Coagulation inhibitors and activated protein C resistance in recurrent pregnancy losses in Indian women.

Background: Thrombophilias, both acquired and inherited, have been investigated in the etiopathogenesis of unexplained recurrent pregnancy loss. Aim: To study coagulation inhibitors and activated protein C resistance (APCR) in recurrent pregnancy losses (RPL) occurring in second and third trimesters. Materials and Methods: A total of 30 pregnant women (group A) with two or more recurrent unexplained fetal loses were evaluated for APCR, protein C deficiency, protein S deficiency, antithrombin deficiency, and antiphospholipid antibodies (APLA). Thirty age-matched controls were taken (group B) comprising of pregnant women with at least one live issue. Statistical Analysis: Comparisons between two group frequencies and group means were made using Chi square test and Student's t test, respectively. Results: Protein C and protein S levels were reduced in group A compared with group B and the difference was statistically significant (P=0.005 and P=0.032, respectively). The mean value of antithrombin was slightly reduced in group A compared with group B. APCR was observed in 16.6% cases and 3.3% controls. However, the difference was not statistically significant. APLA was observed in 20% cases and none of the controls. Of these, lupus anticoagulant was positive in 16.6% cases and anticardiolipin antibodies in 10% cases. Combined defects were seen in seven patients. Conclusion: There is a significant risk of RPL in pregnant women with thrombophilias. Therefore, screening for thrombophilias may be justified in pregnant women with unexplained recurrent fetal wastage, especially in second and third trimester.

Activated protein C resistance and lupus anticoagulant activity induced by plasma and purified monospecific human IgG anti-β2-glycoprotein-I antibodies / Resistencia a la proteína C activada y actividad de anticoagulante lúpico inducidas por plasma y por anticuerpos purificados humanos del IgG anti β2-glicoproteína I

ABSTRACT Introduction. We investigated the activated protein C resistance (APCR) phenotype and the lupus anticoagulant (LA), activity induced by anti-β2-glycoprotein-I (anti-β2GP-I) antibodies. Patients and methods. We studied plasma and sera samples from 29 patients with persistently positive anti-β2GP-I: 22 with thrombosis (12 with primary APS, 10 with APS secondary to SLE) and seven without thrombosis (all with SLE); 25 healthy subjects were studied as controls. We detected anticardiolipin antibodies (ACA); IgG (and its subclasses) and IgM anti-β2GP-I, on irradiated and non-irradiated plates by ELISA. APCR was assessed by the activated partial thromboplastin time (APTT)-based assay and by the modified test. The FV Leiden mutation was studied by PCR. LA determination included screening and confirmatory dRVVT. Serum anti-β2GP-I were affinity purified on sepharose columns and their isotype, subclass, and reactivity against various antigens were studied by ELISA. Results. We found that titers of IgG anti-β2GP-I on irradiated plates were higher than on non-irradiated plates (p = 0.002), IgG2 was the predominant subclass. Fifteen patients (13 with thrombosis) had LA and 15 (also 13 with thrombosis) induced the APCR phenotype. Eleven (all with thrombosis) had both. Two patients were heterozygous for the Leiden mutation. Two purified antibodies, monospecific for β2GP-I, induced an in vitro APCR phenotype and LA activity. Conclusions. Our results seem to indicate that the inhibition of the APC anticoagulant function by IgG2 anti-β2GP-I with LA activity may be one of the responsible mechanisms of thrombophilia in patients with APS.

Introducción. Investigamos la resistencia a la proteína C activada (RPCA) y la actividad de anticoagulante lápico (AL), inducidas por anticuerpos anti-β2-glicoproteína-I (anti-β2GP-I). Pacientes y métodos. Estudiamos los plasmas y sueros persistentemente positivos para anti-β2GP-I de 29 pacientes: 22 tuvieron trombosis (12 con síndrome de antifosfolípidos (SAF) primario y 10 con SAF secundario a lupus erítematoso generalizado (LEG)) y siete sin trombosis (todos con LEG). Como controles estudiamos 25 sueros de personas clínicamente sanas. Detectamos anticuerpos anticardiolipina, anti-β2GP-I IgG (y sus subclases) e IgM por ELISA en placas irradiadas y no irradiadas. Evaluamos la RPCA por medio del tiempo parcial de tromboplastina activada y por la prueba modificada. Estudiamos la mutación FV de Leiden por PCR y el anticoagulante lápico con el método de dRVVT screening y confirmatorio. Después de purificar los anti-β2GP-I séricos con una columna de antígeno unido a sefarosa, analizamos por ELISA sus isotipos, subclases y reactividad contra β2GP-I y algunos fosfolípidos. Resultados. Los títulos de anti-β2GP-I IgG fueron más altos en placas irradiadas que en no irradiadas (p = 0.002), predominó la subclase IgG2. Quince plasmas (13 de pacientes con trombosis) tuvieron AL y 15 (13 también de pacientes con trombosis) indujeron el fenotipo de RPCA. Once plasmas (todos de pacientes con trombosis) indujeron ambas actividades. Dos pacientes fueron heterocigotos para la mutación de Leiden. Dos anticuerpos purificados monoespecíficos para β2GP-I indujeron el fenotipo de la RPCA y la actividad de AL in vitro. Conclusiones. Nuestros resultados sugieren que la RPCA, inducida por los anti-β2GP-I que concomitantemente tienen actividad de AL, puede tener implicaciones patogénicas en la trombofílía del SAF.

