الفهرس 
Antiphospholipid SyndromeOnly 14 pages are availabe for public view
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Abstract
iagnosis of APS is quite challenging. The Clinical and serological classification criteria for APS were first formulated and published in 1999 and called Sapporo criteria. These criteria performed poorly due to many reasons among which there was no clear cut offs for the medium or high titer of ACL IgG & the issue of difference in timing of laboratory testing in relation to the clinical event was not clarified adequately.
The need for new criteria led to Sydney 2006 where a panel of experts met at a workshop held during ISTH and set their recommendations; where clear cut offs for ACL IgG were defined, β2GPI IgG was included, the timing of laboratory testing with respect to the clinical thrombotic event has been better defined along with other recommendations.
The year 2009 came along with the new update for LA testing & strict guidelines. In which, LA coagulation testing should be done through 3 step procedure; screening, mixing experiment, confirmatory testing. Both APTT-LA and dRVVT tests should be performed together. It was not till 2014 where the guidelines for solid phase assays were published. Both guidelines should be adopted by all laboratories.
Our study aimed to show the prevalence of antiphospholipid antibodies and relation of its increasing titerto recurrent venous thrombosis. We also deduced the sensitivity & specificity for each test to antiphospholipid antibodies in patients with venous thrombosis.
Our study was done on forty patients with history of recurrent venous thrombosis fulfilling Sapporo criteria for diagnosing APS, and exclusion criteria for other causes of venous thrombosis.
The forty patients’ age ranged from 22-52 years, they were not on anticoagulant therapy.
Laboratory testing was done for the forty patients in a two-step procedure for the coagulation assays;
- Screening for LA by APTT-LA & dRVVT screen.
- Positive patients for APTT- LA were further tested after Mixing study, while positive patients for dRVVT screen ratio were tested by dRVVT Confirm.
- All of the forty patients were tested for ACL IgG& β2GPI IgG.
- Patients positive for LA by either Rosner index or dRVVT correction ratio were considered positive for APS. Also, patients’ positive for the ACL IgG & β2GPI IgG were considered positive for APS.
Statistical studies were done to see the prevalence of APL, sensitivity, specificity, PPV, NPV and DA of each test,the concordance and contrast of our results with other researchers. Also, we aimed to highlight the importance of double, triple positivity or more & the risk of thrombosis, & also to find the relation if present between antiphospholipid antibodies’ titer and recurrent venous thrombosis.
Our results showed a significant correlation between increasing age and number of attacks. Also, the only high significant correlation with increasing age was ACL IgG, but only significant correction with Rosner Index. A perfect agreement was between ACL IgG & Rosner Index, between dRVVT screen and APTT-LA and between β2GPI IgG and Rosner index. A fair agreement was found between β2GPI and ACL IgG.
A significant correlation was found between age and both Rosner index and ACL IgG. Both of the previous tests showed also significant correlation with increased number of attacks.
The most striking result was the high sensitivity & specificity of APTT-LA and dRVVT screen ratio test in detection of LA in comparison to other tests.