Case Study

A 30-year-old woman was referred to the hospital for evaluation. She presented with a history of multiple spontaneous abortions. She is currently complaining of pain and swelling in her left thigh. Her family history and her past medical history were unremarkable. The patient is currently on oral contraceptives. The patient's laboratory results were as follows:

8.0 X 109/L (Reference range, 4.4 to 11.0) 4.7 X 1012/L (Reference range, 4.1 to 5.1) 14.0 g/dL (Reference range, 12.3 to 15.3) 43% (Reference range, 36 to 450) 250 X 109/L (Reference range, 150 to 4000) 13.5 seconds (Reference range, 10.9 to 12.0) 52 seconds (Reference range, 34 to 38) Prolonged

Not corrected immediately and after 2 hours' incubation Corrected Present

WBC RBC Hgb Hct

Platelets PT aPTT dRVVT

aPTT 1:1 mixing study dRVV confirm ACA

Insights to the Case Study

The diagnosis of lupus anticoagulant was made based on the physical findings, patient's history, and the laboratory results. Physical finding reveals that the patient had had multiple fetal losses and had pain and swelling in her thigh at the time of medical evaluation. The lack of a positive family history with thrombosis ruled out any inherited throm-botic disorder. Platelet count was normal, indicating that the thrombotic episodes are not related to any cause of platelet activation.

aPTT and dRVVT were both prolonged; however, the patient did not have any bleeding problems. A prolonged aPTT and dRVVT in the absence of bleeding ruled out any clotting factor deficiency. Mixing study with normal plasma differentiates factor deficiency from an inhibitor. Lack of bleeding rules out factor VIII inhibitor. Lupus anticoagulant is

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against in vitro phospholipid-dependent tests. In dRVVT confirmatory tests, excess phospholipids are added to the test system to neutralize the lupus antibodies and therefore correct the prolonged dRVVT initially done. The platelet neutralization test is another confirmatory test used for confirmation of lupus anticoagulant. This test is used for correction of a prolonged aPTT in patients with lupus anticoagulant. Lupus anticoagulant belongs to a group of antibodies called antiphospholipid antibodies (ACA), which include lupus anticoagulant and anticardiolipin antibodies. Lupus anticoagulant may coexist with ACA in some patients. Therefore, it is important to test for both antibodies when lupus anticoagulant is suspected. The ACA antibody can be detected by ELISA and was positive in this patient. This patient was put on Coumadin treatment and was monitored by INR.

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against in vitro phospholipid-dependent tests. In dRVVT confirmatory tests, excess phospholipids are added to the test system to neutralize the lupus antibodies and therefore correct the prolonged dRVVT initially done. The platelet neutralization test is another confirmatory test used for confirmation of lupus anticoagulant. This test is used for correction of a prolonged aPTT in patients with lupus anticoagulant. Lupus anticoagulant belongs to a group of antibodies called antiphospholipid antibodies (ACA), which include lupus anticoagulant and anticardiolipin antibodies. Lupus anticoagulant may coexist with ACA in some patients. Therefore, it is important to test for both antibodies when lupus anticoagulant is suspected. The ACA antibody can be detected by ELISA and was positive in this patient. This patient was put on Coumadin treatment and was monitored by INR.

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