Immune and pathophysiologic profiling of antenatal COVID-19 in the GIFT cohort: A Singaporean case-control study.

BackgroundCOVID-19 has been a major public health threat for the past two years, with disproportionate effects on the elderly, immunocompromised, and pregnant women. While much has been done in delineating immune dysfunctions and pathogenesis in the former two groups, less is known about the diseases progression in expectant women and children born to them. To address this knowledge gap, we profiled the immune responses in maternal and child sera as well as breast milk in terms of antibody and cytokine expression and performed histopathological studies on placentae obtained from mothers convalescent from antenatal COVID-19. Methods and findingsA total of 17 mother-child dyads (8 cases of antenatal COVID-19 and 9 healthy unrelated controls; 34 individuals in total) were recruited to the Gestational Immunity For Transfer (GIFT) study. Maternal and infant sera, and breast milk samples were collected over the first year of life. All samples were analyzed for IgG and IgA against whole SARS-CoV-2 spike protein, the spike receptor-binding domain (RBD), and previously reported immunodominant epitopes, with conventional ELISA approaches. Cytokine levels were quantified in maternal sera using multiplex microbead-based Luminex arrays. The placentae were examined microscopically. We found high levels of virus-specific IgG in convalescent mothers and similarly elevated titers in newborn children. Virus-specific IgG in infant circulation waned within 3-6 months of life. Virus-specific IgA levels were variable among convalescent individuals sera and breast milk. Convalescent mothers also showed a blood cytokine signature indicative of a persistent pro-inflammatory state. Four placentae presented signs of acute inflammation marked by neutrophil infiltration even though >50 days had elapsed between virus clearance and delivery. Administration of a single dose of BNT162b2 mRNA vaccine to mothers convalescent from antenatal COVID-19 increased virus-specific IgG and IgA titers in breast milk. ConclusionsAntenatal SARS-CoV-2 infection led to high plasma titres of virus-specific antibodies in infants postnatally. However, this was not reflected in milk; milk-borne antibody levels varied widely. Additionally, placentae from COVID-19 positive mothers exhibited signs of acute inflammation with neutrophilic involvement, particularly in the subchorionic region. Virus neutralisation by plasma was not uniformly achieved, and the presence of antibodies targeting known immunodominant epitopes did not assure neutralisation. Antibody transfer ratios and the decay of transplacentally transferred virus-specific antibodies in neonatal circulation resembled that for other pathogens. Convalescent mothers showed signs of chronic inflammation marked by persistently elevated IL17RA levels in their blood. A single dose of the Pfizer BNT162b2 mRNA vaccine provided significant boosts to milk-borne virus-specific antibodies, highlighting the importance of receiving the vaccine even after natural infection with the added benefit of enhanced passive immunity. The study is registered at clinicaltrials.gov under the identifier NCT04802278.

Breastfeeding mother-child clinical outcomes after COVID-19 vaccination

This is a prospective cohort study of 88 lactating women in Singapore who received two doses of BNT162b2 vaccination (Pfizer/BioNTech), whereby outcomes of mother-child dyads within 28 days after the second vaccine dose were determined through a structured questionnaire. Minimal effects related to breastfeeding were reported in this cohort; 3 of 88 (3.4%) women had mastitis with 1 of 88 (1.1%) women experiencing breast engorgement. We report an incidence of lymphadenopathy in our cohort at 5 of 88 (5.7%). Reassuringly, there was no change in reported breastmilk supply after vaccination. The most common side effect was pain/redness/swelling at the injection site, which was experienced by 57 of 88 (64.8%) women. There were no serious adverse events of anaphylaxis and hospital admissions. No adverse symptoms were reported in 67 of 88 (76.1%) breastfed children. Whats known on this subjectTwo studies reported no serious adverse effects in both mother-child dyads after mRNA COVID-19 vaccination in mothers. Up to 61.9-67% lactating women experienced minor side effects. What this study addsWe report an incidence of lymphadenopathy in our cohort at 5.7% as opposed to 0.3% from the Pfizer-BioNTech COVID-19 trial. Reassuringly, there was no change in reported milk supply after vaccination. Minimal effects related to breastfeeding were reported in this cohort; 3 (3.4%) women had mastitis with 1 person experiencing breast engorgement. The most common side effect was pain/redness/swelling at the injection site at 64.8%, which was experienced by 57 of 88 (65%) women. No adverse symptoms were reported in the breastfed children.

