Integrative systems immunology uncovers molecular networks of the cell cycle that stratify COVID-19 severity.

Several perturbations in the number of peripheral blood leukocytes, such as neutrophilia and lymphopenia associated with Coronavirus disease 2019 (COVID-19) severity, point to systemic molecular cell cycle alterations during severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, the landscape of cell cycle alterations in COVID-19 remains primarily unexplored. Here, we performed an integrative systems immunology analysis of publicly available proteome and transcriptome data to characterize global changes in the cell cycle signature of COVID-19 patients. We found significantly enriched cell cycle-associated gene co-expression modules and an interconnected network of cell cycle-associated differentially expressed proteins (DEPs) and genes (DEGs) by integrating the molecular data of 1469 individuals (981 SARS-CoV-2 infected patients and 488 controls [either healthy controls or individuals with other respiratory illnesses]). Among these DEPs and DEGs are several cyclins, cell division cycles, cyclin-dependent kinases, and mini-chromosome maintenance proteins. COVID-19 patients partially shared the expression pattern of some cell cycle-associated genes with other respiratory illnesses but exhibited some specific differential features. Notably, the cell cycle signature predominated in the patients' blood leukocytes (B, T, and natural killer cells) and was associated with COVID-19 severity and disease trajectories. These results provide a unique global understanding of distinct alterations in cell cycle-associated molecules in COVID-19 patients, suggesting new putative pathways for therapeutic intervention.

CD40 Ligand Deficiency in Latin America: Clinical, Immunological, and Genetic Characteristics.

CD40 ligand (CD40L) deficiency is a rare inborn error of immunity presenting with heterogeneous clinical manifestations. While a detailed characterization of patients affected by CD40L deficiency is essential to an accurate diagnosis and management, information about this disorder in Latin American patients is limited. We retrospectively analyzed data from 50 patients collected by the Latin American Society for Immunodeficiencies registry or provided by affiliated physicians to characterize the clinical, laboratory, and molecular features of Latin American patients with CD40L deficiency. The median age at disease onset and diagnosis was 7 months and 17 months, respectively, with a median diagnosis delay of 1 year. Forty-seven patients were genetically characterized revealing 6 novel mutations in the CD40LG gene. Pneumonia was the most common first symptom reported (66%). Initial immunoglobulin levels were variable among patients. Pneumonia (86%), upper respiratory tract infections (70%), neutropenia (70%), and gastrointestinal manifestations (60%) were the most prevalent clinical symptoms throughout life. Thirty-five infectious agents were reported, five of which were not previously described in CD40L deficient patients, representing the largest number of pathogens reported to date in a cohort of CD40L deficient patients. The characterization of the largest cohort of Latin American patients with CD40L deficiency adds novel insights to the recognition of this disorder, helping to fulfill unmet needs and gaps in the diagnosis and management of patients with CD40L deficiency.