HIV-1 Transmission During Recent Infection and During Treatment Interruptions as Major Drivers of New Infections in the Swiss HIV Cohort Study.

BACKGROUND  Reducing the fraction of transmissions during recent human immunodeficiency virus (HIV) infection is essential for the population-level success of "treatment as prevention". METHODS  A phylogenetic tree was constructed with 19 604 Swiss sequences and 90 994 non-Swiss background sequences. Swiss transmission pairs were identified using 104 combinations of genetic distance (1%-2.5%) and bootstrap (50%-100%) thresholds, to examine the effect of those criteria. Monophyletic pairs were classified as recent or chronic transmission based on the time interval between estimated seroconversion dates. Logistic regression with adjustment for clinical and demographic characteristics was used to identify risk factors associated with transmission during recent or chronic infection. FINDINGS  Seroconversion dates were estimated for 4079 patients on the phylogeny, and comprised between 71 (distance, 1%; bootstrap, 100%) to 378 transmission pairs (distance, 2.5%; bootstrap, 50%). We found that 43.7% (range, 41%-56%) of the transmissions occurred during the first year of infection. Stricter phylogenetic definition of transmission pairs was associated with higher recent-phase transmission fraction. Chronic-phase viral load area under the curve (adjusted odds ratio, 3; 95% confidence interval, 1.64-5.48) and time to antiretroviral therapy (ART) start (adjusted odds ratio 1.4/y; 1.11-1.77) were associated with chronic-phase transmission as opposed to recent transmission. Importantly, at least 14% of the chronic-phase transmission events occurred after the transmitter had interrupted ART. CONCLUSIONS  We demonstrate a high fraction of transmission during recent HIV infection but also chronic transmissions after interruption of ART in Switzerland. Both represent key issues for treatment as prevention and underline the importance of early diagnosis and of early and continuous treatment.

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.

Cluster of Leptospirosis Acquired Through River Surfing in Switzerland

Background.  In Switzerland, leptospirosis is still considered as a travel-associated disease. After the surprising diagnosis of leptospirosis in a patient who was initially suspected as having primary human immunodeficiency virus infection, we recognized that acquisition of leptospirosis occurred through recreational activities and we identified additional affected individuals. Methods.  Detailed anamnesis, excluding occupational exposure, acquisition abroad, and pet contacts, enabled us to detect the source of infection and identify a cluster of leptospirosis. Convalescent sera testing was performed to confirm Leptospira infection. Microscopic agglutination tests were used to determine the infecting serovar. Results.  We identified a cluster of leptospirosis in young, previously healthy persons. Acquisition of leptospirosis was traced back to a surfing spot on a river in Switzerland (Reuss, Aargau). Clinical presentation was indistinct. Two of the 3 reported cases required hospitalization, and 1 case even suffered from meningitis. Serologic tests indicated infection with the serovar Grippotyphosa in all cases. With the exception of the case with meningitis, no antibiotics were administered, because leptospirosis was diagnosed after spontaneous resolution of most symptoms. Despite a prolonged period of convalescence in 2 cases, full recovery was achieved. Recent reports on beavers suffering from leptospirosis in this region underline the possible water-borne infection of the 3 cases and raise the question of potential wildlife reservoirs. Conclusions.  Insufficient awareness of caregivers, which may be promoted by the missing obligation to report human leptospirosis, combined with the multifaceted presentation of the disease result in significant underdiagnosis. More frequent consideration of leptospirosis as differential diagnosis is inevitable, particularly as veterinary data suggest re-emergence of the disease.

Comparison of telomere length in black and white teachers from South Africa: the sympathetic activity and ambulatory blood pressure in Africans study

