Serologic evolution and follow-up to IgG antibodies of infants born to mothers with gestational COVID

BACKGROUND

It is known that SARS-CoV-2 antibodies from pregnant women with SARS-CoV-2 infection during pregnancy cross the placenta but the duration and the protective effect of these antibodies in infants is scarce.

METHODS

This prospective study included mothers with SARS-COV-2 infection during pregnancy and their infants from April 2020 to March 2021. IgG antibodies to SARS-CoV-2 spike protein were performed on women and infants at birth and at two and six months during follow-up. Anthropometrical measures and physical and neurological examinations and a clinical history of symptoms and COVID-19 diagnosis were collected. Simple linear regression was performed to compare categorical and continuous variables. To compare the mother's and infant's antibody titers evolution, a mixed linear regression model was used. A predictive model of newborn antibody titers at birth has been established by means of simple stepwise linear regression.

RESULTS

51 mother-infant couples were included. 45 (90%) of the mothers and 44 (86.3%) of the newborns had a positive serology al birth. These antibodies were progressively decreasing and were positive in 34 (66.7%) and 7 (13.7%) of infants at 2 and 6 months, respectively. IgG titers of newborns at birth were related to mothers' titers, with a positive moderate correlation (Pearson's correlation coefficient: 0.82, p < 0,001). Fetal/maternal antibodies placental transference rate was 1.3 (IQR: 0.7-2.2). The maternal IgG titers at delivery and the type of maternal infection (acute, recent, or past infection) was significantly related with infants' antibody titers at birth. No other epidemiological or clinical factors were related to antibodies titers. Neurodevelopment, psychomotor development, and growth were normal in 94.2% of infants in the third follow-up visit. No infants had a COVID-19 diagnosis during the follow-up period.

CONCLUSIONS

Transplacental transfer of maternal antibodies is high in newborns from mothers with recent or past infection at delivery, but these antibodies decrease after the first months of life. Infant's IgG titers were related to maternal IgG titers at delivery. Further studies are needed to learn about the protective role of maternal antibodies in infants.

Acute Epstein-Barr virus infection: Diagnostic challenge in young children, risk factors for hospitalization and cytomegalovirus co-detection

AIM

Acute Epstein-Barr virus (aEBV) and cytomegalovirus (CMV) infections frequently have similar manifestations. We aim to evaluate the characteristics of aEBV infection, risk factors for hospitalization, and differences according to CMV IgM detection (EBV-CMV co-detection) in children.

METHODS

Retrospective, single-center study including patients <16 years diagnosed with aEBV infection (positive anti-EBV IgM/Paul-Bunnell test, and acute symptomatology). EBV-CMV co-detection was defined as positive CMV IgM. Factors associated with age, hospitalization and EBV-CMV co-detection were analyzed in a multivariate analysis.

RESULTS

149 patients were included (median age 4.6 years). Most frequent manifestations were fever (77%), cervical lymphadenopathy (64%), and elevated liver enzymes (54%). Younger children had lower rate of positive Paul-Bunnell test (35 vs 87%; p<0.01), but higher rate of EBV-CMV co-detection (54 vs 29%; p=0.03). These children tended to have less typical symptoms of infectious mononucleosis and higher hospitalization rate. The overall antibiotic prescription was 49%. Hospitalization (27 children; 18%) was independently associated with prior antibiotic therapy and anemia. Sixty-two cases (42%) had EBV-CMV co-detection, which was independently associated with elevated liver enzymes and younger age.

CONCLUSION

In this study, younger children with aEBV infection presented more frequently with atypical clinical symptoms, had higher EBV-CMV co-detection rates and were more often hospitalized. Hospitalization was associated with prior antibiotic prescription.

Long term SARS-CoV-2-specific cellular immunity after COVID-19 in liver transplant recipients

PURPOSE

Long-term immunity after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in immunosuppressed patients is not well characterized. We aimed to explore the long-term natural immunity against SARS-CoV-2 in liver transplant (LT) recipients compared to the non-transplanted population (control group).

METHODS

Fifteen LT recipients and 15 controls matched according to variables associated with disease severity were included at 12 months following the coronavirus disease 2019 (COVID-19) onset. Peripheral blood mononuclear cells were stimulated with peptide pools covering spike (S), nucleocapside (N), and membrane (M) proteins. Reactive CD4+ and CD8+ T cells were identified using flow cytometry, and cytokine production was evaluated in the culture supernatants using cytometric bead array. Serum anti-N and anti-S IgG antibodies were detected with chemiluminescence.

RESULTS

The percentage of patients with a positive response in both CD4+ and CD8+ T cells against each viral protein and IL2, IL10, TNF-α, and IFN-γ levels was similar between LT recipients and controls. IFN-γ levels were positively correlated with the percentage of reactive CD4+ (p = 0.022) and CD8+ (p = 0.043) T cells to a mixture of M + N + S peptide pools. The prevalence and levels of anti-N and anti-S IgG antibodies were slightly lower in the LT recipients, but the difference was not statistically significant.

CONCLUSION

LT recipients exhibited a similar T cell response compared to non-transplanted individuals one year after COVID-19 diagnosis.

Decreased Long-Term Severe Acute Respiratory Syndrome Coronavirus 2-Specific Humoral Immunity in Liver Transplantation Recipients 12 Months After Coronavirus Disease 2019

Long-term humoral immunity and its protective role in liver transplantation (LT) patients have not been elucidated. We performed a prospective multicenter study to assess the persistence of immunoglobulin G (IgG) antibodies in LT recipients 12 months after coronavirus disease 2019 (COVID-19). A total of 65 LT recipients were matched with 65 nontransplanted patients by a propensity score including variables with recognized impact on COVID-19. LT recipients showed a lower prevalence of anti-nucleocapsid (27.7% versus 49.2%; P = 0.02) and anti-spike IgG antibodies (88.2% versus 100.0%; P = 0.02) at 12 months. Lower index values of anti-nucleocapsid IgG antibodies were also observed in transplantation patients 1 year after COVID-19 (median, 0.49 [interquartile range, 0.15-1.40] versus 1.36 [interquartile range, 0.53-2.91]; P < 0.001). Vaccinated LT recipients showed higher antibody levels compared with unvaccinated patients (P < 0.001); antibody levels reached after vaccination were comparable to those observed in nontransplanted individuals (P = 0.70). In LT patients, a longer interval since transplantation (odds ratio, 1.10; 95% confidence interval, 1.01-1.20) was independently associated with persistence of anti-nucleocapsid IgG antibodies 1 year after infection. In conclusion, compared with nontransplanted patients, LT recipients show a lower long-term persistence of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. However, SARS-CoV-2 vaccination after COVID-19 in LT patients achieves a significant increase in antibody levels, comparable to that of nontransplanted patients.