Management of thrombosis in women with antiphospholipid syndrome

Usefulness of low-dose combined spinal epidural anesthesia for a woman with systemic lupus erythematosus, mechanical prosthesis in the mitral valve position, and worsening heart failure presenting for cesarean delivery

A 31-year-old woman, gravida one, para zero, at 32 weeks, 4 days gestation, with a history of antiphospholipid antibody syndrome, mitral valve replacement requiring anticoagulation, chronic diastolic heart failure, and systemic lupus erythematous was admitted to the hospital for worsening cardiac decompensation with superimposed pneumonia. She was on warfarin for anticoagulation at the time of hospital admission and eventually started on an intravenous heparin infusion. Cesarean delivery was planned due to comorbidities and anticoagulation status. After administration of betamethasone for fetal lung maturity, the patient's heparin infusion was discontinued approximately 16 hours prior to cesarean delivery. Upon obtaining laboratory testing that confirmed appropriate coagulation status, a low-dose combined spinal epidural anesthetic technique was used for cesarean delivery and the expected hemodynamic shifts due to spinal anesthesia were mitigated with a prophylactic norepinephrine infusion.

Plasma ADAMTS13, von Willebrand Factor (VWF), and VWF Propeptide Profiles in Patients With Connective Tissue Diseases and Antiphospholipid Syndrome

Thrombotic thrombocytopenic purpura (TTP) frequently develops in patients with connective tissue diseases (CTDs). ADAMTS13 and von Willebrand factor (VWF) are closely related to the onset of TTP. We investigated the roles of ADAMTS13 and VWF in thrombotic events of patients with CTD. ADAMTS13 activity and VWF and VWF propeptide (VWFpp) levels in CTD, primary antiphospholipid antibody syndrome (pAPS), and controls were measured to examine their relationship with thrombosis. ADAMTS13 activity levels were significantly low in the patients with CTD but not in the patients with pAPS. No significant difference in the ADAMTS13 activity levels among the various CTD subgroups was found. The levels of VWF and VWFpp were significantly elevated in the patients with pAPS and CTD compared with that of control groups. Eleven patients with CTD developed TTP, and their ADAMTS13 activity levels were significantly lower than patients having CTD without TTP. However, the ADAMTS13 activity levels showed no difference between the patients having CTD with and without thrombotic events. The VWF antigen levels were significantly high in the patients having CTD with TTP. There were no significant differences in the VWF levels of the patients having CTD with TTP and thrombosis. The VWFpp levels were significantly high in the patients having CTD with TTP and thrombosis. The VWF and VWFpp levels were significantly high in the patients with pAPS. Decreased ADAMTS13 activity and elevated VWF and VWFpp levels were observed in patients with CTD. These abnormalities in patients with CTD may represent the increased risk of thrombosis in CTD.

Presence of Antiphospholipid Antibodies as a Risk Factor for Thrombotic Events in Patients with Connective Tissue Diseases and Idiopathic Thrombocytopenic Purpura

OBJECTIVE

Antiphospholipid syndrome (APS) is a well-known complication of habitual abortion and/or thrombosis and is frequently associated with autoimmune diseases.

METHODS

We retrospectively investigated the relationships between the presence of antiphospholipid antibodies (aPLs) and the incidence of thrombotic events (THEs) in 147 patients with various connective tissue diseases (CTD) suspected of having APS and 86 patients with idiopathic thrombocytopenic purpura (ITP). THEs were observed in 41 patients, including 14 cases of venous thrombosis, 21 cases of arterial thrombosis and eight cases of complications of pregnancy.

RESULTS

The prevalence of THE was significantly high in the systemic lupus erythematosus (SLE) patients compared with the other CTD patients and ITP patients. The frequency of lupus anticoagulant (LA), anticardiolipin antibodies (aCL)-β2-glycoprotein (GPI) complex IgG and aPL was significantly high in the SLE patients compared with the ITP patients. Subsequently, the rate of development of THE was significantly high in the patients with aPLs. In particular, the incidence of THE was significantly high in the SLE or ITP patients with LA, aCL-β2GPI IgG or aPL. The optimal cut-off values for LA, aCL IgG and aCL-β2GPI complex IgG for the risk of THEs were higher in the SLE patients in comparison to the values obtained when using the kit provided by the manufacturer.

