A retrospective analysis of clinical features of patients hospitalized with SARS-CoV-2 Omicron variants BA.1 and BA.2.

The causative agent of the ongoing Corona virus disease 2019 (COVID-19) pandemic, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has acquired a considerable amount of mutations, leading to changes in clinical manifestations and increased transmission. Recent studies based on animal disease models and data from the general population were reporting a higher pathogenicity of the BA.2 sublineage compared to BA.1. The aim of this study was to provide real world data on patients with the SARS-CoV-2 Omicron BA.1 and BA.2 subvariants treated at our center, highlighting similarities and differences in the clinical disease course. We retrospectively collected and analyzed the data of adult patients admitted with confirmed SARS-CoV-2 infection at the Department for Infectious Diseases and Tropical Medicine, Klinik Favoriten, Vienna, Austria. Patient characteristics including age, underlying diseases, vaccination status and outcome were compared between patients with the BA.1 and BA.2 subvariants. Between January 2022 and May 2022 we included 168 patients infected with Omicron BA.1 and 100 patients with BA.2. Patients admitted with BA.2 were significantly older, more often fully immunized and required less dexamethasone than patients with BA.1. No substantial differences were identified between patients infected with BA.1 and BA.2 regarding BMI, laboratory findings, need for supplemental oxygen, mortality and other evaluated comorbidities excepting active malignancies. The significantly larger percentage of fully immunized patients admitted with BA.2 is pointing to an increased transmissibility of this subvariant, while the comparable outcome of a somewhat older and sicker patient population might be indicative of reduced virulence.

Evaluation of Five Commercial SARS-CoV-2 Antigen Tests in a Clinical Setting.

BACKGROUND: Point-of-care antigen tests (AgTs) for the detection of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) enable the rapid testing of infected individuals and are easy-to-use. However, there are few studies evaluating their clinical use. OBJECTIVE: The present study aimed to evaluate and compare the clinical performance characteristics of various commercial SARS-CoV-2 AgTs. DESIGN: The sensitivity of five AgTs, comprising four rapid antigen tests (RAT; AMP Rapid Test SARS-CoV-2 Ag, NADAL COVID-19 Antigen Rapid Test, CLINITEST Rapid COVID-19 Antigen Test, and Roche SARS-CoV-2 Rapid Antigen Test) and one sandwich chemiluminescence immunoassay (CLIA; LIAISON SARS-CoV-2 Assay), were evaluated in 300 nasopharyngeal (NP) swabs. Reverse transcriptase (RT) polymerase chain reaction (PCR) was used as a reference method. PARTICIPANTS: NP swabs were collected from patients admitted to hospital due to COVID-19. KEY RESULTS: Sensitivities of the AgTs ranged from 64.9 to 91.7% for samples with RT-PCR cycle threshold (Ct) values lower than 30 and were 100% for cycle threshold (Ct) values lower than 20. The highest sensitivity was observed for CLINITEST Rapid COVID-19 Antigen Test, and Roche SARS-CoV-2 rapid antigen test. Multivariate analysis using time from symptom onset and the Ct value for AgT sensitivity showed an inverse correlation. Further, the female sex was an independent factor of lower RAT sensitivity. CONCLUSIONS: Antigen tests from NP swab samples show high sensitivity in patients with a Ct value < 20. The best clinical sensitivity can be obtained using AgTs within the first 6 days after symptom onset.

COVID-19 serology in nephrology healthcare workers.

BACKGROUND: Chronic kidney disease patients show a high mortality in cases of a severe acute respiratory syndrome coronavirus-2 (SARS-CoV­2) infection. Thus, information on the sero-status of nephrology personnel might be crucial for patient protection; however, limited information exists about the presence of SARS-CoV­2 antibodies in asymptomatic individuals. METHODS: We examined the seroprevalence of SARS-CoV­2 IgG and IgM antibodies among healthcare workers of a tertiary care kidney center during the the first peak phase of the corona virus disease 2019 (COVID-19) crisis in Austria using an orthogonal test strategy and a total of 12 commercial nucleocapsid protein or spike glycoprotein-based assays as well as Western blotting and a neutralization assay. RESULTS: At baseline 60 of 235 study participants (25.5%, 95% confidence interval, CI 20.4-31.5%) were judged to be borderline positive or positive for IgM or IgG using a high sensitivity/low specificity threshold in one test system. Follow-up analysis after about 2 weeks revealed IgG positivity in 12 (5.1%, 95% CI: 2.9-8.8%) and IgM positivity in 6 (2.6%, 95% CI: 1.1-5.6) in at least one assay. Of the healthcare workers 2.1% (95% CI: 0.8-5.0%) showed IgG nucleocapsid antibodies in at least 2 assays. By contrast, positive controls with proven COVID-19 showed antibody positivity among almost all test systems. Moreover, serum samples obtained from healthcare workers did not show SARS-CoV­2 neutralizing capacity, in contrast to positive controls. CONCLUSION: Using a broad spectrum of antibody tests the present study revealed inconsistent results for SARS-CoV­2 seroprevalence among asymptomatic individuals, while this was not the case among COVID-19 patients. TRIAL REGISTRATION NUMBER: CONEC, ClinicalTrials.gov number NCT04347694.

