Large Cell Lymphoma: Correlation of HIV Status and Prognosis with Differentiation Profiles Assessed by Immunophenotyping

MYC status in HIV-associated plasmablastic lymphoma: dual-colour CISH, FISH and immunohistochemistry

AIMS

We utilised chromogenic and fluorescence in-situ hybridisation (CISH and FISH) to evaluate MYC gene copy numbers and rearrangements within HIV-associated plasmablastic lymphomas (PBLs). Thereafter, clinicopathological features were explored retrospectively.

METHODS AND RESULTS

Sixty-seven (n = 67) patients were included and the HIV seropositive status was confirmed in 98% (63 of 64) with a median viral load of 55 587 (IQR 273 582) copies/ml and median CD4 count of 170 (IQR 249) cells/µl. The mean age was 41 ± 10.1 years and females comprised 54%. PBL was documented predominantly at extra-oronasal topographic regions. Starry-sky (SS) appearance was evident in 33% in association with monomorphic morphology (P-value 0.02). c-MYC protein was expressed in 81% and latent EBV infection was detected in 90%. EBER ISH-positive status and MYC rearrangement occurred in 67% of HIV PBL. MYC aberrations included MYC rearrangement (70%), low-level increase in MYC gene copy numbers (43%), concurrent MYC rearrangement and increased MYC gene copy numbers (49%) as well as low-level chromosome 8 polysomy (6%). MYC aberrations in HIV PBLs were significantly associated with SS appearance (P -0.01), monomorphic morphology (P - 0.03), c-MYC protein expression ≥40% (P - 0.03) and mortality (P - 0.03). There was advanced stage (Ann Arbor III/IV) at presentation (77%) and the median overall survival for HIV PBL was 75 days (95% CI 14-136).

CONCLUSION

Majority of the HIV-associated PBL tumours harbour MYC aberrations. Due to the persistently inferior survival outcome of HIV-associated PBL in the era of antiviral treatment, targeted and/or intensified therapy of oncogenic MYC may need to be explored in future.

Genomic Characterization of HIV-Associated Plasmablastic Lymphoma Identifies Pervasive Mutations in the JAK–STAT Pathway

Plasmablastic lymphoma (PBL) is an aggressive B-cell non-Hodgkin lymphoma associated with immunodeficiency in the context of Human Immunodeficiency Virus (HIV) infection or iatrogenic immunosuppression. While a rare disease in general, the incidence is dramatically increased in regions of the world with high HIV prevalence. The molecular pathogenesis of this disease is poorly characterized. Here, we defined the genomic features of PBL in a cohort of 110 patients from South Africa (15 by whole exome sequencing and 95 by deep targeted sequencing). We identified recurrent mutations in genes of the JAK-STAT signaling pathway, including STAT3 (42%), JAK1 (14%) and SOCS1 (10%), leading to its constitutive activation. Moreover, 24% of cases harbored gain-of-function mutations in RAS family members (NRAS and KRAS). Comparative analysis with other B-cell malignancies uncovered PBL-specific somatic mutations and transcriptional programs. We also found recurrent copy number gains encompassing the CD44 gene (37%), which encodes for a cell surface receptor involved in lymphocyte activation and homing, and was found expressed at high levels in all tested cases, independent of genetic alterations. These findings have implications for the understanding of the pathogenesis of this disease and the development of personalized medicine approaches.

Diffuse large B-cell lymphoma in a South African cohort with a high HIV prevalence: an analysis by cell-of-origin, Epstein-Barr virus infection and survival

Diffuse large B-cell lymphoma, not otherwise specified (DLBCL NOS) is subdivided according to the cell-of-origin (COO) classification into germinal centre B-cell (GCB) and activated B-cell (ABC) subtypes, each with different molecular profiles and clinical behaviour. This study aims to describe the pattern of the COO subtypes, the proportion of Epstein-Barr virus (EBV) co-infection, and their influence on survival outcomes in a setting of high HIV prevalence. This retrospective cohort study included patients diagnosed with de novo DLBCL NOS at our tertiary academic centre in Cape Town, South Africa over a 14-year period. Immunohistochemical stains were performed for COO classification, according to the Hans algorithm. Tumour EBV co-infection was established by EBV-encoded ribonucleic acid in situ hybridisation (EBER-ISH) staining. The effect of the COO subtypes and EBV co-infection on overall survival were described by means of univariate, bivariate and multivariate analyses. A total of 181 patients with DLBCL NOS were included, which comprised 131 HIV-uninfected and 50 HIV-infected patients. There was an equal distribution of GCB and ABC subtypes in the HIV-infected and HIV-uninfected groups. EBV co-infection was detected in 16% of the HIV-infected cases and in 7% of the HIV-uninfected cases (p=0.09). There was no significant difference in the incidence of EBV co-infection between the GCB and ABC subtypes (p=0.67). HIV-infected patients with CD4 ≥150 cells/mm³ had similar survival to HIV-uninfected patients (p=0.005). Multivariate regression analysis showed that in the HIV-infected group with marked immunosuppression (CD4 <150 cells/mm³), there was significantly poorer overall survival compared to the HIV-uninfected group (HR 2.4, 95% CI 1.3-4.1). There were no statistically significant differences in overall survival by DLBCL COO subtype. There was no difference in the proportion of DLBCL COO subtypes, regardless of HIV status. EBV co-infection was more common in the HIV-infected group, but less than described in the literature. Unexpectedly, there were no significant differences in survival outcomes between the GCB and ABC subtypes. Higher CD4 counts in the HIV-infected group had good survival outcomes, while lower CD4 counts predicted adverse survival outcomes. Further research is needed to explore the genetic mutational landscape of HIV-associated DLBCL.

