Rituximab plus liposomal doxorubicin in HIV-infected patients with KSHV-associated multicentric Castleman disease

Inflammasome activation in patients with Kaposi sarcoma herpesvirus-associated diseases

ABSTRACT

Kaposi sarcoma herpesvirus (KSHV)-associated diseases include Kaposi sarcoma (KS), primary effusion lymphoma (PEL), KSHV-associated multicentric Castleman disease (MCD), and KS inflammatory cytokine syndrome (KICS). PEL, MCD, and KICS are associated with elevated circulating inflammatory cytokines. However, activation of the inflammasome, which generates interleukin-1β (IL-1β) and IL-18 via active caspase-1/4/5, has not been evaluated in patients with KSHV-associated diseases (KADs). Herein we report that patients with HIV and ≥1 KAD present with higher plasma levels of IL-18 and increased caspase-1/4/5 activity in circulating monocytes compared with HIV-negative healthy volunteers (HVs) or people with HIV (PWH) without KAD. Within KAD subtypes, KICS and MCD shared enhanced caspase-1/4/5 activity and IL-18 production compared with HVs and PWH, whereas patients with PEL showed remarkably high levels of inflammasome complex formation (known as apoptosis-associated speck-like protein containing a caspase recruitment domain). Moreover, caspase-1/4/5 activity and IL-18 plasma levels correlated with KSHV viral load, indicating KSHV-driven inflammasome activation in KAD. Accordingly, factors released by cells latently infected with KSHV triggered inflammasome activation and cytokine production in bystander monocytes in vitro. Finally, both supervised and unsupervised analyses with inflammasome measurements and other inflammatory biomarkers demonstrate a unique inflammatory profile in patients with PEL, MCD, and KICS as compared with KS. Our data indicate that detrimental inflammation in patients with KAD is at least partially driven by KSHV-induced inflammasome activation in monocytes, thus offering novel approaches to diagnose and treat these complex disorders. These trials were registered at www.ClinicalTrials.gov as #NCT01419561, NCT00092222, NCT00006518, and NCT02147405.

Factors affecting Kaposi's sarcoma-associated herpesvirus transmission in rural Ugandan households, a longitudinal study

BACKGROUND

We report the impact of HIV infection within a household on oral Kaposi's sarcoma-associated herpesvirus (KSHV) shedding.

METHODS

We enrolled 469 individuals from 90 households. Mouthwash rinse samples collected at three monthly visits were analyzed for KSHV DNA using quantitative polymerase chain reaction (qPCR). Generalized linear mixed effects logistic models were applied to analyze factors associated with KSHV ever shedding, and among shedders, always versus intermittent shedding. Linear mixed effects models were applied to models of KSHV viral loads. Intraclass correlation coefficients (ICCs) were calculated to assess the contribution of household-level factors to variations in shedding probabilities. Hotspot analyses of geospatial feature clusters were calculated using Getis-Ord Gi* statistic and visualized using inverse distance weighted interpolation.

RESULTS

Analyses included 340 KSHV seropositive individuals, aged 3 + years, with qPCR results from 89 households. Forty households had 1 + persons living with HIV (PLWH), while 49 had none. Among participants, 149(44%) were KSHV ever shedders. Of 140 who shed KSHV at two or more visits, 34(24%) were always shedders. Increasing number of KSHV seropositive household members was significantly associated with ever shedding [Odds ratio(OR) (95% Confidence Interval(95%CI)):1.14(1.03,1.26);p = 0.013]. Among KSHV shedders, a statistically significant age-related trend was identified with 10-19 years being more likely to be always shedders (type III test p = 0.039) and to have higher viral loads (type III test p = 0.027). In addition, higher viral loads were significantly associated with increasing number of household members [coefficient(95%CI):0.06(0.01,0.12);p = 0.042], increasing number of KSHV seropositive members [coefficient(95%CI):0.08(0.01,0.15);p = 0.021], and living in households with 1 + PLWH [coefficient(95%CI):0.51(0.04,0.98);p = 0.033]. Always shedders exhibited higher viral loads than intermittent shedders [coefficient(95%CI):1.62(1.19,2.05);p < 0.001], and viral loads increased with the number of visits where KSHV DNA was detected in saliva (type III test p < 0.001). Household-level factors attributed for 19% of the variability in KSHV shedding (ICC:0.191;p = 0.010). Geospatial analysis indicated overlapping hotspots of households with more KSHV seropositive individuals and KSHV shedders, distinct from areas where PLWH were clustered.

DISCUSSION

KSHV oral shedding is influenced by multiple factors at the individual, household, and regional levels. To mitigate ongoing KSHV transmission a comprehensive understanding of factors contributing to oral KSHV reactivation and transmission within households is needed.

Overview of Research Status in Castleman Disease

Castleman disease (CD) is characterized by the proliferation of lymphoid tissue and encompasses a range of disorders that vary in clinical presentation, histopathological features, and therapeutic approaches. This article presents a comprehensive review of the current state of CD research, emphasizing the etiology, pathogenesis, clinical manifestations, diagnostic criteria, treatment options, and prognostic factors. CD is a relatively rare condition infrequently encountered in clinical practice. Certain subtypes of CD progress rapidly and pose a significant threat to patient health. Consequently, a timely and accurate diagnosis is crucial. This article aimed to equip clinicians and researchers with an updated and detailed understanding of CD, thereby enhancing the management of this complex condition.

The clinical picture of Castleman disease: a systematic review and meta-analysis

ABSTRACT

Castleman disease (CD) encompasses a spectrum of rare disorders, including unicentric CD (UCD), idiopathic multicentric CD (iMCD), and human herpesvirus 8-associated MCD (HHV8+ MCD). We performed a systematic review of publications reporting ≥5 cases of CD between 1995 and 2021, following preferred reporting items for systematic reviews and meta-analyses guidelines, to describe and compare subtypes. We extracted data on clinical symptoms and laboratory parameters as stated in international consensus diagnostic criteria for iMCD and estimated the frequency of each criterion using meta-analyses. We analyzed 32 studies describing 559 UCD, 1023 iMCD, and 416 HHV8+ MCD cases. Although many symptoms and laboratory abnormalities occurred at similar rates in patients with iMCD and HHV8+ MCD, patients with HHV8+ MCD had significantly higher rates of constitutional symptoms (46.6% vs 98.6%; P = .038) and splenomegaly (48.2% vs 89.2%; P = .031). Renal dysfunction was significantly more common in patients with iMCD than in patients with HHV8+ MCD before adjustment (36.9% vs 17.4%; P = .04; adjusted P = .1). Patients with UCD had lower rates of symptoms and laboratory abnormalities, although these were present in 20% of patients and were particularly pronounced in pediatric UCD. There are many similarities in the symptomatology of iMCD and HHV8+ MCD; many patients experience constitutional symptoms and organ dysfunction. Differences between these subtypes likely reflect differences in pathophysiology and/or comorbidity burdens.

