Prevalence of Overweight and Obesity, Its Complications, and Progression in a 10-Year Follow-Up in the Gutenberg Health Study (GHS).

INTRODUCTION: Overweight and obesity lead to numerous complications and their treatment. The associated costs represent a health and sociopolitical burden. Therefore, the development of overweight and obesity is of great importance for health policy. METHODS: The Gutenberg Health Study (GHS), a population-based observational study of individuals aged 35-74 years in the city of Mainz and the district of Mainz-Bingen, examined current data on the prevalence and development of overweight and obesity and their association with concomitant diseases and medication use. RESULTS: Among men, 48.1% were overweight and 26.3% had obesity. Among women, these proportions were 32.1% and 24.1%, respectively. Elevated body mass index (BMI) was associated with numerous complications, particularly insulin resistance and type 2 diabetes, arterial hypertension, elevated triglycerides and low HDL cholesterol, and cardiovascular disease. Accordingly, medications to treat these conditions were used significantly more often in individuals with elevated BMI. During the 10-year observation period, mean weight increased in the population. Both men and women had a moderate but significant increase in BMI compared to men and women of the same age at baseline. Individual weight changes over the 10-year observation period, on the other hand, were age-dependent. In the two younger age decades, weight gain was observed, while in the oldest age decade, mean body weight decreased. CONCLUSION: These current data confirm that overweight and obesity are associated with relevant complications and that these complications lead to significant use of appropriate medications. The study also suggests that there is a significant trend toward increased prevalence of obesity (BMI ≥30) over the 10-year period.

Open ADAMTS-13 conformation index predicts earlier relapse in immune-mediated thrombotic thrombocytopenic purpura.

BACKGROUND: ADAMTS-13 adopts an open conformation in patients with immune-mediated thrombotic thrombocytopenic purpura (iTTP) in acute phase while being closed in healthy donors. We reported that a substantial number of patients with iTTP in remission with restored ADAMTS-13 activity (>50%) still had an open ADAMTS-13 conformation, although a closed conformation is expected given the extent of remission. OBJECTIVES: To investigate whether open ADAMTS-13, represented by a conformation index >0.5, is associated with a risk of earlier ADAMTS-13 and/or clinical relapse. METHODS: We collected follow-up data (ADAMTS-13 parameters, ADAMTS-13 and clinical relapse, and treatment) from 81 patients with iTTP in remission with ADAMTS-13 activity >50%. RESULTS: During follow-up, 19 ADAMTS-13 and 10 clinical relapses were reported (median follow-up period, 20 months). First, open or closed ADAMTS-13 conformation was dichotomized based on the 0.5 conformation index cutoff. Open ADAMTS-13 (conformation index, >0.5) was not identified as a risk factor for ADAMTS-13 and clinical relapse (log-rank test and Cox regression model). In contrast, by identifying the optimal conformation index cutoff for relapse prediction, using classification and regression tree analysis, a conformation index >0.645 and >0.835 was shown to be a risk factor for ADAMTS-13 relapse (hazard ratio, 3.3; 95% CI, 1.3-8.3; P = .01) and clinical relapse (hazard ratio, 4.4; 95% CI, 1.3-15.3; P = .02), respectively. CONCLUSION: Patients with open ADAMTS-13 with a conformation index >0.645 and >0.835 have a >3- and >4-fold higher risk of earlier ADAMTS-13 and clinical relapse, respectively. Hence, ADAMTS-13 conformation index could be used to complement ADAMTS-13 activity monitoring to timely notice ADAMTS-13 relapse and prevent clinical relapse.

Hereditary Spherocytosis: Can Next-Generation Sequencing of the Five Most Frequently Affected Genes Replace Time-Consuming Functional Investigations?