Novel tumor markers provide improved prediction of survival after diagnosis of human immunodeficiency virus (HIV)-related diffuse large B-cell lymphoma

Existing prognostic tools for HIV + diffuse large B-cell lymphoma (DLBCL) fail to accurately predict patient outcomes. To develop a novel prognostic algorithm incorporating molecular tumor characteristics and HIV disease factors, we included 80 patients with HIV-related DLBCL diagnosed between 1996 and 2007. Immunohistochemistry staining was used to analyze the expression of 26 tumor markers. Clinical data were collected from medical records. Logistic regression and bootstrapping were used to select and assess stability of the prognostic model, respectively. Of the tumor markers examined, expression of cMYC, Ki 67, CD44, EBV, SKP2, BCL6, p53, CD20 and IgM were associated with two-year mortality. The final prognostic model, confirmed in bootstrapped samples, included IPI, circulating CD4 cell count, history of clinical AIDS, and expression of CD44, p53, IgM and EBV. This model incorporating HIV disease history and tumor markers, achieved better prediction for two-year mortality [AUC = 0.87, 95% CI: 0.78-0.96] compared with IPI alone [AUC = 0.63 (0.51-0.75)].

Head and neck lymphomas: A 20-year review in an Oral Pathology Unit, Johannesburg, South Africa, a country with the highest global incidence of HIV/AIDS

OBJECTIVES

Non-Hodgkin lymphoma occurs with increasing frequency in HIV/AIDS. As South Africa has the highest incidence of HIV/AIDS worldwide, an epidemiologic study of this nature provides insight into head and neck lymphomas in a defined South African population. This retrospective review evaluated frequency and clinico-pathologic characteristics of patients diagnosed with head and neck lymphoma at the Oral Pathology Department, University of Witwatersrand between 1993 and 2012.

MATERIALS AND METHODS

Histopathology reports of patients with head and neck lymphomas (n=504) were reviewed. Demographic (age, gender), clinical (site and size of tumour), laboratory and histological parameters were recorded.

RESULTS

There were 504 patients with head and neck lymphomas. The mean age was 40.4years. The male:female ratio was 1.1:1. The cervical lymph node was the most common anatomic site (115 cases) and the maxilla (60 cases) the most common extranodal site. Plasmablastic lymphoma (159 cases) was the most common histologic subtype, seen more frequently as a result of its strong association with HIV/AIDS. The most common Hodgkin's lymphoma was the nodular sclerosing variant (21 cases). Of the head and neck lymphomas in patients with a known HIV status, 56% had plasmablastic lymphoma, 43.9% diffuse large B cell lymphoma and 25% Burkitt lymphoma.

CONCLUSION

There is an increase in head and neck lymphoma frequency, contrary to that found in Western countries. The high HIV prevalence in certain lymphomas provides strong indication of the role of HIV/AIDS in pathogenesis of lymphomas. This study serves as a baseline for future studies, especially in South Africa.

Right iliac fossa lymphoma in an HIV positive patient: A diagnostic dilemma

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An association has been established between HIV and lymphoma.

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Lymphoma can present with non-specific or unusual symptoms.

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Lymphoma can also present in patients with well-controlled HIV.

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Lymphoma in HIV patients is an important differential but is often diagnosed at a late stage in the UK.

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It is important that suspicion of lymphoma is raised in patients with HIV.

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It is important that a multidisciplinary approach to diagnosis is taken early on to allow prompt management of this condition

Lymphoma should be considered early in patients with HIV when there is a history of weight loss. Although B-cell lymphoma is an AIDS-defining cancer, and many reports of lymphoma in HIV positive patients exist in the literature, this case report illustrates that even in patients with well-controlled HIV the diagnosis must be considered, and puts forward an unusual presentation in an otherwise asymptomatic patient.

A 52 year old woman presented for a routine HIV follow-up appointment and was found to be experiencing weight loss. An abdominal examination revealed a right iliac fossa mass. Subsequent CT thorax, abdomen, pelvis imaging confirmed a large mass but did not allow determination of the primary source. Serological tumour marker investigations were unyielding. Trans-vaginal ultrasound guided biopsy of the mass demonstrated diffuse large B-cell lymphoma.

This case report emphasises the importance of having a high index of suspicion for these cancers even in patients with low viral load who are on anti-retroviral treatment. It also demonstrates the importance of taking a multidisciplinary approach to diagnosis of the condition to enable prompt treatment and thus improve the outcome for the patient.

HIV-associated lymphoma sub-type distribution, immunophenotypes and survival in an urban clinic population

HIV-infected patients have an increased risk for both Hodgkin and non-Hodgkin lymphomas. A retrospective cohort of all HIV-infected patients diagnosed with lymphoma in urban clinics from 2000-2013 was evaluated to characterize the distribution and determine effects of sub-type and immunophenotype on survival. Of 160 cases identified, 131 (82%) had complete information and were analyzed. The most common sub-types were diffuse large B cell (41%), Burkitt (21%) and Hodgkin lymphoma (18%). Advanced (78% stage III/IV) and extranodal disease (82%) at presentation were common. CD20 was the most commonly expressed immunophenotypic marker (89%). Overall mortality rate was high (26.1 per 100 person-years). Lower mortality was noted in CD10 + and CD20 + lymphomas, but differences were not statistically significant. After adjustment, low CD4 count (≤ 200) at diagnosis was associated with higher mortality (adjusted hazard ration (AHR) = 1.75; 95% CI = 1.00-3.61). Mortality in this cohort of patients with HIV-associated lymphomas was high and exceeds that from published data from the general population.