COVID-19 mRNA vaccine immunogenicity decay and breakthrough illness in adolescents and young adults with childhood-onset rheumatic diseases

OBJECTIVES

To evaluate the humoral immunogenicity for 6 months after the two-dose coronavirus disease 2019 (COVID-19) mRNA vaccination in adolescents and young adults (AYAs) with childhood-onset rheumatic diseases (cRDs).

METHODS

This monocentric observational study was conducted between August 2020 and March 2022. Humoral immunogenicity was assessed at 2-3 weeks after first vaccine dose and 1, 3 and 6 months after the second dose by the cPass™ severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralization antibody (nAb) assay. An inhibition signal of ≥30% defined the seroconversion threshold and the readings were calibrated against the World Health Organization International Standard for SARS-CoV-2 antibodies.

RESULTS. ONE HUNDRED AND SIXTY-NINE

AYAs with cRDs were recruited [median age 16.8 years (interquartile range, IQR 14.7-19.5), 52% female, 72% Chinese]. JIA (58%) and SLE (18%) comprised the major diagnoses. After second vaccine dose, 99% seroconverted with a median nAb titre of 1779.8 IU/ml (IQR 882.8-2541.9), declining to 935.6 IU/ml (IQR 261.0-1514.9) and 683.2 IU/ml (IQR 163.5-1400.5) at the 3- and 6-month timepoints, respectively. The diagnosis of JIA [odds ratio (OR) 10.1, 95% CI 1.8-58.4, P = 0.010] and treatment with anti-TNF-α (aTNF) (OR 10.1, 95% CI 1.5-70.0, P = 0.019) were independently associated with a >50% drop of nAb titres at 6 months. Withholding MTX or MMF did not affect the vaccine response or decay rate. The COVID-19 breakthrough infection was estimated at 18.2 cases/1000 patient-months with no clinical risk factors identified.

CONCLUSION

Over half of AYAs with cRDs had a significant drop in SARS-CoV-2 nAb at 6-month despite an initial robust humoral response. JIA and aTNF usage are predictors of a faster decay rate.

Robust neutralizing antibody response to SARS-CoV-2 mRNA vaccination in adolescents and young adults with childhood-onset rheumatic diseases

OBJECTIVES

Immunogenicity to the SARS-CoV-2 mRNA vaccines in adolescents and young adults (AYA) with childhood-onset rheumatic diseases (cRD) is unknown. We aimed to evaluate the humoral immunogenicity and safety of the vaccines in our AYA with cRD.

METHODS

A monocentric observational study with 159 AYA (50.3% female and 70.4% Chinese). Humoral immunogenicity was assessed at 2-3 and 4-6 weeks following first and second vaccination by cPass™ SARS-CoV-2 Neutralization Antibody Assay. Inhibition signal of ≥30% defined the cut-off for positive detection of the SARS-CoV-2 neutralizing antibodies. Vaccine safety and disease activity were assessed within 6 weeks after second vaccination.

RESULTS

A total of 64.9% and 99.1% of 159 patients (median age: 16.9, IQR: 14.7-19.5) mounted positive SARS-CoV-2 neutralizing responses after first and second vaccination, respectively. Most patients (89.8%) had ≥90% inhibition signal after second vaccination. Methotrexate and mycophenolate mofetil increased the risk associated with negative cPass neutralization responses following the first vaccination. Holding both medications after each vaccination did not affect immunogenicity. There was no symptomatic COVID-19 infection. Local reaction remained the most common (23.3-25.2%) adverse event, without serious complication. Two and seven patients flared following the first and second vaccination, respectively. Subgroup analyses of the 12-18-year-old cohort did not show any differences in vaccine efficacy, predictors of poor response and general safety, but higher proportion of disease flares.

CONCLUSIONS

SARS-CoV-2 mRNA vaccines were efficacious after the two-dose regimen in almost all AYA with cRD without serious adverse event. The rate of disease flare observed is 4.4% after the second mRNA vaccine dose.

