Retraction: Samaha et al. Effects of a Single Dose of Ivermectin on Viral and Clinical Outcomes in Asymptomatic SARS-CoV-2 Infected Subjects: A Pilot Clinical Trial in Lebanon. Viruses 2021, 13, 989.

The journal retracts the article, Effects of a Single Dose of Ivermectin on Viral and Clinical Outcomes in Asymptomatic SARS-CoV-2 Infected Subjects: A Pilot Clinical Trial in Lebanon [...].

Effects of a Single Dose of Ivermectin on Viral and Clinical Outcomes in Asymptomatic SARS-CoV-2 Infected Subjects: A Pilot Clinical Trial in Lebanon.

OBJECTIVE: This study was designed to determine the efficacy of ivermectin, an FDA-approved drug, in producing clinical benefits and decreasing the viral load of SARS-CoV-2 among asymptomatic subjects that tested positive for this virus in Lebanon. METHODS: A randomized controlled trial was conducted in 100 asymptomatic Lebanese subjects that have tested positive for SARS-CoV2. Fifty patients received standard preventive treatment, mainly supplements, and the experimental group received a single dose (according to body weight) of ivermectin, in addition to the same supplements the control group received. RESULTS: There was no significant difference (p = 0.06) between Ct-values of the two groups before the regimen was started (day zero), indicating that subjects in both groups had similar viral loads. At 72 h after the regimen started, the increase in Ct-values was dramatically higher in the ivermectin than in the control group. In the ivermectin group, Ct increased from 15.13 ± 2.07 (day zero) to 30.14 ± 6.22 (day three; mean ± SD), compared to the control group, where the Ct values increased only from 14.20 ± 2.48 (day zero) to 18.96 ± 3.26 (day three; mean ± SD). Moreover, more subjects in the control group developed clinical symptoms. Three individuals (6%) required hospitalization, compared to the ivermectin group (0%). CONCLUSION: Ivermectin appears to be efficacious in providing clinical benefits in a randomized treatment of asymptomatic SARS-CoV-2-positive subjects, effectively resulting in fewer symptoms, lower viral load and reduced hospital admissions. However, larger-scale trials are warranted for this conclusion to be further cemented.

The protein kinase A negatively regulates reactive oxygen species production by phosphorylating gp91phox/NOX2 in human neutrophils.

Superoxide anion production by neutrophils is essential for host defense against microbes. Superoxide anion generates other reactive oxygen species (ROS) that are very toxic for microbes and host cells, therefore their excessive production could induce inflammatory reactions and tissue injury. Cyclic adenosine monophosphate (cAMP) elevating agents are considered to be physiological inhibitors of superoxide production by neutrophils but the mechanisms involved in this inhibitory effect are poorly understood. Superoxide is produced by the phagocyte NADPH oxidase, a complex enzyme composed of two membrane subunits, gp91phox or NOX2 and p22phox, and four cytosolic components p47phox, p67phox, p40phox, and Rac2. Except Rac2, these proteins are known to be phosphorylated upon neutrophil stimulation. Here we show that forskolin, an activator of the adenylate cyclase-cAMP-PKA pathway, induced phosphorylation of gp91phox/NOX2 and inhibited fMLF-induced NADPH oxidase activation in human neutrophils. H89, a PKA inhibitor prevented the forskolin-induced phosphorylation of gp91phox and restored NADPH oxidase activation. Furthermore, PKA phosphorylated the recombinant gp91phox/NOX2-cytosolic C-terminal region in vitro only on a few specific peptides containing serine residues, as compared to PKC. Interestingly, phosphorylation of NOX2-Cter by PKA alone did not induce interaction with the cytosolic components p47phox, p67phox and Rac2, however it induced inhibition of PKC-induced interaction. Furthermore, PKA alone did not induce NOX2 electron transfer activity, however it inhibited PKC-induced activation. These results suggest that PKA phosphorylates NOX2 in human neutrophils, a process essential to limit ROS production and inflammation under physiological conditions. Our data identify the cAMP-PKA-NOX2-axis as a critical gatekeeper of neutrophil ROS production.