OBJECTIVE Telomere length is a marker of biological aging that has been linked to cardiovascular disease risk. The black South African population is witnessing a tremendous increase in the prevalence of cardiovascular disease, part of which might be explained through urbanization. We compared telomere length between black South Africans and white South Africans and examined which biological and psychosocial variables played a role in ethnic difference in telomere length. METHODS We measured leukocyte telomere length in 161 black South African teachers and 180 white South African teachers aged 23 to 66 years without a history of atherothrombotic vascular disease. Age, sex, years having lived in the area, human immunodeficiency virus (HIV) infection, hypertension, body mass index, dyslipidemia, hemoglobin A1c, C-reactive protein, smoking, physical activity, alcohol abuse, depressive symptoms, psychological distress, and work stress were considered as covariates. RESULTS Black participants had shorter (median, interquartile range) relative telomere length (0.79, 0.70-0.95) than did white participants (1.06, 0.87-1.21; p < .001), and this difference changed very little after adjusting for covariates. In fully adjusted models, age (p < .001), male sex (p = .011), and HIV positive status (p = .023) were associated with shorter telomere length. Ethnicity did not significantly interact with any covariates in determining telomere length, including psychosocial characteristics. CONCLUSIONS Black South Africans showed markedly shorter telomeres than did white South African counterparts. Age, male sex, and HIV status were associated with shorter telomere length. No interactions between ethnicity and biomedical or psychosocial factors were found. Ethnic difference in telomere length might primarily be explained by genetic factors.

Tuberculosis in Pediatric Antiretroviral Therapy Programs in Low- and Middle-Income Countries: Diagnosis and Screening Practices.

BACKGROUND The global burden of childhood tuberculosis (TB) is estimated to be 0.5 million new cases per year. Human immunodeficiency virus (HIV)-infected children are at high risk for TB. Diagnosis of TB in HIV-infected children remains a major challenge. METHODS We describe TB diagnosis and screening practices of pediatric antiretroviral treatment (ART) programs in Africa, Asia, the Caribbean, and Central and South America. We used web-based questionnaires to collect data on ART programs and patients seen from March to July 2012. Forty-three ART programs treating children in 23 countries participated in the study. RESULTS Sputum microscopy and chest Radiograph were available at all programs, mycobacterial culture in 40 (93%) sites, gastric aspiration in 27 (63%), induced sputum in 23 (54%), and Xpert MTB/RIF in 16 (37%) sites. Screening practices to exclude active TB before starting ART included contact history in 41 sites (84%), symptom screening in 38 (88%), and chest Radiograph in 34 sites (79%). The use of diagnostic tools was examined among 146 children diagnosed with TB during the study period. Chest Radiograph was used in 125 (86%) children, sputum microscopy in 76 (52%), induced sputum microscopy in 38 (26%), gastric aspirate microscopy in 35 (24%), culture in 25 (17%), and Xpert MTB/RIF in 11 (8%) children. CONCLUSIONS Induced sputum and Xpert MTB/RIF were infrequently available to diagnose childhood TB, and screening was largely based on symptom identification. There is an urgent need to improve the capacity of ART programs in low- and middle-income countries to exclude and diagnose TB in HIV-infected children.

Incidence of AIDS-Defining and Other Cancers in HIV-Positive Children in South Africa: Record Linkage Study.

BACKGROUND Little is known on the risk of cancer in HIV-positive children in sub-Saharan Africa. We examined incidence and risk factors of AIDS-defining and other cancers in pediatric antiretroviral therapy (ART) programs in South Africa. METHODS We linked the records of five ART programs in Johannesburg and Cape Town to those of pediatric oncology units, based on name and surname, date of birth, folder and civil identification numbers. We calculated incidence rates and obtained hazard ratios (HR) with 95% confidence intervals (CI) from Cox regression models including ART, sex, age, and degree of immunodeficiency. Missing CD4 counts and CD4% were multiply imputed. Immunodeficiency was defined according to World Health Organization 2005 criteria. RESULTS Data of 11,707 HIV-positive children were included in the analysis. During 29,348 person-years of follow-up 24 cancers were diagnosed, for an incidence rate of 82 per 100,000 person-years (95% CI 55-122). The most frequent cancers were Kaposi Sarcoma (34 per 100,000 person-years) and Non Hodgkin Lymphoma (31 per 100,000 person-years). The incidence of non AIDS-defining malignancies was 17 per 100,000. The risk of developing cancer was lower on ART (HR 0.29, 95%CI 0.09-0.86), and increased with age at enrolment (>10 versus <3 years: HR 7.3, 95% CI 2.2-24.6) and immunodeficiency at enrolment (advanced/severe versus no/mild: HR 3.5, 95%CI 1.1-12.0). The HR for the effect of ART from complete case analysis was similar but ceased to be statistically significant (p=0.078). CONCLUSIONS Early HIV diagnosis and linkage to care, with start of ART before advanced immunodeficiency develops, may substantially reduce the burden of cancer in HIV-positive children in South Africa and elsewhere.