Congenital defects of the erythrocyte membrane are common in northern Europe and all over the world. The resulting diseases, for example, hereditary spherocytosis (HS), are often underdiagnosed, partly due to their sometimes mild and asymptomatic courses. In addition to a broad clinical spectrum, this is also due to the occasionally complex diagnostics that are not available to every patient. To test whether next-generation sequencing (NGS) could replace time-consuming spherocytosis-specific functional tests, 22 consecutive patients with suspected red cell membranopathy underwent functional blood tests. We were able to identify the causative genetic defect in all patients with suspected HS who underwent genetic testing (n = 17). The sensitivity of the NGS approach, which tests five genes (ANK1 (gene product: ankyrin1), EPB42 (erythrocyte membrane protein band4.2), SLC4A1 (band3), SPTA1 (α-spectrin), and SPTB (ß-spectrin)), was 100% (95% confidence interval: 81.5-100.0%). The major advantage of genetic testing in the paediatric setting is the small amount of blood required (<200 µL), and compared to functional assays, sample stability is not an issue. The combination of medical history, basic laboratory parameters, and an NGS panel with five genes is sufficient for diagnosis in most cases. Only in rare cases, a more comprehensive functional screening is required.

Biallelic MAD2L1BP (p31comet) mutation is associated with mosaic aneuploidy and juvenile granulosa cell tumors.

MAD2L1BP-encoded p31comet mediates Trip13-dependent disassembly of Mad2- and Rev7-containing complexes and, through this antagonism, promotes timely spindle assembly checkpoint (SAC) silencing, faithful chromosome segregation, insulin signaling, and homology-directed repair (HDR) of DNA double-strand breaks. We identified a homozygous MAD2L1BP nonsense variant, R253*, in 2 siblings with microcephaly, epileptic encephalopathy, and juvenile granulosa cell tumors of ovary and testis. Patient-derived cells exhibited high-grade mosaic variegated aneuploidy, slowed-down proliferation, and instability of truncated p31comet mRNA and protein. Corresponding recombinant p31comet was defective in Trip13, Mad2, and Rev7 binding and unable to support SAC silencing or HDR. Furthermore, C-terminal truncation abrogated an identified interaction of p31comet with tp53. Another homozygous truncation, R227*, detected in an early-deceased patient with low-level aneuploidy, severe epileptic encephalopathy, and frequent blood glucose elevations, likely corresponds to complete loss of function, as in Mad2l1bp-/- mice. Thus, human mutations of p31comet are linked to aneuploidy and tumor predisposition.

Evidence for the utility of cfDNA plasma concentrations to predict disease severity in COVID-19: a retrospective pilot study.

Background: COVID-19 is a worldwide pandemic caused by the highly infective SARS-CoV-2. There is a need for biomarkers not only for overall prognosis but also for predicting the response to treatments and thus for improvements in the clinical management of patients with COVID-19. Circulating cell-free DNA (cfDNA) has emerged as a promising biomarker in the assessment of various pathological conditions. The aim of this retrospective and observational pilot study was to investigate the range of cfDNA plasma concentrations in hospitalized COVID-19 patients during the first wave of SARS-CoV-2 infection, to relate them to established inflammatory parameters as a correlative biomarker for disease severity, and to compare them with plasma levels in a healthy control group. Methods: Lithium-Heparin plasma samples were obtained from COVID-19 patients (n = 21) during hospitalization in the University Medical Centre of Mainz, Germany between March and June 2020, and the cfDNA concentrations were determined by quantitative PCR yielding amplicons of long interspersed nuclear elements (LINE-1). The cfDNA levels were compared with those of an uninfected control group (n = 19). Results: Plasma cfDNA levels in COVID-19 patients ranged from 247.5 to 6,346.25 ng/ml and the mean concentration was 1,831 ± 1,388 ng/ml (± standard deviation), which was significantly different from the levels of the uninfected control group (p < 0.001). Regarding clinical complications, the highest correlation was found between cfDNA levels and the myositis (p = 0.049). In addition, cfDNA levels correlated with the "WHO clinical progression scale". D-Dimer and C-reactive protein (CRP) were the clinical laboratory parameters with the highest correlations with cfDNA levels. Conclusion: The results of this observational pilot study show a wide range in cfDNA plasma concentrations in patients with COVID-19 during the first wave of infection and confirm that cfDNA plasma concentrations serve as a predictive biomarker of disease severity in COVID-19.

