Islet Autoantibody Standardization Program: interlaboratory comparison of insulin autoantibody assay performance in 2018 and 2020 workshops.

AIMS/HYPOTHESIS: The Islet Autoantibody Standardization Program (IASP) aims to improve the performance of immunoassays measuring autoantibodies in type 1 diabetes and the concordance of results across laboratories. IASP organises international workshops distributing anonymised serum samples to participating laboratories and centralises the collection and analysis of results. In this report, we describe the results of assays measuring IAA submitted to the IASP 2018 and 2020 workshops. METHODS: The IASP distributed uniquely coded sera from individuals with new-onset type 1 diabetes, multiple islet autoantibody-positive individuals, and diabetes-free blood donors in both 2018 and 2020. Serial dilutions of the anti-insulin mouse monoclonal antibody HUI-018 were also included. Sensitivity, specificity, area under the receiver operating characteristic curve (ROC-AUC), partial ROC-AUC at 95% specificity (pAUC95) and concordance of qualitative/quantitative results were compared across assays. RESULTS: Results from 45 IAA assays of seven different formats and from 37 IAA assays of six different formats were submitted to the IASP in 2018 and 2020, respectively. The median ROC-AUC was 0.736 (IQR 0.617-0.803) and 0.790 (IQR 0.730-0.836), while the median pAUC95 was 0.016 (IQR 0.004-0.021) and 0.023 (IQR 0.014-0.026) in the 2018 and 2020 workshops, respectively. Assays largely differed in AUC (IASP 2018 range 0.232-0.874; IASP 2020 range 0.379-0.924) and pAUC95 (IASP 2018 and IASP 2020 range 0-0.032). CONCLUSIONS/INTERPRETATION: Assay formats submitted to this study showed heterogeneous performance. Despite the high variability across laboratories, the in-house radiobinding assay (RBA) remains the gold standard for IAA measurement. However, novel non-radioactive IAA immunoassays showed a good performance and, if further improved, might be considered valid alternatives to RBAs.

Elliptic Solutions of Dynamical Lucas Sequences.

We study two types of dynamical extensions of Lucas sequences and give elliptic solutions for them. The first type concerns a level-dependent (or discrete time-dependent) version involving commuting variables. We show that a nice solution for this system is given by elliptic numbers. The second type involves a non-commutative version of Lucas sequences which defines the non-commutative (or abstract) Fibonacci polynomials introduced by Johann Cigler. If the non-commuting variables are specialized to be elliptic-commuting variables the abstract Fibonacci polynomials become non-commutative elliptic Fibonacci polynomials. Some properties we derive for these include their explicit expansion in terms of normalized monomials and a non-commutative elliptic Euler-Cassini identity.

Islet Autoantibody Standardization Program 2018 Workshop: Interlaboratory Comparison of Glutamic Acid Decarboxylase Autoantibody Assay Performance.

BACKGROUND: The Islet Autoantibody Standardization Program (IASP) aims to improve the performance of immunoassays measuring type 1 diabetes (T1D)-associated autoantibodies and the concordance of results among laboratories. IASP organizes international interlaboratory assay comparison studies in which blinded serum samples are distributed to participating laboratories, followed by centralized collection and analysis of results, providing participants with an unbiased comparative assessment. In this report, we describe the results of glutamic acid decarboxylase autoantibody (GADA) assays presented in the IASP 2018 workshop. METHODS: In May 2018, IASP distributed to participants uniquely coded sera from 43 new-onset T1D patients, 7 multiple autoantibody-positive nondiabetic individuals, and 90 blood donors. Results were analyzed for the following metrics: sensitivity, specificity, accuracy, area under the ROC curve (ROC-AUC), partial ROC-AUC at 95% specificity (pAUC95), and concordance of qualitative and quantitative results. RESULTS: Thirty-seven laboratories submitted results from a total of 48 different GADA assays adopting 9 different formats. The median ROC-AUC and pAUC95 of all assays were 0.87 [interquartile range (IQR), 0.83-0.89] and 0.036 (IQR, 0.032-0.039), respectively. Large differences in pAUC95 (range, 0.001-0.0411) were observed across assays. Of formats widely adopted, bridge ELISAs showed the best median pAUC95 (0.039; range, 0.036-0.041). CONCLUSIONS: Several novel assay formats submitted to this study showed heterogeneous performance. In 2018, the majority of the best performing GADA immunoassays consisted of novel or established nonradioactive tests that proved on a par or superior to the radiobinding assay, the previous gold standard assay format for GADA measurement.