Single-cell transcriptomics and surface epitope detection in human brain epileptic lesions identifies pro-inflammatory signaling

Epileptogenic triggers are multifactorial and not well understood. Here we aimed to address the hypothesis that inappropriate pro-inflammatory mechanisms contribute to the pathogenesis of refractory epilepsy (non-responsiveness to antiepileptic drugs) in human patients. We used single-cell cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) to reveal the immunotranscriptome of surgically resected epileptic lesion tissues. Our approach uncovered a pro-inflammatory microenvironment, including extensive activation of microglia and infiltration of other pro-inflammatory immune cells. These findings were supported by ligand–receptor (LR) interactome analysis, which demonstrated potential mechanisms of infiltration and evidence of direct physical interactions between microglia and T cells. Together, these data provide insight into the immune microenvironment in epileptic tissue, which may aid the development of new therapeutics.

Single-cell analysis of immune cells from surgically resected human epileptic brain tissues showed heterogeneity and pro-inflammatory signaling in microglia and evidence for direct interaction of microglia with T cells.

Pro-Inflammatory Derangement of the Immuno-Interactome in Heart Failure

Chronic heart failure (HF) is a syndrome of heterogeneous etiology associated with multiple co-morbidities. Inflammation is increasingly recognized as a key contributor to the pathophysiology of HF. Heterogeneity and lack of data on the immune mechanism(s) contributing to HF may partially underlie the failure of clinical trials targeting inflammatory mediators. We studied the Immunome in HF cohort using mass cytometry and used data-driven systems immunology approach to discover and characterize modulated immune cell subsets from peripheral blood. We showed cytotoxic and inflammatory innate lymphoid and myeloid cells were expanded in HF patients compared to healthy controls. Network analysis showed highly modular and centralized immune cell architecture in healthy control immune cell network. In contrast, the HF immune cell network showed greater inter-cellular communication and less modular structure. Furthermore, we found, as an immune mechanism specific to HF with preserved ejection fraction (HFpEF), an increase in inflammatory MAIT and CD4 T cell subsets.

Neutralizing Activity and SARS-CoV-2 Vaccine mRNA Persistence in Serum and Breastmilk After BNT162b2 Vaccination in Lactating Women

Background

There is limited information on the functional neutralizing capabilities of breastmilk SARS-CoV-2-specific antibodies and the potential adulteration of breastmilk with vaccine mRNA after SARS-CoV-2 mRNA vaccination.

Methods

We conducted a prospective cohort study of lactating healthcare workers who received the BNT162b2 vaccine and their infants. The presence of SARS-CoV-2 neutralizing antibodies, antibody isotypes (IgG, IgA, IgM) and intact mRNA in serum and breastmilk was evaluated at multiple time points using a surrogate neutralizing assay, ELISA, and PCR, over a 6 week period of the two-dose vaccination given 21 days apart.

Results

Thirty-five lactating mothers, median age 34 years (IQR 32-36), were included. All had detectable neutralizing antibodies in the serum immediately before dose 2, with significant increase in neutralizing antibody levels 7 days after this dose [median 168.4 IU/ml (IQR 100.7-288.5) compared to 2753.0 IU/ml (IQR 1627.0-4712.0), p <0.001]. Through the two vaccine doses, all mothers had detectable IgG1, IgA and IgM isotypes in their serum, with a notable increase in all three antibody isotypes after dose 2, especially IgG1 levels. Neutralizing antibodies were detected in majority of breastmilk samples a week after dose 2 [median 13.4 IU/ml (IQR 7.0-28.7)], with persistence of these antibodies up to 3 weeks after. Post the second vaccine dose, all (35/35, 100%) mothers had detectable breastmilk SARS-CoV-2 spike RBD-specific IgG1 and IgA antibody and 32/35 (88.6%) mothers with IgM. Transient, low intact vaccine mRNA levels was detected in 20/74 (27%) serum samples from 21 mothers, and 5/309 (2%) breastmilk samples from 4 mothers within 1 weeks of vaccine dose. Five infants, median age 8 months (IQR 7-16), were also recruited - none had detectable neutralizing antibodies or vaccine mRNA in their serum.

Conclusion

Majority of lactating mothers had detectable SARS-CoV-2 antibody isotypes and neutralizing antibodies in serum and breastmilk, especially after dose 2 of BNT162b2 vaccination. Transient, low levels of vaccine mRNA were detected in the serum of vaccinated mothers with occasional transfer to their breastmilk, but we did not detect evidence of infant sensitization. Importantly, the presence of breastmilk neutralising antibodies likely provides a foundation for passive immunisation of the breastmilk-fed infant.

