Low Risk of Death, but Substantial Program Attrition, in Pediatric HIV Treatment Cohorts in Sub-Saharan Africa

BACKGROUND: To date, an estimated 10% of children eligible for antiretroviral treatment (ART) receive it, and the frequency of retention in programs is unknown. We evaluated the 2-year risks of death and loss to follow-up (LTFU) of children after ART initiation in a multicenter study in sub-Saharan Africa. METHODS: Pooled analysis of routine individual data from 16 participating clinics produced overall Kaplan-Meier estimates of the probabilities of death or LTFU after ART initiation. Risk factors analysis used Weibull regression, accounting for between-cohort heterogeneity. RESULTS: The median age of 2405 children at ART initiation was 4.9 years (12%, younger than 12 months), 52% were male, 70% had severe immunodeficiency, and 59% started ART with a nonnucleoside reverse transcriptase inhibitor. The 2-year risk of death after ART initiation was 6.9% (95% confidence interval [CI]: 5.9 to 8.1), independently associated with baseline severe anemia (adjusted hazard ratio [aHR]: 4.10 [CI: 2.36 to 7.13]), immunodeficiency (adjusted aHR: 2.95 [CI: 1.49 to 5.82]), and severe clinical status (adjusted aHR: 3.64 [CI: 1.95 to 6.81]); the 2-year risk of LTFU was 10.3% (CI: 8.9 to 11.9), higher in children with severe clinical status. CONCLUSIONS: Once on treatment, the 2-year risk of death is low but the LTFU risk is substantial. ART is still mainly initiated at advanced disease stage in African children, reinforcing the need for early HIV diagnosis, early initiation of ART, and procedures to increase program retention.

Discovery and characterization of a novel non-competitive inhibitor of the divalent metal transporter DMT1/SLC11A2

Divalent metal transporter-1 (SLC11A2/DMT1) uses the H+ electrochemical gradient as the driving force to transport divalent metal ions such as Fe2+, Mn2+ and others metals into mammalian cells. DMT1 is ubiquitously expressed, most notably in proximal duodenum, immature erythroid cells, brain and kidney. This transporter mediates H+-coupled transport of ferrous iron across the apical membrane of enterocytes. In addition, in cells such as to erythroid precursors, following transferrin receptor (TfR) mediated endocytosis; it mediates H+-coupled exit of ferrous iron from endocytic vesicles into the cytosol. Dysfunction of human DMT1 is associated with several pathologies such as iron deficiency anemia hemochromatosis, Parkinson's disease and Alzheimer's disease, as well as colorectal cancer and esophageal adenocarcinoma, making DMT1 an attractive target for drug discovery. In the present study, we performed a ligand-based virtual screening of the Princeton database (700,000 commercially available compounds) to search for pharmacophore shape analogs of recently reported DMT1 inhibitors. We discovered a new compound, named pyrimidinone 8, which mediates a reversible linear non-competitive inhibition of human DMT1 (hDMT1) transport activity with a Ki of ∼20 μM. This compound does not affect hDMT1 cell surface expression and shows no dependence on extracellular pH. To our knowledge, this is the first experimental evidence that hDMT1 can be allosterically modulated by pharmacological agents. Pyrimidinone 8 represents a novel versatile tool compound and it may serve as a lead structure for the development of therapeutic compounds for pre-clinical assessment.

T-cell reprogramming through targeted CD4-coreceptor and T-cell receptor expression on maturing thymocytes by latent Circoviridae family member porcine circovirus type 2 cell infections in the thymus

Although porcine circovirus type 2 (PCV2)-associated diseases have been evaluated for known immune evasion strategies, the pathogenicity of these viruses remained concealed for decades. Surprisingly, the same viruses that cause panzootics in livestock are widespread in young, unaffected animals. Recently, evidence has emerged that circovirus-like viruses are also linked to complex diseases in humans, including children. We detected PCV2 genome-carrying cells in fetal pig thymi. To elucidate virus pathogenicity, we developed a new pig infection model by in vivo transfection of recombinant PCV2 and the immunosuppressant cofactor cyclosporine A. Using flow cytometry, immunofluorescence and fluorescence in situ hybridization, we found evidence that PCV2 dictates positive and negative selection of maturing T cells in the thymus. We show for the first time that PCV2-infected cells reside at the corticomedullary junction of the thymus. In diseased animals, we found polyclonal deletion of single positive cells (SPs) that may result from a loss of major histocompatibility complex class-II expression at the corticomedullary junction. The percentage of PCV2 antigen-presenting cells correlated with the degree of viremia and, in turn, the severity of the defect in thymocyte maturation. Moreover, the reversed T-cell receptor/CD4-coreceptor expression dichotomy on thymocytes at the CD4(+)CD8(interm) and CD4SP cell stage is viremia-dependent, resulting in a specific hypo-responsiveness of T-helper cells. We compare our results with the only other better-studied member of Circoviridae, chicken anemia virus. Our data show that PCV2 infection leads to thymocyte selection dysregulation, adding a valuable dimension to our understanding of virus pathogenicity.

Outcomes of Infants Starting Antiretroviral Therapy in Southern Africa, 2004-2012.