The Swiss National Registry for Primary Immunodeficiencies: report on the first 6 years' activity from 2008 to 2014

The Swiss National Registry for Primary Immunodeficiency Disorders (PID) was established in 2008, constituting a nationwide network of paediatric and adult departments involved in the care of patients with PID at university medical centres, affiliated teaching hospitals and medical institutions. The registry collects anonymized clinical and genetic information on PID patients and is set up within the framework of the European database for PID, run by the European Society of Immunodeficiency Diseases. To date, a total of 348 patients are registered in Switzerland, indicating an estimated minimal prevalence of 4·2 patients per 100 000 inhabitants. Distribution of different PID categories, age and gender are similar to the European cohort of currently 19 091 registered patients: 'predominantly antibody disorders' are the most common diseases observed (n = 217/348, 62%), followed by 'phagocytic disorders' (n = 31/348, 9%). As expected, 'predominantly antibody disorders' are more prevalent in adults than in children (78 versus 31%). Within this category, 'common variable immunodeficiency disorder' (CVID) is the most prevalent PID (n = 98/217, 45%), followed by 'other hypogammaglobulinaemias' (i.e. a group of non-classified hypogammaglobulinaemias) (n = 54/217, 25%). Among 'phagocytic disorders', 'chronic granulomatous disease' is the most prevalent PID (n = 27/31, 87%). The diagnostic delay between onset of symptoms and diagnosis is high, with a median of 6 years for CVID and more than 3 years for 'other hypogammaglobulinaemias'.

Mammalian Snm1 participates in cellular responses to genotoxic and mitotic stress

Eukaryotic cells have evolved a complex network of metabolic processes and regulatory systems to help ensure that hereditary information is protected or restored when exposed to genotoxic agents. Two members of the Snm1 protein family have been characterized; scSNM1/PSO2, a yeast gene responsible for repair of DNA interstrand crosslinks, and hARTEMIS, a human gene that is mutated in radiosensitive severe combined immunodeficiency (RS-SCID). Here we report on another member of this protein family, hSNM1, and its response to DNA damage and mitotic stress. We have found that this protein colocalizes and physically associates with 53BP1, a crucial member of the mammalian response to DNA damage. In addition, hSnm1 interacts with several proteins involved in mitosis, and mSNM1 deficiency causes a mitotic checkpoint defect in mouse embryonic fibroblasts. ^

A cross sectional examination of risky sexual behaviors among a population of drug users

This study is a secondary data analysis that assesses the relationship between risky sexual behaviors and sexually transmitted infections (STIs) among drug users. This study analyzes data collected from drug users in the Houston Metropolitan area during 2004 and through August 2005, by researchers with the DASH (Drugs, AIDS, STDs and Hepatitis) project at The University of Texas at Houston School of Public Health. Specifically, the sexually transmitted infections that will be of interest in this proposed study are Human Immunodeficiency Virus (HIV) and Hepatitis B Virus (HBV). Risky sexual behaviors that will be examined include lack of condom use, sexual orientation, trading sex for drugs, trading sex for money, and number of male and female sexual partners in the last 4 weeks. ^ Unadjusted, gender, sexual orientation, number of recent male and female sex partners, and a history of injection drug use were all found to be significant independent variables that increased the odds of STI status. When included in an overall model, these variables significantly increased the odds of STI status, including HBV infection, HIV infection, and HBV/HIV co-infection. History of injection drug use was significant for both HBV and HBV/HIV co-infection, whereas a gay sexual orientation was significant for both HIV and HBV/HIV co-infection. Additionally, having excessive female sex partners was significant for HIV infection. This significant association increases the need for implementation of stronger intervention programs tailored to suit this population's needs such as a combination of drug and sexually transmitted disease (STD) treatment. ^ The importance of these findings is that they establish the strength of associations between the previously mentioned risky sexual behaviors and STI status among drug users. This is crucial for assessing future risk of infection as well as for serving as a necessary component in intervention and treatment programs both for drug use and STIs. ^

