Prevalence of SARS-CoV-2 antibodies in hospital employees, Central Germany

Objectives Unidentified SARS-CoV-2 infections among hospital staff can become a major burden for healthcare systems worldwide. We hypothesized that the number of previous SARS-CoV-2 infections among hospital employees is substantially higher than known on the basis of direct testing strategies. A serological study was thus performed among staff of Marburg University Hospital, Germany, in May and June 2020. Methods Anti-SARS-CoV-2 antibody titers were measured by spike protein (S1)-specific IgG ELISA (Euroimmun) and by nucleoprotein-(NCP) specific total antibody CLIA (Roche). Selected sera were analyzed by SARS-CoV-2 neutralization test. Participants provided questionnaires regarding occupational, medical, and clinical items. Data for 3,623 individuals (74.7% of all employees) were collected. Results Individuals reactive to both S1 and NCP were defined as seropositive; all of those were confirmed by neutralization test (n=13). Eighty-nine samples were reactive in only one assay, and 3,521 were seronegative. The seroprevalence among hospital employees at Marburg University Hospital was 0.36% (13/3,623). Only five of the 13 seropositive employees had reported a positive SARS-CoV-2 RT-PCR test result. Conclusions Usage of a single S1-specific assay highly overestimated seroprevalence. The data provided no evidence for an increased risk for a SARS-CoV-2 infection for staff involved in patient care compared to staff not involved in patient care.

The investigation of serum protein profiles in anal fistula for potential biomarkers

Objectives An anal fistula is an external abnormal anatomical connection between the rectum and the outer skin of the anus. Symptoms include anorectal pain, abscesses, perianal cellulitis, smelly or bloody drainage of pus, and, in some cases, difficulty controlling bowel movements. Diagnosis and evaluation of anal fistulas is crucial for prognosis and for the choice of the treatment method. In this study, we aimed to discover potential biomarkers from serum proteins for the prediction of anal fistulas. Methods Using antibody array technology, the expression of 40 proteins was simultaneously detected in serum samples from 13 patients with anal fistulas with chronic diarrhea, 14 patients with chronic diarrhea and six healthy volunteers. Differentially expressed proteins were subsequently validated by ELISA, with a sample population expanded to 30 patients with anal fistulas and chronic diarrhea, 30 patients with chronic diarrheas only and 20 healthy controls. Results Quantification analysis identified MIP-1α, MIP-1β and TNF-R1 with significant differential expression between the anal fistula with chronic diarrhea, chronic diarrhea only and healthy control groups. Bioinformatics analyses, including PCA and heat map creation, showed a clear separation between the three groups using the expression of MIP-1α, MIP-1β and TNF-R1. Validation by ELISA with the expanded sample population fistulas showed significant differential expression levels of MIP-1α, MIP-1β and TNF-R1, displaying accuracy rates of 0.898, 0.987 and 1.0 between the anal fistula with chronic diarrhea and healthy control groups. Accuracy rates between the anal fistula with chronic diarrhea and the chronic diarrhea only groups were 0.9768, 0.909 and 0.964, respectively. Conclusions These results suggest the feasibility of employing serum proteins MIP-1α, MIP-1β and TNF-R1 as potential biomarkers for rapid and convenient diagnosis of anal fistula in chronic diarrhea patients.

New and emerging technologies for the diagnosis of urinary tract infections

Urinary tract infections affect 150 million people worldwide, yet the diagnosis of this common infection is not straightforward. Misdiagnoses and incorrect prescriptions are frequent in the treatment of urinary tract infections; this also contributes to the increase in antibiotic resistance among pathogens. Present diagnostic practices take 2–3 days for pathogen identification and antibiotic susceptibility testing. New technologies are urgently needed for improved patient care as well as to promote antibiotic stewardship. An ideal new diagnostic technology will test clinical urine samples directly and identify the pathogen and determine its antibiotic susceptibilities within a few hours such that the patient can be prescribed the appropriate antibiotic treatment the same day. Screening tools, such as flow cytometers and new dipstick assays, can help with rapidly identifying negative samples and improving workflow and reducing costs. Several groups have made progress in optimizing mass spectrometry methods for direct urine processing, and there are also new multiplex PCR panels that are specific for UTI pathogens and antibiotic resistance. We also discuss several emerging technologies – microfluidics, biosensors, real-time microscopy systems, and sequence-based diagnostics – that show huge potential in delivering rapid results.

New reference intervals for endocrinological biomarkers in pediatric patients: what can we learn from the LIFE child study?

Objectives We established reference intervals for serum concentrations of hormones from healthy pediatric subjects and investigated their associations with gender, body mass index (BMI), puberty and oral contraceptives (oC). Methods We calculated reference intervals for the thyroid parameters thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), and calcitonin (Ct); the bone markers osteocalcin, procolagen type 1 N-propeptide, and carboxy-terminal cross-linking telopeptide of type 1 collagen; the calciotropic hormones 25-hydroxyvitamin D (25(OH)D) and parathyroid hormone and the steroids cortisol, progesterone, 17-hydroxyprogesterone, androstenedione, testosterone, estradiol, dehydroepiandrosterone sulfate and aldosterone. Up to 10,002 blood serum samples from 3,229 healthy children and adolescents (age interval: 3 months to 20 years) were measured. To investigate the associations between the hormone levels with age, sex, weight status and the role of puberty-based changes, the measurement and BMI values were transformed into standard deviation scores. Results Most of the hormones depended on age- and gender. Puberty was linked to a, in part, temporary decrease in TSH, FT3 (for females), FT4, Ct, cortisol (for girls) and aldosterone (for boys) and peak in the bone marker and calciotropic hormones (excluding 25(OH)D) and nearly all remaining steroids. BMI had effects on the thyroid, bone, and calciotropic parameters, whereas oC led to increased cortisol, suppressed progesterone and estradiol values. Conclusions Age- and gender-specific reference intervals are essential for the interpretation of pediatric patients’ hormone measurements. Influencing factors as puberty, BMI, or oC should be taken into consideration for diagnosis and treatment monitoring.