Pharmacokinetic evaluation of percutaneous hepatic venous isolation for administration of regional chemotherapy

Hepatic artery infusion (HAI) chemotherapy has been used to treat patients with unresectable liver tumours. We report a preclinical study of the pharmacokinetics of HAI combined with hepatic venous drug extraction (HVDE) for regional administration of doxorubicin. HVDE was aided by a double balloon catheter inserted via femoral vein cutdown into the inferior vena cava to collect all hepatic vein blood. Pigs received doxorubicin 0.5-9.0 mg kg-1 over 90 min via HAI or systemic infusion (SYSI). HVDE was performed for 240 min. SYSI pigs underwent hepatic venous isolation without drug filtration. Doxorubicin levels were assayed using high-pressure liquid chromatography (HPLC). HAI/HVDE reduced systemic exposure to doxorubicin with equivalent hepatic exposure at all doses. Pharmacokinetic enhancement ranged from 7.0 to 22.3 for peak concentration, 8.8-23.2 for the area under the curve and 2.9-4.2 for tissue concentration. HAI/HVDE also prevented the mortality which was observed with SYSI administration of high-dose (5.0 and 9.0 mg kg-1) doxorubicin. We conclude that HAI/HVDE reduces systemic exposure to doxorubicin as compared with SYSI of equivalent doses. Pharmacokinetic enhancement indices suggest that HAI/HVDE may allow equivalent hepatic drug exposure with reduced systemic exposure. This method may be applicable to other drugs and to other anatomic settings in which enhanced regional drug delivery is desirable.     

Increased doxorubicin levels in hepatic tumors with reduced systemic drug exposure achieved with complete hepatic venous isolation and extracorporeal chemofiltration

FIZ15 phage of Pseudomonas aeruginosa causes lysogenic conversion in PAO1 strain. Lysogen shows increased adhesion to human buccal epithelial cells, increased resistance to 75 percent human serum bactericidal effect, and streptomycin resistant. These phenotypes apparently are due to a phage-induced superficial change on its own bacterial receptor, which probably is the O-antigen. In order to begin FIZ15 characterization, nitrous acid-induced clear-plaque mutants were obtained. They belonged to three complementation groups and mapping by two factor crosses revealed that they were closely linked. In a search for phage mutants that do not cause lysogenic conversion, two streptomycin-sensitive mutants were obtained by ethyl methane sulphonate mutagenesis of PAO1 lysogenic for FIZ15 (PIZ15 strain). One mutant (con1) showed and adhesion value similar to that of PAO1 and the other (con2) had an adhesion twofold and 1.3 times greater than PAO1 and PIZ15, respectively. con1 did not show increased serum resistance, whereas con2 was as resistant as PIZ15. Phages were isolated from the streptomycin sensitive mutants and used to relisogenize PAO1 to obtain the con1d and con2d lysogens. Adhesion and serum sensitivity of con1d was identical to that of PAO1 but con2d behaves like PIZ15. FIZ15 phage was unable to adsorb to PIZ15, con2 and con2d. On the other hand, FIZ15 phage adsorbs well to con1 and con1d but not to PIZ15. These results suggest that con1 mutation lies on the phage chromosome and con2 on the bacterial one. Finally, adhesion of all lysogens and PAO1 was stimulated 2-3 times by KCl and this effect was suppressed by and oxidative phosphorylation uncoupler.     

