抗磷脂抗体与抗活化蛋白C抵抗关系的研究

目的探讨抗磷脂抗体(APLs)与抗活化蛋白C(APCR)的关系。方法APCR检测以受检血浆加入活化蛋白C(APC)后的活化的部分凝血活酶时间(APTT)与未加APC血浆的APTT的敏感比值(APC-SR)表示,当APC-SR<2.0为APCR阳性。抗心磷脂抗体(ACL)检测和抗β2糖蛋白(β2GP)-Ⅰ抗体检测采用酶联免疫吸附试验。狼疮抗凝物(LA)采用激活的APTT测定法。结果LA与APCR有显著相关性(!2=16.332,P=0.008);而ACL-IgG、ACL-IgM和ACL-IgA3种ACL亚型均与APCR无统计学关系(!2=0.674,P=0.412;!2=2.978,P=0.071;!2=3.546,P=0.06);抗β2GP-Ⅰ抗体与APCR之间有显著相关性(!2=6.179,P=0.012)。APCR阳性组患者与阴性组患者的血栓形成及反复流产发生率差异有统计学意义(!2=7.347,P=0.007)。同时含有两种以上抗磷脂抗体17例(42.5%),APCR发生率达70.6%;血栓和/或反复流产64.7%,与含有一种APLs的病例比较差异有统计学意义(P=0.002)。结论LA和抗β2GP-Ⅰ抗体与APCR密切相关,APLs对蛋白C系统有抑制作用,APCR可能是诱发血栓的危险因素之一。APLs抗体的联合检测对并发血栓可能有预测价值。     

Antiphospholipid antibodies and hepatitis C virus infection in Iranian thalassemia major patients

Although the precise nature of Antiphospholipid antibodies is still not clearly defined, they are known to have association with thromboembolic events and have been found in hepatitis C virus (HCV) infection. Moreover, high prevalence of HCV infection and thrombotic risk is described in thalassemia. We aimed at investigating the prevalence of anticardiolipin antibodies (aCLAbs), lupus anticoagulant (LA), and their relation with HCV infection in Iranian thalassemic patients. Presence of anti-HCV antibody, serum HCV-RNA, aCLAbs, and LA activity was determined in 131 patients with thalassemia major (male/female: 63/68 aged 3-29 years) registered at thalassemia unit, Dastgheib Hospital, Shiraz, Iran. Sixty-one healthy controls were also included. Anti-HCV antibody was positive in 24 (18.3%), IgG aCLAbs in 56 (42.7%), and LA activity in 9 (6.9%) patients. 87.5% of patients positive for aCLAbs had a low titer of aCLAbs. Although none of the participants had a previous history of thrombosis, higher prevalence of aCLAbs was detected in thalassemic patients compared with controls. No significant difference in the prevalence of aCLAbs was found between HCV-infected and noninfected patients. A high prevalence of aCLAbs, the majority in low titers, was detected in Iranian thalassemic patients irrespective of previous history of thrombosis and presence of HCV infection.     

Protein C deficiency and anticardiolipin antibodies in a family with premature stroke

Anticardiolipin antibodies and, rarely, protein C deficiency have been described in patients with stroke. The familial coexistence of these two prothrombotic defects has not been previously reported. We describe a family with debilitating strokes occurring at an early age in whom both anticardiolipin antibodies and protein C deficiency were found. The propositus and her deceased mother both suffered a stroke at age 50 years. The propositus had both anticardiolipin antibodies and protein C deficiency. After a detailed study of the remainder of the family, the tendency to form anticardiolipin antibodies appeared to be inherited independently of the protein C deficiency. The simultaneous occurrence of these abnormalities in one family suggests that it may be useful to test for both anticardiolipin antibodies and inherited anticoagulant protein deficiencies in patients with unusual or unexplained stroke. The differential expression of both protein C deficiency and anticardiolipin antibody production in various members of the described family may allow insight into the relative contributions of these two prothrombotic abnormalities for the development of thrombotic complications, including stroke.     

