Virginia Sheikh

Evidence for innate immune system activation in HIV type 1-infected elite controllers.

BACKGROUND Elite controllers maintain high CD4(+) T-cell counts and suppress plasma human immunodeficiency virus (HIV) viremia in the absence of antiretroviral therapy (ART). It is unclear whether levels of biomarkers associated with coagulation, monocyte activation, and inflammation, which are linked to HIV-associated mortality, differ among elite controllers, ART recipients with suppressed viremia (plasma HIV type 1 RNA load, <50 copies/mL), and HIV-negative controls. METHODS A total of 68 elite controllers, 68 ART recipients with suppressed viremia, and 35 HIV-negative participants were evaluated. Levels of biomarkers in cryopreserved plasma were measured by enzyme-linked immunosorbent assay and electrochemiluminescence-based assay. Cryopreserved peripheral blood mononuclear cells were used to assess monocyte phenotype and function and interferon-inducible gene expression (IFIG). Nonparametric testing was used to compare median values among groups. RESULTS CD4(+) T-cell counts were similar between elite controllers and HIV-negative controls but significantly lower in ART recipients with suppressed viremia. Levels of C-reactive protein and interleukin 6 were higher and IFIG upregulated in both HIV-positive groups, compared with HIV-negative controls. D-dimer and soluble tissue factor levels were significantly elevated in elite controllers, compared with those in ART recipients with suppressed viremia and HIV-negative controls (P < .01). Monocytes from elite controllers (and ART recipients with suppressed viremia) expressed lower CCR2 and higher CX3CR1 levels than monocytes from HIV-negative controls. In addition, elite controllers had a significantly higher proportion of CD14(++)CD16(+) monocytes, compared with HIV-negative controls. CONCLUSION Elite controllers maintain control of plasma HIV viremia and have evidence of an activated innate immune response.

Markers of endothelial dysfunction, coagulation and tissue fibrosis independently predict venous thromboembolism in Hiv

Objective:HIV infection is associated with coagulation abnormalities and significantly increased risk of venous thrombosis. It has been shown that higher plasma levels of coagulation and inflammatory biomarkers predicted mortality in HIV. We investigated the relationship between venous thrombosis and HIV-related characteristics, traditional risk factors of hypercoagulability, and pre-event levels of biomarkers. Design:A retrospective case–control study of 23 HIV-infected individuals who experienced an incident venous thromboembolic event while enrolled in National Institutes of Health studies from 1995 to 2010 and 69 age-matched and sex-matched HIV-infected individuals without known venous thromboembolism (VTE). Methods:Biomarkers of inflammation, endothelial dysfunction, coagulation, tissue fibrosis, and cytomegalovirus (CMV) reactivation were assessed by ELISA-based assays and PCR using plasma obtained prior to the event. Results:VTE events were related to nadir CD4 cell count, lifetime history of multiple opportunistic infections, CMV disease, CMV viremia, immunological AIDS, active infection, and provocation (i.e., recent hospitalization, surgery, or trauma). VTE events were independently associated with increased plasma levels of P-selectin (P = 0.002), D-dimer (P = 0.01), and hyaluronic acid (P = 0.009) in a multivariate analysis. No significant differences in antiretroviral or interleukin-2 exposures, plasma HIV viremia, or other traditional risk factors were observed. Conclusion:Severe immunodeficiency, active infection, and provocation are associated with venous thromboembolic disease in HIV. Biomarkers of endothelial dysfunction, coagulation, and tissue fibrosis may help identify HIV-infected patients at elevated risk of VTE.

Idiopathic CD4 lymphocytopenia: a case of missing, wandering or ineffective T cells

Idiopathic CD4 lymphocytopenia (ICL) is a presumed heterogenous syndrome with key element low CD4 T-cell counts (below 300/mm3) without evidence of HIV infection or other known immunodeficiency. The etiology, pathogenesis, and management of ICL remain poorly understood and inadequately defined. The clinical presentation can range from serious opportunistic infections to incidentally diagnosed asymptomatic individuals. Cryptococcal and non-tuberculous mycobacterial infections and progressive multifocal leukoencephalopathy are the most significant presenting infections, although the spectrum of opportunistic diseases can be similar to that in patients with lymphopenia and HIV infection. Malignancy is common and related to opportunistic pathogens with an oncogenic potential. Autoimmune diseases are also seen in ICL with an increased incidence. The etiology of ICL is unknown. Mechanisms implicated in CD4 reduction may include decreased production, increased destruction, and tissue sequestration. New distinct genetic defects have been identified in certain patients with ICL, supporting the hypothesis of the lack of a common etiology in this syndrome. The management of ICL is focused on the treatment of opportunistic infections, appropriate prophylactic antibiotics, and close monitoring. In selected patients with life-threatening infections or profound immunodeficiency, strategies to increase T-cell counts or enhance immune function could be considered and have included interleukin-2, interferon-gamma, interleukin-7, and hematopoietic stem cell transplantation. The prognosis is influenced by the accompanying opportunistic infections and may be affected by publication bias of severe cases with unfavorable outcomes. As newer laboratory investigation techniques are being developed and targeted experimental treatments become available, our comprehension and prognosis of this rare syndrome could be significantly improved.