A new method of high-dose intraarterial chemotherapy of the pancreas using direct hemoperfusion (DHP) under portal venous isolation (PVI)

Surgical resection for pancreatic cancer is severely limited by the extent of the disease at the time of diagnosis. Chemotherapy has been the treatment of choice for unresectable cases. We developed a new method of intraarterial chemotherapy for pancreatic body and tail cancers using direct hemoperfusion (DHP) under portal venous isolation (PVI). Adriamycin (ADR, 3 mg/kg) was infused into the splenic arteries of mongrel dogs for 5 min after clamping off blood flow to the stomach and the duodenum. In group A (n = 5), this was simply done, and in group B (n = 5) the portal venous blood was isolated by clamping at the porta hepatis and pumped through the DHP circuit to the jugular vein for 20 min from the start of drug infusion. The peak systemic level (microgram/ml) of group B (0.78 +/- 0.03) was significantly reduced by PVI.DHP as compared to that of group A (3.49 +/- 1.15, P < 0.01). The pancreatic tissue levels (microgram/g. tissue) 30 min after drug infusion of group A (61.2 +/- 13.4) were slightly lower than those in group B (88.9 +/- 27.8), although not statistically significant. However, tissue levels of group B in the liver (27.3 +/- 9.2) and heart (1.8 +/- 0.8) were significantly lower than those of group A (liver; 52.3 +/- 18.5, heart; 4.9 +/- 0.6, P < 0.05). In conclusion, PVI.DHP achieved a significant reduction in systemic drug exposure during intraarterial chemotherapy. Therefore, we consider that this system will allow dose escalation of ADR during intraarterial chemotherapy for pancreatic body and tail cancers.     

Repeated hepatic arterial infusion chemotherapy using an implanted port system in patients with unresectable malignant liver neoplasms: significant factors affecting early hepatic arterial occlusion

The purpose of this study was to identify significant factors affecting early hepatic arterial occlusion in patients who received repeated hepatic arterial infusion chemotherapy using an implanted port system. Eighty-five patients with unresectable liver neoplasms who underwent implantation of the port system were studied. Arterial infusion chemotherapy was performed every 1-4 weeks. Arterial occlusion was evaluated by hepatic arteriography performed via the port every 3 months. Twenty variables were analyzed using univariate and multivariate analyses to identify significant factors affecting early hepatic arterial occlusion. Hepatic arterial occlusion was found in 25.9% (22/85) of the patients. Thirteen of them experienced early arterial occlusion within 6 months. The mean survival period was significantly worse in patients who experienced early arterial occlusion than those who did not (16 months vs. 26 months, p<0.05). In the multivariate analysis, the following 3 variables had independent value for early arterial occlusion; i). diameter of the common hepatic artery, ii). gender, and iii). previous systemic chemotherapy. Early arterial occlusion affects therapeutic effects and survival in patients who undergo arterial infusion chemotherapy with an implanted port. Factors demonstrated here are important to classify patients at risk of early hepatic arterial occlusion.     

Combination chemotherapy using intravenous nedaplatin (254-S) and intraarterial cisplatin (CDDP) with transcatheter arterial embolization (TAE) for a patient with uterine cervical cancer: a case report

1. Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are important in the control of body fluid homeostasis, blood pressure (BP) regulation and vascular remodelling. The genes for these peptides may, therefore, be involved in the pathogenesis of genetic hypertension. We have previously described a quantitative trait locus (QTL) for BP in the ANP gene region on rat chromosome 5. We have now assessed the possibility that this QTL lies at the closely linked BNP locus. 2. Intra-arterial BP and heart weight were measured in 12-week-old (n = 207) and 24-week-old (n = 88) F2 rats derived from crosses between Wistar-Kyoto normotensive rats and spontaneously hypertensive rats. We designed polymerase chain reaction primers to amplify a microsatellite in the BNP gene from genomic DNA. Analysis of variance was used for cosegregation analysis. Linkage mapping and localization of QTL was performed using the Mapmaker computer package. 3. A significant correlation was found between genotype for the BNP gene and systolic BP (P < 0.001) in 12-week-old rats. The ANP gene, but not the BNP gene, was associated with systolic BP in 24 week rats. There was no segregation of heart weight with BNP genotype at 12 or 24 weeks of age. The BNP gene mapped approximately 20 cM from the ANP gene in our rat hybrids, away from the previously described QTL. There was evidence for a second BP locus near to but distinct from the BNP gene. 4. These results suggest that BP QTL are present in the natriuretic peptide gene region but that the ANP and BNP genes themselves have no major effect on BP in this cross.     