A novel von Willebrand factor multimer ratio as marker of disease activity in thrombotic thrombocytopenic purpura.

Immune-mediated thrombotic thrombocytopenic purpura (iTTP), an autoantibody-mediated severe ADAMTS13 deficiency, is caused by insufficient proteolytic processing of von Willebrand factor (VWF) multimers (MMs) and microvascular thrombi. Recurrence of acute iTTP is associated with persistence or reappearance of ADAMTS13 deficiency. Some patients remain in remission despite recurring or persisting severe ADAMTS13 deficiency. In a prospective 2-year observational study, we investigated VWF MM patterns and ADAMTS13 in patients with iTTP in remission and at acute episodes. Of the 83 patients with iTTP, 16 suffered 22 acute episodes whereas 67 remained in clinical remission during follow-up, including 13 with ADAMTS13 <10% and 54 with ADAMTS13 ≥10%. High -molecular weight to low-molecular weight VWF MM ratio based on sodium dodecyl sulfate-agarose gel electrophoresis was compared with ADAMTS13 activity. VWF MM ratio was significantly higher in patients in remission with <10% compared with ≥10% ADAMTS13 activity. Fourteen samples obtained from 13 to 50 days (interquartile range; median, 39) before acute iTTP onset (ADAMTS13 <10% in 9 patients and 10%-26% in 5) showed VWF MM ratios significantly higher than those from 13 patients remaining in remission with ADAMTS13 <10%. At acute iTTP onset, VWF MM ratio decreased significantly and was low in all patients despite <10% ADAMTS13. The VWF MM ratio does not depend exclusively on ADAMTS13 activity. The disappearance of high molecular weight VWF MMs resulting in low VWF MM ratio at iTTP onset may be explained by consumption of larger VWF MMs in the microcirculation. The very high VWF MM ratio preceding acute iTTP recurrence suggests that VWF processing is hampered more than in patients remaining in remission.

One fits all: a highly sensitive combined ddPCR/pyrosequencing system for the quantification of microchimerism after hematopoietic and solid organ transplantation.

OBJECTIVES: A combined digital droplet PCR (ddPCR)/pyrosequencing assay system was developed that demonstrated advantages applicable to multiple qualitative and quantitative molecular genetic diagnostic applications. Data for characterizing this combined approach for hematologic stem cell transplantation (HSCT) and allele quantification from graft-derived cell-free (cf) DNA in solid organ transplantation (SOT) is presented. METHODS: ddPCR and pyrosequencing assays targeting 32 SNPs/markers were established. ddPCR results from 72 gDNAs of 55 patients after allogeneic HSCT and 107 plasma-cfDNAs of 25 liver transplant recipients were compared with established methods/markers, i.e. short-tandem-repeat PCR and ALT, respectively. RESULTS: The ddPCR results were in good agreement with the established marker. The limit of detection was 0.02 % minor allele fraction. The relationship between ddPCR and STR-PCR was linear with R2=0.98 allowing to transfer previously established clinical STR-PCR cut-offs to ddPCR; 50-fold higher sensitivity and a variation coefficient of <2 % enable the use of low DNA concentrations (e.g. pre-sorted cells). ddPCR detected liver allograft injury at least as sensitive as ALT suggesting that ddPCR is a reliable method to monitor the transplant integrity, especially when other biomarkers are lacking (e.g. kidney). CONCLUSIONS: Combining pyrosequencing for genotyping and ddPCR for minor allele quantification enhances sensitivity and precision for the patient after HSCT and SOT. The assay is designed for maximum flexibility. It is expected to be suitable for other applications (sample tracking, prenatal diagnostics, etc.).

CEP162 deficiency causes human retinal degeneration and reveals a dual role in ciliogenesis and neurogenesis.

