Brentuximab vedotin with AVD for stage II-IV HIV-related Hodgkin lymphoma (AMC 085): phase 2 results from an open-label, single arm, multicentre phase 1/2 trial.

BACKGROUND: Brentuximab vedotin in combination with doxorubicin, vinblastine, and dacarbazine (AVD) is approved in the upfront setting for advanced stage classical Hodgkin lymphoma (cHL). People living with HIV have been excluded from these studies. We aimed to understand the activity and safety of brentuximab vedotin-AVD in people living with HIV diagnosed with Hodgkin lymphoma, while focusing on HIV disease parameters and antiretroviral therapy (ART) interactions. METHODS: We present the phase 2 portion of a multicentre phase 1/2 study. Eligible patients were 18 years or older, had untreated stage II-IV HIV-associated cHL (HIV-cHL), a Karnofsky performance status of more than 30%, a CD4+ T-cell count of 50 cells per µL or more, were required to take ART, and were not on strong CYP3A4 or P-glycoprotein inhibitors. Patients were treated intravenously with 1·2 mg/kg of brentuximab vedotin (recommended phase 2 dose) with standard doses of AVD for six cycles on days 1 and 15 of a 28-day cycle. The primary endpoint of the phase 2 portion was 2-year progression-free survival (PFS), assessed in all eligible participants who began treatment. Accrual has been completed. This trial is registered at ClinicalTrials.gov, NCT01771107. FINDINGS: Between March 8, 2013, and March 7, 2019, 41 patients received study therapy with a median follow up of 29 months (IQR 16-38). 34 (83%) of 41 patients presented with stage III-IV and seven (17%) with stage II unfavourable HIV-cHL. 37 (90%) of 41 patients completed therapy, all 37 of whom achieved complete response. The 2-year PFS was 87% (95% CI 71-94) and the overall survival was 92% (78-97). The most common grade 3 or worse adverse events were peripheral sensory neuropathy (four [10%] of 41 patients), neutropenia (18 [44%]), and febrile neutropenia (five [12%]). One treatment-related death was reported, due to infection. INTERPRETATION: Brentuximab vedotin-AVD was highly active and had a tolerable adverse event rate in HIV-cHL and is an important therapeutic option for people with HIV-cHL. The complete reponse rate is encouraging and is possibly related to a unique aspect of HIV-cHL biology. Upcoming 5-year data will evaluate the sustainability of the outcomes obtained. FUNDING: National Institutes of Health and National Cancer Institute.

Progressive multifocal leukoencephalopathy genetic risk variants for pharmacovigilance of immunosuppressant therapies.

Background: Progressive multifocal leukoencephalopathy (PML) is a rare and often lethal brain disorder caused by the common, typically benign polyomavirus 2, also known as JC virus (JCV). In a small percentage of immunosuppressed individuals, JCV is reactivated and infects the brain, causing devastating neurological defects. A wide range of immunosuppressed groups can develop PML, such as patients with: HIV/AIDS, hematological malignancies (e.g., leukemias, lymphomas, and multiple myeloma), autoimmune disorders (e.g., psoriasis, rheumatoid arthritis, and systemic lupus erythematosus), and organ transplants. In some patients, iatrogenic (i.e., drug-induced) PML occurs as a serious adverse event from exposure to immunosuppressant therapies used to treat their disease (e.g., hematological malignancies and multiple sclerosis). While JCV infection and immunosuppression are necessary, they are not sufficient to cause PML. Methods: We hypothesized that patients may also have a genetic susceptibility from the presence of rare deleterious genetic variants in immune-relevant genes (e.g., those that cause inborn errors of immunity). In our prior genetic study of 184 PML cases, we discovered 19 candidate PML risk variants. In the current study of another 152 cases, we validated 4 of 19 variants in both population controls (gnomAD 3.1) and matched controls (JCV+ multiple sclerosis patients on a PML-linked drug ≥ 2 years). Results: The four variants, found in immune system genes with strong biological links, are: C8B, 1-57409459-C-A, rs139498867; LY9 (alias SLAMF3), 1-160769595-AG-A, rs763811636; FCN2, 9-137779251-G-A, rs76267164; STXBP2, 19-7712287-G-C, rs35490401. Carriers of any one of these variants are shown to be at high risk of PML when drug-exposed PML cases are compared to drug-exposed matched controls: P value = 3.50E-06, OR = 8.7 [3.7-20.6]. Measures of clinical validity and utility compare favorably to other genetic risk tests, such as BRCA1 and BRCA2 screening for breast cancer risk and HLA-B*15:02 pharmacogenetic screening for pharmacovigilance of carbamazepine to prevent Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis. Conclusion: For the first time, a PML genetic risk test can be implemented for screening patients taking or considering treatment with a PML-linked drug in order to decrease the incidence of PML and enable safer use of highly effective therapies used to treat their underlying disease.