HIV-associated cancers and lymphoproliferative disorders caused by Kaposi sarcoma herpesvirus and Epstein-Barr virus

SUMMARYWithin weeks of the first report of acquired immunodeficiency syndrome (AIDS) in 1981, it was observed that these patients often had Kaposi sarcoma (KS), a hitherto rarely seen skin tumor in the USA. It soon became apparent that AIDS was also associated with an increased incidence of high-grade lymphomas caused by Epstein-Barr virus (EBV). The association of AIDS with KS remained a mystery for more than a decade until Kaposi sarcoma-associated herpesvirus (KSHV) was discovered and found to be the cause of KS. KSHV was subsequently found to cause several other diseases associated with AIDS and human immunodeficiency virus (HIV) infection. People living with HIV/AIDS continue to have an increased incidence of certain cancers, and many of these cancers are caused by EBV and/or KSHV. In this review, we discuss the epidemiology, virology, pathogenesis, clinical manifestations, and treatment of cancers caused by EBV and KSHV in persons living with HIV.

Factors affecting Kaposi's sarcoma-associated herpesvirus transmission in rural Ugandan households, a longitudinal study

Background

We report the impact of HIV infection within a household on oral Kaposi's sarcoma-associated herpesvirus (KSHV) shedding.

Methods

We enrolled 469 individuals from 90 households. Mouthwash rinse samples collected at three monthly visits, were analyzed for KSHV DNA using quantitative polymerase chain reaction (qPCR). Generalized linear mixed effects logistic models were applied to analyze factors associated with KSHV ever shedding, and among shedders, always versus intermittent shedding. Linear mixed effects models were applied to models of KSHV viral loads. Intraclass correlation coefficients (ICCs) were calculated to assess the contribution of household-level factors to variations in shedding probabilities. Hotspot analyses of geospatial feature clusters were calculated using Getis-Ord Gi* statistic and visualized using inverse distance weighted interpolation.

Results

Analyses included 340 KSHV seropositive individuals, aged 3 + years, with qPCR results from 89 households. Forty households had 1 + persons living with HIV (PLWH), while 49 had none. Among participants, 149(44%) were KSHV ever shedders. Of 140 who shed KSHV at two or more visits, 34(24%) were always shedders. Increasing number of KSHV seropositive household members was significantly associated with ever shedding [Odds ratio(OR) (95% Confidence Interval(95%CI)):1.14(1.03,1.26);p = 0.013]. Among KSHV shedders, a statistically significant age-related trend was identified with 10-19 years being more likely to be always shedders (type III test p = 0.039) and to have higher viral loads (type III test p = 0.027). In addition, higher viral loads were significantly associated with increasing number of household members [coefficient(95%CI):0.06(0.01,0.12);p = 0.042], increasing number of KSHV seropositive members [coefficient(95%CI):0.08(0.01,0.15);p = 0.021], and living in households with 1 + PLWH [coefficient(95%CI):0.51(0.04,0.98);p = 0.033]. Always shedders exhibited higher viral loads than intermittent shedders [coefficient(95%CI):1.62(1.19,2.05);p < 0.001], and viral loads increased with the number of visits where KSHV DNA was detected in saliva (type III test p < 0.001). Household-level factors attributed for 19% of the variability in KSHV shedding (ICC:0.191;p = 0.010). Geospatial analysis indicated overlapping hotspots of households with more KSHV seropositive individuals and KSHV shedders, distinct from areas where PLWH were clustered.

Discussion

KSHV oral shedding is influenced by multiple factors at the individual, household, and regional levels. To mitigate ongoing KSHV transmission a comprehensive understanding of factors contributing to oral KSHV reactivation and transmission within households is needed.

Human immunodeficiency virus-associated Lymphomas: EHA-ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up

This EHA-ESMO Clinical Practice Guideline provides key recommendations for managing HIV-associated lymphomas.The guideline covers clinical, imaging and pathological diagnosis; staging and risk assessment; treatment and follow-up.The author group encompasses a multidisciplinary group of experts from different institutions and countries in Europe.Recommendations are based on available scientific data and the authors' collective expert opinion.

Immunology and targeted therapy in Castleman disease

INTRODUCTION

Castleman disease (CD) is a benign lymphoproliferative disease causing severe systemic inflammation. Interleukin-6 (IL-6) is a major pathogenesis of multicentric CD (MCD), but only 30-60% of patients respond to IL-6 inhibitors. Novel agents for IL-6 inhibitor-refractory cases are needed. Clinical data and samples are being collected on a large scale and the clinical, pathological, and pathogenetic aspects are being elucidated.

AREAS COVERED

The pathological and clinical classification of CD is outlined. Focusing on idiopathic MCD (iMCD), this review identifies therapeutic targets and summarizes currently recommended drugs and promising therapeutic candidates.

EXPERT OPINION

The pathogenesis of MCD has been implicated in the activation of the Janus kinase (JAK)-transcriptional signaling activator (STAT) 3 pathway and the phosphatidylinositol 3-kinase (PI3K)/Akt/mechanical target of rapamycin (mTOR) signaling pathway. iMCD-TAFRO (thrombocytopenia, anasarca, fever/elevated CRP, reticulin myelofibrosis/renal dysfunction, organ enlargement) is resistant to IL-6 inhibitors, and cyclosporine and mTOR inhibitors are sometimes effective. JAK inhibitors and mTOR inhibitors may be therapeutic agents for iMCD. Recently, we have shown that peripheral helper T (Tph) cell abnormalities are at the core of iMCD pathogenesis. Therapies targeting chemokine (C-X-C motif) ligand 13 (CXCL13) produced by Tph cells and blocking the Tph-CXCL13-B cell pathway may satisfy unmet need in refractory cases.

Kv1.3-induced hyperpolarization is required for efficient Kaposi's sarcoma-associated herpesvirus lytic replication

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic herpesvirus that is linked directly to the development of Kaposi's sarcoma. KSHV establishes a latent infection in B cells, which can be reactivated to initiate lytic replication, producing infectious virions. Using pharmacological and genetic silencing approaches, we showed that the voltage-gated K+ channel Kv1.3 in B cells enhanced KSHV lytic replication. The KSHV replication and transcription activator (RTA) protein increased the abundance of Kv1.3 and led to enhanced K+ channel activity and hyperpolarization of the B cell membrane. Enhanced Kv1.3 activity promoted intracellular Ca2+ influx, leading to the Ca2+-driven nuclear localization of KSHV RTA and host nuclear factor of activated T cells (NFAT) proteins and subsequently increased the expression of NFAT1 target genes. KSHV lytic replication and infectious virion production were inhibited by Kv1.3 blockers or silencing. These findings highlight Kv1.3 as a druggable host factor that is key to the successful completion of KSHV lytic replication.