Defects in primary or motile cilia result in a variety of human pathologies, and retinal degeneration is frequently associated with these so-called ciliopathies. We found that homozygosity for a truncating variant in CEP162, a centrosome and microtubule-associated protein required for transition zone assembly during ciliogenesis and neuronal differentiation in the retina, caused late-onset retinitis pigmentosa in 2 unrelated families. The mutant CEP162-E646R*5 protein was expressed and properly localized to the mitotic spindle, but it was missing from the basal body in primary and photoreceptor cilia. This impaired recruitment of transition zone components to the basal body and corresponded to complete loss of CEP162 function at the ciliary compartment, reflected by delayed formation of dysmorphic cilia. In contrast, shRNA knockdown of Cep162 in the developing mouse retina increased cell death, which was rescued by expression of CEP162-E646R*5, indicating that the mutant retains its role for retinal neurogenesis. Human retinal degeneration thus resulted from specific loss of the ciliary function of CEP162.

Severe high-molecular-weight kininogen deficiency: clinical characteristics, deficiency-causing KNG1 variants, and estimated prevalence.

BACKGROUND: Severe high-molecular-weight kininogen (HK) deficiency is a poorly studied autosomal recessive contact system defect caused by pathogenic, biallelic KNG1 variants. AIM: We performed the first comprehensive analysis of diagnostic, clinical, genetic, and epidemiological aspects of HK deficiency. METHODS: We collected clinical information and blood samples from a newly detected HK-deficient individual and from published cases identified by a systematic literature review. Activity and antigen levels of coagulation factors were determined. Genetic analyses of KNG1 and KLKB1 were performed by Sanger sequencing. The frequency of HK deficiency was estimated considering truncating KNG1 variants from GnomAD. RESULTS: We identified 48 cases of severe HK deficiency (41 families), of these 47 have been previously published (n = 19 from gray literature). We genotyped 3 cases and critically appraised 10 studies with genetic data. Ten HK deficiency-causing variants (one new) were identified. All of them were truncating mutations, whereas the only known HK amino acid substitution with a relevant phenotype instead causes hereditary angioedema. Conservative estimates suggest an overall prevalence of severe HK deficiency of approximately one case per 8 million population, slightly higher in Africans. Individuals with HK deficiency appeared asymptomatic and had decreased levels of prekallikrein and factor XI, which could lead to misdiagnosis. CONCLUSION: HK deficiency is a rare condition with only few known pathogenic variants. It has an apparently good prognosis but is prone to misdiagnosis. Our understanding of its clinical implications is still limited, and an international prekallikrein and HK deficiency registry is being established to fill this knowledge gap.

Protective behavior and SARS-CoV-2 infection risk in the population - Results from the Gutenberg COVID-19 study.

BACKGROUND: During the SARS-CoV-2 pandemic, preventive measures like physical distancing, wearing face masks, and hand hygiene have been widely applied to mitigate viral transmission. Beyond increasing vaccination coverage, preventive measures remain urgently needed. The aim of the present project was to assess the effect of protective behavior on SARS-CoV-2 infection risk in the population. METHODS: Data of the Gutenberg COVID-19 Study (GCS), a prospective cohort study with a representative population-based sample, were analyzed. SARS-CoV-2 infections were identified by sequential sampling of biomaterial, which was analyzed by RT-qPCR and two antibody immunoassays. Self-reported COVID-19 test results were additionally considered. Information on protective behavior including physical distancing, wearing face masks, and hand hygiene was collected via serial questionnaire-based assessments. To estimate adjusted prevalence ratios and hazard ratios, robust Poisson regression and Cox regression were applied. RESULTS: In total, 10,250 participants were enrolled (median age 56.9 [43.3/68.6] years, 50.8% females). Adherence to preventive measures was moderate for physical distancing (48.3%), while the use of face masks (91.5%) and the frequency of handwashing (75.0%) were high. Physical distancing appeared to be a protective factor with respect to SARS-CoV-2 infection risk independent of sociodemographic characteristics and individual pandemic-related behavior (prevalence ratio [PR] = 0.77, 95% confidence interval [CI] 0.62-0.96). A protective association between wearing face masks and SARS-CoV-2 transmission was identified (PR = 0.73, 95% CI 0.55-0.96). However, the protective effect declined after controlling for potential confounding factors (PR = 0.96, 95% CI 0.68-1.36). For handwashing, this investigation did not find a beneficial impact. The adherence to protective behavior was not affected by previous SARS-CoV-2 infection or immunization against COVID-19. CONCLUSION: The present study suggests primarily a preventive impact of physical distancing of 1.5 m, but also of wearing face masks on SARS-CoV-2 infections, supporting their widespread implementation. The proper fit and use of face masks are crucial for effectively mitigating the spread of SARS-CoV-2 in the population.