When Immunity Kills: The Lessons of SARS-CoV-2 Outbreak.

Since its emergence at the end of 2019, SARS-CoV-2 has spread worldwide at a very rapid pace. While most infected individuals have an asymptomatic or mild disease, a minority, mainly the elderly, develop a severe disease that may lead to a fatal acute respiratory distress syndrome (ARDS). ARDS results from a highly inflammatory immunopathology process that includes systemic manifestations and massive alveolar damages that impair gas exchange. The present review summarizes our current knowledge in the rapidly evolving field of SARS-CoV-2 immunopathology, emphasizing the role of specific T cell responses. Indeed, accumulating evidence suggest that while T-cell response directed against SARS-CoV-2 likely plays a crucial role in virus clearance, it may also participate in the immunopathology process that leads to ARDS.

Prolonged in-hospital stay and higher mortality after Covid-19 among patients with non-Hodgkin lymphoma treated with B-cell depleting immunotherapy.

Prolonged Covid-19 is an emerging issue for patients with lymphoma or immune deficiency. We aimed to examine prolonged length of in-hospital stay (LOS) due to Covid-19 among patients with lymphoma and assess its determinants and outcomes. Adult patients with lymphoma admitted for Covid-19 to 16 French hospitals in March and April, 2020 were included. Length of in-hospital stay was analyzed as a competitor vs death. The study included 111 patients. The median age was 65 years (range, 19-92). Ninety-four patients (85%) had B-cell non-Hodgkin lymphoma. Within the 12 months prior to hospitalization for Covid-19, 79 patients (71%) were treated for their lymphoma. Among them, 63 (57%) received an anti-CD20 therapy. Fourteen patients (12%) had relapsed/refractory disease. The median LOS was 14 days (range, 1-235). After a median follow-up of 191 days (3-260), the 6-month overall survival was 69%. In multivariable analyses, recent administration of anti-CD20 therapy was associated with prolonged LOS (subdistribution hazard ratio 2.26, 95% confidence interval 1.42-3.6, p < 0.001) and higher risk of death (hazard ratio 2.17, 95% confidence interval 1.04-4.52, p = 0.039). An age ≥ 70 years and relapsed/refractory lymphoma were also associated with prolonged LOS and decreased overall survival. In conclusion, an age ≥ 70 years, a relapsed/refractory lymphoma and recent administration of anti-CD20 therapy are risk factors for prolonged LOS and death for lymphoma patients hospitalized for Covid-19. These findings may contribute to guide the management of lymphoma during the pandemic, support evaluating specific therapeutic approaches, and raise questions on the efficacy and timing of vaccination of this particular population.

Prospective evaluation of blood Epstein-Barr virus DNA load and antibody profile in HIV-related non-Hodgkin lymphomas.

OBJECTIVES: The value of Epstein-Barr virus (EBV) biomarkers on the prognosis of HIV-related non-Hodgkin's lymphoma (NHL) has been poorly explored in the combined antiretroviral therapy (cART) era. DESIGN: We evaluated EBV DNA load and EBV antibodies in HIV-NHL patients enrolled in the French ANRS-CO16 Lymphovir Cohort between 2008 and 2015. METHODS: Whole blood and plasma EBV DNA load and serological profiles were analyzed in 76 HIV-infected patients at diagnosis of NHL and 6 months after the initiation of chemotherapy. RESULTS: Prechemotherapy whole blood (WB) and plasma EBV DNA loads were positive for 80 and 45% of HIV-NHL patients, respectively. Pretreatment WB EBV DNA positivity was associated with a positive plasma HIV-1 RNA load (relative risk (RR), 4.42 [1.33; 14.72]) and plasma EBV DNA positivity with EBV in situ detection (RR 10.62 [2.38; 47.49]). Following chemotherapy, the proportions of patients with positive WB or plasma EBV DNA declined from 81 to 23% (P < 0.0001) and from 43 to 8% (P < 0.0001), respectively. Estimated 2-year progression-free survival did not differ according to prechemotherapy WB positivity (82% versus 67%, P = 0.15) or plasma EBV DNA positivity (76% versus 81%, P  = 0.52). CONCLUSIONS: The plasma EBV DNA load correlates with in situ EBV detection. The WB EBV DNA load correlates with HIV load. WB and plasma EBV DNA loads at NHL diagnosis do not constitute prognostic markers for HIV-NHL patients in the modern cART era.

