Olivier Lambotte

Microbial translocation is a cause of systemic immune activation in chronic HIV infection

Chronic activation of the immune system is a hallmark of progressive HIV infection and better predicts disease outcome than plasma viral load, yet its etiology remains obscure. Here we show that circulating microbial products, probably derived from the gastrointestinal tract, are a cause of HIV-related systemic immune activation. Circulating lipopolysaccharide, which we used as an indicator of microbial translocation, was significantly increased in chronically HIV-infected individuals and in simian immunodeficiency virus (SIV)-infected rhesus macaques (P ≤ 0.002). We show that increased lipopolysaccharide is bioactive in vivo and correlates with measures of innate and adaptive immune activation. Effective antiretroviral therapy seemed to reduce microbial translocation partially. Furthermore, in nonpathogenic SIV infection of sooty mangabeys, microbial translocation did not seem to occur. These data establish a mechanism for chronic immune activation in the context of a compromised gastrointestinal mucosal surface and provide new directions for therapeutic interventions that modify the consequences of acute HIV infection.

Post-Treatment HIV-1 Controllers with a Long-Term Virological Remission after the Interruption of Early Initiated Antiretroviral Therapy ANRS VISCONTI Study

Combination antiretroviral therapy (cART) reduces HIV-associated morbidities and mortalities but cannot cure the infection. Given the difficulty of eradicating HIV-1, a functional cure for HIV-infected patients appears to be a more reachable short-term goal. We identified 14 HIV patients (post-treatment controllers [PTCs]) whose viremia remained controlled for several years after the interruption of prolonged cART initiated during the primary infection. Most PTCs lacked the protective HLA B alleles that are overrepresented in spontaneous HIV controllers (HICs); instead, they carried risk-associated HLA alleles that were largely absent among the HICs. Accordingly, the PTCs had poorer CD8+ T cell responses and more severe primary infections than the HICs did. Moreover, the incidence of viral control after the interruption of early antiretroviral therapy was higher among the PTCs than has been reported for spontaneous control. Off therapy, the PTCs were able to maintain and, in some cases, further reduce an extremely low viral reservoir. We found that long-lived HIV-infected CD4+ T cells contributed poorly to the total resting HIV reservoir in the PTCs because of a low rate of infection of naïve T cells and a skewed distribution of resting memory CD4+ T cell subsets. Our results show that early and prolonged cART may allow some individuals with a rather unfavorable background to achieve long-term infection control and may have important implications in the search for a functional HIV cure.

Management of immune checkpoint blockade dysimmune toxicities: a collaborative position paper.

Monoclonal antibodies targeted against the immune checkpoint molecules CTLA-4 and PD-1 have recently obtained approval for the treatment of metastatic melanoma and advanced/refractory non small-cell lung cancers. Therefore, their use will not be limited anymore to selected hospitals involved in clinical trials. Indeed, they will be routinely prescribed in many cancer centers across the world. Besides their efficacy profile, these immune targeted agents also generate immune-related adverse events (irAEs). This new family of dysimmune toxicities remains largely unknown to the broad oncology community. Although severe irAEs remain rare (∼10% of cases under monotherapy), they can become life-threatening if not anticipated and managed appropriately. Over the last 5 years, Gustave Roussy has accumulated a significant experience in the prescription of immune checkpoint blockade (ICB) antibodies and the management of their toxicities. Together with the collaboration of Gustave Roussys network of organ specialists with expertise in irAEs, we propose here some practical guidelines for the oncologist to help in the clinical care of patients under ICB immunotherapy.