Antiphospholipid antibodies (APLA) in immune thrombocytopenic purpura (ITP) and antiphospholipid syndrome (APS)

Antiphospholipid antibodies (APLA) are associated with anti-phospholipid syndrome (APS), a thrombotic disorder, but they are also frequently detected in immune thrombocytopenic purpura (ITP), a bleeding disorder. To investigate possible differences of APLA between these two disorders, we assayed IgG and IgM APLA by ELISA in 21 patients with ITP and 33 with APS. The APLA reacting against two protein target antigens, beta(2)-glycoprotein 1 (beta2GP1) and FVII/VIIa, and four phospholipids [cardiolipin (CL), phosphatidylcholine (PC), phosphatidylserine (PS), and phosphatidylethanolamine (PE)] as well as lupus anticoagulant (LA) were analyzed. We made the following observations: (i) IgG and IgM antibodies to beta2GP1 and IgM antibodies to FVII/VIIa were more common in APS than ITP, P < 0.05, while IgG antibodies against the phospholipids (aCL, aPC, aPS, aPE) were more common in ITP than APS, P < 0.05; (ii) multiple APLA > or =3 antigens) were more frequent in APS than ITP, P < 0.05; (iii) LA was frequently associated with APS but was absent in ITP; (iv) APLA is quite common in ITP: two-thirds were positive for at least one APLA. In summary, APLA are prevalent in ITP but their profile differs from APS. In APS, antibodies were predominantly against beta2GP1 and 80% had positive LA, while in ITP the APLA reacted most often with the phospholipids without LA. The difference in APLA may result in opposite clinical manifestations in two disorders.     

Clinical significance of anti-annexin V antibodies in patients with systemic lupus erythematosus

Annexin V has a calcium-dependent binding affinity for anionic phospholipids and activated platelets, and prevents prothrombinase activity. We investigated the clinical significance of IgG anti-annexin V antibodies in patients with SLE. The study population consisted of 140 patients with SLE. Sera were examined for IgG anti-annexin V antibodies by ELISA. IgG anti-annexin V antibodies were detected in 27 of 140 patients (19%). Significantly higher incidences of arterial or venous thrombosis, intrauterine fetal loss, and prolonged activated partial thromboplastin time were found in patients with anti-annexin V antibodies than in those without anti-annexin V antibodies. Three patients with thrombosis were found not to have anticardiolipin antibodies, but to show sustained serological reactions for anti-annexin V antibodies, irrespective of prednisolone administration. These results indicated the clinical characteristics of SLE patients with anti-annexin V antibodies, and that these antibodies may be associated with the pathogenesis of thrombotic events. Am. J. Hematol. 54:209–213, 1997 © Wiley-Liss, Inc.     

Antiphospholipid antibodies in adults with immune thrombocytopenic purpura

To determine the clinical significance of antiphospholipid antibodies (aPL) in patients with immune thrombocytopenic purpura (ITP), anticardiolipin (aCL) (IgG and IgM) and lupus anticoagulant (LA) were sought at diagnosis in 215 ITP adults with platelets <50 × 10⁹/l. aPL (aCL and/or LA) were detected in 55 patients (26%): aCL alone in 39 (18%), aCL and LA in 15 (7%) and LA alone in one (0·5%). LA was significantly associated with high IgG-aCL levels ( P  =   0·001). Among age, sex, initial platelet count, bleeding score, acute or chronic ITP outcome, only younger age was significantly associated with LA-positivity (mean age 29 ± 14 years vs. 45 ± 20 years, P  =   0·002). After a median follow-up of 31 months, 14/215 (7%) patients developed thrombosis (four arterial, 10 venous and/or pulmonary embolism); four of them (29%) had high aCL levels and LA. Multivariate analysis significantly associated thrombosis events only with age [hazard ratio (HR)   =   1·6; 95% confidence interval (CI): 1·2–2·4], LA (HR: 9·9; 95% CI: 2·3–43·4) or high IgG-aCL level (HR: 7·5; 95% CI; 1·8–31·5). Although the thrombosis rate was low, the significant associations between thrombosis and LA or high aCL level suggest that aPL should be tested at ITP diagnosis.     