CLSI-Based Validation of Manufacturer-Derived Reference Intervals on the Cobas 8000 Platform.

BACKGROUND: Reference intervals provided by diagnostic test manufacturers should be transferred to clinical laboratories after validation. Although protocols exist, laboratories rarely perform and report on results of validation studies. METHODS: We validated reference intervals (RIs) of 87 analytes on a Cobas 8000 platform according to standards published by the Clinical and Laboratory Standards Institute (CLSI). RESULTS: For 8 analytes, decision limits were provided in the package inserts. Among the 79 RIs subjected to transference validation, 8 were found not valid for transference, including lactate dehydrogenase (LDH) among women, and the following among both sexes: potassium, homocysteine, immunoglobulin E (IgE), free lambda light chain (FLC λ), C3 complement (C3c), folate, and 25-hydroxy vitamin D (25[(OH]D). For LDH, potassium, homocysteine, C3c, folate, and 25(OH)D, RIs or thresholds suitable for transference were available in the literature; however, this was not the case for IgE and FLC λ. CONCLUSION: The present study demonstrates that validation of RIs provided in the manufacturer provided package inserts is indispensable.

Risk for early pregnancy loss by factor XIII Val34Leu: the impact of fibrinogen concentration.

BACKGROUND: We have already described a significantly elevated overall risk for recurrent pregnancy loss (RPL) in women carrying the coagulation factor XIII (FXIII) Val34Leu and/or the plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism assuming that these polymorphisms contribute synergistically to RPL because of impaired hypofibrinolysis. Recent studies on FXIII indicate that the impact of the FXIII 34Leu genotype on fibrin structure and fibrinolysis is affected by fibrinogen concentration. Therefore, we reinvestigated the association between fibrinogen concentrations and FXIII Val34Leu with early RPL. MATERIALS AND METHODS: In this case-control study, we enrolled 49 women with a history of two consecutive or three to six nonconsecutive pregnancy losses between the 8th and 12th week of gestation and 48 healthy controls. The risk for RPL in carriers of FXIII 34Leu at fibrinogen levels above or below the median and first tertile of controls was evaluated. RESULTS: In carriers of the 34Leu allele, fibrinogen levels below the median (i.e., ≤ 300 mg/dl) and the first tertile (i.e., ≤ 284 mg/dl) of controls were associated with an increased risk for RPL [(2.9 (1.1-7.7), 3.9(1.0-15.0)]. CONCLUSIONS: The FXIII Val34Leu polymorphism may be associated with the development of early RPL in association with fibrinogen concentrations. At fibrinogen levels in the low normal range, FXIII 34Leu may modify fibrin structure toward an increased resistance to fibrinolysis.

Overexpression of G protein-coupled receptor 5D in the bone marrow is associated with poor prognosis in patients with multiple myeloma.

BACKGROUND: G protein-coupled receptor 5D (GPRC5D) is a novel surface receptor. As this new subtype of G protein-coupled receptors was discovered, little is known about the role of this gene. MATERIALS AND METHODS: In this retrospective study, we investigated GPRC5D mRNA expression by real-time polymerase chain reaction (RT-PCR) in bone marrow (BM) of 48 patients with multiple myeloma (MM). RESULTS: Highly variable levels of GPRC5D (median, 288; quartiles, 17-928) were detected in patients with MM, whereas only low expression was detected in normal tissues (median, 1; quartiles, 1-23). High mRNA expression of GPRC5D correlated positively with high plasma cell count in bone marrow (r = 0·64, P < 0·001), high ß(2) -microglobulin (r = 0·42, P = 0·003) and poor-risk cytogenetics: deletion 13q14 (rb-1), P = 0·003; and 14q32 translocation t(4;14)(p16;q32), P = 0·029. GPRC5D mRNA expression showed a significant correlation with overall survival (P = 0·031). The estimated overall survival of patients expressing GPRC5D above or below the median of 288 was 43·9% vs. 70·2% at 48 months. Here, we report, for the first time, the association of GPRC5D expression and cancer. CONCLUSIONS: Overexpression in poor-risk myeloma, low expression in normal tissues and cell surface expression identify GPRC5D as a potential novel cancer antigen. Our data demonstrate that GPRC5D is a prognostic factor in MM correlating with other major risk factors.

