Topic identification, selection, and prioritization for health technology assessment in selected countries: a mixed study design.

BACKGROUND: There is limited evidence-informed guidance on TISP processes for countries where health technology assessment (HTA) is in a nascent phase. We aimed to explore the range of topic identification, selection and prioritization (TISP) processes and practices for HTA in selected countries and identify aspects relevant to emerging HTA systems. METHODS: This mixed design study included a systematic literature review, an electronic survey, and individual interviews. We conducted a systematic literature review with criteria that were developed a priori to identify countries deemed to have a recently formalized HTA system. Based on the literature review, a twenty-three item online survey was shared with the identified countries, we completed follow-up interviews with ten participants who have experience with HTA. We analyzed documents, survey responses and interview transcripts thematically to identify lessons related to TISP processes and practices. RESULTS: The literature review identified 29 nine candidate countries as having a "potential" recently formalized HTA system. Twenty-one survey responses were analyzed and supplemented with ten individual interviews. We found variation in countries' approaches to TISP - particularly between pharmaceutical and non-pharmaceutical interventions. Results indicate that TISP is heavily driven by policy makers, expert involvement, and to a lesser extent, relevant stakeholders. The use of horizon-scanning and early warning systems is uncommon. Interviewee participants provided further insight to the survey data, reporting that political awareness and an institutional framework were important to support TISP. TISP can be optimized by stronger national regulations and legislative structures, in addition to education and advocacy about HTA among politicians and decision-makers. In some settings regional networks have been useful, particularly in the development of TISP guidelines and methodologies. Additionally, the technical capacity to conduct TISP, and access to relevant local data were factors limiting TISP in national settings. Increased network collaboration and capacity building were reported as future needs. CONCLUSIONS: This study provides current insights into a topic where there is limited published peer reviewed literature. TISP is an important first step of HTA, and topics should be selected and prioritized based on local need and relevance. The limited capacity for TISP in settings where HTA is emerging may be supported by local and international collaboration to increase capacity and knowledge. To succeed, both TISP and HTA need to be embedded within national health care priority setting and decision-making. More in-depth understanding of where countries are situtated in formalizing the TISP process may help others to overcome factors that facilitate or hinder progress.

A collaborative pilot on current awareness alerts for disinvestment and horizon scanning.

OBJECTIVE: In 2019, members of the Health Technology Assessment international (HTAi) Interest Group for Disinvestment and Early Awareness (DEA-IG) and the HTAi Interest Group for Information Retrieval (IR-IG) agreed to produce quarterly current awareness alerts for members of the DEA-IG. The purpose was to pilot a predefined strategy for sharing new publications on methods and topical issues in this area. METHODS: Literature search strategies for PubMed and Google were developed. Retrieved citations were posted on the DEA-IG Web site. Members of the DEA-IG received an email notification when new alerts were available. An informal survey of the DEA-IG members was used to provide feedback after the pilot. RESULTS: Six alerts were issued during the pilot (June 2019-September 2020) with a total of 170 citations. The bulk of the information were 124 PubMed indexed citations, and of these, 96 were retrieved by the PubMed search strategies. Google searches were not found to be useful, but ongoing horizon scanning work at the Canadian Agency for Drugs and Technologies in Health (CADTH) provided additional information. Based on retrospective sorting, we considered thirty-five PubMed citations to be highly relevant for health technology assessment (HTA). The response rate to the survey was limited (seventeen respondents), but most respondents found the alerts useful for their work. CONCLUSIONS: The results of this pilot project can be used to revise search strategies and information sources, improve the relevance of the alerts, and plan for expanded dissemination strategies.

Comparison of broad range 16S rDNA PCR and conventional blood culture for diagnosis of sepsis in the newborn: a case control study.

