The interplay of co-infections in shaping COVID-19 severity: Expanding the scope beyond SARS-CoV-2

High-Dimensional Immunophenotyping of Post-COVID-19 and Post-Influenza Patients Reveals Persistent and Specific Immune Signatures After Acute Respiratory Infection

Long-term consequences of SARS-CoV-2 infection are unknown since recovered individuals can experience symptoms and latent viral reactivation for months. Indeed, acute post-infection sequelae have also been observed in other respiratory viral infections, including influenza. To characterize post-COVID-19 and post-influenza induced alterations to the cellular immunome, peripheral blood mononuclear cells (PBMCs) were obtained from patients 3 months after recovery from COVID-19 (n = 93) or influenza (n = 25), and from pre-pandemic healthy controls (n = 25). PBMCs were characterized using a 40-plex mass cytometry panel. Principal component analysis (PCA), classification models, and K-means clustering were subsequently applied. PCA identified distinct immune profiles between cohorts, with both post-COVID and post-flu patients displaying an altered chemokine receptor expression compared to pre-pandemic healthy controls. These alterations were more prominent in post-COVID patients since they exhibited highly increased expression of chemokine receptors CXCR3 and CCR6 by various lymphoid populations, while post-influenza patients mainly showed a decrease in CCR4 expression by naïve T cells, monocytes, and conventional dendritic cells. Classification models using immunophenotyping data confirm the three groups, while K-means clustering revealed two subgroups among post-COVID patients, with younger patients showing more pronounced immune alterations in the chemokine receptor profile, independently of long COVID symptoms. In conclusion, post-COVID and post-influenza patients exhibit distinct and unique persistent immune alterations. Understanding these altered immune profiles can guide targeted therapies for post-COVID syndrome and highlight differences in immune recovery from various respiratory infections.

Reactivation of Latent Tuberculosis Following COVID-19 and Epstein-Barr Virus Coinfection: A Case Report

Background: This case is unique in demonstrating the reactivation of latent tuberculosis (TB) following co-infection with SARS-CoV-2 and Epstein-Barr virus (EBV) in an otherwise healthy young adult. It highlights a rare clinical scenario in which viral immune dysregulation likely facilitated TB progression. To date, few reports have explored the complex interplay between COVID-19, EBV reactivation, and TB in a single patient, particularly with isolated extrapulmonary involvement. Case Presentation: A 24-year-old woman presented with persistent low-grade fever, fatigue, night sweats, unintentional weight loss, and progressive cervical and supraclavicular lymphadenopathy. These symptoms emerged shortly after a moderate COVID-19 infection. Laboratory studies revealed elevated inflammatory markers and pronounced lymphopenia. EBV reactivation was confirmed via serology and PCR. Despite antiviral therapy, symptoms persisted, and imaging revealed necrotic lymphadenopathy. Tuberculous lymphadenitis was diagnosed through fine-needle aspiration cytology and PCR detection of Mycobacterium tuberculosis. The patient was treated with a standard anti-tuberculosis regimen, resulting in clinical, radiological, and immunological improvement. Conclusions: This case underscores the importance of considering latent TB reactivation in patients with persistent lymphadenopathy and recent viral infections, particularly in regions with high TB prevalence. It also emphasizes the need for thorough immunological and microbiological assessment in complex post-viral syndromes. The main clinical takeaway is that COVID-19 and EBV co-infection may create a permissive environment for TB reactivation through immune system compromise.

Respiratory virome in hospitalized children and analysis of its correlation with disease severity

PURPOSE

To investigate the composition of respiratory viromes and their association with disease severity among hospitalized pediatric patients.

METHODS

Clinical data and metagenomic next-generation sequencing (mNGS) results were collected from pediatric patients hospitalized at the Children's Hospital of Chongqing Medical University between January 2022 and September 2023. The analyzed specimens included sputum and bronchoalveolar lavage fluid (BALF).

RESULTS

The study included 229 patients (65.07% male, median age 3 years) with 25 sputum and 204 BALF samples, of whom 40.17% met the WHO criteria for severe acute respiratory infection (SARI). Herpesviruses were detected in 166 cases (72.49%), including 85 cases of cytomegalovirus (CMV), 64 cases of Epstein-Barr virus (EBV), 34 cases of human herpesvirus-7 (HHV-7), 12 cases of human herpesvirus-6 (HHV-6), and 6 cases of herpes simplex virus type 1 (HSV-1). Additionally, 53 cases of torque teno virus (TTV) and 7 cases of torque teno mini virus (TLMV) were detected. CMV prevalence was highest in neonates, while EBV peaked in the 3-6 year group (37.78%). HSV-1 and HHV-6 were predominantly identified in severe infections.

CONCLUSION

Herpesviruses, particularly CMV and EBV, were the most frequently detected viruses, followed by anelloviruses. The age-specific viral distribution patterns provide novel epidemiological perspectives for understanding pediatric respiratory pathogenesis, though their clinical significance requires validation through mechanistic studies.

CLINICAL TRIAL NUMBER

Not applicable.

Co-infections and Reactivation of some Herpesviruses (HHV) and Measles Virus (MeV) in Egyptian Cancer Patients infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

BACKGROUND

Coinfections and reactivation of persistent or latent viral infections such as herpesviruses (HHV) and/or measles virus (MeV) have been reported among COVID-19 patients. However, there is limited information regarding cancer patients who experienced severe acute respiratory syndrome corona virus-2 (SARS-CoV-2). The primary purpose of this study was to investigate the interplay between SARS-CoV-2, HHV and MeV in cancer patients, aiming to provide insights into the pathophysiology of these infections and to enhance the patients' health outcomes.

METHODS

A prospective observational study was conducted on 4 groups (n = 147): newly diagnosed cancer patients infected with SARS-CoV-2 (n = 37), newly diagnosed cancer patients non-infected with SARS-CoV-2 (n = 13), apparently normal individuals infected with SARS-CoV-2 (n = 82) and finally a normal control group (n = 15). All samples were tested for SARS-CoV-2 infection using the real-rime quantitative reverse transcription polymerase chain reaction (qRT-PCR). Antibody responses were analyzed using indirect enzyme-linked immunosorbent assay (ELISA), and antibody levels were compared between patients and controls. Potential re-activation was investigated using fourfold (i.e. 400%) rise model criterion.

RESULTS

In all positive cases of SARS-CoV-2, recent infections or re-infection of herpes simplex viruses 1 and 2 (HSV1/2 or HHV1-2) were found to be significantly increased approximately three-fold higher in COVID-19 patients (p = 0.007) identified via pooled HSV1/2 IgM levels in plasma. Furthermore, reactivation of HSV1/2 was 29.7% in cancer/COVID-19 patients (n = 37) versus 0.0% of normal/COVID-19 group (n = 22) (p = 0.008). Likewise, Epstein-Barr Nuclear Antigen-1 (EBNA-1) IgG levels showed a ≥ fourfold increase in 20% (p = 0.034) of cancer patients (n = 50) versus 4.9% of controls (n = 41) for reactivation of Epstein-Barr virus (EBV or HHV-4). Obviously, MeV IgG levels increased up to 78.0% in cancer patients (n = 50) versus 17.5% in non-cancerous group (n = 40, p < 0.001). Reactivation of MeV in cancer and COVID-19 patients was 43.2% versus 30.8% cancer non-COVID-19 group, 3.3% normal COVID-19, and 0.0% in healthy volunteers (p < 0.001).

CONCLUSION

Cancer patients infected with SARS-CoV-2 were at increased risk of HHV and MeV co-infection and reactivation.