up data. Only then will a more complete clinical picture of this little-appreciated and little-understood PEL variant be defined.

Primary effusion lymphoma presenting as a cutaneous intravascular lymphoma

Primary effusion lymphoma (PEL) is a rare and aggressive lymphoma that arises in the context of immunosuppression and is characterized by co-infection with Epstein-Barr virus (EBV) and human herpesvirus-8/Kaposi sarcoma-associated herpesvirus (HHV-8/KSHV). It was originally described as arising in body cavity effusions, but presentation as a mass lesion (extracavitary PEL) is now recognized. Here, we describe a case of PEL with an initial presentation as an intravascular lymphoma with associated skin lesions. The patient was a 53-year-old man with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) who presented with fevers, weight loss and skin lesions concerning for Kaposi sarcoma (KS). A skin biopsy revealed no evidence of KS; however, dermal vessels contained large atypical cells that expressed CD31 and plasma cell markers but lacked most B- and T-cell antigens. The atypical cells expressed EBV and HHV-8. The patient subsequently developed a malignant pleural effusion containing the same neoplastic cell population. The findings in this case highlight the potential for unusual intravascular presentations of PEL in the skin as well as the importance of pursuing microscopic diagnosis of skin lesions in immunosuppressed patients.

A Unique Case of Malignant Pleuropericardial Effusion: HHV-8-Unrelated PEL-Like Lymphoma-A Case Report and Review of the Literature

Primary effusion lymphoma (PEL) or body cavity lymphoma is a rare type of extra nodal lymphoma of B-cell origin that presents as lymphomatous effusion(s) without any nodal enlargement or tumor masses. It belongs to the group of AIDS related non-Hodgkin's lymphomas. First described in 1996 in HIV infected individuals who were coinfected with Kaposi's sarcoma-associated herpesvirus (KSHV) or HHV-8 virus, it was included as a separate entity in WHO classification of tumors of hematopoietic and lymphoid tissue in the year 2001. The definition included association with HHV-8 virus as a mandatory diagnostic criterion. However, cases were later reported where PEL-like disease process was diagnosed in HHV-8 negative patients. This was eventually recognized as a rare but distinct entity termed as “HHV-8-unrelated PEL-like lymphoma”. Herein, we are reporting a case of an elderly patient who presented with a large pleuropericardial effusion and was eventually diagnosed with this entity. Till date, only around 50 cases of HHV-8-unrelated PEL-like lymphoma have been reported and our case being EBV, HIV, and Hepatitis C negative makes it very unique and rare occurrence. We are also presenting a review of relevant literature focused mainly on comparing outcomes in patients treated with and without chemotherapy.

How I treat HHV8/KSHV-related diseases in posttransplant patients

Posttransplantation human herpesvirus-8 (HHV8)/Kaposi sarcoma herpesvirus (KSHV) primary infection and/or reactivations are associated with uncommon and sometimes fatal, neoplastic, and non-neoplastic diseases. HHV8-related clinical manifestations notably range from Kaposi sarcoma (KS) to either primary effusion lymphoma or multicentric Castleman disease B-cell malignancies, and from polyclonal HHV8-positive plasmacytic lymphoproliferative disorders to bone marrow failure and peripheral cytopenias, associated or not with hemophagocytic syndromes, and to acute hepatitis syndromes. We reviewed the patient series reported in the literature and summarized clinical management aspects, in terms of diagnosis, follow-up, and treatment. We described typical clinical presentations and histopathologic diagnostic features of these diseases, and we discussed the role of HHV8-specific serologic, molecular, and immunologic assays, particularly focusing on recent data from HHV8-specific T-cell monitoring in posttransplantation KS patients. We finally discussed actual therapeutic options, namely, the reduction or discontinuation of immunosuppressive therapy or the switch from calcineurin inhibitors to mTOR inhibitors, as alternatives to antineoplastic chemotherapy, along with the use of antiherpesvirus agents as prophylactic or therapeutic measures, and treatment with rituximab in posttrans-plantation multicentric Castleman disease patients and non-neoplastic HHV8-associated syndromes.

Uniform expression of Notch1, suppressor of B-cell-specific gene expression, in plasmablastic lymphoma

CONTEXT

Although the loss of B-lineage-specific gene expression is a distinctive feature of plasmablastic lymphoma, the underlying mechanism remains poorly understood. A candidate for this mechanism is Notch1 signaling, which interferes with the activity of B-cell-specific transcription factors E2A and early B-cell factor and positively regulates the mammalian target of rapamycin (mTOR) pathway.

OBJECTIVE

To explore the mechanism of loss of B-cell phenotype by correlating expression of B-cell markers with that of Notch1 and downstream targets of the mTOR pathway in plasmablastic lymphoma.

DESIGN

A combination of flow cytometric and immunohistochemical immunophenotyping techniques was used on 9 cases of plasmablastic lymphoma to correlate loss of B-cell markers with expression of Notch1 and downstream activation of the mTOR pathway. These results are compared with 5 cases of primary effusion lymphoma and 21 cases of plasma cell myeloma.

RESULTS

Plasmablastic lymphoma cases exhibit nearly complete loss of B-cell-associated markers and uniform expression of Notch1, with a predominantly nuclear staining pattern. There is a concurrent activation of the mTOR pathway, indicated by expression of mTOR targets eukaryotic initiation factor 4E-binding protein 1 and phosphorylated ribosomal protein S6 in most cases. Similar results are seen in cases of primary effusion lymphoma and plasma cell myeloma.

CONCLUSIONS

These findings suggest that activation of Notch1 may be involved in suppression of B-cell-specific gene expression and global loss of the B-cell phenotype in plasmablastic lymphoma, similar to primary effusion lymphoma and plasma cell myeloma. Thus, there might be a role for the Notch1 and mTOR pathways in the pathogenesis and therapy of plasmablastic lymphoma.