Correlation Study Between Lupus Anticoagulant and Antiphosphatidyl Serine/Prothrombin Complex Along with Their Clinical Significance

Introduction: Antiphospholipid syndrome (APS) is typified by the development of antiphospholipid antibodies (aPL) that are persistently positive with the clinical manifestation of thromboembolic problems and pregnancy morbidity. The identification of aPL, specifically lupus anticoagulant (LAC), anticardiolipin (aCL) and antibeta2-glycoprotein I antibodies (aβ2GPI) IgG or IgM, is necessary for the laboratory diagnosis of APS. Also, the diagnostic and risk stratification value of other aPL, known as ‘non-criteria aPL’, has gained importance in recent years. The non-criteria aPL, the antiphosphatidylserine-prothrombin (aPS/PT) antibodies and antibodies against the domain I of beta2-glycoprotein (aDI) have shown relevance in thrombotic events and pregnancy complications. Material and Methods: This was a prospective observational study done on 136 patients with APS profiles, correlating LA and antiphosphatidyl serine/PT complex. Patients on anticoagulants and those who lost to follow-up were excluded. Results: Of the 118 patients who did not have LA, 96.6% (114) had an IgG result of ≤30 (negative), while 3.4% (4) had a result of >30 (positive). Among the 18 patients with LA, 72.2% (13) had a positive result of IgG >30, while 27.8% (5) had a negative result of <=30, indicating a negative predictive value. Similarly, of the 118 patients without LA, 89.8% (106) had an IgM result of <=30 (negative), and 10.2% (12) had a result of >30 (positive). Among the 18 patients with LA, 38.9% (7) had a positive result of IgG >30, while 61.1% (11) had a negative result of <=30, indicating a negative predictive value. Conclusion: Our study showed a statistically significant correlation between LA and aPS/PT complex in patients with arterial thrombotic history. There was a significant association between IgG and LA with a P value of < .001 and between IgM and LA with a P value of < .004.