BNT162b2 vaccination induces SARS-CoV-2 specific antibody secretion into human milk with minimal transfer of vaccine mRNA

ImportanceTo examine the impact of SARS-CoV-2 vaccination of lactating mothers on human milk Objective(1) To quantify SARS-CoV-2-specific immunoglobulin A (IgA) and immunoglobulin G (IgG) in human milk of lactating mothers who received the BNT162b2 vaccine, with reference to a cohort convalescent from antenatal COVID-19, and healthy lactating mothers. (2) To detect and quantify vaccine mRNA in human milk after BNT162b2 vaccination. DesignGestational Immunity For Transfer 2 (GIFT-2) is a prospective cohort study of lactating mothers who were due to receive two doses of BNT162b2 vaccine, recruited between 5th February 2021 and 9th February 2021. SettingLactating healthcare workers living in Singapore ParticipantsConvenience sample of ten lactating healthcare workers. Human milk samples were collected at four time points: pre-vaccination, 1-3 days after dose one, 7-10 days after dose one, and 3-7 days after dose two of the BNT162b2 vaccine. ExposureTwo doses of the BNT162b2 vaccine 21 days apart. Main Outcome and Measure(i) SARS-CoV-2-specific IgA and IgG in human milk of lactating mothers who received BNT162b2 vaccine, (ii) Detection and quantification of vaccine mRNA in human milk after BNT162b2 vaccination. ResultsTen lactating healthcare workers aged 32.5 years (range 29 - 42) were recruited, with 40 human milk samples collected and analysed. SARS-CoV-2-specific IgA was predominant in human milk of lactating mothers who received BNT162b2 vaccine. The sharpest rise in antibody production was 3 -7 days after dose two of the BNT162b2 vaccine, with medians of 1110 picomolar of anti-SARS-CoV-2 spike and 374 picomolar of anti-Receptor Binding Domain IgA. Vaccine mRNA was detected only on rare occasions, at a maximum concentration of 2 ng/mL. Conclusions and RelevanceIn this cohort of ten lactating mothers following BNT162b2 vaccination, nine (90%) produced SARS-CoV-2 IgA, and ten (100%) produced IgG in human milk with minimal amounts of vaccine mRNA. Lactating individuals should continue breastfeeding in an uninterrupted manner after receiving mRNA vaccination for SARS-CoV-2. Trial RegistrationRegistered at clinicaltrials.gov (NCT04802278). Key PointsO_ST_ABSQuestionC_ST_ABSDoes BNT162b2 (i) induce the production and secretion of SARS-CoV-2 specific antibodies into human milk, and/or (ii) get secreted into human milk? FindingsIn this cohort that included ten lactating healthcare workers following BNT162b2 vaccination, 90% produced SARS-CoV-2 immunoglobulin A, and 100% produced immunoglobulin G in human milk, with minimal amounts of vaccine mRNA transfer. MeaningLactating individuals should continue breastfeeding in an uninterrupted manner after receiving SARS-CoV-2 mRNA vaccination.

Case control study of risk factors and ophthalmological outcomes of very low birth weight infants with Type 1 retinopathy of prematurity

INTRODUCTION@#We evaluated the risk factors associated with Type 1 retinopathy of prematurity (ROP) in very low birth weight (VLBW) infants and compared ophthalmologic outcomes between cases with Type 1 ROP who received treatment and gestational age-matched controls with mild or no ROP not requiring treatment.@*METHODS@#This was a retrospective case-control study of VLBW infants born in National University Hospital, Singapore, from January 2001 to December 2013. 17 cases with Type 1 ROP were each matched for gestational age with controls who had either mild (below Stage 2) or no ROP. Antenatal, perinatal and postnatal variables, as well as childhood ophthalmologic outcomes, were collected from their clinical records and analysed.@*RESULTS@#The number of packed cell transfusions and highest fraction of inspired oxygen given at weeks 7-10 were found to be statistically significant on multivariate analysis (p = 0.045 and p = 0.049, respectively). None of the infants had blindness or retinal detachment, and there were no significant differences in refractive errors between the groups at 1-4 years of age. Strabismus at four years of age was more common in the group with Type 1 ROP (p = 0.023).@*CONCLUSION@#Increased episodes of blood transfusions and chronic lung disease requiring high oxygen supplementation at 7-10 weeks of life are significant risk factors associated with Type 1 ROP in VLBW infants in our study. Strabismus at four years is more common in this group of patients. This study highlights the importance of long-term ophthalmologic surveillance for these high-risk children.

