Thrombocytopenia in Patients with Systemic Lupus Erythematosus.

Thrombocytopenia can be one of the first manifestations of systemic lupus erythematosus and occurs in up to 40% of patients. Additionally, approximately 2% of patients with primary immune thrombocytopenia may develop systemic lupus erythematosus. Systemic lupus erythematosus is a highly heterogeneous disease, and in some patients, it may present mainly with hematological findings. Thrombocytopenia associated with systemic lupus erythematosus is also diverse, ranging from asymptomatic to severe, acute, or chronic cases. Several studies suggest that the coexistence of immune thrombocytopenia and systemic lupus erythematosus may be linked to a shared genetic background among various autoimmune diseases. Studies have reported correlations between thrombocytopenia and increased disease activity as well as kidney and central nervous system involvement in systemic lupus erythematosus. Severe thrombocytopenia is considered a poor prognostic factor in systemic lupus erythematosus. Despite this knowledge, the exact cause of reduced platelet count in systemic lupus erythematosus remains relatively unknown. Mainly, an excess of platelet destruction and/or reduced production from megakaryocytes are considered the primary factors contributing to systemic lupus erythematosus-associated thrombocytopenia. Given the prognostic significance of thrombocytopenia, there is a possibility of a pathogenic mechanistic role of thrombocytopenia and platelets in systemic lupus erythematosus. In systemic lupus erythematosus, platelets are activated and play a role in promoting autoimmune and inflammatory responses by interacting with both the innate and adaptive immunity. There is no randomized clinical trial in the treatment of systemic lupus erythematosus-related thrombocytopenia. Treatment approach of thrombocytopenia in lupus is almost similar to the treatment of immune thrombocytopenia. Considering the role of platelets in both inflammation and tissue injury, platelet activation and platelet-immune cell interaction might be important therapeutic strategies in the treatment of systemic lupus erythematosus.