As the world is severely affected by COVID-19 pandemic, the use of chloroquine and hydroxychloroquine in prevention or for the treatment of patients is allowed in multiple countries but remained at ...the center of much controversy in recent days. This review describes the properties of chloroquine and hydroxychloroquine, and highlights not only their anti-viral effects but also their important immune-modulatory properties and their well-known use in autoimmune diseases, including systemic lupus and arthritis. Chloroquine appears to inhibit
SARS virus' replication and to interfere with SARS-CoV2 receptor (ACE2). Chloroquine and hydroxychloroquine impede lysosomal activity and autophagy, leading to a decrease of antigen processing and presentation. They are also known to interfere with endosomal Toll-like receptors signaling and cytosolic sensors of nucleic acids, which result in a decreased cellular activation and thereby a lower type I interferons and inflammatory cytokine secretion. Given the antiviral and anti-inflammatory properties of chloroquine and hydroxychloroquine, there is a rational to use them against SARS-CoV2 infection. However, the anti-interferon properties of these molecules might be detrimental, and impaired host immune responses against the virus. This duality could explain the discrepancy with the recently published studies on CQ/HCQ treatment efficacy in COVID-19 patients. Moreover, although these treatments could be an interesting potential strategy to limit progression toward uncontrolled inflammation, they do not appear
sufficiently potent to control the whole inflammatory process in COVID-19, and more targeted and/or potent therapies should be required at least in add-on.
Children with Down syndrome (DS) suffer from recurrent respiratory infections, which represent the leading cause of mortality during childhood. This susceptibility to infections is usually considered ...multifactorial and related to both impaired immune function and non-immunological factors. Infections are also one of the top causes of death in DS at adulthood. DS is considered an immunodeficiency with syndromic features by some researchers because of this high rate of infection and the immunological characteristics observed in children with DS. Little is known about the immune status of adult patients. Herein, we report the clinical and immune phenotype of 44 adults with DS, correlated with their infectious history. We observed that these adults had an aberrant lymphocyte phenotype with decreased naïve/memory T cell ratios and reduced numbers of switched memory B cells. The lower incidence of infectious events at adulthood distinguish DS from other inborn errors of immunity. Primary immunodeficiency-related features in DS could explain the increased risk of developing autoimmunity, malignancies, and infections. During adulthood, this immune dysfunction may be compensated for in mid-life, and infection-related mortality observed in older patients might be favored by multiple factors such as neurological impairment or nosocomial antigen exposure.
www.ClinicalTrials.gov, identifier NCT01663675 (August 13, 2012).
Down syndrome (DS) is the most common form of viable chromosomal abnormality. DS is associated with recurrent infections, auto-immunity and malignancies in children. Little is known about immunity ...and infections in DS at adulthood.
We studied two separate group of adults (> 18 years old) with DS in a single referral tertiary center (Strasbourg University Hospital). The first group included 37 ambulatory DS patients between November 2014 and May 2017. We analyzed exhaustive serological and immunobiological parameters, at one point, together with the prevalence of infections, autoimmune manifestations and malignancies. The second group included 64 hospitalized patients (138 stays) in the same center, between January 2005 and December 2016.
One hundred and one adult patients with DS were included. Unlike children and despite a global lymphopenia, adults with DS underwent few infections in our ambulatory group. They did not experience any malignancy and, apart from hypothyroidism, they presented only occasional autoimmune manifestations. Hospitalized DS patients were older than ambulatory ones (median age 47 years (18-73) vs. 27 (18-52), p < 0.0001) and admitted mostly for infections (76.8%). Infections were associated with epilepsy and dementia (OR 6.5 (2.2-19), p = 0.001; p = 0.0006 in multivariate analysis) and higher mortality (OR 7.4 (1.4-37), p = 0.01).
Despite persistent immunobiological abnormalities at adulthood, young ambulatory adults with DS remain healthy with a low rate of infections. Infections are associated with neurological degeneration and increase the mortality arguing for a dedicated support of older DS patients.
ClinicalTrials.gov: NCT01663675 (August 13, 2012). Hospital Clinical Research Program (PHRC): number 2012-A00466-37 (Dr Y. Alembik).