Sequencing of Kaposi's Sarcoma Herpesvirus (KSHV) genomes from persons of diverse ethnicities and provenances with KSHV-associated diseases demonstrate multiple infections, novel polymorphisms, and low intra-host variance

Recently published near full-length KSHV genomes from a Cameroon Kaposi sarcoma case-control study showed strong evidence of viral recombination and mixed infections, but no sequence variations associated with disease. Using the same methodology, an additional 102 KSHV genomes from 76 individuals with KSHV-associated diseases have been sequenced. Diagnoses comprise all KSHV-associated diseases (KAD): Kaposi sarcoma (KS), primary effusion lymphoma (PEL), KSHV-associated large cell lymphoma (KSHV-LCL), a type of multicentric Castleman disease (KSHV-MCD), and KSHV inflammatory cytokine syndrome (KICS). Participants originated from 22 different countries, providing the opportunity to obtain new near full-length sequences of a wide diversity of KSHV genomes. These include near full-length sequence of genomes with KSHV K1 subtypes A, B, C, and F as well as subtype E, for which no full sequence was previously available. High levels of recombination were observed. Fourteen individuals (18%) showed evidence of infection with multiple KSHV variants (from two to four unique genomes). Twenty-six comparisons of sequences, obtained from various sampling sites including PBMC, tissue biopsies, oral fluids, and effusions in the same participants, identified near complete genome conservation between different biological compartments. Polymorphisms were identified in coding and non-coding regions, including indels in the K3 and K15 genes and sequence inversions here reported for the first time. One such polymorphism in KSHV ORF46, specific to the KSHV K1 subtype E2, encoded a mutation in the leucine loop extension of the uracil DNA glycosylase that results in alteration of biochemical functions of this protein. This confirms that KSHV sequence variations can have functional consequences warranting further investigation. This study represents the largest and most diverse analysis of KSHV genome sequences to date among individuals with KAD and provides important new information on global KSHV genomics.

Immune deficiency/dysregulation -associated lymphoproliferative disorders. Revised classification and management

Significant advances in the field of lymphoma have resulted in two recent classification proposals, the International Consensus Classification (ICC) and the 5th edition WHO. A few entities are categorized differently in the ICC compared to the WHO. Nowhere is this more apparent than the immunodeficiency lymphoproliferative disorders. The three previous versions of the WHO classification (3rd, 4th and revised 4th editions) and the ICC focused on four clinical settings in which these lesions arise for primary categorization. In contrast the 2023 WHO 5th edition includes pathologic characteristics including morphology and viral status, in addition to clinical setting, as important information for lesion classification. In addition, the 2023 WHO recognizes a broader number of clinical scenarios in which these lesions arise, including not only traditional types of immune deficiency but also immune dysregulation. With this classification it is hoped that new treatment strategies will be developed leading to better patient outcomes.

Successful treatment with bortezomib in combination with dexamethasone in a middle-aged male with idiopathic multicentric Castleman's disease: A case report

Multicentric Castleman disease (MCD) is a heterogeneous, life-threatening disease. A subgroup of HIV-negative and HHV-8-negative MCD is defined as idiopathic MCD (iMCD) with a poor prognosis. Here we report an unusual case of a 47-year-old male patient with iMCD who experienced multiple treatment regimens such as chemotherapy, immunomodulatory therapy, and targeted therapy, all of which were considered ineffective. Subsequently, he was started on bortezomib in combination with dexamethasone for six cycles and he was in complete remission. The patient has survived nearly 13 years to date - the longest survival of any iMCD patient treated with bortezomib in combination with dexamethasone. Bortezomib combined with dexamethasone may be an effective salvage strategy for severe and refractory iMCD.

Stepwise Treatment for TAFRO Syndrome

TAFRO syndrome, a rapidly progressive and fatal disease, is rare, and its etiology remains unknown. It is characterized by thrombocytopenia, anasarca (edema, pleural effusion, and ascites), fever, reticulin fibrosis (or renal insufficiency), and organomegaly with Castleman disease (CD)-like histological features in the lymph nodes. CD is a rare, indolent, lymphoproliferative disorder with no established curative strategies. Most idiopathic multicentric CD cases are controlled with anti-interleukin (IL)-6 therapy (tocilizumab and siltuximab) and/or rituximab. However, it is unclear whether these therapies can be directly applied to treat TAFRO syndrome. Here, we describe stepwise immunotherapy (rituximab induction therapy and cyclosporine maintenance therapy) for two cases of steroid-refractory TAFRO syndrome. A 32-year-old man visited a local hospital with sudden onset of fever and epigastralgia. The diagnosis of TAFRO syndrome was established based on the diagnostic criteria. After rituximab administration, C-reactive protein and IL-6 levels were normalized. However, the ascites persisted, with increased resistance to rituximab. Tocilizumab was also ineffective; therefore, cyclosporine was administered. After the initiation of cyclosporine treatment, the ascites decreased and ultimately disappeared. Twelve months after immunotherapy, the patient remained asymptomatic under cyclosporine maintenance therapy. Similar stepwise immunosuppressive therapy was administered to a 72-year-old man with TAFRO syndrome complicated by renal failure. After rituximab infusion, C-reactive protein was decreased. Although methylprednisolone, rituximab, tocilizumab, and cyclosporine were administered, other laboratory data and clinical symptoms remained unchanged. His level of consciousness subsequently deteriorated due to herpes zoster encephalitis, and he died. We consider the combination of rituximab induction therapy and cyclosporine maintenance therapy to be effective for TAFRO syndrome if initiated at an early stage.

Higher rate of progression in HIV- than in HIV+ patients after rituximab for HHV8+ multicentric Castleman disease

Rituximab has revolutionized the treatment of Kaposi sarcoma-associated herpesvirus/human herpesvirus 8-associated multicentric Castleman disease (HHV8+ MCD), converting a rapidly fatal illness into a relapsing disease. HHV8+ MCD mainly affects patients with HIV infection but can also be observed in patients without HIV infection. We retrospectively analyzed a cohort of 99 patients (73 who tested HIV+ and 26 who tested HIV-), with HHV8+ MCD treated with rituximab-based therapy. Baseline characteristics were similar in patients who had HIV- and HIV+ results, although those who tested HIV- were older (65 vs 42 years) and presented less frequently with Kaposi sarcoma (15% vs 40%). Ninety-five patients (70 HIV+ and 25 HIV-) achieved complete remission (CR) after rituximab-based therapy. After a median follow-up of 51 months, 36 patients (12 HIV- and 24 HIV+) experienced disease progression. The 5-year progression-free survival (PFS) was 54%. The 5-year PFS was lower in HIV- patients than in HIV+ patients : 26% and 62%, respectively (P = .02). A multivariate prognostic factors analysis including time-dependent covariates revealed that HIV- status, reoccurrence of HHV8 DNA >3 log copies per mL, and serum C-reactive protein (CRP) >20 mg/mL were independently associated with an increased risk of progression after rituximab-induced CR (P = .001; P = .01; and P = .01, respectively). The lower rate of progression observed in the population with HIV+ results despite a longer follow-up period might have resulted from the possible immune restoration upon antiretroviral therapy. HHV8 viral load and serum CRP monitoring after rituximab therapy provide information on the progression risk and may help in the decision to resume specific therapy.

Hypoxia and hypoxia-inducible factors in Kaposi sarcoma-associated herpesvirus infection and disease pathogenesis

Kaposi sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi sarcoma and several other tumors and hyperproliferative diseases seen predominantly in human immunodeficiency virus-infected and other immunocompromised persons. There is an increasing body of evidence showing that hypoxia and hypoxia-inducible factors (HIFs) play important roles in the biology of KSHV and in the pathogenesis of KSHV-induced diseases. Hypoxia and HIFs can induce lytic activation of KSHV and KSHV can in turn lead to a hypoxic-like state in infected cells. In this review, we describe the complex interactions between KSHV biology, the cellular responses to hypoxia, and the pathogenesis of KSHV-induced diseases. We also describe how interference with HIFs can lead to decreased tumor growth and/or death of infected cells and KSHV-induced tumors. Finally, we show how these observations may lead to novel strategies for the treatment of KSHV-induced diseases.

