Interleukin (Il)-1 Family Cytokines Could Differentiate Primary Immune Thrombocytopenia From Systemic Lupus Erythematosus-Associated Thrombocytopenia

Background: Primary immune thrombocytopenia (ITP) is an autoimmune-mediated disorder characterized by a decreased platelet count. Systemic lupus erythematosus (SLE) is also an autoimmune disease in which thrombocytopenia is a common hematologic manifestation. Interleukin (IL)-1 family cytokines are major proinflammatory and immunoregulatory mediators. This study aimed to investigate the role of IL-1 cytokines in patients with ITP and SLE and the potential pathophysiologic mechanism to differentiate SLE-associated thrombocytopenia (SLE-TP) from ITP.Methods: Multiplex cytokine assay and real-time polymerase chain reaction (RT-PCR) were used to measure IL-1 cytokines in 17 newly diagnosed FIT patients, 17 SLE-TP patients, 19 SLE; patients without thrombocytopenia (SLE-NTP), and 10 healthy controls.Results: The serum levels of IL-1 beta, IL-18, IL-36 alpha, IL-36 beta, IL-36 gamma, and IL-33 were decreased significantly in ITP patients compared with SLE-TP patients, SLE-NTP patients, and healthy controls (P<0.05). While there was no significant difference in the serum level of IL-37 between FIT and SLE-TP patients, there was a positive correlation between the platelet count and IL-37 level in ITP patients. Our data suggested that serum IL-1 beta, IL-18, IL-36 alpha, IL-36 beta, IL-36 gamma, IL-33, and IL-37 could be considered biomarkers in the diagnosis of ITP.Conclusions: Serum IL-1 beta, IL-18, IL-36 alpha, IL-36 beta, IL-36 gamma, and IL-33 could be considered biomarkers to differentiate SLE-TP from ITP patients.