Background & Objectives
Thrombocytopenia is a common manifestation of antiphospholipid syndrome (APS), occurring in 16–53% of patients with APS. The mechanisms that drive APS-related thrombocytopenia are not completely understood, and no clinical biomarkers are available to predict antiphospholipid antibody-mediated thrombocytopenia. Hoy et al. sought to evaluate the presence, clinical associations and potential mechanistic roles of circulating calprotectin in a cohort of patients with primary APS and those with antiphospholipid antibodies.
Methods
Hoy et al. used a chemiluminescence-based assay to measure levels of circulating calprotectin in plasma. A viability, dye-based platelet assay was used to assess the potential impact of calprotectin on antiphospholipid antibody-mediated thrombocytopenia. Circulating calprotectin was measured in 112 patients with primary APS and 30 patients with antiphospholipid antibodies, but without APS criteria manifestations or lupus and compared the results with those for patients with lupus but without APS, patients with unprovoked venous thrombosis and healthy controls.
Results
Calprotectin levels were higher in patients with primary APS and patients with antiphospholipid antibodies than in healthy controls. After adjustment for age and sex, calprotectin level correlated with increased absolute neutrophil count, increased C-reactive protein levels and decreased platelet count. In addition, elevated calprotectin levels were able to identify patients with extra-criteria manifestations, such as thrombocytopenia.
Conclusion
These data suggest that calprotectin has the potential to be a functional biomarker and a new therapeutic target for APS-related thrombocytopenia.
For complete details, including source material, refer to the full study.
Excerpted and adapted from:
Hoy CK, NaveenKumar SK, Navaz SA, et al. Calprotectin impairs platelet survival in patients with primary antiphospholipid syndrome. Arthritis Rheumatol. 2024 June;76(6).