Proteomic identification and functional characterization of prohibitin 1 and 2 in T cell activation, expansion, survival and disease

Several immune pathologies are the result of aberrant regulation of T lymphocytes. Pronounced T cell proliferation can result in autoimmunity or hematologic malignancy, whereas loss of T cell activity can manifest as immunodeficiency. Thus, there is a critical need to characterize the signal transduction pathways that mediate T cell activation so that novel and rational strategies to detect and effectively control T cell mediated disease can be achieved. ^ The first objective of this dissertation was to identify and characterize novel T cell regulatory proteins that are differentially expressed upon antigen induced activation. Using a functional proteomics approach, two members of the prohibitin (Phb) family of proteins, Phb1 and Phb2, were determined to be upregulated upon activation of primary human T cells. Furthermore, their regulated expression was dependent upon CD3 and CD28 signaling pathways which synergistically increased their expression. In contrast to previous reports of Phb nuclear localization, both proteins were determined to localize to the mitochondrial inner membrane of human T cells. Additionally, novel Phb phosphorylation sites were identified and characterized using mass spectrometry, phosphospecific antibodies and site directed mutagenesis. ^ Prohibitins have been proposed to play important roles in cancer development however the mechanism of action has not been elucidated. The second objective of this dissertation was to define the functional role of Phbs in T cell activity, survival and disease. Compared to levels in normal human T cells, Phb expression was higher in the human tumor T cell line Kit225 and subcellularly localized to the mitochondrion. Ablation of Phb expression by siRNA treatment of Kit225 cells resulted in disruption of mitochondrial membrane potential and significantly enhanced their sensitivity to cell death, suggesting they serve a protective function in T cells. Furthermore, Q-RT-PCR analysis of human oncology cDNA expression libraries indicated the Phbs may represent hematological cancer biomarkers. Indeed, Phb1 and Phb2 protein levels were 6-10 fold higher in peripheral blood mononuclear cells isolated from malignant lymphoma and multiple myeloma patients compared to healthy individuals. ^ Taken together, Phb1 and Phb2 are novel phosphoproteins upregulated during T cell activation and transformation to function in the maintenance of mitochondrial integrity and perhaps energy metabolism, thus representing previously unrecognized intracellular biomarkers and therapeutic targets for regulating T cell activation and hematologic malignancies. ^

Functional analysis of BLAP75, a BLM-associated protein

Bloom syndrome (BS) is an autosomal recessive disorder characterized by dwarfism, immunodeficiency, impaired fertility, and most importantly, early development of a broad range of cancers. The hallmark of BS cells is hyper-recombination, characterized by a drastically elevated frequency of sister chromatid exchange (SCE). BLM, the gene mutated in BS, encodes a DNA helicase of the RecQ protein family. BLM is thought to participate in several DNA transactions and to interact with many proteins involved in DNA replication, recombination, and repair. However, the precise function of BLM and the BLM-dependent anti-tumor mechanism remain obscure. ^ A novel protein, BLAP75 (BLM-associated polypeptide, 75KD), was identified to form an evolutionarily conserved complex with BLM and DNA topoisomerase IIIα (Topo IIIα). Our work demonstrates that loss of BLAP75 destabilized BLM and Topo IIIα proteins. BLAP75 colocalized with BLM in subnuclear foci in response to DNA damage and the recruitment of BLM to these foci was BLAP75-dependent. Moreover, depletion of BLAP75 by siRNA resulted in an elevated SCE rate similar to cells depleted of BLM by siRNA. In addition, RNAi-mediated silencing of BLAP75 greatly diminished cell viability. This cellular deficiency was rescued by expression of wild type BLAP75 but not BLAP75 with mutated conserved domain III, which abrogated the interaction between BLAP75, BLM and Topo IIIα, suggesting that the integrity of BLM-Topo IIIα-BLAP75 complex might be critical for cell survival. Finally, I found that BLAP75 was phosphorylated during mitosis and upon various DNA-damaging agents, implying that BLAP75 might also function in mitosis and DNA damage response. ^ Taken together, this study has defined BLAP75 as an integral component of the BLM complex to maintain genome stability. Our findings provide insights into the molecular mechanisms of the BLM helicase pathway and tumorigenesis process associated with these mechanisms. ^