Combined Flow-Fluorescence in situ hybridization to HHV-8 and EBV reveals the viral heterogeneity of primary effusion lymphoma.

Primary effusion lymphoma (PEL) is a rare B-cell non-Hodgkin lymphoma associated with Kaposi Sarcoma-associated herpesvirus (KSHV/HHV8) infection. Lymphoma cells are coinfected with Epstein-Barr virus (EBV) in 60-80% of cases. Tools allowing a reliable PEL diagnosis are lacking. This study reports PEL diagnosis in 4 patients using a Flow-Fluorescence in situ hybridization (FlowFISH) technique that allowed detection of differentially expressed EBV and HHV8 transcripts within the same sample, revealing viral heterogeneity of the disease. Moreover, infected cells exhibited variable expressions of CD19, CD38, CD40, and CD138. Therefore, FlowFISH is a promising tool to diagnose and characterize complex viral lymphoproliferations.

Unmasking Bartonella henselae infection in the shadows of long COVID thanks to clinical metagenomics.

The diagnosis of long COVID often relies on symptoms post-COVID-19, occasionally lacking biological evidence. This case study illustrates how investigating long COVID uncovered an underlying bartonellosis through clinical metagenomics. Following mild COVID-19, a 26-year-old woman experienced persistent symptoms during 5 months, including axillary adenopathy. Pathological examination, 16 S rRNA PCR, and clinical metagenomic analysis were done on an adenopathy biopsy. The latter revealed Bartonella henselae DNA and RNA. Treatment with clarithromycin improved symptoms. This case underscores the relevance of clinical metagenomics in diagnosing hidden infections. Post-COVID symptoms warrant thorough investigation, and bartonellosis should be considered in polyadenopathy cases, regardless of a recent history of cat or flea exposures.

Paraneoplastic pemphigus uncovers distinct clinical and biological phenotypes of western unicentric Castleman disease.

Unicentric Castleman disease (UCD) is a lymphoproliferative disease of unknown cause. Paraneoplastic pemphigus (PNP) is a major complication shown to be associated with a poor prognosis, with particular severity in patients with bronchiolitis obliterans (BO). This study describes the clinical and biological characteristics of UCD-PNP patients in a large Western cohort. A total of 148 patients diagnosed with UCD were identified, including 14 patients with a defined PNP. PNP was significantly associated with myasthenia gravis (MG) and FDC sarcoma during follow-up (FDCS). PNP was also significantly associated with reduced survival. These data, together with a multivariate analysis by principal components, led to the identification of UCD-PNP as a group at risk of MG, FDCS and death. PDGFRB sequencing performed on UCD lesions from six patients found the gain-of-function p.N666S variant in two. Interestingly, both patients had hyaline-vascular UCD subtype, were in the UCD-PNP subgroup and had FDCS. Sera from 25 UCD-PNP patients and 6 PNP patients without UCD were tested for PNP-associated autoantibodies. Sera from UCD-PNP patients had a strong reactivity against the N-terminal domain of recombinant periplakin (rPPL, 82%) and showed reactivity against at least two domains of rPPL. These features were not found in patients with UCD alone or in the PNP group without UCD. These data indicate that UCD-PNP patients belong to a subgroup sharing strong clinical and biological identity that might help to decipher the different dynamics of UCD natural history.

Lymphoma as an Exclusion Criteria for CVID Diagnosis Revisited.