Increased Production of B-Cell Activating Cytokines and Altered Peripheral B-Cell Subset Distribution during HIV-Related Classical Hodgkin Lymphoma.

Classical Hodgkin Lymphoma incidence increases in HIV-1-infected patients (HIV-cHL). HIV infection is associated with higher B-cell activation. Here, in 38 HIV-cHL patients from the French cohort ANRS-CO16 Lymphovir, we examined longitudinally over 24 months the serum levels of the B-cell activating cytokines IL10, IL6, and BAFF, and blood distribution of B-cell subsets. Fourteen HIV-cHL patients were also compared to matched HIV-infected controls without cHL. IL10, IL6, and BAFF levels were higher in HIV-cHL patients than in controls (p < 0.0001, p = 0.002, and p < 0.0001, respectively). Cytokine levels increased in patients with advanced-stage lymphoma compared to those with limited-stage (p = 0.002, p = 0.03, and p = 0.01, respectively). Cytokine levels significantly decreased following HIV-cHL diagnosis and treatment. Blood counts of whole B-cells were similar in HIV-cHL patients and controls, but the distribution of B-cell subsets was different with higher ratios of naive B-cells over memory B-cells in HIV-cHL patients. Blood accumulation of naive B-cells was more marked in patients with advanced cHL stages (p = 0.06). During the follow-up, total B-cell counts increased (p < 0.0001), and the proportion of naive B-cells increased further (p = 0.04). Together the results suggest that in HIV-infected patients, cHL is associated with a particular B-cell-related environment that includes increased production of B-cell-activating cytokines and altered peripheral distribution of B-cell subsets. This B-cell-related environment may fuel the process of tumorigenesis.

Progressive multifocal leukoencephalopathy on dimethyl fumarate with preserved lymphocyte count but deep T-cells exhaustion.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) among multiple sclerosis (MS) patients receiving dimethyl fumarate (DMF) is associated with iatrogenic lymphopenia, predominating on CD8+ T-cells. OBJECTIVES AND METHODS: We report an unusual case of DMF-related PML in a 66-year-old MS patient with preserved lymphocyte count (nadir: 810/mm3) and normal CD8+ T-cells count. RESULTS: A massive overexpression of the inhibitory receptor Programmed Cell Death 1 (PD-1) on CD8+ and memory effector T-cells together with an impaired anti-JC virus (JCV) specific T-cells response were found, compatible with exhaustion. Following DMF withdrawal, PML progressively regressed, PD-1 was downregulated, and a functional anti-JCV response was established. CONCLUSION: T-cells exhaustion may favor PML onset on DMF independently of lymphocyte count.

Frequent altered distribution of peripheral B-lymphocyte subsets in pediatric and adolescent patients with classical Hodgkin lymphoma.

Peripheral lymphopenia is a well-known negative prognostic marker in classical Hodgkin lymphoma (cHL). We characterized the peripheral B-cell compartment in a prospective cohort of 83 pediatric cHL patients. We observed significantly low total B-cell counts (<100 cells/µl) in 31 of 83 patients (37%). More specifically, there was a smaller peripheral IgDhighCD27- naïve B-cell pool among B-cell lymphopenic patients than for non-B-cell lymphopenic patients (p < 0.01). The B-cell count was lower in patients without in situ Epstein Barr Virus (EBV) expression than among those with in situ EBV expression (p = 0.03). Peripheral B-cell lymphopenia was associated with the presence of poor prognostic features, such as advanced lymphoma stage (p < 0.01) and the presence of B symptoms (p = 0.04). Of interest, B-cell lymphopenia resolved in all six studied patients in long-term remission. Our findings support that cHL tumor-associated factors interfere with the distribution of peripheral B-cell subsets.

