Identification of biomarkers for COVID-19 associated secondary hemophagocytic lymphohistiocytosis.

Objectives: We aimed to define and validate novel biomarkers that could identify individuals with COVID-19 associated secondary hemophagocytic lymphohistiocytosis (sHLH) and to test whether fatalities due to COVID-19 in the presence of sHLH were associated with specific defects in the immune system.

Design: In two cohorts of adult patients presenting with COVID-19 in 2020 and 2021, clinical lab values and serum proteomics were assessed. Subjects identified as having sHLH were compared to those with COVID-19 without sHLH.

Cytokine Storm Syndrome Associated with Systemic Juvenile Idiopathic Arthritis.

The cytokine storm syndrome (CSS) associated with systemic juvenile idiopathic arthritis (sJIA) has widely been referred to as macrophage activation syndrome (MAS). In this chapter, we use the term sJIA-associated CSS (sJIA-CSS) when referring to this syndrome and use the term MAS when referencing publications that specifically report on sJIA-associated MAS.

Immune Mechanisms in Inflammatory Anemia.

Maintaining the correct number of healthy red blood cells (RBCs) is critical for proper oxygenation of tissues throughout the body. Therefore, RBC homeostasis is a tightly controlled balance between RBC production and RBC clearance, through the processes of erythropoiesis and macrophage hemophagocytosis, respectively. However, during the inflammation associated with infectious, autoimmune, or inflammatory diseases this homeostatic process is often dysregulated, leading to acute or chronic anemia.

Postdischarge Glucocorticoid Use and Clinical Outcomes of Multisystem Inflammatory Syndrome in Children.

Importance: Minimal data are available regarding the postdischarge treatment of multisystem inflammatory syndrome in children (MIS-C).

Objectives: To evaluate clinical characteristics associated with duration of postdischarge glucocorticoid use and assess postdischarge clinical course, laboratory test result trajectories, and adverse events in a multicenter cohort with MIS-C.

Design, Setting, And Participants: This retrospective cohort study included patients with MIS-C hospitalized with severe illness and followed up for 3 months in an ambulatory setting.

Signals governing monocyte differentiation during inflammation.

Monocytes are innate immune cells that develop in the bone marrow and are continually released into circulation, where they are poised to enter tissues in response to homeostatic or inflammatory cues. Monocytes are highly plastic cells that can differentiate in tissues into a variety of monocyte-derived cells to replace resident tissue macrophages, promote inflammatory responses, or resolution of inflammation. As such, monocytes can support tissue homeostasis as well as productive and pathogenic immune responses.

B Cells in Systemic Lupus Erythematosus: From Disease Mechanisms to Targeted Therapies.

B cells exert a prominent contribution to the pathogenesis of systemic lupus erythematosus (SLE). Here, we review the immune mechanisms underlying autoreactive B cell activation in SLE, focusing on how B cell receptor and Toll-like receptor signals integrate to drive breaks in tolerance to nuclear antigens. In addition, we discuss autoantibody-dependent and autoantibody-independent B cell effector functions during lupus pathogenesis.

Pervasive transcription of a herpesvirus genome generates functionally important RNAs.

Pervasive transcription is observed in a wide range of organisms, including humans, mice, and viruses, but the functional significance of the resulting transcripts remains uncertain. Current genetic approaches are often limited by their emphasis on protein-coding open reading frames (ORFs). We previously identified extensive pervasive transcription from the murine gammaherpesvirus 68 (MHV68) genome outside known ORFs and antisense to known genes (termed expressed genomic regions [EGRs]).

Latent gammaherpesvirus 68 infection induces distinct transcriptional changes in different organs.

Previous studies identified a role for latent herpesvirus infection in cross-protection against infection and exacerbation of chronic inflammatory diseases. Here, we identified more than 500 genes differentially expressed in spleens, livers, or brains of mice latently infected with gammaherpesvirus 68 and found that distinct sets of genes linked to different pathways were altered in the spleen compared to those in the liver. Several of the most differentially expressed latency-specific genes (e.

Genetic composition of the Bacillus subtilis SOS system.

The SOS response in bacteria includes a global transcriptional response to DNA damage. DNA damage is sensed by the highly conserved recombination protein RecA, which facilitates inactivation of the transcriptional repressor LexA. Inactivation of LexA causes induction (derepression) of genes of the LexA regulon, many of which are involved in DNA repair and survival after DNA damage.