Predicting the Incremental Hospital Cost of Adverse Events Among Medicare Beneficiaries in the Comprehensive Joint Replacement Program During Fiscal Year 2014.

BACKGROUND: The Medicare program's Comprehensive Care for Joint Replacement (CJR) payment model places hospitals at financial risk for the treatment cost of Medicare beneficiaries (MBs) undergoing lower extremity joint replacement (LEJR). METHODS: This study uses Medicare Provider Analysis and Review File and identified 674,777 MBs with LEJR procedure during fiscal year 2014. Adverse events (death, acute myocardial infarction, pneumonia, sepsis or shock, surgical site bleeding, pulmonary embolism, mechanical complications, and periprosthetic joint infection) were studied. Multivariable regressions were modeled to estimate the incremental hospital cost of treating each adverse event. RESULTS: The risk-adjusted estimated hospital cost of treating adverse events varied from a high of $29,061 (MBs experiencing hip fracture and joint infection) to a low of $6308 (MBs without hip fracture that experienced pulmonary embolism). CONCLUSION: Avoidance of adverse events in the LEJR hospitalization will play an important role in managing episode hospital costs in the Comprehensive Care for Joint Replacement program.

Evaluating Quality of "Medical Tourism" For Heart Surgery: Measures That Matter.

There are some success stories. Lowe's pioneering flat-rate deal with the Cleveland Clinic for heart surgery has shown both cost savings and quality improvement. Other large employers, notably Walmart and PepsiCo, have followed suit, signing contracts with self-described, single-hospital "centers of excellence" for a handful of elective procedures.

7 Strategies for Improving Drug Utilization.

When new pharmaceutical products enter the market, the lack of real-world experience with these drugs creates quandaries for payers and providers alike. Often, all there is to go on is the minimum required for FDA approval-non-inferiority to a comparator product in terms of efficacy and safety. Here are a few promising strategies to end this ambiguity.

Preclinical Evaluation of the Stability, Safety, and Efficacy of CD101, a Novel Echinocandin.

Fungal infections pose a significant public health burden with high morbidity and mortality. CD101 is a novel echinocandin under development for the treatment and prevention of systemic Candida infections. Preclinical studies were conducted to evaluate the metabolic stability, plasma protein binding, pharmacokinetics, toxicity, and efficacy of CD101 at various dose levels. CD101 was stable to biotransformation in rat, monkey, and human liver microsomes and rat, monkey, dog, and human hepatocytes. In vitro studies suggest minimal interaction with recombinant cytochrome P450 enzymes (50% inhibitory concentrations [IC50s] of >10 µM). Similar to anidulafungin, CD101 bound avidly (>98%) to human, mouse, rat, and primate plasma proteins. In a 2-week repeat-dose comparison study, CD101 was well tolerated in rats (no effects on body weight, hematology, coagulation, or urinalysis). In contrast, administration of anidulafungin (at comparable exposure levels) resulted in reduced body weight, decreases in red blood cell, hemoglobin, hematocrit, mean cell volume, mean corpuscular hemoglobin, platelet, and reticulocyte counts, increases in neutrophil and eosinophil counts, polychromasia, and decreased activated partial thromboplastin time. Elevated plasma transaminases, total bilirubin, cholesterol, and globulin, dark and enlarged spleens, and single-cell hepatocyte necrosis were also observed for anidulafungin but not CD101. Hepatotoxicity may be due to the inherent chemical lability of anidulafungin generating potentially reactive intermediates. A glutathione trapping experiment confirmed the formation of a reactive species from anidulafungin, whereas CD101 did not exhibit instability or reactive intermediates. CD101 showed antifungal activity against Candida and Aspergillus infections in neutropenic mice. These preclinical studies demonstrated that CD101 is chemically and metabolically stable, well tolerated with no hepatotoxicity, and efficacious as an antifungal agent.