Novel GATA1 Variant Causing a Bleeding Phenotype Associated with Combined Platelet α-/δ-Storage Pool Deficiency and Mild Dyserythropoiesis Modified by a SLC4A1 Variant.

Germline defects in the transcription factor GATA1 are known to cause dyserythropoiesis with(out) anemia and variable abnormalities in platelet count and function. However, damaging variants closely located to the C-terminal zinc finger domain of GATA1 are nearly unknown. In this study, a 36-year-old male index patient and his 4-year-old daughter suffered from moderate mucocutaneous bleeding diathesis since birth. Whole exome sequencing detected a novel hemizygous GATA1 missense variant, c.886A>C p.T296P, located between the C-terminal zinc finger and the nuclear localization sequence with non-random X-chromosome inactivation in the heterozygous daughter. Blood smears from both patients demonstrated large platelet fractions and moderate thrombocytopenia in the index. Flow cytometry and electron microscopy analysis supported a combined α-/δ (AN-subtype)-storage pool deficiency as cause for impaired agonist-induced platelet aggregation (light transmission aggregometry) and granule exocytosis (flow cytometry). The absence of BCAM in the index (Lu(a-b-)) and its low expression in the daughter (Lu(a-b+)) confirmed a less obvious effect of defective GATA1 also on erythrocytes. Borderline anemia, elevated HbF levels, and differential transcription of GATA1-regulated genes indicated mild dyserythropoiesis in both patients. Furthermore, a mild SLC4A1 defect associated with a heterozygous SLC4A1 c.2210C>T p.A737V variant maternally transmitted in the daughter may modify the disease to mild spherocytosis and hemolysis.

Differential Inhibition of Platelet Reactivity by Dual Therapy With Aspirin and Low-Dose Rivaroxaban in Peripheral Arterial Disease: A Pilot Study.

Patients with peripheral arterial disease (PAD) benefit from combination therapy with acetylsalicylic acid (ASA, 100 mg, one time per day) plus low-dose rivaroxaban (2.5 mg, two times per day) compared to ASA monotherapy. In particular, major adverse cardiac and limb events were significantly reduced after peripheral endovascular revascularization (EVR). In this pilot study, the platelet activation status in vivo and platelet reactivity in vitro were longitudinally analyzed by flow cytometric assays and calibrated automated thrombography in platelet-rich plasma (PRP) from 10 patients with PAD receiving ASA (100 mg, one time per day) before EVR, ASA plus clopidogrel (75 mg, one time per day) after EVR, and ASA plus rivaroxaban (2.5 mg, two times per day) during a long-term follow-up. Platelet responsiveness to clopidogrel was compared to additional 10 patients with stable PAD and clopidogrel (75 mg, one time per day) monotherapy. ASA plus rivaroxaban treatment resulted in a significantly decreased thrombin peak in PRP for two triggers, namely, low concentration of tissue factor (TF) and thrombin, compared to ASA monotherapy. TF-controlled thrombin generation was additionally characterized by a significantly prolonged lag time in PRP and platelet-free plasma during ASA plus rivaroxaban combination therapy. In comparison, ASA plus clopidogrel treatment presented a significant reduction of the thrombin peak in PRP, which was less pronounced than during subsequent ASA plus rivaroxaban therapy. Platelet responsiveness to clopidogrel was observed for 60% of patients receiving ASA plus clopidogrel and clopidogrel monotherapy, respectively. Blocking of CD36 on the platelet surface further reduced the thrombin peak in PRP induced by TF for all three therapy regimes. Platelet activation in vivo and in response to the GPVI-agonist convulxin or thrombin in vitro was similar, whereas integrin αIIbß3 activation and α-granule release induced by the PAR-1 activating peptide TRAP-6 were significantly diminished during ASA plus rivaroxaban treatment compared to ASA monotherapy. In conclusion, the data of this pilot study indicate an inhibitory effect of rivaroxaban on the thrombin propagation phase of CD36-sensitive platelet thrombin formation in patients with PAD treated with ASA plus rivaroxaban combination therapy, which is associated with decreased PAR-1 but not thrombin-mediated platelet activation.