PURPOSE: Hypogammaglobulinemia in a context of lymphoma is usually considered as secondary and prior lymphoma remains an exclusion criterion for a common variable immunodeficiency (CVID) diagnosis. We hypothesized that lymphoma could be the revealing symptom of an underlying primary immunodeficiency (PID), challenging the distinction between primary and secondary hypogammaglobulinemia. METHODS: Within a French cohort of adult patients with hypogammaglobulinemia, patients who developed a lymphoma either during follow-up or before the diagnosis of hypogammaglobulinemia were identified. These two chronology groups were then compared. For patients without previous genetic diagnosis, a targeted next-generation sequencing of 300 PID-associated genes was performed. RESULTS: A total of forty-seven patients had developed 54 distinct lymphomas: non-Hodgkin B cell lymphoma (67%), Hodgkin lymphoma (26%), and T cell lymphoma (7%). In 25 patients, lymphoma developed prior to the diagnosis of hypogammaglobulinemia. In this group of patients, Hodgkin lymphoma was overrepresented compared to the group of patients in whom lymphoma occurred during follow-up (48% versus 9%), whereas MALT lymphoma was absent (0 versus 32%). Despite the histopathological differences, both groups presented with similar characteristics in terms of age at hypogammaglobulinemia diagnosis, consanguinity rate, or severe T cell defect. Overall, genetic analyses identified a molecular diagnosis in 10/47 patients (21%), distributed in both groups and without peculiar gene recurrence. Most of these patients presented with a late onset combined immunodeficiency (LOCID) phenotype. CONCLUSION: Prior or concomitant lymphoma should not be used as an exclusion criteria for CVID diagnosis, and these patients should be investigated accordingly.

Positron emission tomography-imaging assessment for guiding strategy in patients with relapsed/refractory large B-cell lymphoma receiving CAR T cells.

The aim of this study was to evaluate the prognostic impact of the F-fluorodeoxyglucose positron emission tomography response at 1 month (M1) and 3 months (M3) after anti-CD19 chimeric antigen receptor (CAR) T-cell therapy in a multicenter cohort of 160 patients with relapsed/refractory large B-cell lymphomas (R/R LBCL). In total, 119 (75%) patients reached M1 evaluation; 64 (53%, 64/119) had a complete response (CR); 91% were Deauville Score (DS) 1-3. Progressionfree survival (PFS) and overall survival (OS) were significantly worse in patients with DS-5 at M1, than in patients with DS 1-3 (PFS hazard ratio [HR]=6.37, 95% confidence interval [CI]: 3.5-11.5 vs. OS HR=3.79, 95% CI: 1.7-8.5) and DS-4 (PFS HR=11.99, 95% CI: 5.0-28.9 vs. OS HR=12.49, 95% CI: 2.8-55.8). The 1-year PFS rates were 78.9% (95% CI: 58.9-89.9) for DS-4 at M1, similar to 67.3% (95% CI: 51.8-78.8) for patients with DS 1-3 at M1, very different to 8.6% (95% CI: 1.8-22.4) for DS-5, respectively. Only eight of 30 (26%) patients with DS-4 progressed. Response at M3 evaluated in 90 (57%) patients was prognostic for PFS with lower discrimination (HR=3.28, 95% CI: 1.5-7.0; P=0.003) but did not predict OS (HR=0.61, 95% CI: 0.2-2.3; P=0.45). Patients with a high baseline total metabolic tumor volume (TMTV) >80 mL had worse PFS (HR=2.05, 95% CI: 1.2-3.5; P=0.009) and OS (HR=4.52, 95% CI: 2.5-8.1; P<0.001) than patients with low TMTV. Multivariable analyses identified baseline elevated lactate dehydrogenase, DS-5, CAR T cells at M1 for PFS and baseline elevated lactate dehydrogenase, TMTV >80 mL, and DS-5 at M1 for OS. In conclusion, baseline TMTV and response at M1 strongly predicts outcomes of patients with R/R LBCL undergoing CAR T-cell therapy.

[Castleman disease]. / La maladie de Castleman.

The term "Castleman disease" covers a variety of entities that have very different clinical, biological, pathological and physiopathological features. In this issue, we review the characteristics of the unicentric Castleman disease, of the HHV8 associated multicentric Castleman disease and the idiopathic multicentric Castleman disease associated or not with TAFRO syndrome ("thrombocytopenia, anasarca, fever, reticulin myelofibrosis and/or renal insufficiency, organomegaly"). We detail the differential diagnostics of these entities.

Long-term outcomes of adult pulmonary Langerhans cell histiocytosis: a prospective cohort.