Prevention of thrombosis in arterial and venous microanastomoses by using topical agents

A replantation model, using the rat's foot severed at the ankle and replanted on an extended vascular pedicle, was used to study the effect of topical vasodilators in preventing microvascular thrombosis. Magnesium sulfate, Xylocaine, and papaverine gave arterial patency rates of 89% or more, compared to 65% for saline alone. There was no appreciable effect on the venous patency rates. The possible mechanisms of action for the various drugs are discussed.     

The correlations between the arterial and venous components of the hemodynamics and cerebrospinal fluid pressure in arterial hypotension

A total of 30 patients with arterial hypotension were examined. Rheoencephalogrammes documented hypotension of the arterial and venous constituents of the brain in one third of the above patients (in those patients with physiological hypotension it was recordable more frequently): in one forth of those cases with primary arterial hypotension presenting with the cerebral crises, moderately severe venous and arterial hypotension was generally seen. In a major proportion of the examinees, a correlation was found between the drop in arterial pressure, vascular tension of the arterial vessels of the brain and an adequate state of the venous tension and liquor pressure. Roentgenography of the skull and ophthalmoscopy do not permit forming an opinion about liquor hypertension since it was not demonstrated on the computerized tomographic scans.     

Differential regulation of hepatic arterial and portal venous vascular resistance by nitric oxide and carbon monoxide in rats

Nitric oxide (NO), a gaseous mediator that accounts for the biological activity of endothelium-derived relaxing factor, has been shown to play an important role in the reduction of basal vascular tone in multiple vascular beds, including the hepatic circulation. On the other hand, recent studies have provided first evidence that endogenously generated carbon monoxide (CO) may exert vasodilatory effects in the hepatic portal vein and within sinusoids. Thus, we defined the differential role of NO and CO in the regulation of vascular resistance in the two inflows to the liver in the normal rat in vivo. Male Sprague-Dawley rats were anesthetized with pentobarbital sodium and surgically instrumented in order to study the change in hepatic arterial (Rha) and portal venous vascular resistance (Rpv) in response to intravenous bolus administration of either the NO-synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) (1 mg/kg; n = 7 animals) or of tin protoporphyrin-IX (SnPP-IX) (50 micromol/kg), a specific inhibitor of the CO-generating enzyme heme oxygenase (n = 8 animals). While L-NAME caused a substantial increase in Rha, Rpv increased only slightly under these conditions. In sharp contrast, SnPP-IX did not affect Rha, but caused a profound increase in Rpv. In conclusion, Rha and Rpv are differentially regulated by NO and CO in the normal rat liver in vivo, i.e., NO serves as a potent vasodilator in the hepatic arterial circulation, but exerts only a minor vasodilatory effect in the portal venous vascular bed. In contrast, while there is no intrinsic CO-mediated vasodilation in the hepatic artery, CO acts to maintain portal venous vascular tone in a relaxed state.     

A case of multiple liver metastasis and local recurrence from rectal cancer effectively treated by arterial infusion chemotherapy using low-dose 5-fluorouracil, cisplatin and LV

The case was a 43-year-old male who complained of anal bleeding and melena. He was diagnosed as rectal cancer with multiple liver metastases. Mile's operation with hepatic arterial cannulation was performed. This patient received 10 courses of arterial infusion chemotherapy using low-dose 5-FU, CDDP and LV. Tumor size of liver lesions significantly decreased. Internal iliac arterial cannulation was also performed for local recurrence. He received 3 courses of arterial infusion chemotherapy using the same regimen. The size of local recurrence also decreased. He had no side effect except mild epigastralgia and dermatitis around the stoma with good QOL.     