A Challenging Case of Kaposi Sarcoma Inflammatory Cytokine Syndrome

Kaposi Sarcoma Inflammatory Cytokine Syndrome (KICS) is a serious, uncommon disease that occurs in patients who are positive for HIV and human herpesvirus-8 (HHV-8). It is characterized by a constellation of clinical findings, including fever, weight loss, and fluid retention, as well as a lack of multicentric Castleman disease (MCD) features on histopathology and an elevated serum HHV-8 viral load. Diagnosis is often delayed, and treatment options are limited, culminating in high mortality rates. We hereby present a 32-year-old male patient with HIV who was untreated for a few years and came with fever, night sweats, pancytopenia, and widespread adenopathy. A thorough evaluation of opportunistic infections was unremarkable. Clinically MCD was suspected, but lymph node biopsy only showed Kaposi sarcoma (KS) with no characteristic features of MCD. However, with clinical deterioration, KICS was strongly suspected. Kaposi sarcoma immune reconstitution syndrome (KS-IRIS) was also a possibility as the patient was restarted on antiretroviral therapy. Rituximab was commenced, but the patient suffered a cardiac arrest and could not be revived. Alternative diagnosis must be explored in patients with HIV presenting with constitutional symptoms, cytopenia, and adenopathy after opportunistic infections and malignancies are ruled out. If they have KS with HHV-8 positivity and there is a lack of characteristic features of MCD in lymph node biopsy, prompt suspicion of KICS should be made, and treatment with rituximab and/or chemotherapy should be instituted rapidly. KS-IRIS is also possible if patients have recently received antiretroviral therapy and have a rapid decline in viral load and increase in CD4 counts (immunological recovery). HHV8 viral load levels may help to distinguish between these two inflammatory conditions.

Clinical management of Kaposi sarcoma herpesvirus-associated diseases: an update on disease manifestations and treatment strategies

INTRODUCTION

Kaposi sarcoma herpes virus (KSHV) is associated with several diseases including Kaposi sarcoma, a form of multicentric Castleman's disease, primary effusion lymphoma, and an inflammatory cytokine syndrome. These KSHV-associated diseases (KAD) can present with heterogenous signs and symptoms that are often associated with cytokine dysregulation that may result in multiorgan dysfunction. The inability to promptly diagnose and treat these conditions can result in long-term complications and mortality.

AREAS COVERED

Existing epidemiological subtypes of existing KSHV-associated diseases, specifically Kaposi sarcoma as well as the incidence of several KSHV-associated disorders are described. We review the KSHV latent and lytic phases as they correlate with KSHV-associated diseases. Given the complicated presentations, we discuss the clinical manifestations, current diagnostic criteria, existing treatment algorithms for individual KAD, and when they occur concurrently. With emerging evidence on the virus and host interactions, we evaluate novel approaches for the treatment of KAD. An extensive literature search was conducted to support these findings.

EXPERT OPINION

KSHV leads to complex and concurrent disease processes that are often underdiagnosed both in the United States and worldwide. New therapies that exist for many of these conditions focus on chemotherapy-sparing options that seek to target the underlying viral pathogenesis or immunotherapy strategies.

Primary Effusion Lymphoma, Multicentric Castleman's Disease, and Kaposi's Sarcoma in an HHV-8 and HIV-Positive Patient: A Case Report

Primary effusion lymphoma (PEL), Kaposi's sarcoma (KS), and multicentric Castleman's disease (MCD) is an uncommon group of diseases included in the same spectrum with related characteristics. The coexistence of all of them in the same individual is a rare occurrence. We present the case of a 25-year-old patient diagnosed with human immunodeficiency virus (HIV) and the development of all these related pathologies. Despite the use of intensive treatment according to the latest recommendations, the evolution was unfavorable. This case reflects the need for new therapies and research in this field.

Daratumumab induces cell-mediated cytotoxicity of primary effusion lymphoma and is active against refractory disease

Primary effusion lymphoma (PEL), an aggressive non-Hodgkin lymphoma caused by Kaposi sarcoma-associated herpesvirus (KSHV), lacks standard therapy and has a median survival of 10-22 months with combination chemotherapy. PEL is a tumor of plasmablast-like B cells generally expressing CD38, the target of daratumumab (Dara). Initially, we assessed PEL cells from eight patients and established that each expressed high levels of CD38 by flow cytometry. PEL cell lines were also evaluated and most had high CD38 expression. We then assessed Dara's effects on complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) of PEL cell lines as well as its clinical benefits on two patients with PEL. Despite high CD38 expression, Dara did not induce CDC of PEL cell lines, due in part to high levels of the complement-inhibitory proteins, CD55 and CD59. However, Dara induced significant and dose-dependent increases in ADCC, particularly in those lines with high CD38 levels. Two FDA-approved drugs, all trans-retinoic acid (ATRA) and pomalidomide (Pom), significantly increased surface CD38 levels in low-CD38 expressing PEL cell lines, resulting in increased Dara-induced ADCC. Two patients with refractory PEL were treated with Dara alone or in combination with Pom. One patient with leptomeningeal PEL had a complete response to Dara and Pom combination treatment. Others had improvement in performance status and resolution of malignant ascites with Dara alone. Together, these data support the use of Dara monotherapy or in combination with ATRA or Pom as a potential therapeutic option for PEL.

Approche thérapeutique des maladies de Castleman : l’émergence des thérapies ciblées

The spectrum of Castleman disease encompasses several different disorders. Nowadays three different forms of the disease are individualized: unicentric Castleman disease, multicentric HHV-8 associated Castleman disease and idiopathic multicentric Castleman disease. In the latter a severe form called TAFRO syndrome (thrombocytopenia, anasarca, myelofibrosis, renal dysfunction, and organomegaly) tend to be individualized. Improvement in the classification and understanding of the physiopathology of CD have allowed improvement in treatment strategies. Treatment of rare but often severe manifestations, such as paraneoplastic pemphigus and bronchiolitis obliterans in unicentric CD and hemophagocytic syndrome and/or Kaposi' sarcoma in HHV8 associated CD, are better adapted. Most of current treatment strategies are based on retrospective and very few prospective studies. Both anti-IL6/6R and anti-CD20 biotherapies have greatly improved the management of certain forms of the disease. We report in this review the most relevant studies and national or international expert consensus statements for the treatment in the different types of CD. © 2022 Published by Elsevier Masson SAS on behalf of Société nationale française de médecine interne (SNFMI).

Immunotherapy for KSHV-associated diseases

Kaposi sarcoma herpesvirus (KSHV)-associated diseases (Kaposi sarcoma, multicentric Castleman disease, primary effusion lymphoma, and KSHV inflammatory cytokine syndrome) are associated with immune suppression and dysregulation and loss of KSHV-specific immunity. These diseases are most frequent in people living with HIV as well as those with primary or iatrogenic immune deficiencies. KSHV itself can modulate the immune system via viral homologs of host cytokines or downregulation of immune-surface markers altering host immune surveillance. These factors make KSHV-associated diseases prime targets for immunotherapy approaches. Several agents have been studied or are under investigation in KSHV-associated diseases, including monoclonal antibodies, immunomodulatory agents, and therapeutic cytokines. Here, we review the role of immunotherapies in KSHV-associated diseases.