BACKGROUND: The long-term outcomes of adult pulmonary Langerhans cell histiocytosis (PLCH), particularly survival, are largely unknown. Two earlier retrospective studies reported a high rate of mortality, which contrasts with our clinical experience. METHODS: To address this issue, all patients with newly diagnosed PLCH referred to the French national reference centre for histiocytoses between 2004 and 2018 were eligible for inclusion. The primary outcome was survival, which was defined as the time from inclusion to lung transplantation or death from any cause. Secondary outcomes included the cumulative incidences of chronic respiratory failure (CRF), pulmonary hypertension (PH), malignant diseases and extrapulmonary involvement in initially isolated PLCH. Survival was estimated using the Kaplan-Meier method. RESULTS: 206 patients (mean age 39±13 years, 60% female, 95% current smokers) were prospectively followed for a median duration of 5.1 years (IQR 3.2-7.6 years). Of these, 12 patients (6%) died. The estimated rate of survival at 10 years was 93% (95% CI 89-97%). The cumulative incidences of CRF and/or PH were <5% at both 5 and 10 years, and 58% of these patients died. 27 malignancies were observed in 23 patients. The estimated standardised incidence ratio of lung carcinoma was 17.0 (95% CI 7.45-38.7) compared to an age- and sex-matched French population. Eight (5.1%) of the 157 patients with isolated PLCH developed extrapulmonary involvement. CONCLUSION: The long-term prognosis of PLCH is significantly more favourable than has previously been reported. Patients must be closely monitored after diagnosis to detect severe complications early.

HHV-8 associated lymphoma.

PURPOSE OF REVIEW: The discovery of Kaposi sarcoma herpesvirus (KSHV) / human herpesvirus 8 (HHV-8) led to recognition of primary effusion lymphoma (PEL) as a distinct lymphoproliferative disorder. Subsequently, two other types of lymphoma have been shown to be associated with HHV-8 : HHV-8 positive diffuse large B cell lymphoma not otherwise specified and germinotropic lymphoproliferative disorder.The pathogenesis of PEL is unique as in most cases the HHV-8+ tumoral cells are coinfected with the Epstein-Barr virus (EBV), suggesting an interplay between these two herpesviruses. This article reviews advances in the field of characterization of the lymphomatous cells, pathogenesis, and targeted therapies. RECENT FINDINGS: The gene expression profile analysis of PEL cells and the experimental coinfection of peripheral B cells with HHV-8 and EBV allow dissection of the mechanisms of lymphomagenesis and of the relative contribution of both viruses. Systemic chemotherapy regimen remains poorly effective but new therapeutic perspectives are open with the use of monoclonal antibodies, immunomodulatory drugs, and immunotherapy. SUMMARY: HHV-8 associated lymphoma is a model for studying virus-induced lymphoproliferation and its relation with host immune response and PEL is a unique model to study the relative contribution of two herpesviruses to lymphomagenesis in coinfected cells.

Genetic landscape of adult Langerhans cell histiocytosis with lung involvement.

The clinical significance of the BRAF V600E mutation in adult Langerhans cell histiocytosis (LCH), including pulmonary Langerhans cell histiocytosis (PLCH), is not well understood. Similarly, the spectrum of molecular alterations involved in adult LCH has not been fully delineated. To address these issues, we genotyped a large number of adult LCH biopsies and searched for an association of identified molecular alterations with clinical presentation and disease outcome.Biopsies from 117 adult LCH patients, 83 with PLCH (median age 36.4 years, 56 females, 38 multisystem disease, 79 single system disease, 65 current smokers) were genotyped for the BRAF V600E mutation. In 69 cases, LCH lesions were also genotyped by whole-exome sequencing (WES) or targeted gene panel next-generation sequencing (NGS). Cox models were used to estimate the association of baseline characteristics with the hazard of LCH progression.MAPK pathway alterations were detected in 59 out of 69 cases (86%) (BRAF V600E mutation: 36%, BRAF N486_P490 deletion: 28%, MAP2K1 mutations: 15%, isolated NRAS Q61 mutations: 4%), while KRAS mutations were virtually absent in PLCH lesions. The BRAF V600E mutation was not associated with LCH presentation at diagnosis, including smoking status and lung function, in PLCH patients. BRAF V600E status did not influence the risk of LCH progression over time.Thus, MAPK alterations are present in most lesions from adult LCH patients, particularly in PLCH. Unlike reports in paediatric LCH, BRAF V600E genotyping did not provide additional information on disease outcome. The search for alterations involved in the MAPK pathway, including BRAF deletions, is useful for guiding targeted treatment in selected patients with refractory progressive LCH.