Genotyping analysis of circulating fetal cells reveals high frequency of vanishing twin following transfer of multiple embryos.

BACKGROUND: Detection of Circulating Fetal Trophoblastic Cells (CFTC) by single cell genotyping not only allows to identify fetal cells from maternal blood, but also to characterize their bi-parental genome. METHODS: We have tested intact fetal trophoblastes recovered at 4th to 10th weeks of gestation (WG) from blood (10 ml per mother) of 13 women after In Vitro Fertilization (IVF) and transfer of one or several embryos. Large cells isolated from blood were individually microdissected and studied by genetic fingerprinting with a mean number of 3 Short Tandem Repeats (STR) markers, known to be informative by testing paternal and maternal blood DNA. RESULTS: CFTC were found in all mothers starting from the 5th WG. A mean number of 2.5 CFTC per ml of blood was found in all the analyzed samples collected at the different terms of pregnancy. All mothers who received the transfer of two or three embryos, including one who delivered twins and one with vanishing twin (identified by ultrasounds), were found to have CFTC with two or three different bi-parental genotypes, belonging to different embryos derived from the same parents. CONCLUSION: CFTC circulation is detectable starting from the 5th WG. A "vanishing twin" phenomenon frequently develops after IVF and transfer of multiple embryos, being undetectable by ultrasounds and revealed by genetic CFTC fingerprinting.

Circulating trophoblastic cells provide genetic diagnosis in 63 fetuses at risk for cystic fibrosis or spinal muscular atrophy.

This study sought to determine whether a reliable non-invasive prenatal diagnosis (NI-PND) of cystic fibrosis (CF) or spinal muscular atrophy (SMA) can be achieved through analysis of circulating fetal trophoblastic cells (CFTC). The kinetics of CFTC circulation were also studied. CFTC were isolated by isolation by size of epithelial tumour/trophoblastic cells at 9-11 weeks of gestation, before chorionic villus sampling (CVS), from the blood of 63 pregnant women at 25% risk for having a child affected by either CF (n=32) or SMA (n=31). Collected cells were laser-microdissected, short tandem repeat-genotyped to determine fetal origin and blindly assessed for mutation analysis. CFTC were independently analysed weekly (4-12 weeks of gestation) in 14 women who achieved pregnancy following IVF. Diagnostic results were compared with those obtained by CVS. All seven CF and seven SMA pregnancies carrying an affected fetus were correctly identified as well as non-affected pregnancies. CFTC provided 100% diagnostic sensitivity (95% CI 76.8-100%) and specificity (95% CI 92.7-100%) in these 63 consecutive pregnancies at risk for CF or SMA. CFTC were found to circulate from 5 weeks of gestation and can be used to develop an early and reliable approach for NI-PND. We sought to determine whether a reliable non-invasive prenatal diagnosis (NI-PND) of two rare genetic diseases - cystic fibrosis (CF) and spinal muscular atrophy (SMA) - can be achieved through analysis of circulating fetal trophoblastic cells (CFTC) in blood of pregnant women. We also studied the time of appearance and circulation of CFTC in maternal blood. CFTC were isolated from maternal blood by isolation by size of epithelial tumour/trophoblastic cells (ISET; an approach for cell isolation from blood) at 9-11 weeks of gestation before chorionic villus sampling (CVS) from the blood of 63 pregnant women at 25% risk for having a child affected by either CF (n=32) or SMA (n=31). Collected cells were analysed by genetic test to determine fetal origin and blindly assessed for mutation analysis. We independently analysed CFTC in maternal blood samples taken weekly (4-12 weeks of gestation) from 14 women who achieved pregnancy following IVF. Diagnostic results were compared with those obtained by CVS. All seven CF and seven SMA pregnancies carrying an affected fetus were correctly identified as well as non-affected pregnancies. CFTC provided 100% diagnostic sensitivity and specificity in these 63 consecutive pregnancies at risk for CF or SMA. CFTC were found to circulate from 5 weeks of gestation and can be used to develop an early and reliable approach for NI-PND.