Apoptotic cell-free DNA promotes inflammation in haemodialysis patients.

BACKGROUND: A proinflammatory environment characterized by the continuous activation of the innate immune system is thought to contribute to the markedly elevated mortality in haemodialysis (HD) patients with end-stage renal disease (ESRD). The presence of circulating cell-free DNA (cfDNA) has been demonstrated as biomarker in many pathologies. METHODS: We evaluated the occurrence of cfDNA in HD patients and its functional relevance for innate immunity and inflammation. RESULTS: Here, we found that cfDNA was enhanced in the plasma of ESRD patients after HD compared to healthy controls. Functionally, cfDNA selectively stimulated the production of the proinflammatory cytokine interleukin (IL)-6 by human monocytes, whereas tumour necrosis factor-α or IL-10 was not induced. Conversely, plasma from HD patients, but not from healthy controls or DNase I-treated HD plasma, induced IL-6 production from monocytes. CONCLUSION: We provide the first evidence that cfDNA has selective immunostimulatory effects on human monocytes. This process may contribute to the proinflammatory milieu observed in HD patients.

Analysing cell-free plasma DNA and SLE disease activity.

BACKGROUND: Over the years, the demonstration and confirmation of cell-free DNA in the circulation has increasingly been recognized as a valuable diagnostic tool. Likewise, it has been known for some time that DNA structures that are targeted by auto-antibodies play a central role in systemic lupus erythematosis (SLE) and that DNA-antibody complexes in the circulation are one of the hallmarks of SLE. Investigating whether and to what degree fluctuations in free plasma DNA levels in patients with SLE might correspond to disease severity was therefore the goal of this investigation. METHODS: Blood from 13 patients with SLE and from 13 healthy controls was taken and analysed for the presence of anti-dsDNA, anti-ssDNA, anti-nucleosome, anti-histone antibodies as well as for cell-free DNA concentrations. For each patient, the SLE disease activity index (SLEDAI) was calculated. RESULTS: As demonstrated herein, compared to healthy subjects, cell-free DNA plasma levels in patients with SLE were significantly increased and so were anti-dsDNA, anti-ssDNA, anti-histone and anti-nucleosome antibodies. Furthermore, a statistically significant correlation was noted between cell-free DNA and anti-histone antibodies in patients with SLE. However, no correlation was noted between disease activity and anti-dsDNA, anti-ssDNA and anti-nucleosome antibody concentrations. Surprisingly, and more important in the context of this study, there was no correlation between cell-free DNA levels and SLEDAI scores. CONCLUSIONS: The presented data seem to exclude measuring free plasma DNA as an inexpensive, simple and quick tool to assess disease activity in patients with SLE. Further studies on a larger patient population would be needed to confirm our results.

Cell-free plasma DNA and purine nucleotide degradation markers following weightlifting exercise.

The present study aimed to investigate the acute effects of a single bout of high-intensive strength training on the production of cell-free plasma DNA (cf-DNA), as well as on the degradation of purine nucleotides as assessed by the concentration of xanthine (XA) and hypoxanthine (HX) in urine and serum. Twelve trained weightlifters performed six sets of six lifting exercises with 90-95% of the one repetition maximum. Blood samples and urine were obtained 1 h before training, immediately after finishing the exercise session and following 2 h of recovery. Cf-DNA, HX, and XA (in serum) significantly increased (P < 0.05-P < 0.001) immediately after heavy lifting exercise when compared with baseline levels, and significantly decreased (P < 0.05-P < 0.001) after 2 h of recovery. These results indicate that, cf-DNA and oxypurines might be relevant biomarkers for cellular damage, mechanical, energetic, and/or ischemic stress in context with exercise.

Comparison of PCR methods for detecting fetal RhDin maternal plasma.