BACKGROUND: Early onset bacterial sepsis is a feared complication of the newborn. A large proportion of infants admitted to the Neonatal Intensive Care Unit (NICU) for suspected sepsis receive treatment with potent systemic antibiotics while a diagnostic workup is in progress. The gold standard for detecting bacterial sepsis is blood culture. However, as pathogens in blood cultures are only detected in approximately 25% of patients, the sensitivity of blood culture is suspected to be low. Therefore, the diagnosis of sepsis is often based on the development of clinical signs, in combination with laboratory tests such as a rise in C-reactive protein (CRP). Molecular assays for the detection of bacterial DNA in the blood represent possible new diagnostic tools for early identification of a bacterial cause. METHODS: A broad range 16S rDNA polymerase chain reaction (PCR) without preincubation was compared to conventional diagnostic work up for clinical sepsis, including BACTEC blood culture, for early determination of bacterial sepsis in the newborn. In addition, the relationship between known risk factors, clinical signs, and laboratory parameters considered in clinical sepsis in the newborn were explored. RESULTS: Forty-eight infants with suspected sepsis were included in this study. Thirty-one patients were diagnosed with sepsis, only 6 of these had a positive blood culture. 16S rDNA PCR analysis of blinded blood samples from the 48 infants revealed 10 samples positive for the presence of bacterial DNA. PCR failed to be positive in 2 samples from blood culture positive infants, and was positive in 1 sample where a diagnosis of a non-septic condition was established. Compared to blood culture the diagnosis of bacterial proven sepsis by PCR revealed a 66.7% sensitivity, 87.5% specificity, 95.4% positive and 75% negative predictive value. PCR combined with blood culture revealed bacteria in 35.1% of the patients diagnosed with sepsis. Irritability and feeding difficulties were the clinical signs most often observed in sepsis. CRP increased in the presence of bacterial infection. CONCLUSION: There is a need for PCR as a method to quickly point out the infants with sepsis. However, uncertainty about a bacterial cause of sepsis was not reduced by the PCR result, reflecting that methodological improvements are required in order for DNA detection to replace or supplement traditional blood culture in diagnosis of bacterial sepsis.

Identification of a high affinity FcgammaRIIA-binding peptide that distinguishes FcgammaRIIA from FcgammaRIIB and exploits FcgammaRIIA-mediated phagocytosis and degradation.

FcgammaRIIA is a key activating receptor linking immune complex formation with cellular effector functions. FcgammaRIIA has 93% identity with an inhibitory receptor, FcgammaRIIB, which negatively regulates FcgammaRIIA. FcgammaRIIA is important in the therapeutic action of several monoclonal antibodies. Binding molecules that discriminate FcgammaRIIA from FcgammaRIIB may optimize receptor activity and serve as a lead for development of therapeutics with FcgammaRIIA as a key target. Here we report the use of phage display libraries to select short peptides with distinct FcgammaRIIA binding properties. An 11-mer peptide (WAWVWLTETAV) was characterized that bound FcgammaRIIA with a K(d) of 500 nm. It mediated cell internalization and degradation of a model antigen. The peptide-binding site on FcgammaRIIA was shown to involve Phe(163) and the IgG binding amino acids Trp(90) and Trp(113). It is thus overlapping but not identical to that of IgG. Neither activating receptors FcgammaRI and FcgammaRIII, nor FcgammaRIIB, all of which lack Phe(163), bound the peptide.

Ligand binding and antigenic properties of a human neonatal Fc receptor with mutation of two unpaired cysteine residues.

The neonatal Fc receptor (FcRn) is a major histocompatibility complex class I-related molecule that regulates the half-life of IgG and albumin. In addition, FcRn directs the transport of IgG across both mucosal epithelium and placenta and also enhances phagocytosis in neutrophils. This new knowledge gives incentives for the design of IgG and albumin-based diagnostics and therapeutics. To study FcRn in vitro and to select and characterize FcRn binders, large quantities of soluble human FcRn are needed. In this report, we explored the impact of two free cysteine residues (C48 and C251) of the FcRn heavy chain on the overall structure and function of soluble human FcRn and described an improved bacterial production strategy based on removal of these residues, yielding approximately 70 mg.L(-1) of fermentation of refolded soluble human FcRn. The structural and functional integrity was proved by CD, surface plasmon resonance and MALDI-TOF peptide mapping analyses. The strategy may generally be translated to the large-scale production of other major histocompatibility complex class I-related molecules with nonfunctional unpaired cysteine residues. Furthermore, the anti-FcRn response in goats immunized with the FcRn heavy chain alone was analyzed following affinity purification on heavy chain-coupled Sepharose. Importantly, purified antibodies blocked the binding of both ligands to soluble human FcRn and were thus directed to both binding sites. This implies that the FcRn heavy chain, without prior assembly with human beta2-microglobulin, contains the relevant epitopes found in soluble human FcRn, and is therefore sufficient to obtain binders to either ligand-binding site. This finding will greatly facilitate the selection and characterization of such binders.

A strategy for bacterial production of a soluble functional human neonatal Fc receptor.

