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The COVID-19 pandemic has highlighted the role of breastfeeding in providing passive immunity to infants via specific anti-SARS-CoV-2 antibodies in breast milk. We aimed to quantify these antibodies across different lactation stages and identify influencing factors. This prospective study involved mother–child dyads from Innsbruck University Hospital, Austria, with a positive maternal SARS-CoV-2 test during pregnancy or peripartum between 2020 and 2023. We collected breast milk samples at various lactation stages and analyzed anti-Spike S1 receptor-binding domain (S1RBD) immunoglobulins (Ig). Maternal and neonatal data were obtained from interviews and medical records. This study included 140 mothers and 144 neonates. Anti-S1RBD-IgA (72.0%), -IgG (86.0%), and -IgM (41.7%) were highly present in colostrum and decreased as milk matured. Mothers with natural infection and vaccination exhibited higher anti-S1RBD-IgA and -IgG titers in all milk stages. Mothers with moderate to severe infections had higher concentrations of anti-S1RBD-IgA and -IgG in transitional milk and higher anti-S1RBD-IgA and -IgM in mature milk compared to those with mild or asymptomatic infections. Variations in antibody responses were also observed with preterm birth and across different virus waves. This study demonstrates the dynamic nature of breast milk Ig and underscores the importance of breastfeeding during a pandemic. [ABSTRACT FROM AUTHOR]

This article, published in Acta Paediatrica, explores the concentration of anti-S1RBD immunoglobulins in breast milk throughout lactation, with a focus on the effect of a second pregnancy. The study included a healthy, unvaccinated primigravida who tested positive for anti-S1RBD immunoglobulins at the birth of her first child and experienced mild COVID-19 symptoms prior. The researchers found that breast milk anti-S1RBD immunoglobulin concentrations increased with the conception of a new pregnancy, while maternal serum concentrations decreased. Similar increases were observed in breast milk samples from other participants. The findings highlight the importance of breastfeeding during a pandemic and suggest a possible boost in anti-S1RBD immunoglobulin secretion into breast milk with the conception of a new pregnancy. [Extracted from the article]

Objective: To characterize the nature of hepatitis G virus (HGY) infections in hemodialysis patients and to determine the responsiveness of HGV to antiviral therapy in these patients. Methods: HGV, a recently identified flavivirus, is associated with non-A-E viral hepatitis infections. We studied HGV infections in hepatitis C virus (HCV)-infected hemodialysis patients over a 1-yr period, using two independent PCR assays and nucleic acid sequencing. Thirty-four of 63 study patients were treated with interferon. Results: We observed a 27% prevalence ('763 patients) and a 4% annual incidence of HGV infections in the study population. HGV was not detected in any of the 10 HGV-infected patients immediately after interferon therapy. Although seven of these 10 patients developed HGV relapses, three had long-term responses. The interferon responsiveness of HGV and HCV appeared to bunrelated. In contrast, all seven untreated HGV-infected patients remained viremic. Sequence analyses of the different HGV isolates revealed only very limited genetic variability in the polymerase chain reaction-amplified regions of HGV during 1 yr of observation. Conclusions: Our data suggest that HCV-infected hemodialysis patients are at substantial risk of acquiring HGV infection and that HGV infections are prevalent in this population. In addition, HGV infections become chronic but are responsive to interferon treatment. [ABSTRACT FROM AUTHOR]

Objectives: Chronic hepatitis C virus (HCV) infection is common in patients who receive hemodialysis (HD). The aim of this study was to determine the natural history of hepatitis C viremia and the clinical utility of quantitation and genotyping of HCV in this population of patients. Methods: Consecutive sera from two groups of HD patients who were HCV RNA positive, a group of 33 patients treated with interferon alfa (5 MU, three times a week for 4 months) and a group of 31 untreated patients, were analyzed by qualitative polymerase chain reaction, quantitative polymerase chain reaction, and a line probe assay for genotyping. Results: Serum HCV RNA was detected continuously in 20 of 31 untreated patients (65%), and 11 patients (35%) showed a fluctuating pattern of viremia with virus-free intervals of up to 4 wk. Twenty-five of 33 patients (76%) treated with interferon alfa became HCV RNA negative during therapy; eight of these 25 patients had a breakthrough, which was transient in seven patients and persistent in one. Of the remaining 24 end-of-treatment responders, 17 relapsed after completion of therapy, and seven (21%) had a sustained response with undetectable serum HCV RNA for 1 yr of follow-up. Initial serum HCV RNA levels in HD patients were generally low (median, 1 x 105 genome eq/ml). Sustained responders had significantly lower median levels of viremia (4 x 104 eq/ml) than relapsers and nonresponders (9 x 104 and 1.8 x 105 eq/ml, respectively). Genotyping revealed a predominance of genotype 1a (33%) and 1b (48%). Conclusions: This study documents that fluctuating hepatitis C viremia with periods of undetectable HCV RNA is common and that low viral load predicts a sustained response to interferon therapy in HD patients. Diagnosis of chronic hepatitis C and monitoring of interferon therapy in HD patients should include initial HCV RNA quantitation and repeated qualitative measurements of HCV RNA. [ABSTRACT FROM AUTHOR]

Abstract: Background: Perinatal brain injury in preterm infants is a major cause of neurological handicap. The role of the neurotrophin receptor p75 (p75NTR) in the pathogenesis and repair of neonatal excitotoxic brain injury is unknown. Depending on a complex interplay of neurotrophin signalling, p75NTR can, in addition to its trophic function, also induce apoptosis. Hypothesis: We hypothesised that excitotoxicity increases p75NTR expression and p75NTR knockout (KO) mice have a significantly smaller lesion size upon excitotoxicity as compared to wild-type (WT) mice. Methods: We used an established animal model of neonatal excitotoxic brain injury mimicking several key aspects of human preterm brain damage. We subjected five-day-old WT and KO mice to excitotoxic injury by means of a single intracranial ibotenate injection (N-methyl-D-aspartate receptor agonist, NMDAR) into one brain hemisphere. Lesion size, number of activated caspase-3- and apoptosis-inducing factor (AIF)-positive cells were determined as outcome parameters. Gender analyses were taken into account retrospectively. Results: NMDAR-mediated excitotoxicity induced an upregulation of p75NTR expression in the peri-lesion area. Lesion size was significantly increased in female KO as compared to male KO animals. Knockout of p75NTR reduced the number of activated caspase-3 but not AIF-positive cells after NMDAR-mediated excitotoxic injury independently of gender. Conclusion: Since NMDAR-mediated excitotoxic brain injury induced p75NTR expression and caspase-3-activated apoptosis in p75NTR KO animals was decreased, we conclude that activation of p75NTR contributes to NMDAR-mediated apoptosis in the neonatal brain. An increase in lesion size in female animals after excitotoxic brain injury suggests that in females p75NTR seems to play a dual role. [Copyright &y& Elsevier]