Germline Genetic Risk Variants for Progressive Multifocal Leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating disorder of the brain caused by reactivation of the JC virus (JCV), a polyomavirus that infects at least 60% of the population but is asymptomatic or results in benign symptoms in most people. PML occurs as a secondary disease in a variety of disorders or as a serious adverse event from immunosuppressant agents, but is mainly found in three groups: HIV-infected patients, patients with hematological malignancies, or multiple sclerosis (MS) patients on the immunosuppressant therapy natalizumab. It is severely debilitating and is deadly in ~50% HIV cases, ~90% of hematological malignancy cases, and ~24% of MS-natalizumab cases. A PML risk prediction test would have clinical utility in all at risk patient groups but would be particularly beneficial in patients considering therapy with immunosuppressant agents known to cause PML, such as natalizumab, rituximab, and others. While a JC antibody test is currently used in the clinical decision process for natalizumab, it is suboptimal because of its low specificity and requirement to periodically retest patients for seroconversion or to assess if a patient's JCV index has increased. Whereas a high specificity genetic risk prediction test comprising host genetic risk variants (i.e., germline variants occurring at higher frequency in PML patients compared to the general population) could be administered one time to provide clinicians with additional risk prediction information that is independent of JCV serostatus. Prior PML case reports support the hypothesis that PML risk is greater in patients with a genetically caused immunodeficiency disorder. To identify germline PML risk variants, we performed exome sequencing on 185 PML cases (70 in a discovery cohort and 115 in a replication cohort) and used the gnomAD variant database for interpretation. Our study yielded 19 rare variants (maximum allele frequency of 0.02 in gnomAD ethnically matched populations) that impact 17 immune function genes (10 are known to cause inborn errors of immunity). Modeling of these variants in a PML genetic risk test for MS patients considering natalizumab treatment indicates that at least a quarter of PML cases may be preventable.

Hepatitis C virus or hepatitis B virus coinfection and lymphoma risk in people living with HIV.

OBJECTIVE: Chronic hepatitis C virus (HCV) and hepatitis B virus (HBV) infections are associated with increased risks of lymphomas in the non-HIV setting. Their impacts on HIV-associated lymphomas deserved further studies in the modern combined antiretroviral therapy (cART) era. DESIGN: We evaluated the associations between HCV, HBV and HIV-related lymphomas in the Lymphovir-ANRS-CO16 cohort. METHODS: Prevalence of HCV seropositivity and chronic HBV infections were compared with those observed in the French Hospital Database on HIV (FHDH-ANRS-CO4). RESULTS: Between 2008 and 2015, 179 patients with HIV-related lymphomas from 32 French hospitals were enrolled, 69 had Hodgkin's lymphoma (39%), and 110 non-Hodgkin's lymphoma (NHL) (61%). The prevalence of HCV infection was higher in patients with NHL than in the FHDH-ANRS-CO4 [26 versus 14%, odd ratio (OR): 2.15; 95% confidence interval (1.35-3.32)] whereas there was no association between Hodgkin's lymphoma and chronic HCV infection. Chronic HBV infection was not associated with NHL in our cohort with a prevalence of 5 versus 7% in FHDH-ANRS-CO4 but tended to be associated with Hodgkin's lymphoma [prevalence of 14%, OR: 2.16 (0.98-4.27)]. Chronic HCV infection tended to pejoratively impact 2-year overall survival in patients with NHL: 72% [57%, 91%] versus 82% [74%, 91%], hazard ratio: 2.14 [0.95-4.84]. In contrast, chronic HBV infection did not correlate with outcome. CONCLUSION: In the modern cART era, chronic HCV infection is associated with an increased risk of NHL in PLWHIV and tends to pejoratively impact overall survival. HBV infection is not associated with the risk of NHL but with a borderline increase of Hodgkin's lymphoma risk.

Follicular CD4 T Cells Tutor CD8 Early Memory Precursors: An Initiatory Journey to the Frontier of B Cell Territory.

