Immunodeficiency and Cancer in 3.5 Million People Living With Human Immunodeficiency Virus (HIV):the South African HIV Cancer Match Study

BACKGROUND We analysed associations between immunodeficiency and cancer incidence in a nationwide cohort of people living with the human immunodeficiency virus (HIV) in South Africa. METHODS We used data from the South African HIV Cancer Match study built on HIV-related laboratory measurements from the National Health Laboratory Services and cancer records from the National Cancer Registry. We evaluated associations between time-updated CD4 cell count and cancer incidence rates using Cox proportional hazards models. We reported adjusted hazard ratios (aHR) over a grid of CD4 values and estimated the aHR per 100 CD4 cells/µl decrease. RESULTS Of 3,532,266 people living with HIV (PLWH), 15,078 developed cancer. The most common cancers were cervical cancer (4,150 cases), Kaposi sarcoma (2,262 cases), and non-Hodgkin lymphoma (1,060 cases). The association between lower CD4 cell count and higher cancer incidence rates was strongest for conjunctival cancer (aHR per 100 CD4 cells/µl decrease: 1.46, 95% confidence interval [CI] 1.38-1.54), Kaposi sarcoma (aHR 1.23, 95% CI 1.20-1.26), and non-Hodgkin lymphoma (aHR 1.18, 95% CI 1.14-1.22). Among infection-unrelated cancers, lower CD4 cell counts were associated with higher incidence rates of oesophageal cancer (aHR 1.06, 95 CI 1.00-1.11), but not breast, lung, or prostate cancer. CONCLUSIONS Lower CD4 cell counts were associated with an increased risk of developing various infection-related cancers among PLWH. Reducing HIV-induced immunodeficiency may be a potent cancer prevention strategy among PLWH in sub-Saharan Africa, a region heavily burdened by cancers attributable to infections

Cohort profile: the South African HIV Cancer Match (SAM) Study, a national population-based cohort.

PURPOSE The South African HIV Cancer Match (SAM) Study is a national cohort of people living with HIV (PLWH). It was created using probabilistic record linkages of routine laboratory records of PLWH retrieved by National Health Laboratory Services (NHLS) and cancer data from the National Cancer Registry. The SAM Study aims to assess the spectrum and risk of cancer in PLWH in the context of the evolving South African HIV epidemic. The SAM Study's overarching goal is to inform cancer prevention and control programmes in PLWH in the era of antiretroviral treatment in South Africa. PARTICIPANTS PLWH (both adults and children) who accessed HIV care in public sector facilities and had HIV diagnostic or monitoring laboratory tests from NHLS. FINDINGS TO DATE The SAM cohort currently includes 5 248 648 PLWH for the period 2004 to 2014; 69% of these are women. The median age at cohort entry was 33.0 years (IQR: 26.2-40.9). The overall cancer incidence in males and females was 235.9 (95% CI: 231.5 to 240.5) and 183.7 (181.2-186.2) per 100 000 person-years, respectively.Using data from the SAM Study, we examined national cancer incidence in PLWH and the association of different cancers with immunodeficiency. Cancers with the highest incidence rates were Kaposi sarcoma, cervix, breast, non-Hodgkin's lymphoma and eye cancer. FUTURE PLANS The SAM Study is a unique, evolving resource for research and surveillance of malignancies in PLWH. The SAM Study will be regularly updated. We plan to enrich the SAM Study through record linkages with other laboratory data within the NHLS (eg, tuberculosis, diabetes and lipid profile data), mortality data and socioeconomic data to facilitate comprehensive epidemiological research of comorbidities among PLWH

Methicillin-Susceptible Staphylococcus aureus in Skin and Soft Tissue Infections, Northern Italy

Summary statement: A community outbreak with intrafamilial skin infections was associated with an MSSA clone

Rapid Increase of Genetically Diverse Methicillin-Resistant Staphylococcus aureus, Copenhagen, Denmark

Community-onset MRSA with diverse genetic backgrounds is rapidly emerging in this previously low MRSA prevalence area