Epstein-Barr Virus-Associated Post-Transplantation Lymphoproliferative Disease in Patients Who Received Anti-CD20 after Hematopoietic Stem Cell Transplantation.

Post-transplantation lymphoproliferative disease (PTLD) is a serious complication associated with Epstein-Barr virus (EBV) infection after hematopoietic stem cell transplantation (HSCT). Although anti-CD-20 therapy is now used as a preemptive strategy for EBV reactivation, PTLD still occurs in some patients. Here we analyzed outcomes and risk factors associated with PTLD transformation in 208 HSCT recipients who were diagnosed with EBV-DNAemia and received at least 1 course of rituximab. The median patient age was 42.52 years (range, 8.35 to 74.77 years), and the median duration of follow-up was 47.33 months (range, 3.18 to 126.20 months). The 2-year overall survival of the entire cohort was 62.8 (95% confidence interval [CI], 56.4 to 69.9), and the 2-year cumulative incidence function of PTLD was 6.3% (95% CI, 3.5% to 10.1%), for a median follow-up of patients diagnosed with PTLD of 37.85 months. Multivariable analysis identified 4 risk factors associated with PTLD: HSCT from an unrelated donor, recipient HLA-DRB1*11:01, fever at diagnosis of EBV infection, and donor-recipient sex-mismatched HSCT. The presence of more than 2 of these risk factors was associated with an increased risk of developing PTLD. This retrospective study identifies risk factors associated with PTLD in EBV-infected patients after HSCT and defines patient subgroups that may benefit from intensified preemptive strategies.

Treatment and outcome of Unicentric Castleman Disease: a retrospective analysis of 71 cases.

We retrospectively analysed 71 cases of Unicentric Castleman disease, a rare, usually asymptomatic, benign lymphoproliferative disorder presenting as a unique nodal mass. Although surgery is considered as the gold standard therapy, only 38 patients (54%) underwent initial surgical resection and 95% were cured. An additional 9 patients had surgery after an attempt at medical reduction. Reduction therapy was used in 21 patients with a 55% response rate, but without evidence for an optimal regimen. Radiotherapy was limited to 8 patients because of associated toxicity. Watch and wait was considered in 13 asymptomatic patients and 11 of these remained stable for up to 17 years.

Clinical spectrum, evolution, and management of autoimmune cytopenias associated with angioimmunoblastic T-cell lymphoma.

OBJECTIVE: Angioimmunoblastic T-cell lymphoma (AITL) is frequently associated with autoimmune cytopenia (AIC). Whether such patients have a particular phenotype and require particular management is unclear. METHOD: Angioimmunoblastic T-cell lymphoma patients from the multicentric database of the Lymphoma Study Association presenting with AIC during disease course were included and matched to AITL patients without AIC (1/5 ratio). RESULTS: At diagnosis, AIC patients (n = 28) had more spleen and bone marrow involvement (54% vs 19% and 71% vs 34%, P < 0.001), Epstein-Barr virus replication (89% vs 39%, P < 0.001), gamma globulin titers (median 23 vs 15 g/L, P = 0.002), and proliferating B cells and plasmablasts in biopsies, as compared to control patients (n = 136). The 28 AIC patients had 41 episodes of AIC, diagnosed concomitantly with AITL in 23 (82%) cases. After a median follow-up of 24 months (range 3-155), 10 patients relapsed, all associated with AITL relapse. CONCLUSION: Our results provide new insight into AIC associated with AITL by highlighting the significant interplay between AITL and B-cell activation leading to subsequent autoimmunity.