Disease-free survival in a patient with squamous cell lung carcinoma following complete response with the combination chemotherapy of cisplatin and etoposide

Disease-free survival is reported in a patient with non-small cell lung carcinoma successfully treated with the combination chemotherapy of cisplatin and etoposide (CDDP-ETOP). An 80-year-old woman was diagnosed as having squamous cell carcinoma of the lung with bone metastasis. Chest X-ray showed a tumor (64 x 68 mm in size) in the S1/4 segment of the right lobe, and CT scan revealed no apparent metastasis of hilar lymphnode. In March 1989, the patient achieved a complete response (CR) after two courses of CDDP-ETOP therapy, followed by ETOP(100mg) every two weeks and daily UFT (400 mg) for 10 months. Subsequently, a single course of CDDP-ETOP was administered as a consolidation therapy. The patient is alive with no evidence of recurrent disease for 3 years and half after achieving CR.     

A comparison of the effects of bradykinin, 5-hydroxytryptamine and histamine on the hepatic arterial and portal venous vascular beds of the dog: histamine H1 and H2-receptor populations

1 The hepatic arterial and hepatic portal venous vascular beds of anaesthetized dogs were separately perfused in different experiments.2 From measurements of perfusion pressures and blood flows in the two series of experiments, hepatic arterial vascular resistance (HAVR) and hepatic portal venous vascular resistance (HPVR) respectively were calculated.3 Bradykinin, 5-hydroxytryptamine (5-HT) and histamine were injected intra-arterially and intra-portally and dose-response curves constructed from these data.4 Bradykinin injected intra-arterially caused dose-dependent hepatic arterial vasodilatation, and with an ED(50) of 2.66 x 10(-13) mol was more potent than any other vasodilator agent yet examined on this vascular bed.5 Bradykinin injected intraportally at doses up to 10 times those which were maximal on the arterial circuit did not alter the calculated HPVR.6 5-HT injected intra-arterially caused weak and variable rises in HAVR, indicating vasoconstriction. The maximum rise in HAVR was much less than that attained with noradrenaline in the same preparations.7 5-HT injected intraportally caused dose-dependent rises in HPVR indicating portal constriction at doses above 15-100 mug: in some experiments small doses of 5-HT resulted in reductions in calculated HPVR.8 Histamine has previously been shown to cause hepatic arterial vasodilatation: by intraportal injection, it caused dose-dependent rises in HPVR.9 In order to examine the receptors responsible for the effects of histamine, dose-response curves were constructed before and after mepyramine and metiamide.10 On the hepatic arterial vascular bed, metiamide did not antagonize the vasodilator effects of intra-arterial histamine, but these effects were antagonized by mepyramine.11 Similarly on the hepatic portal bed, the rises in HPVR due to histamine were antagonized by mepyramine but not by metiamide.12 The effects of histamine on both the hepatic arterial and portal venous vascular beds of the dog are therefore mediated predominantly by histamine H(1)-receptors.     

Randomized comparison of progenitor-cell mobilization using chemotherapy, stem-cell factor, and filgrastim or chemotherapy plus filgrastim alone in patients with ovarian cancer

PURPOSE: This was the first randomized study to investigate the efficacy of peripheral-blood progenitor cell (PBPC) mobilization using stem-cell factor (SCF) in combination with filgrastim (G-CSF) following chemotherapy compared with filgrastim alone following chemotherapy. PATIENTS AND METHODS: Forty-eight patients with ovarian cancer were treated with cyclophosphamide and randomized to receive filgrastim 5 microg/kg alone or filgrastim 5 microg/kg plus SCF. The dose of SCF was cohort-dependent (5, 10, 15, and 20 microg/kg), with 12 patients in each cohort, nine of whom received SCF plus filgrastim and the remaining three patients who received filgrastim alone. On recovery from the WBC nadir, patients underwent a single apheresis. RESULTS: SCF in combination with filgrastim following chemotherapy enhanced the mobilization of progenitor cells compared with that produced by filgrastim alone following chemotherapy. This enhancement was dose-dependent for colony-forming unit-granulocyte-macrophage (CFU-GM), burst-forming unit-erythrocyte (BFU-E), and CD34+ cells in both the peripheral blood and apheresis product. In the apheresis product, threefold to fivefold increases in median CD34+ and progenitor cell yields were obtained in patients treated with SCF 20 microg/kg plus filgrastim compared with yields obtained in patients treated with filgrastim alone. Peripheral blood values of CFU-GM, BFU-E, and CD34+ cells per milliliter remained above defined threshold levels longer with higher doses of SCF. The higher doses of SCF offer a greater window of opportunity in which to perform the apheresis to achieve high yields. CONCLUSION: SCF (15 or 20 microg/kg) in combination with filgrastim following chemotherapy is an effective way of increasing progenitor cell yields compared with filgrastim alone following chemotherapy.     