CONCLUSION

Although aPLs is frequently associated with SLE and is a causative factor for thrombosis, the optimal cut-off value for aPL for predicting the occurrence of THEs varies among different underlying diseases.

Complement the hemostatic system: an intimate relationship

The complement system is important part of our innate immune system and interacts directly with the hemostatic system. Disorders of complement activation or dysregulation resulting in excess complement generation, such as Paroxysmal Nocturnal Hemoglobinuria (PNH), atypical Hemolytic uremic Syndrome (aHUS) and antiphospholipid syndrome (APLS) have been associated with significant thrombophilia. Terminal Complement (C5b-9) deposition on endothelial and tumor cell membranes has also been reported in a variety of cancer. Recent developments in complement inhibition have given us new insights into the mechanism of thrombosis in these disorders.

[Antiphospholipid syndrome and pregnancy: Obstetrical prognosis according to the type of APS]

OBJECTIVE

The objective of our study was to compare treatment-based obstetrical outcomes in women with either thrombotic or obstetrical antiphospholipid syndrome (APS).

MATERIALS AND METHODS

This was a historical cohort study conducted between 1998 and 2009 in 23 patients who had a total of 83 pregnancies. The syndrome was diagnosed using the 2006 Sapporo criteria.

RESULTS

Thirty-one of these 83 pregnancies were valid before the diagnosis was made. A live infant was born in 22% of them, the infant being small for gestational age in 26% of cases. The fetus died in utero in a further 26% of cases. Pregnancies were subdivided into 2 groups depending on whether the initial event leading to APS diagnosis was obstetrical or thrombotic. Treatment (aspirin and low molecular weight heparin) was based on this classification: the latter was given in a curative dose for thrombotic events, in a preventive dose for obstetrical events. No fetal loss was observed when treatment was administered according to the protocol. Nevertheless, 20% of the pregnancies with obstetrical APS were complicated by smallness for gestational age and only 38% of the infants were live births. More than 87% of the thrombotic forms treated were free of complications and led to birth of a living child.

CONCLUSION

Appropriate treatment appears to improve the prognosis for pregnancies in patients with APS. These patients are nevertheless at increased risk of an obstetrical event and require close monitoring, especially in obstetrical manifestations, which appear to have a poorer prognosis. Multidisciplinary follow-up by an experienced team is essential.

Presence of antiphospholipid antibody is a risk factor in thrombotic events in patients with antiphospholipid syndrome or relevant diseases

Antiphospholipid antibodies (aPL) including lupus anticoagulant (LA), anticardiolipin antibodies (aCL) IgG and aCL-β2-glycoprotein I (β2GPI) complex IG are causative factors for thrombotic event (THE). We retrospectively investigated relationships between aPLs and THE in 458 patients suspected of having antiphospholipid syndrome. THEs were observed in 232 of 458 patients, including 148 cases of venous thrombosis, 59 of arterial thrombosis, 18 of microthrombosis, and 20 of complications of pregnancy. The frequency of THE was significantly high in patients positive for LA and/or aPL. In patients with autoimmune disease (AID), the frequency of THE was significantly high in patients with any types of aPLs. Additionally, risk of THE was significantly increased in patients with more than two types of aPLs. Prolonged activated partial thromboplastin time indicated a high risk for THE. However, neither thrombocytopenia nor AID was a risk for THE. In conclusion, the presence of aPL is an indicator for high risk of THE in patients in whom THE was suspected. However, the risk of THE in aPL-positive patients varied among patients with different underlying diseases.