Graves’ disease as immune reconstitution disease in Hiv-positive patients is associated with naive and primary thymic emigrant Cd4+ T-cell recovery

Objective:Immune restoration disease (IRD) can develop in HIV-infected patients following antiretroviral therapy (ART) initiation as unmasking or paradoxical worsening of opportunistic infections and, rarely, autoimmune phenomena. Although IRD usually occurs in the first months of ART during memory CD4+ T-cell recovery, Graves’ disease occurs as a distinctive late-onset IRD and its pathogenesis is unclear. Design:Seven patients who developed Graves’ disease following ART initiation from the primary HIV care clinic at the National Institutes of Health were retrospectively identified and each was matched with two HIV-infected controls based on age, sex, and baseline CD4+ T-cell count. Laboratory evaluations on stored cryopreserved samples were performed. Methods:Immunophenotyping of peripheral blood mononuclear cells (PBMCs), T-cell receptor excision circle (TREC) analysis in PBMCs, measurement of serum cytokines, and luciferase immunoprecipitation systems (LIPS) analysis for autoimmune antibodies were performed on stored samples for cases and controls at baseline and longitudinally following ART initiation. TSH/thyrotropin receptor (TSH-R) antibody testing was performed on serum from cases. Data were analyzed using nonparametric testing. Results:In comparison with controls, the proportion of naive CD4+ T cells increased significantly (P = 0.0027) in the Graves’ disease-IRD patients. TREC/106 PBMCs also increased significantly following ART in Graves’ disease-IRD patients compared with controls (P = 0.0071). Similarly, LIPS analysis demonstrated increases in nonthyroid-related autoantibody titers over time following ART in cases compared with controls. Conclusion:Our data suggest that Graves’ disease-IRD, in contrast to early-onset IRD, is associated with naive and primary thymic emigrant CD4+ T-cell recovery and inappropriate autoantibody production.

Administration of interleukin-7 increases CD4 T cells in idiopathic CD4 lymphocytopenia.

Idiopathic CD4 lymphopenia (ICL) is a rare syndrome defined by low CD4 T-cell counts (<300/µL) without evidence of HIV infection or other known cause of immunodeficiency. ICL confers an increased risk of opportunistic infections and has no established treatment. Interleukin-7 (IL-7) is fundamental for thymopoiesis, T-cell homeostasis, and survival of mature T cells, which provides a rationale for its potential use as an immunotherapeutic agent for ICL. We performed an open-label phase 1/2A dose-escalation trial of 3 subcutaneous doses of recombinant human IL-7 (rhIL-7) per week in patients with ICL who were at risk of disease progression. The primary objectives of the study were to assess safety and the immunomodulatory effects of rhIL-7 in ICL patients. Injection site reactions were the most frequently reported adverse events. One patient experienced a hypersensitivity reaction and developed non-neutralizing anti-IL-7 antibodies. Patients with autoimmune diseases that required systemic therapy at screening were excluded from the study; however, 1 participant developed systemic lupus erythematosus while on study and was excluded from further rhIL-7 dosing. Quantitatively, rhIL-7 led to an increase in the number of circulating CD4 and CD8 T cells and tissue-resident CD3 T cells in the gut mucosa and bone marrow. Functionally, these T cells were capable of producing cytokines after mitogenic stimulation. rhIL-7 was well tolerated at biologically active doses and may represent a promising therapeutic intervention in ICL. This trial was registered at www.clinicaltrials.gov as #NCT00839436.

