Shulan Zhang1,2, Ziyan Wu1,2, Wen Zhang1,2, Jiuliang Zhao1,2, Gary L Norman3, Xiaofeng Zeng1,2, Fengchun Zhang1,2, Yongzhe Li1,4. 1. Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, P.R. China. 2. Peking Union Medical College, Key Laboratory of Rheumatology and Clinical Immunology, Ministry of Education, Beijing, P.R. China. 3. Inova Diagnostics Inc, San Diego, CA, USA. 4. Peking Union Medical College, Key Laboratory of Rheumatology and Clinical Immunology, Ministry of Education, No. 1 Shuai Fu Yuan, Eastern District, Beijing 100730, P.R. China.
Abstract
BACKGROUND: Increasing evidence has highlighted the role of non-criteria antiphospholipid antibodies (aPLs) as important supplements to the current criteria aPLs for the diagnosis of antiphospholipid syndrome (APS). In this retrospective study, we evaluated the clinical relevance of antibodies to phosphatidylserine/prothrombin (aPS/PT) in Chinese patients with APS. METHODS: A total of 441 subjects were tested, including 101 patients with primary APS (PAPS), 140 patients with secondary APS (SAPS), 161 disease controls (DCs) and 39 healthy controls (HCs). Serum IgG/IgM aPS/PT was determined by ELISA. RESULTS: The levels of IgG/IgM aPS/PT were significantly increased in patients with APS compared with DCs and HCs. IgG and IgM aPS/PT were present in 29.7% and 54.5% of PAPS, and 42.1% and 53.6% of SAPS, respectively. For diagnosis of APS, IgG aCL exhibited the highest positive likelihood ratio (LR+) of 21.60, followed by LA (13.84), IgG aβ2GP1 (9.19) and IgG aPS/PT (8.49). aPS/PT was detected in 13.3% of seronegative PAPS patients and 31.3% of seronegative SAPS patients. LA exhibited the highest OR of 3.64 in identifying patients with thrombosis, followed by IgG aCL (OR, 2.63), IgG aPS/PT (OR, 2.55) and IgG aβ2GP1 (OR, 2.33). LA and IgG aCL were correlated with both arterial and venous thrombosis, whereas IgG aPS/PT and IgG aβ2GP1 correlated with venous or arterial thrombosis, respectively. CONCLUSIONS: Our findings suggest that the inclusion of IgG/IgM aPS/PT may enhance the diagnostic performance for APS, especially in those in whom APS is highly suspected, but conventional aPLs are repeatedly negative. In addition, IgG aPS/PT may contribute to identify patients at risk of thrombosis.
BACKGROUND: Increasing evidence has highlighted the role of non-criteria antiphospholipid antibodies (aPLs) as important supplements to the current criteria aPLs for the diagnosis of antiphospholipid syndrome (APS). In this retrospective study, we evaluated the clinical relevance of antibodies to phosphatidylserine/prothrombin (aPS/PT) in Chinese patients with APS. METHODS: A total of 441 subjects were tested, including 101 patients with primary APS (PAPS), 140 patients with secondary APS (SAPS), 161 disease controls (DCs) and 39 healthy controls (HCs). Serum IgG/IgM aPS/PT was determined by ELISA. RESULTS: The levels of IgG/IgM aPS/PT were significantly increased in patients with APS compared with DCs and HCs. IgG and IgM aPS/PT were present in 29.7% and 54.5% of PAPS, and 42.1% and 53.6% of SAPS, respectively. For diagnosis of APS, IgG aCL exhibited the highest positive likelihood ratio (LR+) of 21.60, followed by LA (13.84), IgG aβ2GP1 (9.19) and IgG aPS/PT (8.49). aPS/PT was detected in 13.3% of seronegative PAPSpatients and 31.3% of seronegative SAPSpatients. LA exhibited the highest OR of 3.64 in identifying patients with thrombosis, followed by IgG aCL (OR, 2.63), IgG aPS/PT (OR, 2.55) and IgG aβ2GP1 (OR, 2.33). LA and IgG aCL were correlated with both arterial and venous thrombosis, whereas IgG aPS/PT and IgG aβ2GP1 correlated with venous or arterial thrombosis, respectively. CONCLUSIONS: Our findings suggest that the inclusion of IgG/IgM aPS/PT may enhance the diagnostic performance for APS, especially in those in whom APS is highly suspected, but conventional aPLs are repeatedly negative. In addition, IgG aPS/PT may contribute to identify patients at risk of thrombosis.