Clinical and laboratory characteristics of children positive for antiphospholipid antibodies

Background.

It is difficult to estimate the actual prevalence of antiphospholipid syndrome (APS) in the paediatric population since there are no standardised criteria. We aimed to assess clinical and laboratory characteristics of a cohort of children positive for antiphospholipid antibodies (aPL) to contribute to the understanding of the heterogeneous aPL-related features in childhood.

Materials and methods.

Forty-four patients with prolonged activated partial thromboplastin time were enrolled and assigned to group I (“transiently positive”) or group II (“persistently positive”), based on the detection of elevated aPL plasma levels [lupus anticoagulant (LA), anticardiolipin (aCL), and anti-β2-glycoprotein I (anti-β2GPI) antibodies] on, respectively, one or more occasions, at least 12 weeks apart, by standard procedures. The clinical history and symptoms of all patients were recorded.

Results.

Thirty-three (75%) patients were assigned to group I, while the other 11 (25%) formed group II. Major associated diseases in group I were urticarial vasculitis (21%), acute infections (18%) and thalassaemia (12%). Five subjects (15%) were asymptomatic. Four out of the 11 subjects (36%) in group II had thrombotic events; they were all persistently aPL-positive and two of them had concomitant systemic lupus erythematosus. The rate of detection of LA-positivity was not significantly different between the two groups (76% vs 91%, p>0.05), whereas the percentage of patients positive for overall aCL was higher in group II than in group I (54% vs 42%, respectively; p<0.05). Specifically, aCL IgG and anti-β2GPI IgM subtypes were significantly more represented in group II than in group I (100% vs 62% and 75% vs 33%, respectively; p<0.05).

Discussion.

Our study shows that aPL-positive children have different features that should be taken into account in the classification of criteria for paediatric APS.     

Prevalence and clinical significance of anticardiolipin and anti-beta2-glycoprotein-I antibodies in patients with non-Hodgkin's lymphoma

The association of antiphospholipid antibodies (APA) has been reported in several cases of patients with non-Hodgkin's lymphoma (NHL) with or without thromboembolic complications. The purpose of this study was to analyse systematically the prevalence of APA and its clinical significance in lymphoma patients. Sera of 90 consecutive unselected patients with NHL were tested for the presence of anticardiolipin (aCL) antibodies and anti-beta2-glycoprotein-I (anti-beta2-GPI) antibodies. The patients were followed up over a median period of 14 months to note the occurrence of thromboembolism. We found APA in 24 out of 90 NHL patients (26.6%). Elevated APA were more often detected in women and in the elderly. The presence of elevated APA was not correlated with the histology and the stage of the lymphoma. None of the 24 patients with elevated APA developed a thromboembolic event in the follow-up period. Thromboembolic events were observed in 12 patients (13.3%), all with negative APA. High APA titres and the combination of positive aCL- and anti-beta2-GPI antibodies, features which are known to be more strongly correlated with thrombosis among patients with antiphospholipid syndrome and systemic lupus erythematous (SLE), were very uncommon in our cohort of NHL patients (3.3%). Vessel compression by lymphoma but not elevated APA remains the main cause of thrombosis in NHL patients.     

Anti-prothrombin antibodies: assay conditions and clinical associations in the anti-phospholipid syndrome

Anti-phospholipid antibodies (aPL) are associated with an increased risk of thrombosis and recurrent fetal loss. Antibodies to prothrombin (aPT) have been associated with the anti-phospholipid syndrome (aPS). We assessed variations in aPT assay methodology to optimize an aPT method that was used to screen patients with aPS (n = 66). Detection of aPT using enzyme-linked immunosorbent assay was influenced by the concentration of the capture antigen, the microtitre plate type and the buffer system. The combination of gamma-irradiated plates, a phosphate-buffered saline buffer and coating antigen of 10 microg/ml prothrombin was the most sensitive. Both serum and citrate samples are suitable for the detection of aPT. Under these conditions aPT IgM but not IgG were found to be associated with thrombosis and/or fetal loss.     