Lower respiratory tract amyloidosis: Presentation, survival and prognostic factors. A multicenter consecutive case series.

Lower-respiratory-tract (LRT) amyloidosis has rarely been investigated. Our study presents characteristics, outcomes and survival of LRT amyloidosis. This multicenter retrospective study, from 1995 to 2017, included 73 patients with amyloidosis and LRT involvement. Respiratory patterns were: tracheobronchial (n = 17), nodular (n = 10), interstitial (n = 14) or composite (several respiratory involvements, n = 32). Interstitial and composite patterns were associated with multi-organ amyloidosis (n = 37, 80%) while tracheobronchial and nodular patterns were associated with organ-limited amyloidosis (n = 21, 78%). Amyloid light chain (AL) amyloidosis was diagnosed in 43 patients (59%), mainly of lambda type (n = 33, 77%). Smokers' proportion was higher in tracheobronchial (71%) and nodular (90%) patterns than in interstitial (14%) and composite (34%) patterns. The B-cell neoplasms involved 15 patients (21%), solid neoplasms 8 (11%), connective tissue diseases 8 (11%) and multiple myeloma 6 (8%). The B-cell and solid neoplasms were most prevalent in nodular pattern. Median follow-up was 4.4 years (2.2-8.9). Twenty-four patients died, mostly from respiratory infection. Survival at 1, 5, 10 years was respectively 88%, 70% and 54% for multi-organ amyloidosis, 96%, 89% and 69% for organ-limited amyloidosis (P = .125). Tracheobronchial and nodular patterns survival was better than in other respiratory patterns (P = .039). Death risk factors (multivariate analysis) were: cardiac localization (hazard-ratio [HR] 4.3 [95% confidence interval 1.6-11.5]; P = .004), age (HR 2.1 [1.2-3.7]; P = .008) and dyspnea at diagnosis (HR 4.0 [1.3-12.3]; P = .014). Various LRT amyloidosis patterns depend on smoking habits, organ-limited or multi-organ extension and comorbidities. They are associated with a different survival, which is also predicted by age, cardiac localization and dyspnea at presentation.

The full spectrum of Castleman disease: 273 patients studied over 20 years.

The spectrum of Castleman disease (CD) has considerably extended since its first description in 1956. Recently, an international collaborative working group has reached consensus on the diagnostic criteria and classification of CD. We herein report 273 patients with lymph node histopathology consistent with CD and investigate the newly established diagnostic criteria. Twenty of these patients with Castleman-like histopathology were removed from analyses, because they were diagnosed with an exclusionary disorder (18 with haematological malignancy). Among the 253 remaining patients, 57 were considered unicentric CD (UCD), 169 were multicentric CD associated with Human Herpesvirus 8 (HHV-8+MCD), including 140 patients with human immunodeficiency virus (HIV) infection and 29 patients without HIV infection, and 27 were HHV-8 negative/idiopathic multicentric CD (iMCD). 2-(18 F)fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography was useful in 62 patients for staging/classification of the disease and for excluding associated lymphoma. UCD was mainly associated with hyaline-vascular histopathological features, and most patients were asymptomatic. Of the 27 patients that we had originally diagnosed with iMCD, 26 met the newly established diagnostic criteria. Patients with iMCD and HHV-8+ MCD demonstrated similar characteristics, including fever, splenomegaly, cytopenia and inflammatory symptoms. However, the disease was more aggressive in HHV-8+ MCD, particularly in HIV-infected patients.

A comprehensive analysis of Lymphoma-associated haemophagocytic syndrome in a large French multicentre cohort detects some clues to improve prognosis.