Relationship between mixed venous saturation and cardiac index, hemoglobin and oxygen consumption in aortic surgery]

Recent evidence from studies of receptor occupancy and regulation in post-mortem brains of patients with neuropsychiatric disorders and in non-human primates is providing new leads in the ongoing quest to understand the pathophysiology and causes of schizophrenia and to develop more effective methods of treatment. These studies suggest that the cerebral cortex may harbour the elusive common sites of action of antipsychotic medications and indicate that chronic treatment with these drugs differentially regulates both families of dopamine receptors in this structure. Upregulation of the cortical dopamine D2 receptors is accompanied by a downregulation of the D1 sites. Balancing the opposing actions of dopamine D1 and D2 receptor regulation may hold the key to optimal drug therapy and to understanding the pathophysiology of schizophrenia. In this article, Michael Lidow, Graham Williams and Patricia Goldman-Rakic review the evidence supporting the cerebral cortex as a pivotal site for these mechanisms underlying the action of antipsychotics.     

Comparative study on quality of life between weekly and monthly chemotherapy with cisplatin, vindesine and mitomycin C in patients with non-small cell lung cancer

A comparative study between weekly and monthly chemotherapy with CDDP, VDS and MMC was performed on the basis of QOL in patients (stage III A/III B/IV) with non-small lung cancer from September 1993 to August 1996. Arm A received CDDP (80 mg/m2) monthly on day 1, VDS (3 mg/m2) on days 1 and 8, MMC (8 mg/m2) on day 1. Arm B received CDDP (40 mg/m2), VDS (3 mg/m2) and MMC (4 mg/m2) on day 1, and followed by CDDP (20 mg/m2), VDS (1.5 mg/m2) and MMC (2 mg/m2) weekly. A diary-type QOL self-rating questionnaire was devised for this study, consisting of 5 scales including 13-item questionnaires and a face scale as the global scale. Chronological QOL data from 20 days during chemotherapy (total dose of CDDP was 80 mg/m2 in both A and B arm) were analyzed using summary measures. In the 78 eligible subjects of the study, 34 were QOL subjects of the 27 eligible subjects, 13 were in arm A and 14 in arm B. 1. The questionnaire was confirmed to be satisfactory with regard to reliability and validity as a questionnaire for the evaluation of this study by factor and correlation analysis. 2. Although each scale changed to the worth level after chemotherapy, there was no significant difference between arm A and B. 3. Summary statistics were assessed using indices of the area under the curve (AUC) and the maximum fluctuations of QOL scores (Dif max) arm B showed a tendency to smaller changes than arm A in AUC and Dif max. There was a significant difference in the physical well-being scale of Dif max. 4. Three items, including the physical well-being in arm B, revealed a better score than those of arm A. Abdominal condition showed a significant difference between the two arms. 5. No obvious difference in anti-cancer effectiveness was found between arm A and B. Arm B showed a longer median survival, less nausea and vomiting, leukopenia and thrombocytopenia compared with arm A. The above results suggested that weekly chemotherapy is as effective, less toxic and shows less influence against patients QOL than the conventional monthly chemotherapy in this study.     