Prevalence of antiphospholipid antibodies in psychiatric patients users and non‐users of antipsychotics

Past reports have suggested that antiphospholipid (aPL) antibodies may emerge as a response to antipsychotics treatment, as a high prevalence of aPL antibodies in antipsychotics users has been observed. However, no control group of non‐medicated psychiatric patients was included in these reports. In a cross sectional study we determined the prevalence of aPL antibodies in 333 psychiatric inpatients. We compared the proportions of positive aPL antibodytests between users and non‐users of antipsychotics with adjustments for potential confounders. The proportion of antipsychotics users carrying at least one aPL antibody ranged from 10·8% to 27·0% compared with 6·8% to 27·2% in non‐users (P = 0·24, P = 0·24) depending on the method of detection of lupus anticoagulant (LA). The prevalence of LA detected by dilute Russell viper venom time or partial thromboplastin time‐LA was not different between antipsychotics users and non‐users (8·1% vs. 5·4%, P = 0·53 and 18·4% vs. 18·2%, P = 0·22), as well as the prevalence of IgM and IgG anti‐β2‐glycoprotein‐I antibodies, IgM and IgG anti‐cardiolipin antibodies(3·8% vs. 2·0%, P = 0·75, 0·0% vs. 0·0%, P = not applicable, 1·1 vs. 1·4%, P = 0·91, 2·7% vs. 3·4%, P = 0·71). In conclusion, aPL antibodies were frequently found in patients with psychiatric diseases and no significant increase in the prevalence of aPL antibodies was observed in antipsychotics users.     

Antiphospholipid antibodies associated with malignancies: clinical and pathological characteristics of 120 patients

OBJECTIVE: To describe the different types of malignancies associated with antiphospholipid antibodies (aPL). METHODS: We performed a computer-assisted (MEDLINE, National Library of Medicine, Bethesda, MD) search of the literature from 1966 to 2003 to identify all cases of malignancies having aPL. RESULTS: One hundred twenty patients were found. The mean age was 56+/-17 years (range 5 to 88). Sixty-two (52%) patients were men and 58 (48%) were women. A heterogeneous group of malignancies were found. Regarding hematological malignancies, 10 (8%) patients suffered from B-cell lymphoma, 8 (7%) from spleen lymphoma, 7 (6%) from chronic myeloid leukemia, and 6 (5%) from non-Hodgkin's lymphoma (NHL). Regarding solid tumors, renal cell carcinoma was diagnosed in 7 (6%) patients, primary tumor with unknown origin in 7 (6%), lung adenocarcinoma in 6 (5%), breast carcinoma in 6 (5%), and melanoma in 6 (5%). The main aPL-related manifestations were thrombocytopenia (25%), cerebrovascular accidents (24%), deep vein thrombosis (19%), pulmonary embolism (15%), and heart valve lesions (9%). In 17 cases, catastrophic antiphospholipid syndrome was considered to be triggered by the malignancy. Seventy-one (63%) of 113 patients recovered or are still alive after cancer treatment. Twenty-three (35%) of 65 patients achieved aPL remission after proper treatment of the malignancy. CONCLUSIONS: It is important to bear in mind, especially in elderly patients, that thrombotic events associated with aPL can be the first manifestation of malignancy. At the same time, the presence of aPL in patients with malignancies has important implications in their treatment and prognosis.     

Intestinal involvement secondary to the antiphospholipid syndrome (APS): clinical and immunologic characteristics of 97 patients: comparison of classic and catastrophic APS