Population Structure of a Hybrid Clonal Group of Methicillin-Resistant Staphylococcus aureus, ST239-MRSA-III

The methicillin-resistant Staphylococcus aureus (MRSA) clonal group known as ST239-MRSA-III is notable for its hybrid origin and for causing sustained hospital epidemics worldwide since the late 1970s. We studied the population structure of this MRSA clonal group using a sample of 111 isolates that were collected over 34 years from 29 countries. Genetic variation was assessed using typing methods and novel ascertainment methods, resulting in approximately 15 kb of sequence from 32 loci for all isolates. A single most parsimonious tree, free of homoplasy, partitioned 28 haplotypes into geographically-associated clades, including prominent European, Asian, and South American clades. The rate of evolution was estimated to be approximately 100× faster than standard estimates for bacteria, and dated the most recent common ancestor of these isolates to the mid-20th century. Associations were discovered between the ST239 phylogeny and the ccrB and dru loci of the methicillin resistance genetic element, SCCmec type III, but not with the accessory components of the element that are targeted by multiplex PCR subtyping tools. In summary, the evolutionary history of ST239 can be characterized by rapid clonal diversification that has left strong evidence of geographic and temporal population structure. SCCmec type III has remained linked to the ST239 chromosome during clonal diversification, but it has undergone homoplasious losses of accessory components. These results provide a population genetics framework for the precise identification of emerging ST239 variants, and invite a re-evaluation of the markers used for subtyping SCCmec

Preparation of bispecific antibody-protein adducts by site-specific chemo-enzymatic conjugation

Historically, bispecific antibodies have been constructed through the genetic fusion of additional binding domains to the constant domains of the antibody heavy- or light chains. We present an alternative method for the introduction of additional functional domains to an antibody: site-specific chemo-enzymatic conjugation. This method relies on the combination of site-specific transpeptidases and bioorthogonal chemistry. Transpeptidases are used to site-specifically introduce chemical handles, which can then be used to couple new functional groups by means of a bioorthogonal chemical reaction. We demonstrate site-specific chemo-enzymatic linkage using the transpeptidase sortase (hereafter: sortase) and either a strain-promoted alkyne-azide cycloaddition (SPAAC) or an inverse-electron demand Diels-Alder reaction. Other transpeptidases and bioorthogonal reactions suitable for this purpose exist. Site-specific chemo-enzymatic linkage is a modular method. After introduction of a chemical handle in the antibody, any functional group of interest may then be attached. The modularity of this conjugation method allows for a ‘plug-and-play’ approach to prepare new antibody conjugates, thus bypassing the need for (potentially) laborious genetic fusions. Moreover, as sortase is used to specifically modify the exact C-termini of the antibody chains, the final product will be fused in a C-to-C orientation, which is impossible to achieve by genetic manipulations alone. Here we demonstrate the utility of site-specific chemo-enzymatic conjugation to prepare antibody heterodimers, bispecific T-cell engager antibodies, and immunocytokines, discussing purification methods and describing possible pitfalls

Spatiotemporal modelling and mapping of cervical cancer incidence among HIV positive women in South Africa: a nationwide study.