Nonclinical Safety Assessment of SYN-004: An Oral ß-lactamase for the Protection of the Gut Microbiome From Disruption by Biliary-Excreted, Intravenously Administered Antibiotics.

SYN-004 is a first in class, recombinant ß-lactamase that degrades ß-lactam antibiotics and has been formulated to be administered orally to patients receiving intravenous ß-lactam antibiotics including cephalosporins. SYN-004 is intended to degrade unmetabolized antibiotics excreted into the intestines and thus has the potential to protect the gut microbiome from disruption by these antibiotics. Protection of the gut microbiome is expected to protect against opportunistic enteric infections such as Clostridium difficile infection as well as antibiotic-associated diarrhea. In order to demonstrate that oral SYN-004 is safe for human clinical trials, 2 Good Laboratory Practice-compliant toxicity studies were conducted in Beagle dogs. In both studies, SYN-004 was administered orally 3 times per day up to the maximum tolerated dose of the formulation. In the first study, doses of SYN-004 administered over 28 days were safe and well tolerated in dogs with the no-observed-adverse-effect level at the high dose of 57 mg/kg/day. Systemic absorption of SYN-004 was minimal and sporadic and showed no accumulation during the study. In the second study, doses up to 57 mg/kg/day were administered to dogs in combination with an intravenous dose of ceftriaxone (300 mg/kg) given once per day for 14 days. Coadministration of oral SYN-004 with intravenous ceftriaxone was safe and well tolerated, with SYN-004 having no noticeable effect on the plasma pharmacokinetics of ceftriaxone. These preclinical studies demonstrate that SYN-004 is well tolerated and, when coadministered with ceftriaxone, does not interfere with its systemic pharmacokinetics. These data supported advancing SYN-004 into human clinical trials.

Getting Medical Directors Out of the C-Suite and Closer to Points of Care.

Physicians, more than anyone else, can influence peers when it comes to talking about evidence-based care, even when it runs counter to customary, but costly, practice patterns. The timing couldn't be better to put physicians in this leadership role because of the growing use of value-based payment models.

Lack of neuropathological changes in rats administered tedizolid phosphate for nine months.

Tedizolid, a novel oxazolidinone antibacterial, was administered to Long Evans rats by oral gavage once daily for up to 9 months at doses near the maximum tolerated dose (MTD) to evaluate for potential neurotoxicity. Mean plasma exposures of tedizolid at the low-, medium-, and high-dose levels (7.5, 15, and 30 mg/kg of body weight/day for males; 2.5, 5, and 10 mg/kg/day for females) were similar between males and females and were 1.8-, 3.9-, and 8.0-fold greater than exposures in patients at the therapeutic dose (200 mg once daily). Evaluated endpoints included survival, clinical observations, body weight, and food consumption. At 1, 3, 6, and 9 months, ophthalmic examinations, functional observational batteries, and locomotor activity measures were conducted, brain weights/sizes were recorded, and perfusion-fixed tissues were collected from 12 rats/sex/group/time point. A detailed morphological assessment was conducted on brain, eyes, optic nerve/tract, spinal cord, peripheral nerves (includes sciatic, sural, tibial, peroneal, trigeminal), and skeletal muscle. At the end of 9 months, less body weight gain was seen in high-dose males (-6.7%) and females (-5.8%) compared with that seen in controls. There were no tedizolid-related adverse neurobehavioral effects or tedizolid-related histopathologic changes in the central/peripheral nervous systems, including the optic nerve. Results of this study indicate that tedizolid was not neurotoxic when administered long term to pigmented rats at doses near the MTD, which were up to 8-fold higher than the human therapeutic exposure.

Systemic IFNγ predicts local implant macrophage response.