A Virus-Specific Immune Rheostat in the Immunome of Patients Recovering From Mild COVID-19

An accurate depiction of the convalescent COVID-19 immunome will help delineate the immunological milieu crucial for disease resolution and protection. Using mass cytometry, we characterized the immune architecture in patients recovering from mild COVID-19. We identified a virus-specific immune rheostat composed of an effector T (T_eff) cell recall response that is balanced by the enrichment of a highly specialized regulatory T (T_reg) cell subset. Both components were reactive against a peptide pool covering the receptor binding domain (RBD) of the SARS-CoV-2 spike glycoprotein. We also observed expansion of IFNγ⁺ memory CD4⁺ T cells and virus-specific follicular helper T (T_FH) cells. Overall, these findings pinpoint critical immune effector and regulatory mechanisms essential for a potent, yet harmless resolution of COVID-19 infection.

The EPIC data analytics platform for clinical mass cytometry

Single cell technologies, such as high-dimensional cytometry, promise to enable the discovery of immune cell populations that will serve as clinical biomarkers. Recently, we reported the creation of a reference database of the healthy immune system from birth to old age and the development of the EPIC (Extended Poly-dimensional Immunome characterisation) data mining platform (Nature Biotech, accepted). Here we extend the analytics pipeline to facilitate detection of clinically stratifying cell populations in mass cytometry (CyTOF or cytometry by time-of-flight) data. Data structures called immune maps are used to integrate single cell protein expression data (over 40) of multiple samples with clinical metadata and phenotypic information inferred from automated clustering and assisted cell type annotation. Clustering is combined with batch effect correction to reduce technical while preserving biological variations. Subsequent single cell exploratory data analysis and statistical tests help to identify cell populations whose frequencies differ significantly between groups of patients. To gain further insights, users can compare their cytometry data with the healthy reference immunome by performing two types of analysis; (1) mapping to existing clusters helps obtain abundance estimates of immune cell types, (2) reclustering of uploaded data merged with reference immunomes uncovers differences to healthy immune profiles of different ages. We implemented the EPIC pipeline using R Shiny to provide interactive visualisation and an intuitive user interface. We will show examples on how the EPIC platform can characterise cellular diversity in the context of disease and the morphogenesis of the healthy immune system.

Immunome perturbation is present in patients with juvenile idiopathic arthritis who are in remission and will relapse upon anti-TNFα withdrawal

Objectives

Biologics treatment with antitumour necrosis factor alpha (TNFα) is efficacious in patients with juvenile idiopathic arthritis (JIA). Despite displaying clinical inactivity during treatment, many patients will flare on cessation of therapy. The inability to definitively discriminate patients who will relapse or continue to remain in remission after therapy withdrawal is currently a major unmet medical need. CD4 T cells have been implicated in active disease, yet how they contribute to disease persistence despite treatment is unknown.

Methods

We interrogated the circulatory reservoir of CD4⁺ immune subsets at the single-cell resolution with mass cytometry (cytometry by time of flight) of patients with JIA (n=20) who displayed continuous clinical inactivity for at least 6 months with anti-TNFα and were subsequently withdrawn from therapy for 8 months, and scored as relapse or remission. These patients were examined prior to therapy withdrawal for putative subsets that could discriminate relapse from remission. We verified on a separate JIA cohort (n=16) the dysregulation of these circulatory subsets 8 months into therapy withdrawal. The immunological transcriptomic signature of CD4 memory in relapse/remission patients was examined with NanoString.

Results

An inflammatory memory subset of CD3⁺CD4⁺CD45RA⁻TNFα⁺ T cells deficient in immune checkpoints (PD1⁻CD152⁻) was present in relapse patients prior to therapy withdrawal. Transcriptomic profiling reveals divergence between relapse and remission patients in disease-centric pathways involving (1) T-cell receptor activation, (2) apoptosis, (3) TNFα, (4) nuclear factor-kappa B and (5) mitogen-activated protein kinase signalling.

Conclusions

A unique discriminatory immunomic and transcriptomic signature is associated with relapse patients and may explain how relapse occurs.