BACKGROUND Disparities in invasive cervical cancer (ICC) incidence exist globally, particularly in HIV positive women who are at elevated risk compared to HIV negative women. We aimed to determine the spatial, temporal, and spatiotemporal incidence of ICC and the potential risk factors among HIV positive women in South Africa. METHODS We included ICC cases in women diagnosed with HIV from the South African HIV cancer match study during 2004-2014. We used the Thembisa model, a mathematical model of the South African HIV epidemic to estimate women diagnosed with HIV per municipality, age group and calendar year. We fitted Bayesian hierarchical models, using a reparameterization of the Besag-York-Mollié to capture spatial autocorrelation, to estimate the spatiotemporal distribution of ICC incidence among women diagnosed with HIV. We also examined the association of deprivation, access to health (using the number of health facilities per municipality) and urbanicity with ICC incidence. We corrected our estimates to account for ICC case underascertainment, missing data and data errors. RESULTS We included 17,821 ICC cases and demonstrated a decreasing trend in ICC incidence, from 306 to 312 in 2004 and from 160 to 191 in 2014 per 100,000 person-years across all municipalities and corrections. The spatial relative rate (RR) ranged from 0.27 to 4.43 in the model without any covariates. In the model adjusting for covariates, the most affluent municipalities had a RR of 3.18 (95% Credible Interval 1.82, 5.57) compared to the least affluent ones, and municipalities with better access to health care had a RR of 1.52 (1.03, 2.27) compared to municipalities with worse access to health. CONCLUSIONS The results show an increased incidence of cervical cancer in affluent municipalities and in those with more health facilities. This is likely driven by better access to health care in more affluent areas. More efforts should be made to ensure equitable access to health services, including mitigating physical barriers, such as transportation to health centres and strengthening of screening programmes

Highly efficient mono-functionalization of knob-in-hole antibodies with strain-promoted click chemistry

Knob-in-hole antibodies can be utilized to introduce a single tag for chemo-enzymatic functionalization. By either introducing a single C-terminal sortase tag (sortase-tag expressed protein ligation) or tyrosine tag (G4Y), mono-functionalization of the monoclonal antibody trastuzumab was achieved rapidly and in high yields. This method was applied to selectively and efficiently introduce a single fluorescent tag, cytokine or single-chain variable fragment, as well as produce clean homo dimers of trastuzumab.<br/

Cancer risk in adolescents and young adults living with HIV in South Africa: a nationwide cohort study.

BACKGROUND Literature on cancer in adolescents and young adults (AYA; aged 15-24 years) living with HIV is scarce. We studied cancer incidence in AYA living with HIV in South Africa between 2004 and 2014. METHODS In this nationwide cohort study, we included individuals between 15 and 24 years old who had at least two HIV-related laboratory measurements on separate days between Jan 1, 2004, and Dec 31, 2014, recorded in the National Health Laboratory Service database. We used privacy-preserving probabilistic record linkage methods to identify HIV-related laboratory records that most likely belonged to the same individual and to then link these individuals to cancer diagnoses from the National Cancer Registry. We computed incidence rates for the most common cancers in AYA living with HIV, and we assessed associations between these cancers and sex, age, calendar year, and CD4 cell count using Cox proportional hazards models and adjusted hazard ratios (aHRs). FINDINGS We included 782 454 AYA living with HIV (698 066 [89·2%] women) with 1 428 114 person-years of follow-up. Of those, 867 developed incident cancer (incidence rate 60·7 per 100 000 person-years), including 429 who developed Kaposi sarcoma (30·0 per 100 000 person-years), 107 non-Hodgkin lymphoma (7·5 per 100 000 person-years), 48 Hodgkin lymphoma (3·4 per 100 000 person-years), 45 cervical cancer (3·4 per 100 000 woman-years), and 32 leukaemia (2·2 per 100 000 person-years). Kaposi sarcoma was more common in the 20-24 year age group than the 15-19 year age group (aHR 1·39, 95% CI 1·03-1·86). Male sex was associated with higher rates of Kaposi sarcoma (2·06, 1·61-2·63), non-Hodgkin lymphoma (3·17, 2·06-4·89), Hodgkin lymphoma (4·83, 2·61-8·93), and leukaemia (unadjusted HR 5·90, 95% CI 2·87-12·12). Cancer rates decreased over the study period, driven by declining Kaposi sarcoma rates. Lower baseline CD4 cell counts were associated with higher rates of Kaposi sarcoma, cervical cancer, non-Hodgkin lymphoma, and Hodgkin lymphoma, but not leukaemia. INTERPRETATION Infection-related cancers were the most common cancer types in AYA living with HIV in South Africa, and their incidence rates increased with lower CD4 cell counts. Therefore, innovative strategies to maintaining high CD4 cell counts are needed to reduce the cancer burden in this vulnerable population. FUNDING US National Institutes of Health and Swiss National Science Foundation