The Influence of Ethnicity on Exclusively Breast-Fed Infants' Anthropometry in a Multiethnic Asian Population

<p><b>INTRODUCTION</b>We studied the effects of ethnicity on early infant growth patterns in exclusively breast-fed (EBF) infants from a Singaporean multiethnic population. This was a prospective cohort study conducted in National University Hospital, Singapore.</p><p><b>MATERIALS AND METHODS</b>Healthy, EBF infants born at-term completing 37 weeks and above, and whose birthweight was appropriate for gestational age (>10 centile, <90 centile) were recruited. Infants were required to be EBF at least until the minimum age of weaning. All infants who were preterm and premature, formula-fed, required Intensive/High Dependency care, or born with major congenital anomalies were excluded. A multivariable linear regression analysis was conducted at 5 predetermined time-points (birth; 4-8 weeks; 3-4, 5-8, 12 months) to study the effects of antenatal/parental factors on infant growth.</p><p><b>RESULTS</b>A total of 213 infants were recruited. Maternal age, height and body mass index positively influenced birthweights while maternal hypertension and paternal smoking negatively influenced birthweights. Mean duration of breastfeeding was 8.9 months. Chinese ethnicity did not influence birth anthropometry, but was the single consistent factor that significantly increased weight and length Z-scores from 4-8 weeks until 8 months of life. Chinese ethnicity did not influence head growth throughout the first year of life.</p><p><b>CONCLUSION</b>EBF Chinese infants have increased weights and lengths compared to non-Chinese infants until 8 months' age, despite similar birth anthropometry. This period of discrepant growth coincides with the average duration of breastfeeding. We hypothesise that ethnic variations in breast milk macronutrient composition influence early somatic growth in infants.</p>

Management and Outcomes of Fetal Hydrops in a Tertiary Care Centre in Singapore

: Fetal hydrops is a serious condition which can be caused by immune and non-immune aetiologies. We aimed to review the management of fetal hydrops at our hospital.: A retrospective review of all cases of fetal hydrops diagnosed in our institution from 2006 to 2013 was carried out.: Out of the 30 cases of fetal hydrops diagnosed antenatally, 17 were cases of Bart's hydrops which were all terminated in-utero. Of the remaining 13 cases, 11 cases consisted of non-immune causes of hydrops. Planned antenatal interventions including in-utero blood transfusions (n = 4) and thoracentesis (n = 5) as well as planned caesarean deliveries (n = 11) were performed in the majority of cases. Postnatal neonatal intensive care with interventions including chest drainage and transfusions were also performed. A majority, 92%, of the cases survived the perinatal period following a variable length of hospital stay ranging from a week to 3 months.: Management of fetal hydrops is complex. Close coordination between the obstetric and neonatal teams was the key to good short-term survival of neonates with antenatally diagnosed hydrops, as it allows timely antenatal intervention and anticipation of potential perinatal complications.

Limited benefit of hepatitis B immunoglobulin prophylaxis in children of hepatitis B e antigen-negative mothers

<p><b>INTRODUCTION</b>In 2006, Singapore adopted the universal hepatitis B immunoglobulin (HBIg) policy. Since then, all infants of hepatitis B surface antigen (HBsAg)-positive mothers receive HBIg, irrespective of maternal hepatitis B e antigen (HBeAg) status. However, the benefits of HBIg for infants of HBeAg-negative mothers are unclear. We compared the vertical transmission rates among children of HBeAg-negative mothers who were given HBIg versus a retrospective cohort who were not given HBIg, to determine its protective effect.</p><p><b>METHODS</b>This observational study involved pregnant HBsAg-positive women seen at National University Hospital, Singapore, between June 2009 and December 2013. If the infants of these mothers completed the recommended vaccination schedule, they were recruited into the study, along with their older siblings. Serological testing for the children was performed three months after completion of the last dose of vaccine, and hepatitis B virus (HBV) surface gene sequencing was carried out if HBV DNA was detected.</p><p><b>RESULTS</b>A total of 111 infants and 47 siblings were recruited. 2 (1.5%) children were found to have vertical transmission despite receiving HBIg, while no incidences of vertical transmission were found among the historical controls who did not receive HBIg (p = 1.00).</p><p><b>CONCLUSION</b>The overall effectiveness of the hepatitis B vaccination programme for children of HBsAg-positive mothers was high, regardless of HBIg administration. The addition of HBIg did not appear to confer additional benefits, in terms of vertical transmission rate, among infants born to HBeAg-negative mothers.</p>

Clinical report: a case of Williams Syndrome and Klinefelter Syndrome

<p><b>INTRODUCTION</b>Williams syndrome (WS) is a rare but well recognised neurodevelopmental disease affecting the connective tissue and the central nervous system. Many patients are identified through the presence of dysmorphic features and associated cardiac abnormalities. Klinefelter syndrome (KS) is associated with gynaecomastia, small testes, azoospermia and elevated gonadotropin levels. They are recognised in the second decade of life by their tall stature and delay in pubertal development. A combination of constitutive WS and KS has yet to be described.</p><p><b>CLINICAL PICTURE</b>We report a child with these genetic aberrations, highlighting the clinical characteristics of such an individual.</p><p><b>CONCLUSION</b>The manifestations and interactions of both conditions are also discussed.</p>