The early events of CD8 memory generation remain largely unknown. Here we report that as early as 2 days after antigen priming, very early memory precursors can be identified by their expression of the chemokine receptor CXCR5. These early precursors, which have an effector phenotype, expand and temporarily migrate to the T-B cell zone junction where they interact with follicular CD4+ T cells (Tfh). Remarkably, this interaction with Tfh, hitherto considered as exclusive B cell helpers, is required for CD8 memory precursors to become highly competent memory cells. CD40 and interleukin-21 signaling are involved in the help provided to CXCR5+CD8 memory precursors. This study thus unveils critical early steps in the generation of CD8 memory, identifies CXCR5 as the earliest known marker of CD8 memory precursors, suggests a major helper role for Tfh, and points to possible coordination between the pathways of CD8 and B cell memory generation at the T-B-cell zone junction.

Epstein-Barr virus biomarkers have no prognostic value in HIV-related Hodgkin lymphoma in the modern combined antiretroviral therapy era.

OBJECTIVES: Epstein-Barr virus (EBV) has been implicated in lymphomagenesis of HIV-related classical Hodgkin lymphoma (HIV-cHL). The utility of EBV molecular and serological biomarkers has scarcely been examined in HIV-cHL in the recent combined antiretroviral therapy (cART) era. DESIGN: We evaluated EBV DNA load and a panel of EBV antibodies in HIV-cHL patients prospectively enrolled in the French ANRS-CO16 Lymphovir cohort between 2008 and 2015. METHODS: Pretreatment whole blood, plasma EBV DNA load and serological profiles were analysed in 63 HIV-infected patients diagnosed with cHL. For the 42 patients with available material, comparisons were performed between values at diagnosis and 6 months after the initiation of chemotherapy. RESULTS: Pretreatment whole blood and plasma EBV DNA loads were positive in 84 and 59% of HIV-cHL patients, respectively. Two-year progression-free survival estimates did not differ between the patients with pretreatment whole blood (n = 53) or plasma (n = 37) EBV DNA(+) and the patients with pretreatment whole blood (n = 10) or plasma (n = 26) EBV DNA(-) (92 vs. 80% or 89 vs. 92%, P = 0.36 and 0.47, respectively). At diagnosis, 47% of patients harboured an EBV reactivation serological profile. Following chemotherapy, whole blood and plasma EBV DNA levels significantly declined from medians of 1570 [interquartile range, 230-3760) and 73 (0-320) copies/ml to 690 (0-1830) and 0 (0-0) copies/ml, respectively (P = 0.02 and P < 0.0001, respectively]. Anti-EBV IgG antibody level significantly dropped at 6-month follow-up (P = 0.004). CONCLUSION: Whole blood and plasma EBV DNA loads do not constitute prognostic markers in HIV-cHL patients in the modern cART era.

Increase In Il-31 Serum Levels Is Associated With Reduced Structural Damage In Early Axial Spondyloarthritis.

In spondyloarthritis, little is known about the relation between circulating cytokines and patient phenotype. We have quantified serum levels of T helper type 1 cell (Th1), Th2 and Th17 cytokines in patients with recent-onset axial spondyloarthritis (AxSpA) from the DESIR cohort, a prospective, multicenter French cohort consisting of 708 patients with recent-onset inflammatory back pain (duration >3 months but <3 years) suggestive of AxSpA. Serum levels of Th1, Th2, and Th17 cytokines were assessed at baseline in patients from the DESIR cohort fulfilling the ASAS criteria (ASAS+) and were compared with age- and sex-matched healthy controls. At baseline, ASAS+ patients (n = 443) and healthy controls (n = 79) did not differ in levels of most of the Th1, Th2 and Th17 cytokines except for IL-31, and sCD40L, which were significantly higher for ASAS+ patients than controls (p < 0.001 and p = 0.012, respectively). On multivariable analysis of ASAS+ patients, IL-31 level was associated with sCD40L level (p < 0.0001), modified Stoke AS Spine Score (mSASSS) < 1 (p = 0.035). The multivariable analyses showed that IL-31 was an independent factor associated with mSASSS < 1 (p = 0.001) and low bone mineral density (p = 0.01). Increased level of IL-31 might protect against structural damage but is also related to low BMD.

Outcomes for HIV-associated diffuse large B-cell lymphoma in the modern combined antiretroviral therapy era.

