Quantitative measurement of IgG to SARS-CoV-2 antigens using monoclonal antibody-based enzyme-linked immunosorbent assays.

OBJECTIVE: Standardised quantitative analysis of the humoral immune response to SARS-CoV-2 antigens may be useful for estimating the extent and duration of immunity. The aim was to develop enzyme-linked immunosorbent assays (ELISAs) for the quantification of human IgG antibodies against SARS-CoV-2 antigens. METHODS: Enzyme-linked immunosorbent assays were developed based on monoclonal antibodies against human IgG and recombinant SARS-CoV-2 antigens (Spike-S1 and Nucleocapsid). The WHO 67/086 immunoglobulin and WHO 20/136 SARS-CoV-2 references were used for standardisation. Sera of a study group of COVID-19-positive subjects (n = 144), pre-pandemic controls (n = 135) and individuals vaccinated with BioNTech-Pfizer BNT162b2 vaccine (n = 48) were analysed. The study group sera were also tested using EuroImmun SARS-CoV-2-ELISAs and a quantitative S1-specific fluorescence enzyme immunoassay (FEIA) from Thermo Fisher. RESULTS: The ELISA results were repeatable and traceable to international units because of their parallelism to both WHO references. In the study group, median anti-S1-IgG concentrations were 102 BAU mL-1, compared to 100 and 1457 BAU mL-1 in the vaccination group after first and second vaccination, respectively. The ELISAs achieved an area under the curve (AUC) of 0.965 (S1) and 0.955 (Nucleocapsid) in receiver operating characteristic (ROC) analysis, and a specificity of 1 (S1) and 0.963 (Nucleocapsid) and sensitivity of 0.903 (S1) and 0.833 (Nucleocapsid) at the maximum Youden index. In comparison, the commercial assays (S1-FEIA, S1 and Nucleocapsid ELISA EuroImmun) achieved sensitivities of 0.764, 0.875 and 0.882 in the study group, respectively. CONCLUSIONS: The quantitative ELISAs to measure IgG binding to SARS-CoV-2 antigens have good analytical and clinical performance characteristics and units traceable to international standards.

[The prevalence rate of anti-SARS-CoV-2-IgG is 1.2% - Screening in asymptomatic outpatients in Germany (Northrhine-Westfalia)]. / Die Prävalenz von SARS-CoV-2-IgG-AK liegt bei 1,2% : Screening bei asymptomatischen ambulanten Patienten.

Patients with newly diagnosed COVID-19 (coronavirus disease 2019) develop antibodies against SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). To date, few data have been obtained of the prevalence of SARS-CoV-2-antibodies in general population and in asymptomatic outpatients in Germany.From March 26 to June 4 2020, 415 asymptomatic outpatients were tested prospectively in Northrhine-Westfalia (Germany), to detect SARS-CoV-2-IgG-antibodies. In case of a positive result, anti-SARS-CoV-2-IgA was determined additionally.5 of 415 asymptomatic outpatients had positive SARS-CoV-2-IgG-antibodies with a calculated prevalence of 1.2%. Reference range of anti-SARS-CoV-2-IgA and IgG was defined as ratio for negative < 0.8, borderline 0.8-1.1 and > 1.1 positive. The mean concentration of SARS-CoV-2-IgG-antibodies of the positive 5 outpatients was lower than in symptomatic patients with COVID-19 (n = 12) and positive PCR of SARS-CoV-2 (3.04 ± 2.58 versus 8.05 ± 6.70; p = 0.002). 4 of 5 patients had elevated SARS-CoV-2-IgA-antibodies (1.61 ± 0.82). In 408 screening-outpatients with negative anti-SARS-CoV-2-ELISA-IgG (< 0.8), the mean ratio was 0.25 ± 0.13. Two patients were in the borderline range (0.83 and 0.86).The prevalence of 1.2% of SARS-CoV-2-IgG-antibodies and consequently the rate of infection in asymptomatic outpatients in Northrhine-Westfalia (Germany) is low. The impact of virus neutralisation by antibodies and consequently immunization is the challenge of further investigations.

Variability in ratings of trustworthiness across the menstrual cycle.

This study investigated how trusting behavior varies in naturally cycling women, as a function of sex and attractiveness of players in a trust game, at three distinct phases of the menstrual cycle. Women acted more cautiously in an investment game at the preovulatory phase, compared to the menstrual and the mid-luteal phase. Reduced willingness to trust in strangers was particularly expressed toward male players at this time. The increase of estradiol levels from menses to the preovulatory phase was negatively correlated with trust in attractive male other players, whereas the increase of progesterone levels from menses to the mid-luteal phase was positively associated with trust in unattractive female other players. No particular contribution of a single hormone level could be identified for the generally reduced willingness to trust in strangers in the preovulatory phase. Thus, the results emphasize the impact of the menstrual cycle on interpersonal trust, although the exact mode of hormonal action needs to be further investigated.

