Association Between a History of Dengue Fever and the Risk of Systemic Autoimmune Rheumatic Diseases: A Nationwide, Population-Based Case-Control Study

The Janus face of proliferating plasmablasts in dengue and COVID-19 infections

Introduction

B cells play an integral role in the immune response to both dengue fever and COVID-19. Prior scRNAseq analyses of peripheral plasmablasts in COVID-19 have revealed a heterogeneous population with distinct cell subsets associated with proliferation; prior studies in patients with dengue fever have likewise shown the presence of proliferative pre-plasmablasts in the circulation. These findings may have implications for disease severity. In this study, we sought to gain a mechanistic understanding of the intracellular processes in naive and memory B cells that are associated with and may lead to an expanded proliferative plasmablast population in the circulation.

Methods

We analyzed age-controlled (pediatric and adult), peripheral blood mononuclear cell scRNAseq datasets from patients infected with either dengue (primary or secondary) or COVID-19 (non-severe or severe) from previously published studies. Our preliminary analysis showed that pediatric patients with dengue and adults with COVID-19 had an expanded proliferative plasmablast (p-PB) population. By contrast, neither the adults with dengue nor the children with COVID-19 in our dataset had p-PBs. We used this distinctive preliminary signature to guide our analyses design and expanded our analyses to naive and memory B cells.

Results

In age/disease conditions with and without p-PBs, we found differences in cell sensing and activation, including via the B cell receptor and downstream signal transduction. Likewise, inflammation was mediated differently: relative to groups without p-PBs, those with p-PBs had increased expression of interferon response and S100 genes (particularly severe COVID-19). Furthermore, several transcription factors at the nexus of activation, inflammation, and cell fate decisions were expressed differently in groups with and without p-PBs.

Discussion

We used dengue and COVID-19 infections in adult and pediatric patients (focusing on naive B, memory B, and plasmablast cells) as a model to better understand the mechanisms that may give rise to p-PB populations in the circulation. Our results indicate that a more pro-inflammatory state in naive and memory B cells correlated with - and could influence the generation of- proliferating plasmablasts. Further exploration of these mechanisms will have implications for immune memory, vaccine development, and post-viral autoimmune syndromes.

Re-examination of the risk of autoimmune diseases after dengue virus infection: A population-based cohort study

Previous studies suggested that dengue was associated with an increased risk of several autoimmune diseases. However, this association still needs to be explored due to the limitations of these studies. A population-based cohort study was conducted using national health databases in Taiwan and included 63,814 newly diagnosed, laboratory-confirmed dengue patients between 2002 and 2015 and 1:4 controls (n = 255,256) matched by age, sex, area of residence and symptom onset time. Multivariate Cox proportional hazard regression models were used to investigate the risk of autoimmune diseases after dengue infection. Dengue patients had a slightly higher risk of overall autoimmune diseases than non-dengue controls (aHR 1.16; P = 0.0002). Stratified analyses by specific autoimmune diseases showed that only autoimmune encephalomyelitis remained statistically significant after Bonferroni correction for multiple testing (aHR 2.72; P < 0.0001). Sixteen (0.025%) dengue patients and no (0%) controls developed autoimmune encephalomyelitis in the first month of follow-up (HR >9999, P < 0.0001), but the risk between groups was not significantly different thereafter. Contrary to previous studies, our findings showed that dengue was associated with an increased short-term risk of a rare complication, autoimmune encephalomyelitis, but not associated with other autoimmune diseases.

Autoimmune hepatitis unmasked by dengue infection - An unexplored and rare association

Dengue hepatitis is mostly asymptomatic but can lead to liver failure. Autoimmune hepatitis is mainly the disease of females and a potentially treatable cause of chronic liver disease. We report a rare case in which autoimmune hepatitis was unmasked by Dengue infection. The patient was managed for AIH with steroids and azathioprine and became asymptomatic in 30 days. Dengue is a proven risk factor for many autoimmune conditions but its association with AIH is not studied.

Antigen-experienced CXCR5- CD19low B cells are plasmablast precursors expanded in SLE

OBJECTIVES

Altered composition of the B cell compartment in the pathogenesis of systemic lupus erythematosus (SLE) is characterized by expanded plasmablast (PB) and IgD^- CD27^- double negative (DN) B cell populations. Previous studies showed that DN B cells represent a heterogeneous subset and further characterization is needed.

METHODS

Therefore, we analyzed two independent cohorts of healthy donors and SLE patients using a combined approach of flow (HD: n=16; SLE: n=28,) and mass cytometry (HD: n=18; SLE: n=24) and targeted RNA sequencing. To study B cell subsets formation in acute immune response versus autoimmunity we investigated HDs at various time points upon vaccination with BNT162b2 or during acute COVID-19 infection using flow cytometry.

RESULTS

We have found that IgD^- CD27⁺ switched and atypical IgD^- CD27^- memory B cells, which are increased in SLE, represent heterogeneous populations composed of three different subsets each. Populations of CXCR5⁺ CD19^int , CXCR5^- CD19^high and CXCR5^- CD19^low are found in both compartments suggesting their relationship. We characterize a hitherto unknown and antigen-experienced CXCR5^- CD19^low subset enhanced in SLE carrying a PB phenotype with diminished B cell receptor responsiveness and expression of CD38, CD95, CD71, PRDM1, XBP-1, and IRF4. CXCR5^- CD19^low subsets are increased and correlate with PB frequencies in SLE and upon BNT162b2-vaccination of HD suggesting their interrelationship and contribution to plasmacytosis. The demonstration of CXCR5^- CD19^low B cells amongst both CD27+ and CD27- cells questions the role of CD27 as reliable marker for B cell differentiation.

CONCLUSION

Our data suggest that CXCR5^- CD19^low B cells are precursors of plasmablasts, thus co-targeting this subset may have therapeutic value in SLE.

Herpes Zoster in a Patient With Dengue Infection: A Case Report of a Rare Co-Infection

Dengue is an infectious disease that plays an essential role in morbidity and mortality in developing countries. Occasionally, it presents with rare presentations and co-infections. Co-infection of herpes zoster and dengue is possible in countries such as these where both infections are common. Varicella-zoster infection is one of the self-limiting viral infections, and dengue fever is an endemic infection in Sri Lanka. When there is suspicion in diagnosis due to a change of natural course or overlapping of clinical features, concurrent co-infections have to be strongly suspected. We present the case of a 46-year-old female who had herpes zoster and dengue infection and was managed with a multidisciplinary team approach. The patient improved without any complications.