Second MAFA Variant Causing a Phosphorylation Defect in the Transactivation Domain and Familial Insulinomatosis.

Adult-onset familial insulinomatosis is a rare disorder with recurrent, severe hypoglycemia caused by multiple insulin-secreting pancreatic tumors. The etiology was unclear until the variant p.Ser64Phe in the transcription factor MAFA, a key coordinator of ß-cell insulin secretion, was defined as the cause in two families. We here describe detailed genetic, clinical, and family analyses of two sisters with insulinomatosis, aiming to identify further disease causes. Using exome sequencing, we detected a novel, heterozygous missense variant, p.Thr57Arg, in MAFA's highly conserved transactivation domain. The impact of the affected region is so crucial that in vitro expression studies replacing Thr57 have already been performed, demonstrating a phosphorylation defect with the impairment of transactivation activity and degradation. However, prior to our study, the link to human disease was missing. Furthermore, mild hyperglycemia was observed in six additional, heterozygote family members, indicating that not only insulinomatosis but also MODY-like symptoms co-segregate with p.Thr57Arg. The pre-described MAFA variant, p.Ser64Phe, is located in the same domain, impairs the same phosphorylation cascade, and results in the same symptoms. We confirm MAFA phosphorylation defects are important causes of a characteristic syndrome, thus complementing the pathophysiological and diagnostic disease concept. Additionally, we verify the high penetrance and autosomal dominant inheritance pattern.

Hypermethylation of RAD9A intron 2 in childhood cancer patients, leukemia and tumor cell lines suggest a role for oncogenic transformation.

Most childhood cancers occur sporadically and cannot be explained by an inherited mutation or an unhealthy lifestyle. However, risk factors might trigger the oncogenic transformation of cells. Among other regulatory signals, hypermethylation of RAD9A intron 2 is responsible for the increased expression of RAD9A protein, which may play a role in oncogenic transformation. Here, we analyzed the RAD9A intron 2 methylation in primary fibroblasts of 20 patients with primary cancer in childhood and second primary cancer (2N) later in life, 20 matched patients with only one primary cancer in childhood (1N) and 20 matched cancer-free controls (0N), using bisulfite pyrosequencing and deep bisulfite sequencing (DBS). Four 1N patients and one 2N patient displayed elevated mean methylation levels (≥ 10 %) of RAD9A. DBS revealed ≥ 2 % hypermethylated alleles of RAD9A, indicative for constitutive mosaic epimutations. Bone marrow samples of NHL and AML tumor patients (n=74), EBV (Epstein Barr Virus) lymphoblasts (n=6), tumor cell lines (n=5) and FaDu subclones (n=13) were analyzed to substantiate our findings. We find a broad spectrum of tumor entities with an aberrant methylation of RAD9A. We detected a significant difference in mean methylation of RAD9A for NHL versus AML patients (p ≤0.025). Molecular karyotyping of AML samples during therapy with hypermethylated RAD9A showed an evolving duplication of 1.8 kb on Chr16p13.3 including the PKD1 gene. Radiation, colony formation assays, cell proliferation, PCR and molecular karyotyping SNP-array experiments using generated FaDu subclones suggest that hypermethylation of RAD9A intron 2 is associated with genomic imbalances in regions with tumor-relevant genes and survival of the cells. In conclusion, this is the very first study of RAD9A intron 2 methylation in childhood cancer and Leukemia. RAD9A epimutations may have an impact on leukemia and tumorigenesis and can potentially serve as a biomarker.

Anti-ADAMTS13 autoantibody profiling in patients with immune-mediated thrombotic thrombocytopenic purpura.