Implantation of biomaterials can cause complications often associated with inflammatory reactions. However, repeated evaluation of the implant site would be burdening for patients. Alternatively, blood examinations with analysis of inflammatory serum markers could potentially be useful to reflect the local cellular response for detection and/or prediction of inflammation-related complications. Therefore, following intramuscular implantation of surface-modified Ti implants in rats, this study aimed at examining possible associations between the post-implantation time course of pro-inflammatory (INFγ, IL-2) and anti-inflammatory (IL-4, IL-10) cytokine serum concentrations and the local peri-implant tissue response after 56 days (pro-inflammatory CD68-positive monocytes/macrophages, anti-inflammatory CD163-positive macrophages, MHC class II-positive cells, activated natural killer cells and mast cells). Multivariate correlation analysis revealed a significant interaction between serum IFNγ and peri-implant tissue CD68-positive monocytes/macrophages (p = 0.001) while no interactions were found for other cytokines and cell types. Additional Pearson correlation analysis of IFNγ serum concentrations on each experimental day vs. the CD68-positive monocytes/macrophages response on day 56 demonstrated a consistently positive correlation that was strongest during the first three weeks. Thus, high early pro-inflammatory IFNγ serum concentration was associated with high late number of pro-inflammatory CD68-positive monocyte/macrophages and low early serum IFNγ with low late CD68-positive monocyte/macrophage numbers. Further studies aimed at examination of patient samples could establish the relevance of this association to predict clinical complications. After implantation of titanium samples, high early IFNγ serum concentrations were associated with a pronounced late pro-inflammatory CD68-positive monocyte/ macrophage (red circle) response, while no correlation was found for other investigated cytokines and inflammatory cells (green circle). In contrast, low early IFNγ serum concentrations were correlated with low late monocyte/ macrophage numbers.

GAD autoantibody affinity in schoolchildren from the general population.

AIMS/HYPOTHESIS: Subtyping GAD autoantibody (GADA) responses using affinity measurement allows the identification of GADA-positive children with a family history of type 1 diabetes who are at risk of developing diabetes. Here, we asked whether GADA affinity is a useful marker to stratify the risk of type 1 diabetes in GADA-positive schoolchildren from the general population. METHODS: GADA affinity was measured by competitive binding experiments with [(125)I]-labelled and unlabelled human 65 kDa isoform of GAD (GAD65) in sera from 97 GADA-positive children identified in the Karlsburg Type 1 Diabetes Risk Study of a general schoolchild population in north-eastern Germany. GADA epitope specificity was determined using radiobinding assays with [(35)S]-labelled GAD65/67 kDa isoform of GAD (GAD67) chimeric proteins. RESULTS: GADA affinity was high, ≥ 10(10) l/mol, in 33 of 35 multiple islet autoantibody-positive children. In contrast, the affinity ranged widely among 62 single GADA-positive children (median 3.1 × 10(9) l/mol; range 5.6 × 10(6) to >4.0 × 10(11) l/mol; p < 0.0001). High-affinity GADA were associated with HLA-DRB1*03 (p = 0.02) and predominantly directed against the C-terminal and/or middle part of the GAD65 protein. At follow-up, the affinity remained relatively constant. Five of the single GADA-positive children developed additional islet autoantibodies and had high-affinity GADA. Twenty-six children progressed to type 1 diabetes; among them, 23 had GADA affinities of ≥ 10(10) l/mol before disease onset. CONCLUSIONS/INTERPRETATION: Schoolchildren from the general population may develop heterogeneous GADA responses, and a high affinity can identify those GADA-positive children who are more likely to progress to type 1 diabetes.

Quantitative analysis of trabecular bone tissue cryosections via a fully automated neural network-based approach.

Cryosectioning is known as a common and well-established histological method, due to its easy accessibility, speed, and cost efficiency. However, the creation of bone cryosections is especially difficult. In this study, a cryosectioning protocol for trabecular bone that offers a relatively cheap and undemanding alternative to paraffin or resin embedded sectioning was developed. Sections are stainable with common histological dying methods while maintaining sufficient quality to answer a variety of scientific questions. Furthermore, this study introduces an automated protocol for analysing such sections, enabling users to rapidly access a wide range of different stainings. Therefore, an automated 'QuPath' neural network-based image analysis protocol for histochemical analysis of trabecular bone samples was established, and compared to other automated approaches as well as manual analysis regarding scattering, quality, and reliability. This highly automated protocol can handle enormous amounts of image data with no significant differences in its results when compared with a manual method. Even though this method was applied specifically for bone tissue, it works for a wide variety of different tissues and scientific questions.

In vivo examination of the local inflammatory response after implantation of Ti6Al4V samples with a combined low-temperature plasma treatment using pulsed magnetron sputtering of copper and plasma-polymerized ethylenediamine.