Cardiovascular risk factors in patients with uncontrolled and long-term acromegaly: comparison with matched data from the general population and the effect of disease control.

CONTEXT: Data on cardiovascular risk in acromegaly are scanty and lack a clear correlation to epidemiological data. OBJECTIVE: Our aim was an evaluation of cardiovascular risk factors in patients with active acromegaly, a calculation of the Framingham risk score (FRS) compared with age- and gender-matched controls of the general population, and an evaluation of the effect of IGF-I normalization. DESIGN AND SETTING: We conducted a retrospective, comparative study at a university referral center. PATIENTS: A total of 133 patients with acromegaly (65 men, aged 45-74 yr) from the German Pegvisomant Observational Study were matched to 665 controls from the general population. MAIN OUTCOME MEASURES: Risk factors were measured at baseline and after 12 months of treatment with pegvisomant (n=62). RESULTS: Patients with acromegaly had increased prevalence of hypertension, mean systolic and diastolic blood pressure (BP), history of diabetes mellitus and glycosylated hemoglobin (all P<0.001) and decreased high-density lipoprotein, low-density lipoprotein, and total cholesterol (all P<0.001). FRS was significantly higher in patients with acromegaly compared with controls (P<0.001). At 12 months, systolic BP (P=0.04) and glycosylated hemoglobin (P=0.02) as well as FRS (P=0.005) decreased significantly. IGF-I was normalized in 62% (41 of 62). In these patients, glucose and systolic and diastolic BP was significantly lower than in partially controlled patients. SUMMARY: We found an increased prevalence of cardiovascular risk factors in acromegalic patients compared with controls. Control of acromegaly led to a significant decrease of FRS, implying a reduced risk for coronary heart disease. This was most significant in those patients who completely normalized their IGF-I levels. CONCLUSION: Disease control is important to reduce the likelihood for development of coronary heart disease.

Changes in calf muscle elasticity in hypogonadal males before and after testosterone substitution as monitored by magnetic resonance elastography.

PURPOSE: We sought to determine whether differences in muscle elasticity between healthy age-related controls and patients with hypogonadism could be measured by a new, non-invasive method termed magnetic resonance elastography (MRE). MATERIALS AND METHODS: Twelve hypogonadal (21-68 years) and twenty-seven healthy age-related men (20-76 years) were examined. In the hypogonadism group, serum testosterone levels were compared and MRE was conducted prior to and after 6 months of therapy in 6 of the 12 patients. MRE was performed by mechanically exciting the soleus muscle that was used because of its uniformly distributed muscle fibers, size, and accessibility, with a custom designed piezoelectric-actuator using a modified phase-contrast sequence. For mechanical excitation the actuator lever was placed on the anterior surface of the calf. The subjects had to maintain a force of 0-20% of their maximum voluntary contraction against a home-built footplate that was mounted on the MR table. All images were phase unwrapped and reconstructed into shear modulus elastograms using the local frequency estimation technique. RESULTS: Testosterone levels were significantly higher after 6 months of treatment. A statistical difference in the shear modulus was observed prior to and after 6 months of testosterone therapy and was nearly the same as in the healthy age-related control group. CONCLUSION: MRE seems to be a promising technique for the evaluation of therapeutic effects in patients with hypogonadism and possibly in other diseases with muscular effects.

The peroxisome proliferator activated receptor gamma Pro12Ala polymorphism is associated with a lower hirsutism score and increased insulin sensitivity in women with polycystic ovary syndrome.

BACKGROUND: Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism and chronic anovulation. The genetic background of the insulin resistance frequently associated with PCOS is unclear. OBJECTIVES: To examine the influe nce of the Pro12Ala polymorphism of the peroxisome proliferator activated receptor gamma (PPARgamma), which is thought to play a role in the regulation of insulin sensitivity, on endocrine and metabolic parameters in PCOS patients. METHODS: PPARgamma alleles were analysed in 102 PCOS patients (age 27 +/- 5.3 years) and 104 age matched control women. PCOS was defined by the NIH-criteria as the presence of chronic oligo- or anovulation and hyperandrogenism. Family history and clinical parameters were evaluated by personal interview and physical examination, parameters of insulin resistance [homeostasis model assessment (HOMA) and Matsuda-index] were evaluated with a glucose tolerance test. RESULTS: Seventy-nine (77.5%) PCOS patients were carriers of the wild-type PPARgamma allele (Pro/Pro), while 23 (22.5%) had at least one Ala allele (X/Ala), with an equal distribution in controls. X/Ala PCOS women were more insulin-sensitive, evidenced by lower fasting insulin, HOMA index and insulin secretion. Differences in insulin resistance did not depend on body mass index. The genotype had no influence on lipid status, leptin, adiponectin, ghrelin, or family history of type 2 diabetes. A significantly lower proportion of Pro/Ala patients had hirsutism and they had on average lower hirsutism scores than Pro/Pro patients. No relationship was found between the Pro/Ala polymorphism and other signs of hyperandrogenism. CONCLUSION: The Pro12Ala polymorphism of the PPARgamma gene is associated with increased insulin sensitivity and lower hirsutism scores in PCOS women.