A Study of Prevalence of Activated Protein C Resistance and Leiden Mutation among Korean Patients with Venous Ulcers / 대한피부과학회지

BACKGROUND: Recently, resistance to activated protein C(APC) is known to be an important risk factor for venous leg ulcers. Leiden mutation in clotting factor V is the most common genetic defect leading to APC resistance in western countries. Until now, the prevalence of APC resistance and Leiden mutation in Korean patients with venous ulcers has been ill defined. OBJECTIVE: We performed this study in order to investigate the prevalence of APC resistance and Leiden mutation in Korean patients with venous ulcers. METHODS: The functional analysis for APC resistance(APC resistance ratio) and genetic study for Leiden mutation were conducted in 40 patients with venous ulcers. RESULTS: 1. Of the 40 patients with venous ulcers, resistance to APC was documented in 11 individuals (27.5%). 2. We could not find factor V Leiden mutation in 40 patients. 3. Patients with APC resistance more frequently represented recurrence of venous ulcers and venous thrombosis than in their non-APC resistant counterparts. CONCLUSION: APC resistance may be one of the thrombophilic defects in relation with venous ulcers in Korea. However, Leiden mutation may be rare in Korean patients with venous ulcers than in Caucasians. These findings suggested that the other genetic or non-genetic factors may be involved in the pathogenesis of APC resistance in Korea.

The relationship between anti-phospholipid antibodies and activated protein C resistance / 中华风湿病学杂志

Objective To investigate the relationship between the anti-phospholipid antibodies (APLs)and activated protein C resistance (APCR). Methods The response to activated protein C (APC) was studied by an APTT-based (clotting) assay with a Stago autoanalyzer and expressed as the ratio between the APTT obtained in the presence and absence of exogenous APC. APC sensitive ratio higher than 2 was regarded as APCR. Anti-?2-glycoprotein Ⅰ (?2GP-Ⅰ) antibody and anti-cardiolipin antibodies (ACL) were measured by an enzyme-linked immunosorbent assay (ELISA). Lupus anticoagulant (LA) was tested by activated partial thromboplastin time (APTT). Results The existence of LA and acquired APCR showed significant correlation (?2=16.332, P=0.008). Acquired APCR was significantly associated with the presence of anti-?2GP-Ⅰ antibody (?2=6.179, P=0.012), but not ACL. The presence of APCR was associated with an increased frequency of history of thromboembolic events and/or recurrent abortions (?2=7.347, P=0.01). Conclusion This study suggests that APCR is linked to the presence of LA and anti-?2GP-Ⅰ antibody. APLs may interfere with the activation of protein C. APCR phenotype may be a major risk factor for thrombophilia in patients with APLs. Combined detection of APLs has the potential value for predicting thrombosis.

Activated Protein C Resistance and Factor V Leiden Mutation in Patients with Arterial Ischemic Stroke

BACKGROUND: In the western hemisphere, resistance to activated protein C (APCR) is the most common risk factor for venous thromboembolic disease. A one-point mutation in the coagulation factor V that renders it APCR is found in more than 90% of patients with APC-resistant venous thrombosis. In Hispanic and Caucasian patients with arterial ischemic stroke, the prevalence of APC-R is approximately 10%. To determine the prevalence of APC resistance and its causative factor V mutation (Arg 506 Gln) in Koreans, we screened a group of Korean ischemic stroke patients. METHODS: We evaluated 60 Korean patients with arterial ischemic stroke diagnosed by either magnetic resonance neu-roimaging, conventional angiogram, or both, after 2 weeks of symptom onset. The mean age of the subjects was 59.2 years (13-82 years). APC resistance was expressed as a ratio of the activated partial thromboplastin time (aPTT) with and without adding APC to the subject's plasma. The presence of the factor V Leiden (Arg 506 Gln) mutation was determined by a direct polymerase chain reaction-based assay on peripheral blood leukocytes. RESULTS: Only one patient (n=1/60, 1.6%) had APC resistance and none were found to have the factor V Leiden (Arg 506 Gln) mutation. CONCLUSIONS: APCR and the factor V Leiden mutation do not seem to be a significant genetic risk factor for arterial ischemic stroke in Koreans.