OBJECTIVE: To analyze the clinical and laboratory characteristics of 97 patients with intestinal involvement secondary to the antiphospholipid syndrome (APS) (37 patients with classic APS and 60 with catastrophic APS). METHODS: A computer-assisted (PubMed) search of the literature was performed to identify all cases of intestinal involvement associated with the APS from 1983 to December 2005. In addition, we analyzed the web-site-based international registry of patients with catastrophic APS ("CAPS Registry"). RESULTS: There were no differences in distribution by gender, mean age, and previous clinical manifestations of APS between the 2 groups. The prevalence of abdominal pain as the presenting manifestation of intestinal ischemia was higher in patients with classic APS (76% versus 37%; P < 0.005). The main difference in histopathologic findings between the 2 groups was the higher rate of microthrombosis in patients with catastrophic APS (75% versus 4%; P < 0.0005). The mortality rate was higher in patients with catastrophic APS (55% versus 17%; P < 0.0005). Follow-up was available in 22 patients with classical APS: 17 of them were discharged on oral anticoagulation and with a mean follow-up of 13 months (range, 1 to 48); all were in good health without the development of new thrombotic events. CONCLUSIONS: Intestinal involvement, although infrequent, is an important complication in patients with APS, especially in those with catastrophic APS. This would support the need for systematic screening for aPL in all cases of mesenteric thrombosis or ischemic colitis without clear underlying predisposing factors, and for systematic screening procedures in all classic APS patients complaining of abdominal pain.     

Arterial thrombosis associated with anticardiolipin and anti-beta2-glycoprotein-I antibodies in patients with non-Hodgkin's lymphoma: a report of two cases

Autoimmune phenomena in lymphoid malignancies are often observed. However, clinical manifestations such as a secondary antiphospholipid syndrome in the presence of antiphospholipid antibodies are rarely reported. Furthermore, in the few cases of lymphomas so far reported with thrombosis associated with elevated antiphospholipid antibodies, the anti-beta2-glycoprotein-I antibodies have not been studied. We report on two cases of arterial thrombosis occuring in patients with B-cell lymphoma who presented with positive anticardiolipin and anti-beta2-glycoprotein-I antibodies. Our observation suggests that patients with non-Hodgkin's lymphoma and both anticardiolipin and anti-beta2-glycoprotein-I antibodies may be, similar to lupus patients, at considerable risk towards thrombosis, especially towards arterial thrombosis.     

Thrombotic risk in patients with immune thrombocytopenia and its association with antiphospholipid antibodies

Patients with immune thrombocytopenia (ITP) paradoxically have an increased risk of thrombosis. The presence of antiphospholipid antibodies (aPL) has been observed in a substantial proportion of ITP patients, but its clinical significance remains to be established. This study retrospectively investigated the prevalence and clinical significance of aPL in ITP patients and assessed the risk factors for thrombosis. One hundred and sixty‐five subjects with ITP were included in the study and followed for a mean period of 63·4 months. Sixty‐nine (41·6%) patients were positive for aPL at diagnosis, and their clinical characteristics and course of ITP were not different from those of aPL‐negative patients. Twenty‐one (12·7%) patients developed a thrombotic event during follow‐up and the cumulative incidence rate ratio of aPL‐positive to aPL‐negative patients for thromboembolism was 3·15 [95% confidence interval (CI) 1·21–8·17] after adjusting for confounding factors. Lupus anticoagulant and hypertension were identified by Cox regression analysis as independent risk factors for thrombosis [hazard ratio (HR) 4·1, 95% CI 1·4–11·9, P = 0·009 and HR 5·6, 95% CI 1·9–15·8, P = 0·001, respectively]. Our results showed that a substantial proportion of ITP patients were aPL‐positive, and that lupus anticoagulant and hypertension were independent risk factors for thrombosis. Detection of aPL can provide useful information for identifying patients at high‐risk for developing thrombosis.     

Risk of arterial thrombosis in patients with anticardiolipin antibodies and lupus anticoagulant