Copper (Cu) could serve as antibacterial coating for Ti6Al4V implants. An additional cell-adhesive layer might compensate Cu cytotoxicity. This study aimed at in vitro and in vivo evaluation of low-temperature plasma treatment of Ti6Al4V plates with Ti/Cu magnetron sputtering (Ti6Al4V-Ti/Cu), plasma-polymerized ethylenediamine (Ti6Al4V-PPEDA), or both (Ti6Al4V-Ti/Cu-PPEDA). Ti6Al4V-Ti/Cu and Ti6Al4V-Ti/Cu-PPEDA had comparable in vitro Cu release and antibacterial effectiveness. Following intramuscular implantation of Ti6Al4V-Ti/Cu, Ti6Al4V-PPEDA, Ti6Al4V-Ti/Cu-PPEDA and Ti6Al4V controls for 7, 14 and 56 days with 8 rats/day, peri-implant tissue was immunohistochemically examined for different inflammatory cells. Ti6Al4V-PPEDA had more mast cells and NK cells than Ti6Al4V, and more tissue macrophages, T lymphocytes, mast cells and NK cells than Ti6Al4V-Ti/Cu-PPEDA. Ti6Al4V-Ti/Cu had more mast cells than Ti6Al4V and Ti6Al4V-Ti/Cu-PPEDA. Results indicate that PPEDA-mediated cell adhesion counteracted Cu cytotoxicity. Ti6Al4V-Ti/Cu-PPEDA differed from Ti6Al4V only for mast cells on day 56. Altogether, implants with both plasma treatments had antibacterial properties and did not increase inflammatory reactions.

On the infinite Borwein product raised to a positive real power.

In this paper, we study properties of the coefficients appearing in the q-series expansion of ∏n≥1[(1-qn)/(1-qpn)]δ, the infinite Borwein product for an arbitrary prime p, raised to an arbitrary positive real power δ. We use the Hardy-Ramanujan-Rademacher circle method to give an asymptotic formula for the coefficients. For p=3 we give an estimate of their growth which enables us to partially confirm an earlier conjecture of the first author concerning an observed sign pattern of the coefficients when the exponent δ is within a specified range of positive real numbers. We further establish some vanishing and divisibility properties of the coefficients of the cube of the infinite Borwein product. We conclude with an Appendix presenting several new conjectures on precise sign patterns of infinite products raised to a real power which are similar to the conjecture we made in the p=3 case.

Three families of q-supercongruences modulo the square and cube of a cyclotomic polynomial.

In this paper, three parametric q-supercongruences for truncated very-well-poised basic hypergeometric series are proved, one of them modulo the square, the other two modulo the cube of a cyclotomic polynomial. The main ingredients of proof include a basic hypergeometric summation by George Gasper, the method of creative microscoping (a method recently introduced by the first author in collaboration with Wadim Zudilin), and the Chinese remainder theorem for coprime polynomials.

New q-Analogues of Van Hamme's (E.2) Supercongruence and of a Supercongruence by Swisher.

In this paper, a couple of q-supercongruences for truncated basic hypergeometric series are proved, most of them modulo the cube of a cyclotomic polynomial. One of these results is a new q-analogue of the (E.2) supercongruence by Van Hamme, another one is a new q-analogue of a supercongruence by Swisher, while the other results are closely related q-supercongruences. The proofs make use of special cases of a very-well-poised 6 ϕ 5 summation. In addition, the proofs utilize the method of creative microscoping (which is a method recently introduced by the first author in collaboration with Wadim Zudilin), and the Chinese remainder theorem for coprime polynomials.

Serum profile of pro- and anti-inflammatory cytokines in rats following implantation of low-temperature plasma-modified titanium plates.