The prevalence of hereditary thrombophilia in the Trakya region of Turkey

The prevalences of deficiencies in antithrombin III (AT III), protein C (PC), protein S (PS) and in the activated protein C (APC) resistance in the thrombotic population of the Trakya region, Turkey were investigated. 37 patients with venous thrombosis (VT) and 17 patients with arterial thrombosis (ArT) were included in this study. The mean ages of the patients with VT and ArT were 46 years (range 20-70) and 38 years (range 32-40), respectively. The activity of AT III was measured by commercially available immuno-turbidimetric assay. The activities of PC and PS were determined by coagulometric assay. The APC resistance was measured using a modified APTT-based clotting assay. Among the VT patients, there were 2 cases (5.4%) with AT III, 5 (13.51%) with PC deficiency, 5 (13.51%) with PS deficiency and 2 (5.4%) with APC resistance. In the ArT patient group, there was 1 patient (5.88%) with AT III, 3 (17.64%) with PC deficiency, 1 (5.88%) with PS deficiency and no APC resistant patients, while there was one (2.08%) with PC deficiency and one (2.08%) with APC resistance in the control group (49 persons, mean age 41 years). The relative risk of thrombosis (odds ratio) was 1.7 in the deficiency of PC and 5.6 in the deficiency of PS. The data presented suggests that the prevalences of AT III, PC and PS deficiencies causing thrombophilia in the Trakya region of Turkey are higher than in other reported studies while the APC resistance is lower than in others. Further studies including more patients would be required to clarify these discrepancies.

Antiphospholipid Antibodies and Activated Protein C Resistance in Patients with Leg Ulcers / 대한피부과학회지

BACKGROUND: Antiphospholipid antibodies(APA) including anticardiolipin antibodies(ACA) are significantly associated with ulcerations of the leg. Moreover, resistance to activated protein C(aPC) may be an important risk factor in leg ulcerations. Until now, there has been no clinical investigation about the positivity of APA or resistance to aPC in patients with leg ulcers in Korea. OBJECTIVE: We investigated the positivity to APA and the presence of resistance to aPC in patients with leg ulcers in Korea. METHODS: Venous or arterial ultrasonic Doppler, semiquantitative assay for serum APA and functional analysis for aPC resistance were conducted in 32 patients with leg ulcers. RESULTS: 1. Of the 32 patients with leg ulcers, 34,3% had a positive APA. APA were more frequently associated with venous ulcerations of the leg than in subjects with leg ulcers of arterial or mixed origin. 2. aPC resistance based upon the functional analysis, occurred in 43.7% to 46.8% of leg ulcer patients. 3. Livedo reticularis (38.1%) and superficial thrombophlebitis (19.0%) were the most common cutaneous manifestations accompanied by leg ulcers in 21 APA-positive and/or aPC resistant patients. Deep vein thrombosis of extremities was the most common complication (47.6%) among the systemic thrombotic sequelaes in APA-positive and/or aPC resistant patients. CONCLUSION: APA positivity and aPC resistance may be relatively common anticoagulant defects among patients with leg ulcerations in Korea. APA positivity and aPC resistance should be considered important risk factors for the development of not only leg ulcers but also systemic thrornbotic complications.

The Effects of Anticoagulant Proteins Defect in Maternal Plasma on Spontaneous Abortion / 中华围产医学杂志

Objective To investigate the mechanism of anticoagulant proteins defect in patients with unexplained miscarriage. Methods Fifty-seven patients with a history of unexplained abortion in Peking union hospital during may. 1999 to April 2000. were tested for protein S, protein C, and antithrombin(AT)Ⅲ, activated protein C resistance(APC-R).The control group consisted of 50 healthy women with a history of normal pregnancy and delivery. Blood samples were taken for measuring protein S, protein C, AT-Ⅲ and APC-R. Patients with APC-R positive were measured for FV Leiden gene mutation by PCR-RFLP method. Results Of the 57 patients, there were 21.1%?1.8% and 8.8% with protein S?protein C and AT-Ⅲ deficiency respectively. For APC-R 22.8% of the 57 patients were positive .In control group, 4.0% were protein S deficiency; None was protein C and AT-Ⅲ deficiency ; 6.0% were positive for APC-R .No FV Leiden gene mutation was found in all the patients with APC-R positive .The incidence of anticoagulant proteins defect is higher in late spontaneous abortion group than that in early abortion group. Conclusions This study demonstrate that anticoagulant protein defects may be associated with pregnancy loss, especially the late spontaneous abortion.

Study on Activated Protein C in Patients with Neuropsychiatric Lupus Erythematosus / 中华皮肤科杂志

Objective To explore the significance of activated protein C resistance (APCR) and antiphospholipid antibody(APA) in patients with neuropsychiatric lupus erythematosus(NPLE). Methods APCR, anticardiolipid antibody (ACA)(IgG, M, A), lupus anticoagulant (LA) were measured with APTT? APC, ELISA, PTT－ LA methods, respectively, in 21 NPLE patients and 88 SLE patients without NPLE(NNPLE). Results The positive rates of APCR and ACA(IgG) in NPLE group were 78.9％ (15/19) and 52.4％ (11/21), respectively, which were significantly higher than those in NNPLE group: 44.3％ (39/88) and 22.7％ (20/88), respectively (P