OBJECTIVE: Non-Hodgkin's lymphoma (NHL) remains among the most frequent malignancies in persons living with HIV (PLWHIV). Survival among patients with HIV-associated diffuse large B-cell lymphoma (DLBCL), the most frequent NHL subtype, has improved markedly in recent years. We aimed to analyze characteristics and outcomes of DLBCL in HIV-infected patients in the era of modern combined antiretroviral therapy (cART). DESIGN: PLWHIV with lymphoma were prospectively enrolled in the French ANRS-CO16 Lymphovir cohort between 2008 and 2015. We compared the patients treated with R-CHOP) (rituximab, cyclophosphamide, daunorubicin, vin-cristine, prednisolone) with HIV-negative DLBCL patients enrolled simultaneously in the R-CHOP arms of Lymphoma Study Association trials. RESULTS: Among 110 PLWHIV with NHL, 52 (47%) had systemic DLBCL. These 52 cases had frequent extranodal disease (81%), poor performance status (35%) and advanced age-adjusted international prognostic index (aaIPI) (58%), and were mainly treated with R-CHOP (n = 44, 85%). Their median CD4 T-cell count was 233 cells/µl, and 79% of patients were on cART. The 2-year overall and progression-free survival rates were both 75% (95% confidence interval: 64%, 88%). Factors associated with progression or death in univariate analysis were poor performance status [hazard ratio: 3.3 (1.2, 8.9)], more than one extranodal site [hazard ratio: 3.4 (1.1, 10.5)] and an advanced aaIPI [hazard ratio: 3.7 (1.0, 13.1)]. Progression-free survival after R-CHOP therapy did not differ from that of the HIV-negative counterparts (P = 0.11). CONCLUSION: In the recent cART era, despite frequent high-risk features, the 2-year overall survival of HIV-DLBCL patients reaches 75%. Outcomes after R-CHOP therapy are similar to those of HIV-negative patients with similar aaIPI.

Refractory T-Cell Anergy and Rapidly Fatal Progressive Multifocal Leukoencephalopathy After Prolonged CTLA4 Therapy.

Progressive multifocal leukoencephalopathy (PML) is a deadly demyelinating disease due to central nervous system replication of the human polyomavirus JC virus (JCV) in immunosuppressed patients. The only effective therapeutic approach is to restore anti-JCV T-cell responses. In this study, we describe a case of rapidly fatal PML with JCV T-cell anergy in a renal transplant patient treated with CTLA4-Ig (belatacept, a CD28-B7 costimulation blocker and T-cell anergy inducer). T-cell anergy could not be reversed despite several therapeutic approaches. Progressive multifocal leukoencephalopathy secondary to biotherapy-induced T-cell anergy may thus represent a subset of PML with major resistance to anti-JCV immune recovery.

Serum IL-33, a new marker predicting response to rituximab in rheumatoid arthritis.

BACKGROUND: Recent works have suggested a possible link between interleukin (IL)-33 and B-cell biology. We aimed to study the possible association between serum IL-33 detection and response to rituximab (RTX) in rheumatoid arthritis (RA) patients in different cohorts with an accurate enzyme-linked immunosorbent assay (ELISA). METHODS: Serum IL-33, rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP), and high serum immunoglobulin (Ig)G levels were assessed in 111 RA patients receiving a first course of 2 g RTX (cohort 1) in an observational study and in 74 RA patients treated with the same schedule in routine care (cohort 2). Univariate and multivariate analyses identified factors associated with a European League Against Rheumatism (EULAR) response at 24 weeks. RESULTS: At week 24, 84/111 (76%) and 54/74 (73%) patients reached EULAR response in cohorts 1 and 2, respectively. Serum IL-33 was detectable in only 33.5% of the patients. In the combined cohorts, the presence of RF or anti-CCP (odds ratio (OR) 3.27, 95% confidence interval (CI) 1.13-9.46; p = 0.03), high serum IgG (OR 2.32, 95% CI 1.01-5.33; p = 0.048), and detectable serum IL-33 (OR 2.40, 95% CI 1.01-5.72; p = 0.047) were all associated with RTX response in multivariate analysis. The combination of these three factors increased the likelihood of response to RTX. When serum IL-33 detection was added to seropositivity and serum IgG level, 100% of the patients with the three risk factors (corresponding to 9% of the population) responded to RTX (OR versus patients with none of the three risk factors 29.61, 95% CI 1.30-674.79; p = 0.034). CONCLUSION: Detectable serum IL-33 may predict clinical response to RTX independently of, and synergistically with, auto-antibodies and serum IgG level. TRIAL REGISTRATION: NCT01126541 ; 18 May 2010.