[Cardiovascular effects of oral hypoglycemie drugs]. / Kardiovaskuläre Effekte oraler Antidiabetika.

In the recent years there has been increasing interest in the effects of oral hypoglycemic drugs on the cardiovascular system. This has arisen because of recognitions that thiazolidine-diones, peroxisome proliferators-activated receptor gamma (PPAR-gamma), may have antiatherogenic actions and that sulphonylureas are capable of closing the ATP-dependent potassium channel. PPAR-gamma agonists exert antiatherogenic action by inhibition the production of monocyte inflammatory cytokines, inhibition of expression of adhesion molecules in endothelial cells, inhibition of the proliferation of vascular smooth muscle cells and have antioxidative effects. The United Kingdom Prospective Diabetes Study (UKPDS), published in 1998, found that the use of sulphonylureas had no increase in cardiovascular mortality and that metformin therapy in obese individuals with type 2 diabetes mellitus was associated with reduced cardiovascular death. Recently, the STOP-NIDDM trial has been shown that patients with impaired glucose tolerance treated with the alpha-glucosidase inhibitor acarbose had a significant reduction in the risk of cardiovascular disease. Currently, the results of the UKPDS trial are the only available clinical data on which to base the choice of treatment for type 2 diabetic patients. When a glucose-lowering oral drug is considered necessary and is not contraindicated, the firstline choice is a sulphonylurea or a glinide (repaglinide or nateglinide) for diabetics who are not overweight and metformin for those who are.

Acromegaly: evidence for a direct relation between disease activity and cardiac dysfunction in patients without ventricular hypertrophy.

BACKGROUND AND AIMS: Cardiac abnormalities, such as cardiomegaly and congestive heart failure, occur frequently in advanced acromegaly. Abnormalities of systolic and diastolic function, mostly associated with left ventricular (LV) hypertrophy, have been reported. The impact of disease activity on LV performance in patients with normal or slightly elevated LV muscle mass has not been demonstrated. PATIENTS AND METHODS: Conventional two-dimensional/Doppler echocardiography and tissue Doppler imaging (TDI) of the mitral annulus were performed in 13 patients with active acromegaly (AA) and normal or slightly elevated LV muscle mass (< 140 g/m2) and in 19 cured/well-controlled patients (CA). A group of 21 volunteers without symptoms or signs of cardiac disease served as controls (CON). The combined myocardial performance index (Tei-Index) was determined in all patients and controls. RESULTS: Muscle mass index of the left ventricle, ejection fraction, fractional shorting, E/ET-ratio, systolic (ST) and late diastolic (AT) annular velocities did not differ significantly between the three groups. In the AA group, the early diastolic annular velocity ET[7.13 +/- 2.11 (AA); 9.83 +/- 3.29 (CA); 10.10 +/- 1.70 m/s (CON); P < 0.05 AA vs. CA, P < 0.005 AA vs. CON] and the ET/AT-ratio [0.71 +/- 0.26 (AA); 0.95 +/- 0.33 (CA); 1.00 +/- 0.15 m/s (CON); P < 0.05 AA vs. CA, P < 0.005 AA vs. CON] were significantly reduced. Patients with AA had a longer deceleration time [209 +/- 19 (AA); 179 +/- 22 (CA); 185 +/- 26 ms (CON); P < 0.05]. The Tei-Index was significantly higher in AA in comparison with CON [0.50 +/- 0.15 (AA); 0.48 +/- 0.12 (CA); 0.41 +/- 0.10 (CON); P < 0.05 AA vs. CON]. Subjects with CA did not differ significantly from controls with respect to 2-D/Doppler echo- and TDI-derived parameters. CONCLUSION: The data demonstrate that diastolic dysfunction can be verified by tissue Doppler imaging in patients with active acromegaly with normal or slightly elevated muscle mass of the left ventricle and seems to be related to disease activity. The Tei-Index as a sensitive combined myocardial performance index can be used to complete the assessment of systolic and diastolic LV performance in acromegalic patients.