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.

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 β(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.

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.

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 &lt;0.05) after 20 min of treatment with HD. Post-HD concentrations of DNA were significantly higher compared with pre-HD and controls (P &lt;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 &lt;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.

Responses of N-Terminal Pro-Brain Natriuretic Peptide (NT-proBNP) and Cardiac Troponin I (cTnI) to Competitive Endurance Exercise in Recreational Athletes

The present study was designed to investigate whether the stress of a half-marathon race can induce myocardial cell injury or left ventricular dysfunction in moderately trained runners of both gender, as assessed by post-race plasma concentrations of biochemical cardiac-specific markers and by quantitative echocardiographic measurements. We examined 12 male (mean+/-SD); age: 42.8+/-7.3 yr; height: 177.6+/-7.4 cm; body mass: 75.6+/-9.4 kg; BMI: 24.1+/-1.8 and 13 female (mean+/-SD); age: 39.0+/-6.5 yr; height: 164.6+/-6.2 cm; body mass: 58.4+/-9.8 kg; BMI: 21.5+/-3.4 recreational runners, who completed a half-marathon race. Blood samples were collected from each subject before the half-marathon race as well as 20 min and 2 h post-race and cardiac troponin I (cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured. Quantitative echocardiographic analyses of wall dimensions and ejection fraction were also obtained from 14 of 25 subjects within 1 wk after the race. Both blood markers showed significant changes (p<0.05-0.001) over the time course of the three blood draws. A significant percentage of laboratory analytes analyzed in this study were outside the reference ranges and fulfilled conventional criteria for cardiac muscle damage. However, echocardiography within one week following the competition did not show any evidence that running a half-marathon competition damages the myocardium. Strenuous endurance exercise in middle-aged recreational runners induces a significant elevation of biochemical cardiac-specific markers, which may reflect transient subclinical myocardial damage, but can also reflect a physiological reparative or adaptive process.