Type I interferon response and vascular alteration in chilblain-like lesions during the COVID-19 outbreak

Background

The outbreak of chilblain‐like lesions (CLL) during the COVID‐19 pandemic has been reported extensively, potentially related to SARS‐CoV‐2 infection, yet its underlying pathophysiology is unclear.

Objectives

To study skin and blood endothelial and immune system activation in CLL in comparison with healthy controls and seasonal chilblains (SC), defined as cold‐induced sporadic chilblains occurring during 2015 and 2019 with exclusion of chilblain lupus.

Methods

This observational study was conducted during 9–16 April 2020 at Saint‐Louis Hospital, Paris, France. All patients referred with CLL seen during this period of the COVID‐19 pandemic were included in this study. We excluded patients with a history of chilblains or chilblain lupus. Fifty patients were included.

Results

Histological patterns were similar and transcriptomic signatures overlapped in both the CLL and SC groups, with type I interferon polarization and a cytotoxic–natural killer gene signature. CLL were characterized by higher IgA tissue deposition and more significant transcriptomic activation of complement and angiogenesis factors compared with SC. We observed in CLL a systemic immune response associated with IgA antineutrophil cytoplasmic antibodies in 73% of patients, and elevated type I interferon blood signature in comparison with healthy controls. Finally, using blood biomarkers related to endothelial dysfunction and activation, and to angiogenesis or endothelial progenitor cell mobilization, we confirmed endothelial dysfunction in CLL.

Conclusions

Our findings support an activation loop in the skin in CLL associated with endothelial alteration and immune infiltration of cytotoxic and type I IFN‐polarized cells leading to clinical manifestations.

HHV-6 reactivation as a cause of fever in autologous hematopoietic stem cell transplant recipients

OBJECTIVES

We report the biological and clinical impacts possibly associated with HHV-6 reactivation in autologous hematopoietic stem cell transplant (AHSCT) recipients after intensive chemotherapy regimen for lymphoma.

METHODS

We retrospectively reviewed clinical, biological, radiological, treatment and outcomes of patients with positive HHV-6 DNA in whole blood following autologous hematopoietic stem cell transplantation.

RESULTS

Blood HHV-6 reactivation was reported in 27 (8.5%) patients among 316 AHSCT recipients after high dose therapy for lymphoma. Thirteen (4.1%) patients were symptomatic with fever (100%), diarrhea (61.5%), skin rash (46.1%), and pneumonia (23.1%). Antiviral treatment was administered in 9 (69%) patients and outcome was favorable in all cases.

CONCLUSION

Our study suggests a possible pathogenic role of HHV-6 in AHSCT recipients and suggests an impact of antiviral treatments on viral replication and clinical signs resolution.

Significance of herpesvirus 6 in BAL fluid of hematology patients with acute respiratory failure

PURPOSE

Human herpesvirus 6 (HHV6) is an emerging cause of interstitial pneumonia in immunocompromised hosts. However, the clinical significance of a positive PCR test for HHV6 in respiratory samples from patients with hematological malignancies remains unclear.

METHODS

We retrospectively studied the features and outcomes of 29 critically ill hematology patients with acute respiratory failure and lung pulmonary infiltrates visible on a chest radiograph, who tested positive for a qualitative PCR for HHV6 in bronchoalveolar lavage fluid.

RESULTS

Of the 29 patients, 18 (62%) were stem cell transplant recipients and 11 (38%) had received chemotherapy. All patients had a fever. Clinical manifestations consistent with extra-pulmonary HHV6 disease were noted in 17 (59%) patients. One or more co-pathogens were found in 25 (86%) patients. The four remaining patients diagnosed with HHV6 pneumonia and subsequently recovered with foscarnet therapy. Antiviral therapy was also given to seven patients with co-infections, of whom two ultimately died.

CONCLUSIONS

In most cases, HHV6 recovered from BAL fluid is a co-pathogen whose clinical relevance remains undetermined. However, in some cases, HHV6 is the only pathogen, along with disseminated systemic viral disease, and the patient is likely to benefit from foscarnet therapy.