Efficacy and Safety of Regimens Used for the Treatment of Multicentric Castleman Disease: A Systematic Review

OBJECTIVES

Treatment options for multicentric Castleman disease (MCD) remain limited. The only FDA-approved drug is siltuximab for idiopathic MCD (iMCD), but the response rate with siltuximab is less than 50%. We performed a systematic review to examine the efficacy and safety of various regimens used for the treatment of MCD.

METHODS

A database search on PubMed, Embase, Cochrane, Web of Science, and Clinicaltrials.gov using the terms "Castleman disease," "treatment outcome" and "patient safety" was done.

RESULTS AND CONCLUSIONS

Results from a randomized controlled trial (RCT) and an extension study highlighted the efficacy and long-term safety of siltuximab for iMCD; other trials showed tocilizumab to be a suitable alternative. A recent trial reported high response rates with thalidomide in iMCD patients. Promising results were reported for bortezomib in relapsed/ refractory MCD. For human herpesvirus 8 (HHV-8) associated MCD, rituximab along with doxorubicin therapy followed by maintenance with zidovudine and valganciclovir is the most effective therapy. A single-arm trial has highlighted the potential role of tocilizumab in HHV-8 MCD. Data for these regimens are limited and mostly comprise non-randomized trials. Further research on emerging agents could have a major impact on the treatment of this rare disease.

KSHV/HHV8-mediated hematologic diseases

Kaposi sarcoma (KS) herpesvirus (KSHV), also known as human herpesvirus 8, is the causal agent of KS but is also pathogenetically related to several lymphoproliferative disorders, including primary effusion lymphoma (PEL)/extracavitary (EC) PEL, KSHV-associated multicentric Castleman disease (MCD), KSHV+ diffuse large B-cell lymphoma, and germinotropic lymphoproliferative disorder. These different KSHV-associated diseases may co-occur and may have overlapping features. KSHV, similar to Epstein-Barr virus (EBV), is a lymphotropic gammaherpesvirus that is preferentially present in abnormal lymphoid proliferations occurring in immunecompromised individuals. Notably, both KSHV and EBV can infect and transform the same B cell, which is frequently seen in KSHV+ EBV+ PEL/EC-PEL. The mechanisms by which KSHV leads to lymphoproliferative disorders is thought to be related to the expression of a few transforming viral genes that can affect cellular proliferation and survival. There are critical differences between KSHV-MCD and PEL/EC-PEL, the 2 most common KSHV-associated lymphoid proliferations, including viral associations, patterns of viral gene expression, and cellular differentiation stage reflected by the phenotype and genotype of the infected abnormal B cells. Advances in treatment have improved outcomes, but mortality rates remain high. Our deepening understanding of KSHV biology, clinical features of KSHV-associated diseases, and newer clinical interventions should lead to improved and increasingly targeted therapeutic interventions.

Oncologic Treatment of HIV-Associated Kaposi Sarcoma 40 Years on

The observation in 1981 of the emergence of Kaposi sarcoma (KS) among young men who had sex with men was one of the first harbingers of the HIV epidemic. With advances in HIV care, the incidence of HIV-associated KS (HIV⁺KS) has decreased over time in the United States. However, it remains a persistent malignancy among some HIV-infected populations and is one of the most common tumors in sub-Saharan Africa. Because of the relapsing and remitting nature of this cancer, patients with HIV⁺KS can experience significant, long-term, morbidity. Patients with severe HIV⁺KS may also have concurrent lymphoproliferative syndromes, malignancies, and/or infections that can contribute to mortality. Several chemotherapy agents were explored in clinical trials for HIV⁺KS during the early stage of the epidemic. As HIV⁺KS emerges with CD4 lymphopenia and immunodysregulation, T-cell-sparing options are important to consider. Here, we explore the pathogenesis of HIV⁺KS and the current evidence for immunotherapy and therapies that potentially target KS pathogenesis. This review provides the current landscape of therapies for HIV⁺KS and highlights management issues for patients with HIV and cancer.

Human herpesvirus 8-associated multicentric Castleman disease in a patient with advanced HIV infection: A case report

RATIONAL

Multicentric Castleman disease (MCD) is a nonclonal lymphoproliferative disorder that is rarely reported from Southeast Asian countries. Here, we report a case of human herpesvirus 8 (HHV-8)-associated MCD in a patient with advanced human immunodeficiency virus (HIV) infection who presented with prolonged intermittent fever, urticarial rash, hepatosplenomegaly, and generalized lymphadenopathy.

PATIENT CONCERNS

A 34-year-old man with advanced HIV infection who was in good compliance with his antiretroviral treatment regimen presented with intermittent fever, weight loss, marked hepatosplenomegaly, and generalized lymphadenopathy. Recurrent symptoms of high-grade fever, abdominal discomfort, pancytopenia, and high C-reactive protein level occurred for 16 months.

DIAGNOSES

Histopathological findings of left inguinal lymph node revealed diffuse effacement of lymph node architecture with coexpression of HHV-8 latency-associated nuclear antigen 1 from immunohistochemical staining. The HHV-8 viral load was 335,391 copies/mL.

INTERVENTIONS

The patient was treated initially with one dose of intravenous rituximab (375 mg/m2) followed by subcutaneous rituximab (1400 mg) weekly for 5 weeks.

OUTCOMES

The patient's recurrent systemic symptoms subsided dramatically, and he has now been in remission for almost two years.

LESSONS

HHV8-associated MCD remains a diagnostic challenge in advanced HIV disease and should be suspected in those with recurrent flares of systemic inflammatory symptoms. Lymph node histopathology is essential for diagnosis and for excluding clonal malignancy. HHV-8 viral load is also useful for diagnosis and for monitoring disease activity.

[HHV-8 Related immunological and hematological diseases]

HHV-8 is an oncogenic Gammaherpesvirinae discovered in 1994 during the HIV pandemic. It is the causative agent of Kaposi's sarcoma, and is also associated with the occurrence of several aggressive B lymphoproliferative disorders. Most of them occur in an immunosuppression setting, usually due to HIV infection. Multicentric HHV8-associated Castleman's disease and KSHV Inflammatory Cytokine Syndrome (KICS) are primarily reactive entities with prominent systemic features. They illustrate the cytokinic storm induced by HHV-8 in its cell host. On the other hand, HHV-8 can drive proliferation and lymphomagenesis of its plasmablastic cell host, and is associated with a risk to develop aggressive lymphomas with plasmacytic differenciation. Primary effusion lymphoma usually localizes in body cavities and may affect other extra-nodal sites ; its prognostic is poor. Diffuse large B-cell lymphoma HHV-8, NOS affect more commonly nodes and blood and evolve from infected cell of HHV-8 associated Castleman disease. On the contrary, germinotropic lymphoproliferative disorders presents mainly as localized adenopathy with indolent course, and show polyclonality. Histology plays a key role in distinguishing these different entities and need expert reviewing, especially since they may be associated with each other. Besides lymphoproliferative disorders, HHV8 is associated with various hematological manifestations. The aim of this review is to provide an update on the presentation, diagnosis, and management of immunologic and hematologic complications associated with HHV-8.