Safety profiles of anti-CTLA-4 and anti-PD-1 antibodies alone and in combination

Inhibition of immune checkpoints using anti-programmed cell death-1 (PD-1) or anti cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4) monoclonal antibodies has revolutionized the management of patients with advanced-stage melanoma and is among the most promising treatment approaches for many other cancers. Use of CTLA-4 and PD-1 inhibitors, either as single agents, or in combination, has been approved by the US FDA for the treatment of metastatic melanoma. Treatment with these novel immunotherapies results in a unique and distinct spectrum of adverse events, which are mostly related to activation of the immune system and are, therefore, an unwanted consequence of their mechanisms of action. Adverse effects of CTLA-4 and/or PD-1 inhibition are most commonly observed in the skin, gastrointestinal tract, liver and endocrine systems and include pruritus, rash, nausea, diarrhoea and thyroid disorders. In this Review, the authors describe the adverse event profile of checkpoint inhibitors targeting CTLA-4 and PD-1, used both as monotherapies and in combination and aim to provide some general guidelines, based upon the mechanisms of action of these therapies and on the management of these immune-related adverse events.

HIV disease progression despite suppression of viral replication is associated with exhaustion of lymphopoiesis

The mechanisms of CD4(+) T-cell count decline, the hallmark of HIV disease progression, and its relationship to elevated levels of immune activation are not fully understood. Massive depletion of CD4(+) T cells occurs during the course of HIV-1 infection, so that maintenance of adequate CD4(+) T-cell levels probably depends primarily on the capacity to renew depleted lymphocytes, that is, the lymphopoiesis. We performed here a comprehensive study of quantitative and qualitative attributes of CD34(+) hematopoietic progenitor cells directly from the blood of a large set of HIV-infected persons compared with uninfected donors, in particular the elderly. Our analyses underline a marked impairment of primary immune resources with the failure to maintain adequate lymphocyte counts. Systemic immune activation emerges as a major correlate of altered lymphopoiesis, which can be partially reversed with prolonged antiretroviral therapy. Importantly, HIV disease progression despite elite control of HIV replication or virologic success on antiretroviral treatment is associated with persistent damage to the lymphopoietic system or exhaustion of lymphopoiesis. These findings highlight the importance of primary hematopoietic resources in HIV pathogenesis and the response to antiretroviral treatments.

Development and Validation of the HScore, a Score for the Diagnosis of Reactive Hemophagocytic Syndrome

Because it has no unique clinical, biologic, or histologic features, reactive hemophagocytic syndrome may be difficult to distinguish from other diseases such as severe sepsis or hematologic malignancies. This study was undertaken to develop and validate a diagnostic score for reactive hemophagocytic syndrome.

Association Study of Common Genetic Variants and HIV-1 Acquisition in 6,300 Infected Cases and 7,200 Controls

Multiple genome-wide association studies (GWAS) have been performed in HIV-1 infected individuals, identifying common genetic influences on viral control and disease course. Similarly, common genetic correlates of acquisition of HIV-1 after exposure have been interrogated using GWAS, although in generally small samples. Under the auspices of the International Collaboration for the Genomics of HIV, we have combined the genome-wide single nucleotide polymorphism (SNP) data collected by 25 cohorts, studies, or institutions on HIV-1 infected individuals and compared them to carefully matched population-level data sets (a list of all collaborators appears in Note S1 in Text S1). After imputation using the 1,000 Genomes Project reference panel, we tested approximately 8 million common DNA variants (SNPs and indels) for association with HIV-1 acquisition in 6,334 infected patients and 7,247 population samples of European ancestry. Initial association testing identified the SNP rs4418214, the C allele of which is known to tag the HLA-B*57:01 and B*27:05 alleles, as genome-wide significant (p = 3.6×10−11). However, restricting analysis to individuals with a known date of seroconversion suggested that this association was due to the frailty bias in studies of lethal diseases. Further analyses including testing recessive genetic models, testing for bulk effects of non-genome-wide significant variants, stratifying by sexual or parenteral transmission risk and testing previously reported associations showed no evidence for genetic influence on HIV-1 acquisition (with the exception of CCR5Δ32 homozygosity). Thus, these data suggest that genetic influences on HIV acquisition are either rare or have smaller effects than can be detected by this sample size.