Anti-A Disintegrin and Metalloproteinase with a ThromboSpondin type 1 motif, member 13 (ADAMTS13) autoantibodies cause a severe ADAMTS13 deficiency in immune-mediated thrombotic thrombocytopenic purpura (iTTP). ADAMTS13 consists of a metalloprotease (M), a disintegrin-like (D) domain, 8 thrombospondin type 1 repeats (T1-T8), a cysteine-rich (C), a spacer (S), and 2 CUB domains (CUB1-2). We recently developed a high-throughput epitope mapping assay based on small, nonoverlapping ADAMTS13 fragments (M, DT, CS, T2-T5, T6-T8, CUB1-2). With this assay, we performed a comprehensive epitope mapping using 131 acute-phase samples and for the first time a large group of remission samples (n = 50). Next, samples were stratified according to their immunoprofiles, a field that is largely unexplored in iTTP. Three dominant immunoprofiles were found in acute-phase samples: profile 1: only anti-CS autoantibodies (26.7%); profile 2: both anti-CS and anti-CUB1-2 autoantibodies (12.2%); and profile 3: anti-DT, anti-CS, anti-T2-T5, anti-T6-T8, and anti-CUB1-2 autoantibodies (8.4%). Interestingly, profile 1 was the only dominant immunoprofile in remission samples (52.0%). Clinical data were available for a relatively small number of patients with acute iTTP (>68), and no correlation was found between immunoprofiles and disease severity. Nevertheless, profile 1 was linked with younger and anti-T2-T5 autoantibodies with older age and the absence of anti-CUB1-2 autoantibodies with cerebral involvement. In conclusion, identifying acute phase and remission immunoprofiles in iTTP revealed that anti-CS autoantibodies seem to persist or reappear during remission providing further support for the clinical development of a targeted anti-CS autoantibody therapy. A large cohort study with acute iTTP samples will validate possible links between immunoprofiles or anti-domain autoantibodies and clinical data.

Distribution of HOMA-IR in a population-based cohort and proposal for reference intervals.

OBJECTIVES: Insulin resistance (IR) is a hallmark of type 2 diabetes mellitus (DM). The homeostatic model assessment of insulin resistance (HOMA-IR) provides an estimate for IR from fasting glucose and insulin serum concentrations. The aim of this study was to obtain a reference interval for HOMA-IR for a specific insulin immunoassay. METHODS: The Gutenberg Health Study (GHS) is a population-based, prospective, single-center cohort study in Germany with 15,030 participants aged 35-74 years. Fasting glucose, insulin, and C-peptide were available in 10,340 participants. HOMA-IR was calculated in this group and three reference subgroups with increasingly more stringent inclusion criteria. Age- and sex-dependent distributions of HOMA-IR and reference intervals were obtained. In a substudy three insulin assays were compared and HOMA-IR estimated for each assay. RESULTS: Among the 10,340 participants analyzed there were 6,590 non-diabetic, 2,901 prediabetic, and 849 diabetic individuals. Median (interquartile range [IQR]) HOMA-IR was 1.54 (1.13/2.19), 2.00 (1.39/2.99), and 4.00 (2.52/6.51), respectively. The most stringently selected reference group consisted of 1,065 persons. Median (IQR) HOMA-IR was 1.09 (0.85/1.42) with no significant difference between men and women. The 97.5th percentile was 2.35. There was a non-significant trend towards higher values with older age. Comparison of three immunoassays for insulin showed an unsatisfactory correlation among the assays and systematic differences in calculated HOMA-IR. CONCLUSIONS: We present HOMA-IR reference intervals for adults derived by more or less stringent selection criteria for the reference cohort. In addition we show that assay specific reference intervals for HOMA-IR are required.

Pathogenic lipid-binding antiphospholipid antibodies are associated with severity of COVID-19.

