Objective:To analyze the levels of thrombin generation and activated protein C resistance (APC-R) in lupus anticoagulant (LA)-positive patients, and to assess their effectiveness in predicting thrombotic risk in these patients.Methods:Retrospective case-control study. A total of 185 patients with positve LA [91 males, 94 females; age (47.59±19.14) years] in Ruijin Hospital of Shanghai Jiaotong University School of Medicine from November 1st, 2024 to March 31st, 2025 were included. Patients were stratified into thrombotic ( n=91) and non-thrombotic groups ( n=94) based on clinical diagnosis and imaging evidence of thrombosis. The basic characteristics and routine laboratory coagulation levels of LA-positive patients were analyzed. Post-test plasma samples were collected from 43 cases with positive or strongly positive LA, categorized into thrombotic ( n=23) and non-thrombotic ( n=20) groups. Additionally, plasma was collected from 80 healthy controls [40 males and 40 females, age (38.37±15.74) years]. Using simple random sampling method, plasma samples from 10 selected males and 10 selected females were mixed to make 1 group of healthy control, thus accordingly resulted in a total of 4 healthy control groups. Thrombin generation assays (TGA) were then employed to measure prothrombin generation and activated protein C resistance (APC-R) levels in the healthy control, non-thrombotic, and thrombotic groups. One-way analysis of variance was utilized to compare thrombin generation and APC-R levels across these groups. Results:Among the routine laboratory coagulation indexes, the median levels of activated partial thromboplastin time (APTT), fibrin degradation product (FDP) and protein C (PC) in thrombotic group were 30.9 (28.8, 35.5) s, 2.5 (1.3, 2.8) mg/L, and 107.0 (93.0, 127.0)%, respectively, which were significantly higher compared with the non-thrombosis group (all P<0.05). However, between the thrombotic and non-thrombotic group, no statistically significant differences were observed for the levels of prothrombin time (PT), thrombin time (TT), fibrinogen (Fg), or D-dimer (D-D) ( P>0.05). The TGA results showed that the total thrombin generation, the maximal thrombin generation and APC-R levels of patients in the thrombotic group were (1 118.72±387.34) nmol/L·min, (106.01±59.00) nmol/L and (0.33±0.22), respectively, which were significantly higher compared with those in the non-thrombotic group (all P<0.05). Conclusion:Significantly increased thrombin generation and enhanced APC-R were present in the LA-positive patients with thrombosis, indicating the important values of thrombin generation and APC-R in assessing thrombosis risk among this population.

Objective:To analyze the levels of thrombin generation and activated protein C resistance (APC-R) in lupus anticoagulant (LA)-positive patients, and to assess their effectiveness in predicting thrombotic risk in these patients.Methods:Retrospective case-control study. A total of 185 patients with positve LA [91 males, 94 females; age (47.59±19.14) years] in Ruijin Hospital of Shanghai Jiaotong University School of Medicine from November 1st, 2024 to March 31st, 2025 were included. Patients were stratified into thrombotic ( n=91) and non-thrombotic groups ( n=94) based on clinical diagnosis and imaging evidence of thrombosis. The basic characteristics and routine laboratory coagulation levels of LA-positive patients were analyzed. Post-test plasma samples were collected from 43 cases with positive or strongly positive LA, categorized into thrombotic ( n=23) and non-thrombotic ( n=20) groups. Additionally, plasma was collected from 80 healthy controls [40 males and 40 females, age (38.37±15.74) years]. Using simple random sampling method, plasma samples from 10 selected males and 10 selected females were mixed to make 1 group of healthy control, thus accordingly resulted in a total of 4 healthy control groups. Thrombin generation assays (TGA) were then employed to measure prothrombin generation and activated protein C resistance (APC-R) levels in the healthy control, non-thrombotic, and thrombotic groups. One-way analysis of variance was utilized to compare thrombin generation and APC-R levels across these groups. Results:Among the routine laboratory coagulation indexes, the median levels of activated partial thromboplastin time (APTT), fibrin degradation product (FDP) and protein C (PC) in thrombotic group were 30.9 (28.8, 35.5) s, 2.5 (1.3, 2.8) mg/L, and 107.0 (93.0, 127.0)%, respectively, which were significantly higher compared with the non-thrombosis group (all P<0.05). However, between the thrombotic and non-thrombotic group, no statistically significant differences were observed for the levels of prothrombin time (PT), thrombin time (TT), fibrinogen (Fg), or D-dimer (D-D) ( P>0.05). The TGA results showed that the total thrombin generation, the maximal thrombin generation and APC-R levels of patients in the thrombotic group were (1 118.72±387.34) nmol/L·min, (106.01±59.00) nmol/L and (0.33±0.22), respectively, which were significantly higher compared with those in the non-thrombotic group (all P<0.05). Conclusion:Significantly increased thrombin generation and enhanced APC-R were present in the LA-positive patients with thrombosis, indicating the important values of thrombin generation and APC-R in assessing thrombosis risk among this population.