BACKGROUND There are limited published data on the outcomes of infants starting antiretroviral therapy (ART) in routine care in Southern Africa. This study aimed to examine the baseline characteristics and outcomes of infants initiating ART. METHODS We analyzed prospectively collected cohort data from routine ART initiation in infants from 11 cohorts contributing to the International Epidemiologic Database to Evaluate AIDS in Southern Africa. We included ART-naive HIV-infected infants aged <12 months initiating ≥3 antiretroviral drugs between 2004 and 2012. Kaplan-Meier estimates were calculated for mortality, loss to follow-up (LTFU), transfer out, and virological suppression. We used Cox proportional hazard models stratified by cohort to determine baseline characteristics associated with outcomes mortality and virological suppression. RESULTS The median (interquartile range) age at ART initiation of 4945 infants was 5.9 months (3.7-8.7) with follow-up of 11.2 months (2.8-20.0). At ART initiation, 77% had WHO clinical stage 3 or 4 disease and 87% were severely immunosuppressed. Three-year mortality probability was 16% and LTFU 29%. Severe immunosuppression, WHO stage 3 or 4, anemia, being severely underweight, and initiation of treatment before 2010 were associated with higher mortality. At 12 months after ART initiation, 17% of infants were severely immunosuppressed and the probability of attaining virological suppression was 56%. CONCLUSIONS Most infants initiating ART in Southern Africa had severe disease with high probability of LTFU and mortality on ART. Although the majority of infants remaining in care showed immune recovery and virological suppression, these responses were suboptimal.

Alcoholic Cirrhosis Increases Risk for Autoimmune Diseases: A Nationwide Registry-Based Cohort Study

BACKGROUND & AIMS Alcoholic cirrhosis is associated with hyperactivation and dysregulation of the immune system. In addition to its ability to increase risk for infections, it also may increase the risk for autoimmune diseases. We studied the incidence of autoimmune diseases among patients with alcoholic cirrhosis vs controls in Denmark. METHODS We collected data from nationwide health care registries to identify and follow up all citizens of Denmark diagnosed with alcoholic cirrhosis from 1977 through 2010. Each patient was matched with 5 random individuals from the population (controls) of the same sex and age. The incidence rates of various autoimmune diseases were compared between patients with cirrhosis and controls and adjusted for the number of hospitalizations in the previous year (a marker for the frequency of clinical examination). RESULTS Of the 24,679 patients diagnosed with alcoholic cirrhosis, 532 developed an autoimmune disease, yielding an overall increased adjusted incidence rate ratio (aIRR) of 1.36 (95% confidence interval [CI], 1.24-1.50). The strongest associations were with Addison's disease (aIRR, 2.47; 95% CI, 1.04-5.85), inflammatory bowel disease (aIRR, 1.56; 95% CI, 1.26-1.92), celiac disease (aIRR, 5.12; 95% CI, 2.58-10.16), pernicious anemia (aIRR, 2.35; 95% CI, 1.50-3.68), and psoriasis (aIRR, 4.06; 95% CI, 3.32-4.97). There was no increase in the incidence rate for rheumatoid arthritis (aIRR, 0.89; 95% CI, 0.69-1.15); the incidence rate for polymyalgia rheumatica decreased in patients with alcoholic cirrhosis compared with controls (aIRR, 0.47; 95% CI, 0.33-0.67). CONCLUSIONS Based on a nationwide cohort study of patients in Denmark, alcoholic cirrhosis is a risk factor for several autoimmune diseases.

Telomerase Inhibitor Imetelstat in Patients with Essential Thrombocythemia.

BACKGROUND Imetelstat, a 13-mer oligonucleotide that is covalently modified with lipid extensions, competitively inhibits telomerase enzymatic activity. It has been shown to inhibit megakaryocytic proliferation in vitro in cells obtained from patients with essential thrombocythemia. In this phase 2 study, we investigated whether imetelstat could elicit hematologic and molecular responses in patients with essential thrombocythemia who had not had a response to or who had had unacceptable side effects from prior therapies. METHODS A total of 18 patients in two sequential cohorts received an initial dose of 7.5 or 9.4 mg of imetelstat per kilogram of body weight intravenously once a week until attainment of a platelet count of approximately 250,000 to 300,000 per cubic millimeter. The primary end point was the best hematologic response. RESULTS Imetelstat induced hematologic responses in all 18 patients, and 16 patients (89%) had a complete hematologic response. At the time of the primary analysis, 10 patients were still receiving treatment, with a median follow-up of 17 months (range, 7 to 32 [ongoing]). Molecular responses were seen in 7 of 8 patients who were positive for the JAK2 V617F mutation (88%; 95% confidence interval, 47 to 100). CALR and MPL mutant allele burdens were also reduced by 15 to 66%. The most common adverse events during treatment were mild to moderate in severity; neutropenia of grade 3 or higher occurred in 4 of the 18 patients (22%) and anemia, headache, and syncope of grade 3 or higher each occurred in 2 patients (11%). All the patients had at least one abnormal liver-function value; all persistent elevations were grade 1 or 2 in severity. CONCLUSIONS Rapid and durable hematologic and molecular responses were observed in patients with essential thrombocythemia who received imetelstat. (Funded by Geron; ClinicalTrials.gov number, NCT01243073.).