A comparison between the Fick method and indirect calorimetry for determining oxygen consumption in patients with fulminant hepatic failure

OBJECTIVE: To compare the Fick method of determining oxygen consumption (VO2) with a gas exchange method in a group of patients in whom the cardiac output and mixed venous oxygen saturation values were consistently high. DESIGN: A prospective, observational study. SETTING: A ten-bed intensive therapy unit at a university teaching hospital. PATIENTS: Seventeen patients suffering from fulminant hepatic failure who required ventilatory support and invasive hemodynamic monitoring. All patients were sedated and paralyzed throughout the study period. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: VO2 was determined simultaneously by indirect calorimetry and by the Fick method five or six times in each patient over a 5-hr period after resuscitation with fluids and, if clinically indicated, norepinephrine infusion. The agreement between the methods was poor (limits of agreement +19 to -101 mL/min/m2) and the Fick method consistently underestimated gas exchange measurements (mean bias 41 mL/min/m2). The bias varied widely, both between and within individual patients. The reproducibility of the Fick-derived VO2 was worse than the indirect calorimetry measurements, indicating that the dispersion of data attributable to measurement error was greater with the Fick method. CONCLUSIONS: Under clinical conditions, the agreement between Fick calculations and indirect calorimetry measurements of VO2 in hyperdynamic patients with fulminant hepatic failure was extremely poor. The reproducibility of Fick calculations was less than the reproducibility derived by gas exchange measurements because of the large measurement errors that may occur with the Fick method when the cardiac output is large and the arterial-venous oxygen content difference is small. Fick calculations systematically underestimate gas exchange measurements. The Fick method is inaccurate and unreliable when an estimation of VO2 is required in patients with this hemodynamic pattern.     

A comparison between magnetic resonance and other imaging technics in the study of cardiac pathology]

In this report, rat hypothalamic nitric oxide synthase (NOS) activity is shown to be partially inhibited by physiological concentrations of the pineal hormone melatonin. In vitro studies demonstrate that 1 nM melatonin, which approximates the physiological concentration of the hormone at night, significantly inhibited NOS activity. In vivo studies show that administering melatonin or collecting the hypothalamus from animals at night, when endogenous melatonin levels are elevated, results in a significant decrease of NOS activity. Results also show that calmodulin may be involved in this process since its presence in the incubation medium prevents the inhibitory effect of melatonin on NOS activity.     

Long-term survival in a case of multiple liver metastasis from postoperative gastric cancer effectively treated by hepatic intraarterial infusion chemotherapy using MMC and pirarubicin

We experienced a case of multiple liver metastasis from postoperative gastric cancer who showed long-term survival with hepatic arterial infusion chemotherapy (HAI) of MMC and pirarubicin. A catheter was inserted into the hepatic artery, and 4 mg of MMC and 20 mg of pirarubicin were administered through an implantable port catheter every two to four weeks. The total dose of MMC and pirarubicin by the time of this report was 164 mg and 820 mg, respectively. The follow-up CT scan 2 months after the beginning of HAI showed a decrement of the liver tumors. The decrease rate at 12 and 17 months was 50% and 70%, respectively, which was diagnosed as partial response (PR). The therapeutic effect at 49 months is still PR without any sign of tumor enlargement of extra hepatic lesion.     

Efficacy and safety of two methods of administration of granisetron injection for nausea and vomiting induced by chemotherapy for tumors in hematopoietic organs--a randomized crossover comparison between intravenous drip infusion and intravenous bolus injection]

We investigated the efficacy and safety of two methods of granisetron injection to treat nausea and vomiting induced by chemotherapy for tumors in hematopoietic organs. The methods of administration were intravenous drip infusion over 30 minutes, which is the conventional method, and intravenous bolus injection. In this study, 89.5% of patients in both groups (17/19 for each) were free from vomiting. No serious adverse events were observed in either administration group. Abnormal laboratory test values suspected to be related to granisetron were observed in 3 cases in the bolus injection group and in 2 cases in the drip infusion group. but did not pose any clinical problem. These results demonstrated the safety of both methods of administration. In conclusion, it is considered that granisetron intravenous bolus injection can be considered as the method of choice for the prevention of nausea and vomiting induced by chemotherapy for tumors in hematopoietic organs.     