Prevalence of Strongyloides stercoralis in an urban US AIDS cohort

Abstract Objectives: We examined the prevalence of Strongyloides stercoralis (Ss) infection in a cohort of AIDS patients from a US urban centre. We monitored our cohort for possible cases of dissemination or immune reconstitution inflammatory syndrome after antiretroviral therapy (ART) initiation. Methods: One hundred and three HIV-infected participants were prospectively sampled from a cohort observational study of ART-naive HIV-1-infected patients with CD4 ⩽100 T cells/μl. Clinical symptoms, corticosteroid therapy, eosinophilia, CD4 count, and plasma HIV-RNA were reviewed. Sera were tested by an enzyme-linked immunosorbent assay (CrAg-ELISA) to crude Ss extract or to an Ss-specific recombinant protein (NIE) and by luciferase immunoprecipitation system assay (LIPS) for Ss-specific antibodies. Results: Twenty-five per cent of study participants were Strongyloides seropositive by CrAg-ELISA and 62% had emigrated from Strongyloides-endemic areas. The remaining 38% of the seropositives were US born and tested negative by NIE and LIPS. CrAg-ELISA-positive participants had a median CD4 count of 22 T cells/μl and a median HIV-RNA of 4·87 log10 copies/ml. They presented with diarrhea (27%), abdominal pain (23%), and skin manifestations (35%) that did not differ from seronegative patients. Peripheral blood eosinophilia was common among seropositive patients (prevalence of 62% compared to 29% in seronegatives, P = 0·004). Seropositive patients were treated with ivermectin. There were no cases of hyperinfection syndrome. Discussion: Strongyloidiasis may be prevalent in AIDS patients in the USA who emigrated from Ss-endemic countries, but serology can be inconclusive, suggesting that empiric ivermectin therapy is a reasonable approach in AIDS patients originating from Strongyloides endemic areas.

Preliminary evaluation of a highly automated instrument for the selection of CD34+ cells from mobilized peripheral blood stem cell concentrates

Cell selection is an important part of manufacturing cellular therapies. A new highly automated instrument, the CliniMACS Prodigy (Miltenyi Biotec), was evaluated for the selection of CD34+ cells from mobilized peripheral blood stem cell (PBSC) concentrates using monoclonal antibodies conjugated to paramagnetic particles.

Cerebrospinal Fluid HIV-1 Compartmentalization in a Patient With AIDS and Acute Varicella-Zoster Virus Meningomyeloradiculitis

We report a case of AIDS presenting as varicella-zoster virus (VZV) meningomyeloradiculitis associated with human immunodeficiency virus (HIV) quasispecies compartmentalization within the cerebrospinal fluid (CSF), and a CSF viral load that was 1 log higher than in peripheral blood. Prolonged antiviral therapy for both VZV and HIV type 1 was associated with partial resolution.

Inflammatory monocytes expressing tissue factor drive SIV and HIV coagulopathy

Activated monocytes in blood promote chronic inflammation and persistent coagulation in HIV-infected patients and SIV-infected macaques. Curbing complications in chronic HIV HIV-infected patients who have viral suppression due to treatment are still at enhanced risk of comorbidities such as neurological or cardiovascular complications, so Schechter et al. explored how inflammation and coagulation intersect in chronic HIV. To do so, they examined monocytes that express tissue factor in samples from patients or macaques infected with SIV. These monocytes appear to be crucial to coagulopathy. Treatment with a compound isolated from tick saliva, Ixolaris, can interrupt this damaging pathway. It is possible in the future that HIV patients would be treated with Ixolaris to stem some of the side effects of chronic infection. In HIV infection, persistent inflammation despite effective antiretroviral therapy is linked to increased risk of noninfectious chronic complications such as cardiovascular and thromboembolic disease. A better understanding of inflammatory and coagulation pathways in HIV infection is needed to optimize clinical care. Markers of monocyte activation and coagulation independently predict morbidity and mortality associated with non-AIDS events. We identified a specific subset of monocytes that express tissue factor (TF), persist after virological suppression, and trigger the coagulation cascade by activating factor X. This subset of monocytes expressing TF had a distinct gene signature with up-regulated innate immune markers and evidence of robust production of multiple proinflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor–α (TNF-α), and IL-6, ex vivo and in vitro upon lipopolysaccharide stimulation. We validated our findings in a nonhuman primate model, showing that TF-expressing inflammatory monocytes were associated with simian immunodeficiency virus (SIV)–related coagulopathy in the progressive [pigtail macaques (PTMs)] but not in the nonpathogenic (African green monkeys) SIV infection model. Last, Ixolaris, an anticoagulant that inhibits the TF pathway, was tested and potently blocked functional TF activity in vitro in HIV and SIV infection without affecting monocyte responses to Toll-like receptor stimulation. Strikingly, in vivo treatment of SIV-infected PTMs with Ixolaris was associated with significant decreases in D-dimer and immune activation. These data suggest that TF-expressing monocytes are at the epicenter of inflammation and coagulation in chronic HIV and SIV infection and may represent a potential therapeutic target.

A Paradoxical Treatment for a Paradoxical Condition: Infliximab Use in Three Cases of Mycobacterial IRIS

The management of corticosteroid refractory immune reconstitution inflammatory syndrome (IRIS) is currently unclear. Infliximab administration was associated with clinical improvement without significant adverse events in 3 patients with mycobacterial IRIS. Immunologic and virologic responses to antiretroviral therapy were unaffected. Tumor necrosis factor blockade may be beneficial for IRIS and warrants further study in clinical trials.