Cytokine Storm Syndromes in Pediatric Patients

C3 as a predictive and prognostic biomarker in adult hemophagocytic lymphohistiocytosis: a large cohort study in China

ABSTRACT

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome. Complement component 3 (C3), a central effector molecule in 3 separate complement pathways, has been linked to inflammatory diseases. Hence, we aimed to investigate the clinical significance of C3 in adult HLH. In this retrospective cohort study, patients meeting ≥5 of 8 HLH-2004 criteria were classified as the HLH group (n = 627), whereas those meeting 1 to 4 criteria were the partial HLH group (n = 588). C3 was significantly lower in the HLH group than the partial HLH group (P < .0001), and low C3 was an independent factor predicting progression from partial HLH to HLH (odds ratio, 3.94; P < .001). Low C3 was associated with more severe cytopenia, coagulation abnormalities, and liver dysfunction. Additionally, patients with low C3 had poorer overall survival (P = .00099), and low C3 was an independent risk factor for early death in HLH (hazard ratio, 1.64; P = .019). Most patients with HLH had normal C3 before HLH onset, followed by a decline after HLH development (P < .0001). Moreover, survivors showed an increase in C3 (P = .0003), whereas nonsurvivors exhibited a decrease in C3 (P = .90). In conclusion, our study identified C3 as a valuable predictive and prognostic biomarker in adult HLH. Monitoring the dynamic changes in C3 levels may reflect therapeutic response and guide timely clinical interventions.

Cytokine Storm Syndrome Responsive to IL-1 Inhibition in Trisomy 21

Background

Cytokine storm syndromes (CSS) are life-threatening systemic inflammatory disorders caused by immune system dysregulation. They can lead to organ failure and are triggered by various factors, including infections, malignancy, inborn errors of immunity, and autoimmune conditions. Trisomy 21 (TS21), also known as Down syndrome, is a genetic disorder associated with immune dysfunction, increased infection susceptibility, and inflammation. While TS21 has been linked to infectious-triggered hyperinflammation, its role as a primary cause of CSS has not been confirmed. Case Presentation. We present a case of a 16-year-old male with TS21 with fever, rash, joint pain, and abdominal symptoms. Extensive investigations ruled out infections, autoimmune conditions, malignancies, and inborn errors of immunity as triggers for a CSS. The patient's symptoms improved with treatment using IL-1 inhibition and corticosteroids.

Conclusions

This case reinforces that TS21 is an immune dysregulation disorder and highlights the importance of considering CSS in TS21 patients, even when triggers are unclear. The positive response to IL-1 inhibition in this patient suggests that dysregulation of the IL-1 superfamily and the NLRP3 inflammasome may contribute to CSS in TS21. This finding raises the possibility of using IL-1 inhibition as a treatment approach for CSS in TS21 patients.