Multicentric Castleman disease and the evolution of the concept

The term multicentric Castleman disease (MCD) encompasses a spectrum of conditions that share some overlapping clinicopathological manifestations. The fundamental pathogenetic mechanism involves dysregulated cytokine activity, causing systemic inflammatory symptoms as well as lymphadenopathy. Some of the histological changes in lymph nodes resemble the histology of unicentric Castleman disease (UCD). However, based on current knowledge, the use of this shared nomenclature is unfortunate, since these disorders differ in pathogenesis and prognosis. In Kaposi sarcoma-associated herpesvirus (KSHV)-associated MCD, cytokine overactivity is caused by viral products, which can also lead to atypical lymphoproliferations and potential progression to lymphoma. In idiopathic MCD, the hypercytokinemia can result from various mechanisms, which ultimately lead to different constellations of clinical presentations and varied pathology in lymphoid tissues. The authors review the evolving concepts and definitions of the various conditions under the eponym of multicentric Castleman disease.

Recent Advances in Developing Treatments of Kaposi's Sarcoma Herpesvirus-Related Diseases

Kaposi-sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8 (HHV-8) is the causative agent of several malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (MCD). Active KSHV replication has also been associated with a pathological condition called KSHV inflammatory cytokine syndrome (KICS), and KSHV may play a role in rare cases of post-transplant polyclonal lymphoproliferative disorders. Several commonly used herpesviral DNA polymerase inhibitors are active against KSHV in tissue culture. Unfortunately, they are not always efficacious against KSHV-induced diseases. To improve the outcome for the patients, new therapeutics need to be developed, including treatment strategies that target either viral proteins or cellular pathways involved in tumor growth and/or supporting the viral life cycle. In this review, we summarize the most commonly established treatments against KSHV-related diseases and review recent developments and promising new compounds that are currently under investigation or on the way to clinical use.

A retrospective study of 44 patients with head and neck Castleman's disease

PURPOSE

To explore the clinical and pathological features, therapy and prognosis of Castleman's disease (CD) in the head and neck.

METHODS

We retrospectively analyzed the clinical and pathological data of 44 patients with head and neck CD who were diagnosed in the Fujian Medical University Union hospital (Fujian, China) between May 2008 and June 2021. According to the clinical classification, they were divided into two groups, the unicentric CD (UCD, n = 20) and the multicentric CD (MCD, n = 24). Their clinical features, imaging findings, laboratory examination, and treatment results were, respectively, analyzed.

RESULTS

The age of UCD patients was younger than that of MCD patients. Most of the UCD patients (80%) were female, with asymptomatic single lymphadenectasis, and the prognosis was favorable; while 70.8% of the MCD patients were male, with multiple lymph nodes throughout the body, and more prone to hepatosplenomegaly, pneumonia, serous effusion, anemia, hypoalbuminemia, elevated globulin, coagulation disorders, etc., the prognosis was bleak. Two cases of MCD patients were with systemic lupus erythematosus (SLE).

CONCLUSIONS

UCD usually manifests as asymptomatic single lymph node enlargement, complete surgical resection was the mainstay of treatment modality. MCD has relatively complicated clinical symptoms and poor prognosis, and anti-IL-6 therapy may be effective.

Hematological cancers in individuals infected by HIV

HIV infection increases cancer risk and is linked to cancers associated to infectious agents classified as carcinogenic to humans by the International Agency for Research on Cancer. Lymphomas represent one of the most frequent malignancies among individuals infected by HIV. Diffuse large B-cell lymphoma remains a leading cancer after the introduction of combined antiretroviral therapy (cART). The incidence of other lymphomas including Burkitt lymphoma, primary effusion lymphomas, and plasmablastic lymphoma of the oral cavity remain stable, while the incidence of Hodgkin lymphoma and Kaposi sarcoma-associated herpesvirus (KSHV)-associated Multicentric Castleman Disease has increased. The heterogeneity of lymphomas in individuals infected by HIV likely depends on the complexity of involved pathogenetic mechanisms, i.e. HIV-induced immunosuppression, genetic abnormalities, cytokine dysregulation, co-infection with the gamma-herpesviruses, Epstein Barr virus and KSHV, and the dysregulation of the immune responses controlling these viruses. In the modern cART era, standard treatments for HIV-associated lymphoma including stem cell transplantation in relapsed/refractory disease, mirrors that of the general population. The combination of cART and anti neoplastic treatments has resulted in remarkable prolongation of long-term survival. However, oncolytic and immunotherapic strategies, and therapies targeting specific viral oncogenes will need to be developed primarily.

What to Do for Increasing Cancer Burden on the African Continent? Accelerating Public Health Diagnostics Innovation for Prevention and Early Intervention on Cancers

No other place illustrates the increasing burden of cancer than in Africa and in particular, sub-Saharan Africa. Many of the individuals to be diagnosed with cancer will be in low-resource settings in the future due to, for example, an increase in populations and aging, and high co-morbidity with infections with viruses such as human immunodeficiency virus (HIV) and human papillomavirus (HPV), as well as the presence of infectious agents linked to cancer development. Due to lack of prevention and diagnostic innovation, patients present with advanced cancers, leading to poor survival and increased mortality. HIV infection-associated cancers such as B cell lymphomas, Kaposi's sarcoma, and HPV-associated cancers such as cervical cancer are particularly noteworthy in this context. Recent reports show that a host of other cancers are also associated with viral infection and these include lung, oral cavity, esophageal, and pharyngeal, hepatocellular carcinoma, and anal and vulvar cancers. This article examines the ways in which diagnostic innovation empowered by integrative biology and informed by public health priorities can improve cancer prevention or early intervention in Africa and beyond. In addition, I argue that because diagnostic biomarkers can often overlap with novel therapeutic targets, diagnostics research and development can have broader value for and impact on medical innovation.

Pegylated liposomal doxorubicin as first line treatment in aids-related Kaposi's sarcoma: a real-life study

Despite the introduction of effective combination antiretroviral therapy (cART) AIDS-related Kaposi Sarcoma (AIDS-KS) remains the most common malignancy in HIV positive patients. In advanced stage or progressive forms, chemotherapy (CT) in combination with cART is the treatment of choice. The aim of the study is to evaluate efficacy and tolerability of Pegylated Liposomal Doxorubicin (PLD) as first line CT in AIDS-KS. In this single institution retrospective study PLD (20 mg/m2 IV every 2 weeks for 6 or 12 cycles) in combination with cART was administered in poor risk and some cases of good prognosis or limited cutaneous disease. Response rate and adverse events to treatment was evaluated. We enrolled 33 patients with AIDS-KS: median age 44ys, male 90.9%, Caucasian 72.7%, cART-naïve (simultaneous diagnosis of HIV infection and KS) 84.4%, median lymphocyte CD4+ count 134cells, median HIV viral load 4.9 log10 copies/ml. 32 patients were assigned to a Poor Risk KS stage. Grade 3-4 toxicity was reported in 9 patients. No cardiovascular events or severe sepsis were described. Complete response was reported in 25 of 31 patients evaluable for efficacy. After a median follow-up of 52 months the 3-years PFS was 68.6%. PLD associated with cART is an effective, feasible and well tolerated first-line CT in advanced AIDS-KS.

Multicentric Castleman's disease in HIV patients: a single-center cohort diagnosed from 2008 to 2018

Purpose

Castleman’s disease (CD) is a well-established entity but there is a lack of available data regarding the management and therapy of HIV- and HHV-8-positive multicentric CD (MCD). We provide our own single-center experience with HIV-associated MCD.

