COVID-19 in Patients with Hematologic Malignancies: Clinical Manifestations, Persistence, and Immune Response.

BACKGROUND: The clinical presentation of coronavirus disease 19 (COVID-19) is the result of intricate interactions between the novel coronavirus and the immune system. In patients with hematologic malignancies (HM), these interactions dramatically change the clinical course and outcomes of COVID-19. SUMMARY: Patients with HM and COVID-19 are at an increased risk for prolonged viral shedding, more protracted and severe presentation, and death, even when compared to other immunocompromised hosts. HM (e.g., multiple myeloma, chronic lymphocytic leukemia) and anticancer treatments (e.g., anti-CD20 agents) that impair humoral immunity markedly increase the risk of severe COVID-19 as well as protracted viral shedding and possibly longer infectivity. Cytokine release syndrome (CRS) is an important player in the pathophysiology of severe and fatal COVID-19. Treatments targeting specific cytokines involved in CRS such as interleukin-6 and Janus kinase have proven beneficial in COVID-19 patients but were not assessed specifically in HM patients. Although neutropenia (as well as neutrophilia) was associated with increased COVID-19 mortality, granulocyte colony-stimulating factors were not beneficial in patients with COVID-19 and may have been associated with worse outcomes. Decreased levels of T lymphocytes and especially decreased CD4+ counts, and depletion of CD8+ lymphocytes, are a hallmark of severe COVID-19, and even more so among patients with HM, underlying the important role of T-helper dysfunction in severe COVID-19. In HM patients with intact cellular immunity, robust T-cell responses may compensate for an impaired humoral immune system. Further prospective studies are needed to evaluate the mechanisms of severe COVID-19 among patients with HM and assess the efficacy of new immunomodulating COVID-19 treatments in this population. KEY MESSAGES: Understanding the immunopathology of COVID-19 has greatly benefited from the previous research in patients with HM. So far, no COVID-19 treatments were properly evaluated in patients with HM. Patients with HM should be included in future RCTs assessing treatments for COVID-19.

Host-Viral Infection Maps Reveal Signatures of Severe COVID-19 Patients.

Viruses are a constant threat to global health as highlighted by the current COVID-19 pandemic. Currently, lack of data underlying how the human host interacts with viruses, including the SARS-CoV-2 virus, limits effective therapeutic intervention. We introduce Viral-Track, a computational method that globally scans unmapped single-cell RNA sequencing (scRNA-seq) data for the presence of viral RNA, enabling transcriptional cell sorting of infected versus bystander cells. We demonstrate the sensitivity and specificity of Viral-Track to systematically detect viruses from multiple models of infection, including hepatitis B virus, in an unsupervised manner. Applying Viral-Track to bronchoalveloar-lavage samples from severe and mild COVID-19 patients reveals a dramatic impact of the virus on the immune system of severe patients compared to mild cases. Viral-Track detects an unexpected co-infection of the human metapneumovirus, present mainly in monocytes perturbed in type-I interferon (IFN)-signaling. Viral-Track provides a robust technology for dissecting the mechanisms of viral-infection and pathology.