BACKGROUND: Aim of this study was to establish the method yielding the highest sensitivity routinely used to determine fetal RhD type and gender from maternal cell-free plasma DNA in different periods of gestation. METHODS: Plasma DNA concentrations were measured from 46 pregnant women in different gestational periods and tested for RhD using three different PCR methods on exon 7: Thermal Cycler, Taqman method on LightCycler, and melting curve analysis on LightCycler. In addition, fetal gender was determined by PCR. Cell-free plasma DNA was measured in 100 healthy volunteers as a reference group. RESULTS: The mean value of cell-free plasma DNA in the reference group was 10.9 pg/microL mean, (standard deviation (SD): 3.66) in 50 healthy women and 12.7 pg/microL (SD: 8.2) in 50 healthy men. In the first trimester of pregnancy cell-free plasma DNA was 14.9 pg/microL mean, (SD: 4.2), in the second trimester 15.4 pg/microL mean, (SD: 4.96), and the maximum was achieved in the third trimester of pregnancy 15.6 pg/microl mean, (SD: 6.49). TaqMan probes had the same accuracy, when compared with Thermal Cycler technology (46 samples, 6 failures). Using real-time PCR with melting curve analysis 12 of 17 samples were correctly tested. Gender determination was correctly in 41 of 46 samples. CONCLUSION: RhD determinations with TaqMan and Thermal Cycler technology are useful methods for fetal RhD prediction. To increase the accuracy of RhD determination it is necessary to test on other exons in addition.

Effects of ultra-marathon on circulating DNA and mRNA expression of pro- and anti-apoptotic genes in mononuclear cells.

We investigated the effects of an ultra-marathon on cell-free plasma DNA as well as on mRNA expression of pro-apoptotic (Bax, Bad), anti-apoptotic (Bcl-2) and cell-protective (Hsp70, Hsp27 and Hsp32) genes in mononuclear blood cells (MNCs). Blood samples were drawn from 14 athletes before and immediately after 6-h run. In addition, blood samples were also collected and analyzed 2 and 24 h after the end of the run. Levels of plasma DNA were significantly increased immediately after the marathon (P < 0.001) and were still higher 2 h later (P < 0.005), but significantly lower than those immediately after the race (P < 0.05). Cell-free plasma DNA returned to pre-race levels 24 h after the run. mRNA expressions of Hsp70, Hsp32 and Bax significantly increased in MNCs after the race, whereas Hsp27 and Bad mRNA expression levels showed no significant changes. Bcl-2 expressions decreased immediately after the race (P < 0.001), but increased in the 24 h later (P < 0.05). We conclude that apoptotic ladders of cell-free DNA following exhaustive exercise originate from apoptotic cells and that not only skeletal muscle cells but also leukocytes contribute to this phenomenon.

Association of endothelial protein C receptor haplotypes, factor V Leiden and recurrent first trimester pregnancy loss.

OBJECTIVES: We evaluated whether the endothelial protein C receptor (EPCR) haplotypes A1 and A3 exert effects on the development of recurrent pregnancy loss (RPL) in association with factor V Leiden. DESIGN AND METHODS: We determined the EPCR haplotypes A1 and A3 and factor V Leiden in 49 women with a history of RPL and 48 parous controls. RESULTS: In carriers of factor V Leiden the A1 haplotype decreased the relative risk for RPL from 2.2 to 1.0. CONCLUSIONS: The EPCR A1 haplotype tends to modulate the risk for RPL in carriers of factor V Leiden.

Cell-free plasma DNA: a marker for apoptosis during hemodialysis.

BACKGROUND: We evaluated whether cell-free plasma DNA might be an appropriate marker for cell damage during hemodialysis (HD) and whether it correlated with annexin V expression and 7-amino-actinomycin D (7AAD) nuclear staining of blood leukocytes. METHODS: Circulating DNA, annexin V, and 7AAD were measured in HD patients before HD, 20 min after start of HD, and after HD had ended. Healthy volunteers provided control measurements. Necrosis and apoptosis were monitored by gel electrophoresis. RESULTS: Plasma DNA concentrations were not significantly different between controls and patients before HD. Circulating DNA increased significantly (P < 0.05) after 20 min of treatment with HD. Post-HD concentrations of DNA were significantly higher compared with pre-HD and controls (P < 0.005). Agarose gel electrophoresis showed ladders typical of apoptosis in post-HD samples. Two subpopulations of CD45+ leukocytes were defined by flow cytometry: annexin V+/7AAD+ population for apoptosis, and annexin V+/7AAD- for early apoptosis. Compared with healthy controls, mean fluorescence (MF) of 7AAD+ apoptotic cells in the annexin V+/7AAD+ subpopulation before HD was not significantly increased. HD increased MF of 7AAD+ cells in the annexin V+/7AAD+ subpopulation. In this subpopulation, MF of annexin V+ cells was significantly higher (P < 0.01). MF of annexin V+ cells in the annexin V+/7AAD+ subpopulation increased during HD. CONCLUSIONS: During HD, cell-free plasma DNA concentrations, annexin V expression, and 7AAD uptake in leukocytes increases. The increase in plasma DNA, appearing as ladders typical of apoptosis, and the 7AAD uptake in leukocytes demonstrate that the predominant portion of circulating DNA in HD patients originates from apoptotic leukocytes.