Pro-inflammatory, IL-17 pathways dominate the architecture of the immunome in pediatric refractory epilepsy

Drug refractory epilepsy (RE) is a chronic neurological disease with varied etiology that represents a group of patients whose seizures do not respond to antiepileptic drugs. The immune system may have a role in seizure and epilepsy development, but the specific mechanisms of inflammation that lead to epileptogenesis and contribute to RE are unknown. Here, we used mass cytometry to comprehensively study the immune system of pediatric patients with RE and compared their immune profile and function with patients with age-matched autoimmune encephalitis (AIE) and healthy controls. Patients with RE and AIE displayed similar immune profiles overall, with changes in CD4⁺ and CD8⁺ T cell subsets and an unbalance toward proinflammatory IL-17 production. In addition, patients with RE uniquely showed an altered balance in NK cell subsets. A systems-level intercellular network analysis identified rewiring of the immune system, leading to loss of inhibitory/regulatory intercellular connections and emergence of proinflammatory pathogenic functions in neuroinflammatory immune cell networks in patients with AIE and RE. These data underscore the contribution of systemic inflammation to the pathogenesis of seizures and epileptogenesis and have direct translational implications in advancing diagnostics and therapeutics design.

The architecture of the immunome in pediatric refractory epilepsy is dominated by a emergence of pro-inflammatory, IL-17 dependent pathways.

Association of the drug of abuse in road traffic collision death in Hospital Kuala Lumpur

INTRODUCTION

The role of pathologist not only confined in performing post mortem but also can assist in prevention. The aim of this study to determine the prevalence and association of drug of abuse (DoA) in road traffic collision (RTC) at Hospital Kuala Lumpur.

METHODS

This is a retrospective study of post mortem cases at Hospital Kuala Lumpur from 2014 to 2016. Deaths from RTC were included while decomposed and homicide cases were excluded. We performed Spearman Correlation statistical test to relate RTC and positive DoA results.

RESULTS

A total of 523 RTC cases were identified in which either blood or urine or both samples were taken for toxicology. 93 cases were positive for both DoA and therapeutic drugs. A total of 37 cases were positive for DoA. Alcohol was present in 5 out of 37 DoA positive cases. Most of the cases seen among 16 to 45 years old (69%) and predominantly in males (93.1%). 29 out of 37 were motorcyclist and the rest were pillion rider and pedestrian. Spearman Correlation statistical test showed a negative relationship between RTC and positive DoA results.

DISCUSSION AND CONCLUSION

Majority of the DoA cases in RTC were identified in the younger age group and among the motorcyclist. Spearman Correlation statistical test showed that more cases of DoA died in natural or suicidal manner compared to RTC. However, this doesn't reflect the true association of DoA in RTC. This is because of mainly two factors which the delayed effect of DoA that gives negative toxicology test and also the influence of other road users on DoA.

Immune checkpoint inhibitors enhance cytotoxicity of cytokine-induced killer cells against human myeloid leukaemic blasts

We studied whether blockade of inhibitory receptors on cytokine-induced killer (CIK) cells by immune checkpoint inhibitors could increase its anti-tumour potency against haematological malignancies. CIK cultures were generated from seven normal donors and nine patients with acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL) or multiple myeloma (MM). The inhibitory receptors B and T lymphocyte attenuator, CD200 receptor, lymphocyte activation gene-3 (LAG-3) and T cell immunoglobulin and mucin-domain-containing-3 (TIM-3) were present at variable percentages in most CIK cultures, while cytotoxic T lymphocyte-associated protein 4 (CTLA-4), programmed death-1 (PD-1) and killer cell immunoglobulin-like receptors (KIR2DL1/2/3) were expressed at low level in most cultures. Without blockade, myeloid leukaemia cells were susceptible to autologous and allogeneic CIK-mediated cytotoxicity. Blockade of KIR, LAG-3, PD-1 and TIM-3 but not CTLA-4 resulted in remarkable increase in killing against these targets, even in those with poor baseline cytotoxicity. ALL and MM targets were resistant to CIK-mediated cytotoxicity, and blockade of receptors did not increase cytotoxicity to a meaningful extent. Combination of inhibitors against two receptors did not further increase cytotoxicity. Interestingly, potentiation of CIK killing by blocking antibodies was not predicted by expression of receptors on CIK and their respective ligands on the targets. Compared to un-activated T and NK cells, blockade potentiated the cytotoxicity of CIK cells to a greater degree and at a lower E:T ratio, but without significant increase in cytotoxicity against normal white cell. Our findings provide the basis for clinical trial combining autologous CIK cells with checkpoint inhibitors for patients with AML.