Browsing by Author "Charepe, N"
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- Balance Between Maternal Antiviral Response and Placental Transfer of Protection in Gestational SARS-CoV-2 InfectionPublication . Gonçalves, J; Melro, M; Alenquer, M; Araújo, C; Castro-Neves, J; Amaral-Silva, D; Ferreira, F; Ramalho, JS; Charepe, N; Serrano, F; Pontinha, C; Amorim, MJ; Soares, HThe intricate interplay between maternal immune response to SARS-CoV-2 and the transfer of protective factors to the fetus remains unclear. By analyzing mother-neonate dyads from second and third trimester SARS-CoV-2 infections, our study shows that neutralizing antibodies (NAbs) are infrequently detected in cord blood. We uncovered that this is due to impaired IgG-NAb placental transfer in symptomatic infection and to the predominance of maternal SARS-CoV-2 NAbs of the IgA and IgM isotypes, which are prevented from crossing the placenta. Crucially, the balance between maternal antiviral response and transplacental transfer of IgG-NAbs appears to hinge on IL-6 and IL-10 produced in response to SARS-CoV-2 infection. In addition, asymptomatic maternal infection was associated with expansion of anti-SARS-CoV-2 IgM and NK cell frequency. Our findings identify a protective role for IgA/IgM-NAbs in gestational SARS-CoV-2 infection and open the possibility that the maternal immune response to SARS-CoV-2 infection might benefit the neonate in 2 ways, first by skewing maternal immune response toward immediate viral clearance, and second by endowing the neonate with protective mechanisms to curtail horizontal viral transmission in the critical postnatal period, via the priming of IgA/IgM-NAbs to be transferred by the breast milk and via NK cell expansion in the neonate.
- COVID-19 mRNA Vaccine and Antibody Response in Lactating Women: a Prospective Cohort StudyPublication . Charepe, N; Gonçalves, J; Juliano, AM; Lopes, D; Canhão, H; Soares, H; Serrano, FBackground: Immunological protection via breastfeeding is well known. The immunological profile of human milk changes during lactation. No clinical trials have been conducted in lactating women with the newest mRNA vaccines against SARS- CoV-2. A Few studies have shown the presence of antibodies in breastmilk after vaccination. The aim of this work is to study possible antibodies transfer via breastmilk and also the immunological characteristics of lactating women compared to non-lactating women, after using the BNT162b2 Pfizer vaccine. Methods: This is a prospective cohort study with a convenience homogenous sample of 24 healthcare workers (14 lactating and 10 non-lactating women) enrolled at the time of COVID-19 vaccination. Clinical data was registered in a questionnaire. Titers of SARS-CoV-2 spike IgG, IgA and IgM were quantified in post vaccination blood and human milk. Antibody quantification was performed by an in-house ELISA to SARS-CoV-2 trimeric spike protein. Results: All women showed immunity after vaccination with positive antibodies for IgM, IgA and IgG antibodies. The dominant serum antibody response was IgG. Modest levels of antibodies in breastmilk of lactating mothers were observed in this study, especially IgG in 42.9%. There was a moderate association between higher titers of IgG and a longer duration of breastfeeding (R= 0.55, p=0.041). Conclusions: Evidence of antibody transfer in human milk after COVID-19 vaccination is scarce. The presence of antibodies in human milk is reported, but immunization through breastfeeding is still to be established.
- Recurrent Acute Pancreatitis in PregnancyPublication . Charepe, N; Rodrigues, AS; Massa, AC; Alves, MJIntroduction: During pregnancy pancreatitis is a rare and diagnosis is difficult. Cholelithiasis is the most frequent risk factor. Case report: A 26-year-old pregnant woman with abdominal pain, vomiting and low-grade fever. Hyperamylasemia and cholelithiasis was found and pancreatitis diagnosis was made. A second episode of acute pancreatitis was observed and treated with medical therapy. There was no foetal or neonatal complications. In puerperium a third pancreatitis occurred, a laparoscopic cholecystectomy was performed. Discussion: Diagnosis of acute pancreatitis in pregnancy is challenging and it may have serious maternal-fetal implications. Recurrent pattern should be taken into account when choosing the best treatment.
- Secretory IgA and T Cells Targeting SARS-CoV-2 Spike Protein Are Transferred to the Breastmilk Upon mRNA VaccinationPublication . Gonçalves, J; Juliano, AM; Charepe, N; Alenquer, M; Athayde, D; Ferreira, F; Archer, M; Amorim, MJ; Serrano, F; Soares, HIn view of the scarcity of data to guide decision making, we evaluated how BNT162b2 and mRNA-1273 vaccines affect the immune response in lactating women and the protective profile of breastmilk. Compared with controls, lactating women had a higher frequency of circulating RBD memory B cells and higher anti-RBD antibody titers but similar neutralizing capacity. We show that upon vaccination, immune transfer to breastmilk occurs through a combination of anti-spike secretory IgA (SIgA) antibodies and spike-reactive T cells. Although we found that the concentration of anti-spike IgA in breastmilk might not be sufficient to directly neutralize SARS-CoV-2, our data suggest that cumulative transfer of IgA might provide the infant with effective neutralization capacity. Our findings put forward the possibility that breastmilk might convey both immediate (through anti-spike SIgA) and long-lived (via spike-reactive T cells) immune protection to the infant. Further studies are needed to address this possibility and to determine the functional profile of spike T cells.