BACKGROUND: Coronavirus disease 19 (COVID-19)-associated coagulopathy is a hallmark of disease severity and poor prognosis. The key manifestations of this prothrombotic syndrome-microvascular thrombosis, stroke, and venous and pulmonary clots-are also observed in severe and catastrophic antiphospholipid syndrome. Antiphospholipid antibodies (aPL) are detectable in COVID-19 patients, but their association with the clinical course of COVID-19 remains unproven. OBJECTIVES: To analyze the presence and relevance of lipid-binding aPL in hospitalized COVID-19 patients. METHODS: Two cohorts of 53 and 121 patients from a single center hospitalized for PCR-proven severe acute respiratory syndrome-coronavirus 2 infection were analyzed for the presence of aPL and clinical severity of COVID-19. RESULTS: We here demonstrate that lipid-binding aPL are common in COVID-19. COVID-19 patients with lipid-binding aPL have higher median concentrations of C-reactive protein and D-dimer, and are more likely to have a critical clinical course and fatal outcome. Lipid-binding aPL isolated from COVID-19 patients target the recently described cell surface complex of lysobisphosphatidic acid (LBPA) with the protein C receptor (EPCR) to induce prothrombotic and inflammatory responses in monocytes and endothelial cells. We show that B1a cells producing lipid-reactive aPL of the IgG isotype circulate in the blood of COVID-19 patients. In vivo, COVID-19 aPL accelerate thrombus formation in an experimental mouse model dependent on the recently delineated signaling pathway involving EPCR-LBPA. CONCLUSIONS: COVID-19 patients rapidly expand B1a cells secreting pathogenic lipid-binding aPL with broad thrombotic and inflammatory effects. The association with markers of inflammation and coagulation, clinical severity, and mortality suggests a causal role of aPL in COVID-19-associated coagulopathy.

Distribution of estimated glomerular filtration rate and determinants of its age dependent loss in a German population-based study.

Glomerular filtration rate (GFR) declines with age by approx. 1 ml/min/m2 per year beginning in the third decade of life. At 70 years of age > 40 ml/min/m2 of GFR will be lost. Thus, factors affecting loss of GFR have significant public health implications. Furthermore, the definition of chronic kidney disease based on GFR may not be appropriate for the elderly. We analyzed factors affecting absolute and relative change of eGFR over a 5 year period in 12,381 participants of the Gutenberg Health Study. We estimated GFR at baseline and after 5 years of follow-up by two different equations. Association with the decline of estimated GFR (eGFR) was assessed by multivariable regression analysis. We confirmed a median loss of eGFR per year of approx. 1 ml/min/m2. Aside from albuminuria systolic blood pressure was most strongly associated with faster decline of eGFR followed by echocardiographic evidence of left ventricular diastolic dysfunction and reduced ejection fraction. White blood cell count showed a moderate association with eGFR loss. Diastolic blood pressure, serum uric acid and serum albumin were associated with slower GFR decline in multivariable analysis. Sensitivity analysis with exclusion of individuals taking diuretics, antihypertensive, antidiabetic, or lipid lowering drugs confirmed these associations.

Evaluation of a laboratory-based high-throughput SARS-CoV-2 antigen assay for non-COVID-19 patient screening at hospital admission.

Several rapid antigen tests (RATs) for the detection of SARS-CoV-2 were evaluated recently. However, reliable performance data for laboratory-based, high-throughput antigen tests are lacking. Therefore and in response to a short-term shortage of PCR reagents, we evaluated DiaSorin's LIAISON SARS-CoV-2 antigen test in comparison to RT-qPCR, and concerning the application of screening non-COVID-19 patients on hospital admission. Applying the manufacturer-recommended cut-off of 200 arbitrary units (AU/mL) the specificity of the LIAISON Test was 100%, the overall analytical sensitivity 40.2%. Lowering the cut-off to 100 AU/mL increased the sensitivity to 49.7% and decreased the specificity to 98.3%. Confining the analysis to samples with an RT-qPCR result < 25 Ct resulted in a sensitivity of 91.2%. The quality of the LIAISON test is very similar to that of good RATs described in the literature with the advantage of high throughput and the disadvantage of relatively long analysis time. It passes the WHO quality criteria for rapid antigen tests and is characterized by particularly high specificity. The LIAISON test can therefore be used for the same applications as recommended for RATs by the WHO. Due to limited sensitivity, the LIAISON test should only be used for screening, if PCR-based assays are not available.