The Antiphospholipid Syndrome: What are We Really Measuring? How do We Measure it? And How do We Treat it?

Abstract

The antiphospholipid syndrome is described with a review of its historical development as a recognized syndrome, what constitutes an antiphospholipid antibody, how it is measured, and how the syndrome is treated. Antiphospholipid antibodies are actually antibodies to a protein, most often beta-2-glycoprotein 1, that is usually bound to a phospholipid. Some antibodies are directed towards lipid-bound prothrombin. The antibodies are measured by immunologic assays or by antibody-dependent abnormalities detected in coagulation assays. Although they prolong coagulation assays, they are associated with a thrombotic tendency rather than a bleeding disorder. There are numerous postulated mechanisms to account for the thrombotic tendency. Patients with the antiphospholipid syndrome are treated with long-term oral anticoagulation to prolong the INR to 2.0 to 3.0. For most patients, a more intense level of treatment with a higher INR is not needed.

Thrombosis in Infants and Children

“…There have been recent reports on gene expression profiles to identify subtle distinctions in order to define the clinical relevance of different APA. 40,41 Apart from DVT as the most frequent clinical symptom in children along with the presence of LAC and high risk of recurrence without adequate long-term anticoagulation, there is a subgroup of children presenting with perinatal stroke and no risk of recurrence independent of secondary antithrombotic prophylaxis. 42 This underlines the discordance to adults and the need for diagnostic and therapeutic guidelines to be defined for pediatric patients.…”

Criteria for the diagnosis of antiphospholipid syndrome in patients presenting with dermatologic symptoms

“…This is done to account for transient increases in antibodies that are occasionally seen in the normal population. 15 Common clinical findings in APS such as LR, thrombocytopenia, hemolytic anemia, and cardiac valve disease are not included in the Sapporo criteria. 10 Although these features are frequently seen in APS, they are not specific to the disease.…”

“…This is to account for the transient presence of antiphospholipid antibodies that may be seen in the general population. 15,16 Fourth, the threshold for diagnosing positive anticardiolipin antibodies should be redefined from ''moderate to high titers'' to ''[40 immunoglobulin G phospholipid units or greater than 99th percentile'' as there are no standards to distinguish moderate/high titers from low titers. 9,16 The diagnosis of APS should be guided by the Sapporo criteria.…”

Case studies in anticoagulation management

“…[1,5,17]. For patients like MD, elevated and unstable INR results and challenging warfarin dosing are expected with antiphospholipid syndrome patients [51][52][53][54][55][56][57][58][59][60]. Case reports and one clinical trial have used oral vitamin K doses ranging from 80-500 lg/day [46][47][48][49][50]61].…”