Autoimmune disease as a cause of reproductive failure

High-risk pregnancy is the most common clinical association with antiphospholipid antibodies; the principal manifestations are pregnancy loss and early preeclampsia. Membership in this family of antibodies is continually growing and includes antibodies against a variety of phospholipids, phospholipid-protein complexes, and phospholipid-binding proteins. The current information in the literature is inadequate to clearly implicate a subgroup of antiphospholipid antibodies or a particular pathophysiologic mechanism as being responsible for poor pregnancy outcomes. It is clear, however, that prevalent diagnostic tests for LA and aCL are extremely useful to identify many of these patients, but are inadequate for diagnosis of all patients with autoimmune pregnancy loss or to elucidate the pathophysiology. Many patients who present clinically with autoimmune-like pregnancy complications currently are negative in tests for LA or aCL, but have antibodies against annexin V, phosphatidylserine, or other relevant antigens. The greatest risk for a complicated pregnancy is conveyed by a subgroup of antibodies that affect the normal function of placental trophoblast. As clinical laboratory tests designed to detect more members of the antiphospholipid antibody family become available, understanding of this complicated disease (APS) will increase.

The influence of sex on pharmacokinetics

Biologic differences exist between men and women that can result in differences in responses to drugs. Both pharmacokinetic and pharmacodynamic differences between the sexes exist, with more data on pharmacokinetic differences. On average, men are larger than women. Body size differences results in larger distribution volumes and faster total clearance of most medications in men compared to women. Greater body fat in women (until older ages) may increase distribution volumes for lipophilic drugs in women. Total drug absorption does not appear to be significantly affected by sex although absorption rates may be slightly slower in women. Bioavailability after oral drug dosing, for CYP3A substrates in particular, may be somewhat higher in women compared to men. Bioavailability after transdermal drug administration does not appear to be significantly affected by gender; nor does protein binding. Renal processes of glomerular filtration, tubular secretion, and tubular reabsorption appear to be faster in men compared to women whether considered on a mg/kg basis or total body weight basis. Algorithms to estimate glomerular filtration rate incorporate sex as a factor; some also include weight. For hepatic processes, drugs metabolized by Phase I metabolism (oxidation, reduction, and hydrolysis via cytochrome P450's 1A, 2D6, 2E1), Phase II conjugative metabolism (glucuronidation, conjugation, glucuronyltransferases, methyltransferases, dehydrogenases) and by combined oxidative and conjugation processes are usually cleared faster in men compared to women (mg/kg basis). Metabolism by CYP2C9, CYP2C19, and N-acetyltransferase, appear to be similar in men and women (mg/kg). Clearance of p-glycoprotein substrates appear to be similar in men and women. In contrast, total clearance of a number of CYP3A substrates appear to be mildly or moderately faster (mg/kg) in women compared to men. The clinical significance of reported differences warrants consideration. Clearance reported on a per kg basis directly addresses organ or enzyme clearance. The difference in size between men and women means translating these results to clinical dosage rates should include an adjustment for body size. Unfortunately, this is not standard. Reports of sex differences that persist after considering weight may warrant further dosage adjustments. In addition, investigations are often performed in healthy fasting individuals yet medications are prescribed to patients with confounding influences of disease, co-medications, diet, and social habits. The relative role of sex on pharmacokinetics as compared to genetics, age, disease, social habits and their potential interactions in the clinical setting is not yet fully known but should be routinely considered and further studied.

The relation between antiphospholipid syndrome-related pregnancy morbidity and non-gravid vascular thrombosis: a review of the literature and management strategies

The antiphospholipid syndrome (APS) is associated with pregnancy morbidity and vascular thrombosis in the presence of circulating antiphospholipid (aPL) antibodies. Clinical manifestations of aPL antibodies represent a spectrum (asymptomatic, pregnancy events, vascular events, or both pregnancy and vascular events), and APS should not be considered a single disease with a predictable outcome. Patients with aPL antibodies are at increased risk of vascular thrombotic events during pregnancy, the postpartum period, and even during long-term follow-up after an APS-related pregnancy event. Therefore, the purpose of this paper is to review the relation between APS-related pregnancy morbidity and vascular thrombosis, and to address the importance of prophylactic therapy during and after APS pregnancies to prevent maternal thrombotic complications. During pregnancy, low-dose aspirin (LDA) should be considered for all patients with aPL antibodies and heparin should be added to LDA in patients fulfilling the Sapporo criteria for definite APS. During delivery, especially with caesarian section, periods without anticoagulation should be kept to an absolute minimum. Some data suggest that LDA might be effective against future non-gravid vascular thrombosis in patients with APS and a history of only pregnancy morbidity.