Methods

We performed a retrospective, descriptive study on a cohort of patients with MCD, diagnosed and admitted to the infectious diseases or intensive care unit in the University Hospital Düsseldorf between 2008 and 2018. Included patients had a previous or new HIV diagnosis and clinical signs resembling MCD with evidence of HHV-8 replication or histological diagnosis for MCD.

Results

Nine male patients were included in the study. All patients were treated with Rituximab after diagnosis of MCD, with six of them acquiring resolution of symptoms. Three patients received tocilizumab additionally. Other treatment options included: splenectomy (2/9), valganciclovir (2/9), vincristine and siltuximab (1/9), ruxolitinib and Cytosorb^® (2/9). The relapse rate was 44% (4/9) and the survival rate 87.5% after 1 year (8/9) and 71.4% after 3 years (5/7).

Conclusion

The most effective first-line therapy and retreatment option remains rituximab. The effectiveness of other treatment options like splenectomy or different immunotherapeutic approaches requires confirmation in larger-scale studies.

Characteristics and outcomes of KSHV-associated multicentric Castleman disease with or without other KSHV diseases

Kaposi sarcoma (KS)-associated herpesvirus (KSHV)-associated multicentric Castleman disease (MCD) is a relapsing and remitting systemic lymphoproliferative disorder characterized by severe inflammatory symptoms most common among people living with HIV (PLWH). Patients with KSHV-MCD may present with concurrent KSHV-associated diseases, such as KS and/or primary effusion lymphoma (PEL). We evaluated clinical and immunologic characteristics, the effects of concurrent KSHV malignancies, and treatments from the largest prospective natural history study of participants with KSHV-MCD within the United States. Treatment options administered at investigator discretion included high-dose zidovudine with valganciclovir (AZT/VGC), rituximab, or rituximab with liposomal doxorubicin (R-Dox) during KSHV-MCD flares. Survival analyses and prognostic factors were explored for all participants. Sixty-two participants with HIV were enrolled, including 20 with KSHV-MCD alone, 34 with KSHV-MCD and KS, 1 with KSHV-MCD and PEL, and 7 with all KSHV-associated diseases. Forty-four percent of KSHV-MCD diagnoses were made at our institution. Forty-four participants received rituximab-based therapies, 20 of whom had maintenance AZT/VGC or interferon. Participants receiving R-Dox and then maintenance AZT/VGC had the highest 5-year progression-free survival (89%). Cytokine profiles during KSHV-MCD flares did not differ by the presence of concurrent KSHV-associated diseases. The 10-year survival was 71% (95% confidence interval [CI], 56% to 82%) for all participants. A concurrent diagnosis of PEL negatively impacted survival (PEL hazard ratio, 5.4; 95% CI, 1.8 to 16.8). KSHV-MCD is an underdiagnosed condition among PLWH, including those with KS. KSHV-MCD has an excellent prognosis with appropriate treatment. Physicians should be alert for patients with multiple KSHV diseases, which impact optimal treatment and survival outcomes. This study was registered at www.clinicaltrials.gov as #NCT00099073.

An Immunocompetent HIV-Negative Elderly Patient with Low-Grade Fever, Generalized Lymphadenopathy, Splenomegaly, and Acute Phase Response: Do Not Forget Castleman Disease

Multicentric Castleman disease (MCD) is a rare lymphoproliferative disorder that mainly affects middle-aged patients with human immunodeficiency virus (HIV) infection. However, HIV-negative patients can also be affected representing a small proportion of the total MCD cases. Of note, recent studies from China in HIV-negative patients with MCD have suggested that the onset of the disease can be observed in younger age than previously thought. If undiagnosed and untreated, the MCD has a poor prognosis and may progress to lymphoma. We present an 82-year-old immunocompetent male patient who was admitted to our department because of low-grade fever, cachexia, anasarca, hepatosplenomegaly, and generalized lymphadenopathy. Laboratory findings showed anemia and increased markers of inflammation including hyperferritinemia and polyclonal hyperglobulinemia. Infectious causes including HIV were ruled out. Histological examination of a cervical lymph-node revealed lesions supportive of MCD diagnosis. Of note, the outer-zone plasmablasts' nuclei stained positive for human herpesvirus-8 (HHV8). The patient received 4 cycles of cyclophosphamide, vincristine, and dexamethasone with regression of all symptoms. This case underlines that HHV8-associated MCD should be considered as a rare cause of generalized lymphadenopathy even in HIV-negative immunocompetent patients when other causes have been appropriately excluded because a timely diagnosis can be life-saving.

Elevated IL-13 in effusions of patients with HIV and primary effusion lymphoma as compared with other Kaposi sarcoma herpesvirus-associated disorders

OBJECTIVE

To assess the cytokine and viral profiles of effusions and peripheral blood among patients diagnosed with HIV and Kaposi sarcoma herpesvirus [KSHV, also known as human herpesvirus 8 (HHV-8)]-associated conditions.

DESIGN

Retrospective comparative study evaluating clinicopathologic findings in patients with HIV and KSHV-associated conditions presenting with an effusion between 2010 and 2018.

METHODS

Paired peripheral blood and effusion samples collected at the time of pathological diagnosis of KSHV-associated conditions [Kaposi sarcoma, KSHV-associated multicentric Castleman disease (KSHV-MCD), primary effusion lymphoma (PEL), or KSHV-associated inflammatory cytokine syndrome (KICS)] were evaluated for disease-specific and compartment-specific (effusion vs. blood) characteristics. We assessed 12 cytokines, KSHV viral DNA (KSHV-VL), and Epstein--Barr virus (EBV) viral DNA (EBV-VL).

RESULTS

Nine patients had PEL, five patients had KSHV-MCD, and eight patients met criteria for KICS; all but one patient had concurrent Kaposi sarcoma in addition to these conditions. PEL effusions had substantially higher levels of IL-13 (median 16.9 pg/ml; interquartile range 9.7--26.9 pg/ml) compared with KSHV-MCD (median <0.114 pg/ml; P = 0.0037) or KICS (median <0.114 pg/ml; P = 0.0003) effusions. IL-13 was also higher in PEL effusions as compared with serum (median <0.12 ng/ml; P = 0.007). KSHV-VL levels were significantly higher in PEL effusions as compared with KICS effusions (median 31 × 10 vs. 569 copies/million-cell equivalent; P = 0.0005) or KSHV-MCD effusions (median 231,884 copies/million-cell equivalent; P = 0.02).

CONCLUSION

PEL effusions had a distinct profile as compared to other KSHV-associated diseases with regard to elevated IL-13 and KSHV-VL. These findings may provide insights into PEL pathogenesis and aid in diagnosis.