The major histocompatibility complex (MHC) class I related receptor, the neonatal Fc receptor (FcRn), rescues immunoglobulin G (IgG) and albumin from lysosomal degradation by recycling in endothelial cells. FcRn also contributes to passive immunity by mediating transport of IgG from mother to fetus (human) or newborn (rodents), and may translocate IgG over mucosal surfaces. FcRn interacts with the Fc-region of IgG and domain III of albumin with binding at pH 6.0 and release at pH 7.4. Knowledge of these interactions has facilitated design of recombinant proteins with altered serum half-lives and/or altered biodistribution. To generate further research in this field, there is a great need for large amounts of soluble human FcRn (shFcRn) for in vitro interaction studies. In this report, we describe a novel laboratory scale production of functional shFcRn in Escherichia coli (E. coli) at milligram level. Truncated wild type hFcRn heavy chains were expressed, extracted, purified from inclusion bodies under denaturing non-reducing conditions, and subsequently refolded in the presence of human beta(2)-microglobulin (hbeta(2)m). The secondary structural elements of refolded heterodimeric shFcRn were correctly formed as demonstrated by circular dichroism (CD). Furthermore, functional and stringent pH dependent binding to IgG and human serum albumin were demonstrated by ELISA and surface plasmon resonance (SPR). This method may be easily adapted for the expression of large amounts of other FcRn species and MHC class I related molecules.

Identification of a polymeric Ig receptor binding phage-displayed peptide that exploits epithelial transcytosis without dimeric IgA competition.

The polymeric Ig receptor (pIgR), also called membrane secretory component (SC), mediates epithelial transcytosis of polymeric immunoglobulins (pIgs). J Chain-containing polymeric IgA (pIgA) and pentameric IgM bind pIgR at the basolateral epithelial surface. After transcytosis, the extracellular portion of the pIgR is cleaved at the apical side, either complexed with pIgs as bound SC or unoccupied as free SC. This transport pathway may be exploited to target bioactive molecules to the mucosal surface. To identify small peptide motifs with specific affinity to human pIgR, we used purified free SC and selection from randomized, cysteine-flanked 6- and 9-mer phage-display libraries. One of the selected phages, called C9A, displaying the peptide CVVWMGFQQVC, showed binding both to human free SC and SC complexed with pIgs. However, the pneumococcal surface protein SpsA (Streptococcus pneumoniae secretory IgA-binding protein), which binds human SC at a site distinct from the pIg binding site, competed with the C9A phage for binding to SC. The C9A phage showed greatly increased transport through polarized Madin-Darby canine kidney cells transfected with human pIgR. This transport was not affected by pIgA nor did it inhibit pIgR-mediated pIgA transcytosis. A free peptide of identical amino acid sequence as that displayed by the C9A phage inhibited phage interaction with SC. This implied that the C9A peptide sequence may be exploited for pIgR-mediated epithelial transport without interfering with secretory immunity.

Prolonged and increased expression of soluble Fc receptors, IgG and a TCR-Ig fusion protein by transiently transfected adherent 293E cells.

In studies of the relation between structure and function of proteins of the immune system, there is a continuous need for screening of a large number of protein variants. To optimise the yield following transient gene expression in small or medium culture volumes, several parameters were investigated. First, secretion levels of a soluble form of human Fcgamma receptor IIA (FcgammaRIIA) were measured after transfection of 293, 293E, 293T as well as COS-7 cell lines. The transgene was under cytomegalovirus (CMV) promoter control on the expression vector pcDNA3, which also contains an SV40 origin of replication (SV40 ori). All 293 cell lines secreted more protein than COS-7 cells. Introduction of the Epstein Barr virus (EBV) origin of replication (oriP) greatly increased the protein expression from the 293E cells, both the amount of protein produced per day and the duration of production. At best, 293E cells secreted fully functional protein for 3-4 weeks provided supernatant was harvested every 2-3 days followed by medium replacement. This method was then used for expression of soluble forms of human FcgammaRI, FcgammaRIIB, the human neonatal Fc receptor (FcRn), a T cell receptor (TCR)-immunoglobulin (Ig) fusion protein, and human IgG3. With an initial culture volume of 5 ml, the yield was approximately 200 microg for FcgammaRIIA, 1.5 microg for FcgammaRI, 5 microg for FcRn, 20 microg for FcgammaRIIB, 40 microg for the TCR-Ig fusion protein and 850 microg for IgG3. Culture expansion during the 3 weeks of culture further increased the yield. Protein yield was also improved by scaling up the initial volume. This approach can provide sufficient amounts of protein for screening experiments, and in the case of antibody, milligrams of recombinant protein for extensive structural analysis can be obtained from one single transient transfection. The approach should be of interest to laboratories that do not have access to a bioreactor but still have a requirement for reasonable amounts of protein to be produced in an easy and cost-effective manner.