Systemic lupus erythematosus combined with primary hyperfibrinolysis and protein C and protein S deficiency: A case report

BACKGROUND: Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by systemic involvement and multiple autoantibodies in the serum. Patients with protein C (PC) and protein S (PS) deficiency are prone to thrombosis. In contrast, patients with primary hyperfibrino-lysis tend to bleed. CASE SUMMARY: A 52-year-old female patient with bilateral pleural effusion was diagnosed with "tuberculous pleurisy" and treated with anti-tuberculosis drugs and prednisone. The coagulation-related laboratory results showed decreased fibrinogen, PC activity, PS activity, and antithrombin Ш activity. The immune-related laboratory results showed positive antinuclear antibody, anti-Smith antibody, anticardiolipin antibody (ACL), anti-β2-glycoprotein I antibody (aβ2GPI) and direct Coomb’s test and decreased complement 3 and complement 4. Thoracoscopy was performed and bloody pleural fluid was drained. Pathology of the pleural biopsy showed lymphocytes, plasma cells, and a few eosinophils in adipose and fibrous connective tissue. Results of whole exome sequencing of blood showed no genetic mutations suggesting the presence of hereditary hematological diseases. The patient was finally diagnosed with SLE and primary hyperfibrinolysis, and was treated with prednisolone, hydroxychloroquine, and compound cyclophosphamide. CONCLUSION: PC and PS deficiency in SLE might be related to ACL and aβ2GPI. SLE and primary hyperfibrinolysis can coexist in one patient, with both a risk of thrombosis and a risk of bleeding.