Overview of Castleman disease

Castleman disease (CD) describes a group of at least 4 disorders that share a spectrum of characteristic histopathological features but have a wide range of etiologies, presentations, treatments, and outcomes. CD includes unicentric CD (UCD) and multicentric CD (MCD), the latter of which is divided into idiopathic MCD (iMCD), human herpes virus-8 (HHV8)-associated MCD (HHV8-MCD), and polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes (POEMS)-associated MCD (POEMS-MCD). iMCD can be further subclassified into iMCD-thrombocytopenia, ascites, reticulin fibrosis, renal dysfunction, organomegaly (iMCD-TAFRO) or iMCD-not otherwise specified (iMCD-NOS). Advances in diagnosis, classification, pathogenesis, and therapy are substantial since the original description of UCD by Benjamin Castleman in 1954. The advent of effective retroviral therapy and use of rituximab in HHV8-MCD have improved outcomes in HHV8-MCD. Anti-interleukin-6-directed therapies are highly effective in many iMCD patients, but additional therapies are required for refractory cases. Much of the recent progress has been coordinated by the Castleman Disease Collaborative Network (CDCN), and further progress will be made by continued engagement of physicians, scientists, and patients. Progress can also be facilitated by encouraging patients to self-enroll in the CDCN's ACCELERATE natural history registry (#NCT02817997; www.CDCN.org/ACCELERATE).

A Novel Predictive Model for Idiopathic Multicentric Castleman Disease: The International Castleman Disease Consortium Study

BACKGROUND

Patients with multicentric Castleman disease (MCD) who are negative for human immunodeficiency virus and human herpesvirus 8 are considered to have idiopathic MCD (iMCD). The clinical presentation of iMCD varies from mild constitutional symptoms to life-threatening symptoms or death. The treatment strategy varies from "watchful waiting" to high-dose chemotherapy. This diverse clinical presentation calls for a classification stratification system that takes into account the severity of the disease.

SUBJECTS, MATERIALS, AND METHODS

We analyzed the clinical, laboratory, and pathologic abnormalities and treatment outcomes of 176 patients with iMCD (median follow-up duration 12 years) from the U.S. and China to better understand the characteristics and prognostic factors of this disease. This discovery set of iMCD results was confirmed from the validation set composed of additional 197 patients with iMCD organized from The International Castleman Disease Consortium.

RESULTS

Using these data, we proposed and validated the iMCD international prognostic index (iMCD-IPI), which includes parameters related to patient characteristics (age > 40 years), histopathologic features (plasma cell variant), and inflammatory consequences of iMCD (hepatomegaly and/or splenomegaly, hemoglobin <80 g/L, and pleural effusion). These five factors stratified patients according to their performance status and extent of organ dysfunction into three broad categories: low risk, intermediate risk, and high risk. The iMCD-IPI score accurately predicted outcomes in the discovery study cohort, and the results were confirmed on the validation study cohort.

CONCLUSION

This study represents the largest series of studies on patients with iMCD in the field and proposed a novel risk-stratification model for iMCD-IPI that could be used to guide risk-stratified treatment strategies in patients with iMCD.

IMPLICATIONS FOR PRACTICE

Patients with idiopathic multicentric Castleman disease (iMCD) can benefit from care based on clinical symptoms and disease severity. This study in 176 patients with iMCD constructed an iMCD-IPI score based on five clinical factors, including age >40 years, plasmacytic variant subtype, hepatomegaly and/or splenomegaly, hemoglobin <80 g/L, and pleural effusion, and stratified patients into three risk categories: low risk, intermediate risk, and high risk. The predictive value was validated in an independent set of 197 patients with iMCD from The International Castleman Disease Consortium. The proposed novel model is valuable for predicting clinical outcome and selecting optimal therapies using clinical parameters.

Runaway Kaposi Sarcoma-associated herpesvirus replication correlates with systemic IL-10 levels

KSHV-associated inflammatory cytokine syndrome (KICS) is caused by Kaposi's sarcoma-associated herpesvirus (KSHV). KICS is associated with high-level, systemic replication of KSHV. This study characterized the clinical and virologic features of a KICS patient over time. Additionally, it compared the cytokine profiles of the KICS case to Kaposi's sarcoma (KS) (n = 11) and non-KS (n = 6) cases. This KICS case presented with elevated levels of KSHV and IL-10, as expected. Surprisingly, this case did not have elevated levels of IL-6 or human immunodeficiency virus 1 (HIV-1). Nevertheless, treatment with anti-IL6 receptor antibody (tocilizumab) reduced KSHV viral load and IL-10. The KSHV genome sequence showed no significant changes over time, except in ORF24. Phylogenetic analysis established this isolate as belonging to KSHV clade A and closely related to other US isolates. These findings suggest IL-10 as potential biomarker and therapy target for KICS.

KSHV/HHV8-positive large B-cell lymphomas and associated diseases: a heterogeneous group of lymphoproliferative processes with significant clinicopathological overlap

In this review, we focus on the current understanding of the diagnosis of human herpesvirus 8 (HHV8)-associated lymphoproliferative disorders-a group of entities that range from hyperplastic proliferations to frank lymphomas. These diseases tend to occur in immunodeficient patients, but may occur in immunocompetent individuals as well. In recent years, we have learned of occasional cases with overlapping features among HHV8 entities, such as lesions intermediate between primary effusion lymphoma and HHV8-positive diffuse large B-cell lymphoma, not otherwise specified or cases sharing features of multicentric Castleman disease and germinotropic lymphoproliferative disorder. There is also a significant clinical overlap between these entities. It is important to have a better understanding of the biology of these lesions and to refine diagnostic criteria of these lesions, as the use of immunosuppressive agents to treat a variety of diseases, the expanded use of transplant as a therapeutic modality for a variety of cancers and organ failure patients, and the extended longevity of HIV-positive patients will likely result in an increased incidence of these lymphoproliferative processes in the future.

Systematic Review of Safety and Efficacy of Rituximab in Treating Immune-Mediated Disorders

Background: During the past years biologic agents (also termed biologicals or biologics) have become a crucial treatment option in immunological diseases. Numerous articles have been published on biologicals, which complicates the decision making process on the use of the most appropriate biologic for a given immune-mediated disease. This systematic review is the first of a series of articles assessing the safety and efficacy of B cell-targeting biologics for the treatment of immune-mediated diseases.

Objective: To evaluate rituximab's safety and efficacy for the treatment of immune-mediated disorders compared to placebo, conventional treatment, or other biologics.

Methods: The PRISMA checklist guided the reporting of the data. We searched the PubMed database between 4 October 2016 and 26 July 2018 concentrating on immune-mediated disorders.

Results: The literature search identified 19,665 articles. After screening titles and abstracts against the inclusion and exclusion criteria and assessing full texts, 105 articles were finally included in a narrative synthesis.

Conclusions: Rituximab is both safe and effective for the treatment of acquired angioedema with C1-inhibitor deficiency, ANCA-associated vasculitis, autoimmune hemolytic anemia, Behçet's disease, bullous pemphigoid, Castleman's disease, cryoglobulinemia, Goodpasture's disease, IgG4-related disease, immune thrombocytopenia, juvenile idiopathic arthritis, relapsing-remitting multiple sclerosis, myasthenia gravis, nephrotic syndrome, neuromyelitis optica, pemphigus, rheumatoid arthritis, spondyloarthropathy, and systemic sclerosis. Conversely, rituximab failed to show an effect for antiphospholipid syndrome, autoimmune hepatitis, IgA nephropathy, inflammatory myositis, primary-progressive multiple sclerosis, systemic lupus erythematosus, and ulcerative colitis. Finally, mixed results were reported for membranous nephropathy, primary Sjögren's syndrome and Graves' disease, therefore warranting better quality trials with larger patient numbers.