The relationship between arterial or venous thrombosis and the levels of anticardiolipin antibodies (aCL) and/or existence of lupus anticoagulant (LA) was studied. The 141 patients with systemic lupus erythematosus (SLE) were divided into four groups: aCL single positive (25 cases), LA single positive (11 cases), aCL and LA double positive (25 cases), aCL and LA double negative (80 cases). The prevalence of thrombosis was higher in aCL and LA double positive patients (21/25 cases, 84.0%, P  < 0.01) than that in aCL single positive patients (4/25 cases, 16.0%), LA single positive patients (1/11 cases, 9.1%) and double negative patients (3/80 cases, 3.8%). Furthermore, in these double positive patients, all patients (10/10 cases) with a high positive level of aCL (>10 units/ml) had arterial thrombosis, whereas only 2/15 patients (13.3%) with a low positive level of aCL (3–10 units/ml) were affected. Venous thrombosis was frequently found in the low positive group (9/15 cases, 60.0%). On the contrary, none of 105 LA negative patients had arterial thrombosis and only seven (6.7%) had venous thrombosis. These findings indicate that a high aCL activity combined with a LA positive result might be a risk factor for arterial thrombosis.     

狼疮肾炎肾小球微血栓形成及其与抗凝血相关因子抗体抗磷脂抗体的相关性研究

目的 评估肾小球微血栓(GMT)在狼疮肾炎(LN)中的发生率,并探讨针对某些凝血相关因子的抗体和抗磷脂抗体在LN患者GMT形成中的临床意义.方法 连续收集124例LN患者肾活检组织标本和血浆,观察组织标本中GMT的发生率.并分成LN-GMT组和LN-non-GMT组;比较两组患者的疾病活动度、相关实验室检查指标和肾组织活动,慢性指数;测定患者的狼疮抗凝物(LA)、抗心磷脂抗体(ACL)、抗β2糖蛋白I(抗β2GP I)抗体、抗凝血酶抗体、抗纤溶酶抗体、抗组织型纤溶酶原激活物(t-PA)抗体和抗膜联蛋白AⅡ(Annexin A II)抗体.结果 GMT在LN中的发生率约为20.2%;LN-GMT组系统性红斑狼疮疾病活动指数(SLEDAI)、肾组织病变活动指数、肾组织病变慢性指数、尿蛋白定量(24 h)、血清肌酐、血清尿素氮的水平和高血压的发生率都较LN-non-GMT组高(P＜0.01);LN-GMT组LA、IgG型抗B2GP I抗体和抗凝血酶抗体阳性率均显著高于LN-non-GMT组(P＜0.05);两组IgG型ACL抗体、抗纤溶酶抗体、抗t-PA抗体和抗Annexin A II抗体阳性率差异均无统计学意义(P＞0.05);两组各抗体IgM型差异无统计学意义(P＞0.05).结论 LN中伴有GMT形成的患者肾脏病变重于无GMT者;LA、IgG型抗β2GP I抗体和抗凝血酶抗体与LN患者GMT形成相关.     

Lack of association of beta2-glycoprotein I polymorphisms Val247Leu and Trp316Ser with antiphospholipid antibodies in patients with thrombosis and pregnancy complications

Beta2-glycoprotein I (beta2GPI) is an important target antigen for antiphospholipid antibodies (aPL) and thus beta2GPI polymorphisms may influence aPL production and the development of antiphospholipid syndrome. We have studied the relationship between the Val247Leu and Trp316Ser beta2GPI polymorphisms and the aPL status of 230 patients referred for aPL screening. Sixty-one (26.5%) had persistent aPL [anticardiolipin antibodies (IgG and/or IgM), lupus anticoagulants and/or IgG anti-beta2GPI antibodies]. A comparison of the genotypic and allelic frequencies of these two polymorphisms between the Caucasian patient population and an ethnic-matched normal control group (n = 308) showed no significant differences between aPL-positive patients, aPL-negative patients and the normal control group. This suggests that the Val or Leu allele at position 247 and the Trp or Ser allele at position 316 of beta2GPI do not play a role in the production of aPL. There was a significantly decreased prevalence of the Ser316 allele in aPL-negative women (n = 98) when compared with female normal control subjects (n = 249) [0.020 [95% confidence interval (CI) 0.00-0.04]vs 0.060 (95% CI 0.04-0.08), P = 0.0286]. Subgroup analysis showed no significant difference between female patients with thrombosis and female normal control subjects. Thus, the Ser316 allele may protect women from developing pregnancy complications by influencing an anticoagulant function of beta2GPI via a mechanism distinct from aPL production.