HIV-1 persistence, viral reservoir, and the central nervous system in the HAART era

HAART therapy has led to a significant reduction of general and neurological morbidity, and mortality among HIV‐1 infected patients. It can also decrease HIV‐1 RNA titres in plasma and CSF towards undetectable level. However, the initial hope of achieving total eradication of the virus from the body has vanished. Even in patients who do not develop viral resistance or treatment intolerance, two kinds of viral persistence have been demonstrated both in lymphoid and central nervous system. The first one is a smoldering infection that persists, despite prolonged and apparently efficient HAART, in monocytes, tissue macrophages and most probably microglia. The second one is an integration of proviral DNA in the genome of subpopulations of CD4 lymphocytes of patients receiving efficient HAART. A similar viral integration in astrocytes and less likely in resting microglia is suggested by several studies, although it has yet to be demonstrated conclusively

Peg-IFNα/ribavirin/protease inhibitor combination in hepatitis C virus associated mixed cryoglobulinemia vasculitis: results at week 24

Background The standard-of-care treatment of patients with hepatitis C virus (HCV)-mixed cryoglobulinemia (MC) vasculitis includes pegylated interferon α (PegIFN)-α plus ribavirin and/or rituximab. About 30–40% of patients are non-responders or relapsers to such combination. Objective To analyse the safety and efficacy of Peg-IFNα/ribavirin/protease inhibitor combination in HCV-MC vasculitis. Patients and methods Open-label, prospective, cohort study including 23 patients with HCV-MC vasculitis. Peg-IFNα/ribavirin was associated to telaprevir (375 mg three times daily, for 12 weeks, (n=15)) or boceprevir (800 mg three times daily, for 44 weeks, (n=8)) for 48 weeks. Results The median age was 59 (52.5–66) years, with 48.8% women. Thirteen patients (56.5%) were complete clinical responders, and 10 (43.5%) were partial responders at week 24. The virological response (ie, HCV RNA negativation) was of 69.6% at week 24 (p=0.005). The cryoglobulin level decreased from 0.44 to 0.06 g/l (p=0.0006) and the C4 level increased from 0.09 to 0.15 g/l (p=0.045). Grades 3 and 4 adverse events (mainly anaemia, neutropenia and thrombocytopenia) were observed in 10 cases (43.5%). Twenty patients (87%) received erythropoietin, 9 (39.1%) had red cell transfusion, and 2 (8.7%) had granulocyte stimulating agents. Antiviral therapy discontinuation was required in 8 (34.7%) patients for virological non-response (n=5), virological relapse (n=2) and depression (n=1). Conclusions Peg-IFNα/ribavirin/protease inhibitor combination seems highly effective in HCV-MC. Such therapeutic regimen should be administered cautiously considering the high rate of side effects.

Prognostic factors of early death in a cohort of 162 adult haemophagocytic syndrome: impact of triggering disease and early treatment with etoposide.

Reactive haemophagocytic syndrome is a life‐threatening disease for which factors influencing the outcome remain unclear. We sought to identify determinants of early mortality in patients with reactive haemophagocytic syndrome by conducting a non‐interventional retrospective multicentre study in three tertiary care teaching hospitals over a 6‐year period. The medical files of 162 patients fulfilling our diagnostic criteria of haemophagocytic syndrome were reviewed. Patients were classified according to 30‐d outcome following diagnosis. Thirty‐three patients (20·4%) died within 30 d. Clinical features at diagnosis associated with 30‐d death in univariate analysis were older age (P = 0·004), underlying lymphoma (P = 0·04), lower platelet count (P = 0·001) and elevated aspartate aminotransferase and lactate dehydrogenase (P = 0·04 both). The use of etoposide as a first‐line treatment tended to be associated with a better outcome (P = 0·079). In multivariate analyses, increasing age, decreasing platelet count, underlying lymphoma and no etoposide in the management were associated with a poorer prognosis (P = 0·03, 0·01, 0·003 and 0·04, respectively). These prognostic factors could help to identify those patients more severely affected by reactive haemophagocytic syndrome, who should benefit from aggressive supportive care, combined with specific treatment of the precipitating factor.