Surface modification of Titanium (Ti) by low-temperature plasma influences cell-material interactions. Therefore, this study aimed at examining serum cytokine levels and associations after intramuscular implantation (n = 8 rats/group) of Ti-plates with Plasma Polymerized Allyl Amine (Ti-PPAAm), Plasma Polymerized Acrylic Acid (Ti-PPAAc), and without such layers (Ti-Controls). Pro-inflammatory (IL-2, IFNγ, IL-6) and anti-inflammatory (IL-4, IL-10, IL-13) cytokines were measured weekly for 56 days. Ti-PPAAm caused increased IL-2 (d7-14, d35), increased IFNγ (d35) and decreased IL-10 (d35, d49-56). Ti-PPAAc induced divergent anti-inflammatory cytokine changes with increased IL-4 (d28-56) and decreased IL-10 (d42-56). Ti-Controls elicited increased IL-2 (d42) and IFNγ (d35-42, d56). IL-6 was not detected and IL-13 only in three samples, thus they do not influence the response against these Ti implants. Correlation analysis revealed surface-dependent associations between cytokines indicating the involvement of different inflammatory cell populations. Concluding, different plasma modifications induce specific serum cytokine profiles and associations indicating distinct inflammatory responses.

Association of systemic antibody response against polyethylene terephthalate with inflammatory serum cytokine profile following implantation of differently coated vascular prostheses in a rat animal model.

Experimental studies demonstrated antibodies against matrix and coating of polyester-based vascular prostheses. Thus, this study examined associations of these antibodies with serum cytokines (IL-2, IL-4, and IL-10) and local inflammatory reactions. Rats (n = 8/group) intramuscularly received prosthesis segments [PET-C, PET-G, and PET-A groups: polyethylene terephthalate (PET)-based prostheses coated with bovine collagen and gelatin or human serum albumin, respectively; uncoated polytetrafluoroethylene-based (PTFE) prosthesis], with sham-operated controls. Blood was drawn pre-operatively and weekly until day 22. Polymer-specific or coating-specific antibodies and cytokines were detected by enzyme immunoassays, inflammatory reactions were immunohistochemically evaluated on day 23. Polymer-specific antibodies were detected in all PET-groups using uncoated PET as antigenic target, but not for PTFE or controls, coating-specific antibodies only for PET-A. IL-10 was increased in all PET-groups and correlated with polymer-specific antibodies for PET-G and PET-A. IL-2 was increased for PET-A, but overall correlated with PET-specific antibodies. IL-4 remained unchanged in all groups. Intense local inflammatory reactions (ED1+ /ED2+ macrophages and T lymphocytes) were found within all PET-groups, but only minor for PTFE or controls. In conclusion, PET-specific antibodies were associated with increased IL-10 and along with concurrent coating-specific antibodies also with increased IL-2, indicating a specific T cell response. Thus, matrix and/or coating of polymeric vascular prostheses elicit distinct systemic immune reactions, probably influencing local inflammatory reactions.

Diabetes antibody standardization program: first proficiency evaluation of assays for autoantibodies to zinc transporter 8.

BACKGROUND: Zinc transporter 8 (ZnT8) is a recently identified major autoantigen in type 1 diabetes, and autoantibodies to ZnT8 (ZnT8A) are new markers for disease prediction and diagnosis. Here we report the results of the first international proficiency evaluation of ZnT8A assays by the Diabetes Antibody Standardization Program (DASP). METHODS: After a pilot workshop in 2007, an expanded ZnT8A workshop was held in 2009, with 26 participating laboratories from 13 countries submitting results of 63 different assays. ZnT8A levels were measured in coded sera from 50 patients with newly diagnosed type 1 diabetes and 100 blood donor controls. Results were analyzed comparing area under the ROC curve (ROC-AUC), sensitivity adjusted to 95% specificity (AS95), concordance of sample ZnT8A positive or negative designation, and autoantibody levels. RESULTS: ZnT8A radio binding assays (RBAs) based on combined immunoprecipitation of the 2 most frequent ZnT8 COOH-terminal domain polymorphic variants showed a median ROC-AUC of 0.848 [interquartile range (IQR) 0.796-0.878] and a median AS95 of 70% (IQR 60%-72%). These RBAs were more sensitive than assays using as antigen either 1 ZnT8 variant only or chimeric constructs joining NH(2)- and COOH-terminal domains, assays based on immunoprecipitation and bioluminescent detection, or assays based on immunofluorescent staining of cells transfected with full-length antigen. CONCLUSIONS: The DASP workshop identified immunoprecipitation-based ZnT8A assays and antigen constructs that achieved both a high degree of sensitivity and specificity and were suitable for more widespread clinical application.