Castleman's disease (CD) and thrombotic thrombocytopenic purpura (TTP) are rare diseases that can affect the general population, especially those with HIV. Owing to their rarity, the association ...between CD and TTP remains insufficiently understood. In this study, we present a case of a 53-year-old patient with controlled HIV infection who presented with fever, lymphadenopathy, severe anaemia, and thrombocytopenia. After a series of tests, the diagnosis was concurrent human herpesvirus 8 (HHV8)-related multicentric CD (MCD) and TTP. Only four male patients were previously reported having this association, with HHV8 present in four and HIV in three patients, suggesting that coinfection with HHV8 and HIV is a pivotal factor in MCD with TTP occurrence.
Castleman's disease (CD) and thrombotic thrombocytopenic purpura (TTP) are rare diseases, and their association remains extremely uncommon.We report a case of multicentric CD (MCD) with TTP in a 53-year-old male patient with HIV.Only five patients, including ours, have been reported as having both MCD and TTP, with all five having HHV8 and four having HIV. Thus, coinfection with HHV8 and HIV may be a potential pivotal factor in the occurrence of MCD with TTP.
Disseminated infections due to
Bacillus Calmette-Guérin (BCG) are unusual and occur mostly in patients with inborn error of immunity (IEI) or acquired immunodeficiency. However, cases of secondary ...BCGosis due to intravesical BCG instillation have been described. Herein, we present a case of severe BCGosis occurring in an unusual situation.
We report one case of severe disseminated BCG disease occurring after hematological malignancy in a 48-year-old man without BCG instillation and previously vaccinated in infancy with no complication. Laboratory investigations demonstrated that he was not affected by any known or candidate gene of IEI or intrinsic cellular defect involving IFNγ pathway. Whole genome sequencing of the BCG strain showed that it was most closely related to the
BCG Tice strain, suggesting an unexpected relationship between the secondary immunodeficiency of the patient and the acquired BCG infection.
This case highlights the fact that, in addition to the IEI, physicians, as well as microbiologists and pharmacists should be aware of possible acquired disseminated BCG disease in secondary immunocompromised patients treated in centers that administrate BCG for bladder cancers.
It is now widely accepted that antiphospholipid antibodies (aPL) have direct pathogenic effects and that B cells, notably through aPL production, play a key role in the development of ...antiphospholipid syndrome (APS). Recent findings strengthened the implication of B cells with the description of specific B cell phenotype abnormalities and inborn errors of immunity involving B cell signaling in APS patients. In addition, it has been shown in preclinical models that cross-reactivity between APS autoantigens and mimotopes expressed by human gut commensals can lead to B cell tolerance breakdown and are sufficient for APS development. However, B cell targeting therapies are surprisingly not as effective as expected in APS compared to other autoimmune diseases. Elucidation of the B cell tolerance breakdown mechanisms in APS patients may help to develop and guide the use of novel therapeutic agents that target B cells or specific immune pathway.
•The hypercoagulable state in antiphospholipid syndrome (APS) is related to pathogenic antiphospholipid antibodies (aPL).•B cells, notably through aPL production, have a central role in the pathogenesis of APS.•aPL development may result from mono/polygenic inborn errors of immunity and specific interactions with commensal hosts.•Paradoxically, B cell targeting therapies are disappointing in APS as compared to experiences in other autoimmune diseases.
The management of lymphoma in patients with primary immunodeficiency (PID) is challenging because of its poor prognosis and complex therapeutic approaches. We conducted a systematic literature review ...of case-reports, case-series, and cohorts indexed in MEDLINE reporting the association of lymphoma and PID. One hundred and eighty-two articles were selected out of 787. We identified 386 cases. Median age at diagnosis of PID and lymphoma was 9.5 and 12 years old, respectively. T-cell deficiencies were the main PIDs associated with lymphoma (57%). The most prevalent lymphoma was diffuse large B-cell lymphoma (33.5%). Epstein-Barr Virus-driven lymphomas were mostly observed in innate immunodeficiencies (when reported). Complete response to treatment was observed in 65.8% of the cases. Death occurred in 38.2%. Few allogenic stem cell transplantations were performed (29 cases). Our detailed analysis of the literature provides a landscape of lymphoma's occurrence in PID. Devoted studies in specific sub-groups of patients at risk are needed to develop dedicated protocols.
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