Lymphoma-associated haemophagocytic syndrome (LAHS) accounts for most cases of secondary haemophagocytic syndrome (HS) and has been extensively described in Asian populations. However, little is known about the epidemiology of LAHS in Western countries. We herein report a case series of 71 LAHS patients in which the lymphomas were mainly of the aggressive type. Diagnoses included non-Hodgkin B cell lymphoma (46·5%) including human herpes virus 8-associated non-Hodgkin lymphoma (12·7%), T cell lymphoma (28·2%) and Hodgkin lymphoma (23·9%). An underlying immunodeficiency was described in 30 patients (42·3%). Early mortality within the 30 days following HS diagnosis was observed in 26·8% of cases. The overall survival was estimated at 45·7% [95% confidence interval, CI (35·4-59·0)] at 6 months, and 34·3% [95% CI (24·8-47·4)] at 2 years. Concurrent infection, age over 50 years, ethnicity and etoposide treatment were independently associated with mortality. While it appears that certain types of lymphomas were more prone to trigger HS, LAHS were not restricted to a few types of lymphoma. The overall prognosis was poor, with a particularly high rate of early mortality, highlighting the importance of both early recognition and choice of initial therapeutic management.

Lung histopathology of non-infectious pulmonary complications after allogeneic haematopoietic stem cell transplantation.

AIMS: Non-infectious pulmonary complications (NIPCs) occur frequently following allogeneic haematopoietic stem cell transplantation (HSCT). As there is no consensus on the description of the related pulmonary pathological lesions, pathologist reports and clinical conclusions are largely inconsistent in routine practice. The aim of our study was to provide an accurate overview of post-allogeneic HSCT NIPCs from a large number of lung biopsies. METHODS AND RESULTS: We reviewed 61 lung biopsies in patients with an NIPC, including 51 surgical lung biopsies, four post-mortem biopsies and six lung explants. We found both bronchiolar (n = 59) and alveolar/interstitial pathologies (n = 27). We describe two types of bronchiolar lesions: bronchiolectasies (n = 37) and fibrous and cellular lesions with luminal narrowing (n = 43). We found a wide spectrum of airway/interstitial pathologies that were labelled using the terminology of the 2013 American Thoracic Society and European Respiratory Society (ATS/ERS) classification of idiopathic interstitial pneumonias (IIPs), including the following: organising pneumonia (OP, n = 8), non-specific interstitial pneumonia (NSIP, n = 9), diffuse alveolar damage (DAD, n = 6), lymphoid interstitial pneumonia (LIP, n = 1) and pleuroparenchymal fibroelastosis (PPFE, n = 2), as well as one instance of associated PPFE and NSIP. CONCLUSIONS: Interstitial pathology was associated with bronchiolar lesions in 41% of the cases reviewed (n = 25). Lung airway and interstitial inflammation was still present in lung explants from patients who underwent lung transplantation for post-allogeneic HSCT end-stage respiratory insufficiency. Herein, we describe a wide spectrum of pathological lung lesions encountered in post-allogeneic HSCT NIPCs.

The Impact of Splenectomy in Myelofibrosis Patients before Allogeneic Hematopoietic Stem Cell Transplantation.

Performing a pretransplantation splenectomy in patients with myelofibrosis (MF) is a matter of debate, as while the procedure improves hematological recovery, it may lead to severe morbidities. We retrospectively analyzed data from 85 consecutive patients who underwent transplantation in our center for MF, including 39 patients who underwent splenectomy before their transplantation. A majority of them had primary MF (78%), were considered high-risk patients (84% dynamic international prognostic scoring system intermediate-2 or higher), and had received transplants from HLA-matched sibling donors (56%) after a reduced-intensity conditioning regimen (82%). One-half of all splenectomized patients presented surgical or postsurgical morbidities, most frequently thrombosis and hemorrhage. After adjustment using Cox models, pretransplantation splenectomy was not associated with nonrelapse mortality or post-transplantation relapse but with an improved overall survival (OS) and event-free survival (EFS). We conclude that some patients with huge splenomegaly may undergo pretransplantation splenectomy without a deleterious impact on post-transplantation outcomes. OS and EFS improvement should in confirmed in controlled study.