Diagnosing renal artery stenosis: a comparison between conventional renography, captopril renography and ultrasound Doppler in a large consecutive series of patients with arterial hypertension

PROBLEM: Comparison and characterisation of different lymphocyte subsets in the endometrium of endometriosis patients and in healthy women on every day of the menstrual cycle with special emphasis on the CD4:CD8 ratio in the endometrium. METHOD: Immunohistochemical staining of 253 endometrial biopsies of infertile women with and without endometriosis with Anti-Leu4 (CD3), Anti-Leu3a (CD4), Anti-Leu2a (CD8), Anti-Leu7 and Anti-Human-B-cell (CD22) using the immune peroxidase reaction. Identification and counting of positive lymphocyte were performed on cryostat sections. RESULTS: Endometrial lymphocyte subsets show equal quantity and distribution in endometriosis patients and in the control group. After a peak in the early proliferative phase the absolute number of T lymphocytes decreases while a predominance of T-suppressor/cytotoxic T lymphocytes (CD8) compared to T-helper/inducer lymphocytes (CD4) occurs towards the end of the menstrual cycle. CONCLUSION: Endometrium as the potential parent epithelia of endometriosis lesions seems not to be altered in its lymphatic cell content compared to healthy women. Furthermore, endometrium is clearly characterised as part of the mucosa associated lymphatic tissue (MALT). T lymphocytes show specific quantitative changes due to different phases of the menstrual cycle.     

Lupus anticoagulant is the strongest risk factor for both venous and arterial thrombosis in patients with systemic lupus erythematosus. Comparison between different assays for the detection of antiphospholipid antibodies

Antiphospholipid antibodies (aPL) characterize patients at risk for both arterial and venous thrombotic complications. Recently it has been recognized that the presence of plasma proteins such as beta 2-glycoprotein I(beta 2 GPI) and prothrombin are essential for the binding of aPL to phospholipids and that these proteins are probably the real target of aPL. The discovery of these new antigens for aPL introduces the possibility of new assays to detect the presence of aPL. However, it is not known whether these assays improve the identification of patients at risk for thrombosis. In this retrospective study we compared the value of the classic assays LAC (lupus anticoagulant) and ACA (anticardiolipin antibodies) to detect aPL associated with thrombotic complications, with new assays which are based on the binding of aPL to the plasma proteins prothrombin and beta 2GPI. To do so, we have used these assays in a group of 175 SLE patients and correlated the positivity of the different assays with the presence of a history of venous and arterial thrombosis. Control groups were patients without SLE but with LAC and/or ACA and thrombosis (n = 23), patients with thrombosis without LAC and ACA (n = 40) and 42 healthy controls. In the univariate analysis, in which no distinction has been made between high and low antibody levels, we confirmed LAC and ACA to be related to both arterial and venous thrombosis. Anti-beta 2GPI- and anti-prothrombin-antibodies, both IgG and IgM correlate with venous thrombosis and anti-beta 2GPI-IgM with arterial thrombosis. Multivariate analysis showed that LAC is the strongest risk factor (OR 9.77; 95% CI 1.74-31.15) for arterial thrombosis. None of the other factors is a significant additional risk factor. For venous thrombosis LAC is the strongest risk factor (OR 6.55; 95% CI 2.36-18.17), but ACA-IgM above 20 MPL units also appeared to be a significant (p = 0.0159) risk factor (OR 3.90; 95% CI 1.29-11.80). Furthermore, the presence of anti-beta 2GPI- and/or anti-prothrombin-antibodies in LAC positive patients (n = 60) does not increase the risk for thrombosis. The results showed that (i) the LAC assay correlates best with a history of both arterial and venous thrombosis and (ii) neither the anti-beta 2GPI ELISA nor the anti-prothrombin ELISA gives additional information for a thrombotic risk in SLE patients.