Junzo Nojima

Anti-prothrombin antibodies combined with lupus anti-coagulant activity is an essential risk factor for venous thromboembolism in patients with systemic lupus erythematosus.

Anti‐prothrombin antibodies (anti‐prothrombin) and anti‐β2‐glycoprotein I antibodies (anti‐β2‐GP I) are the most common and characterized anti‐phospholipid antibodies (aPL) detected using specific enzyme‐linked immunosorbent assay (ELISA) systems. Recently, lupus anti‐coagulant (LA) activity detected by a phospholipid‐dependent coagulation assay was reported to be associated with anti‐prothrombin and/or anti–β2‐GP I. Here we show that the co‐existence of IgG anti‐prothrombin and LA activity might be an essential risk factor for venous thromboembolism (VTE) in patients with systemic lupus erythematosus (SLE). We examined not only the levels of antibodies to prothrombin and anti‐β2‐GP I (both IgG and IgM isotypes) using an ELISA system, but also LA activity detected using both diluted Russells viper venom time (dRVVT) and STACLOT LA test in 124 patients with SLE. The SLE patients were divided into four groups according to the results of ELISA and LA assay results for each aPL: group A, ELISA+ and LA+ group B, ELISA+ and LA−; group C, ELISA− and LA+ group D, ELISA− and LA−. Regarding IgG anti‐prothrombin, the prevalence of VTE was significantly higher in group A (16/35 cases, 45·7%, P < 0·001, Fishers exact probability test) than in the other groups (B, 2/30, 6·7%; C, 1/22, 4·5%; D, 1/37, 2·7%). With respect to IgM anti‐prothrombin and IgG or IgM anti‐β2‐GP I, the prevalence of VTE was higher in both groups A and C than in group D, but no statistical difference in prevalence was found between groups A and C. Multivariate logistic regression analysis of risk factors for VTE confirmed that the co‐existence of IgG anti‐prothrombin and LA activity was the only significant risk factor for VTE (odds ratio, 19·13; 95% confidence intervals, 4·74–77·18).

Strong correlation between the prevalence of cerebral infarction and the presence of anti-cardiolipin/ β2-glycoprotein I and anti-phosphatidylserine/prothrombin antibodies Co-existence of these antibodies enhances ADP-induced platelet activation

Cerebral infarction is the most common arterial thromboembolic complication in the anti-phospholipid antibodies (aPL) syndrome. In an effort to clarify the roles of aPL in the pathogenesis of cerebral infarction in patients with SLE, we examined the levels of anti-cardiolipin/2-glycoprotein I antibodies (anti-CL/beta2-GPI) and anti-phosphatidylserine/prothrombin anti-bodies (anti-PS/PT) in addition to lupus anticoagulant (LA) activity in 126 patients with SLE (35 with cerebral infarction and 91 without thrombosis). Both anti-CL/beta2-GPI and anti-PS/PT strongly correlated with the presence of LA activity. The prevalence of cerebral infarction was obviously higher in the patients who had both anti-CL/beta2-GPI and anti-PS/PT (76.5% [26/34 cases], p<0.0001) than in the other patients having anti-CL/beta2-GPI or anti-PS/PT alone or neither of them (9.8% [9/92 cases]). Furthermore, we studied the in vitro effects of anti-CL/beta2-GPI and/or anti-PS/PT on the enhancement of platelet activation induced by stimulation with a low concentration of adenosine diphosphate (ADP). The purified IgG containing both anti-CL/beta2-GPI and anti-PS/PT caused significant enhancement of platelet activation caused by ADP. However, the purified IgG containing either anti-CL/beta2-GPI or anti-PS/PT had no enhancing effects on it. Furthermore, platelet activation was generated by the mixture of anti-CL/beta2-GPI-IgG and anti-PS/PT-IgG prepared from individual patients, but not by each fraction alone. These results indicate that anti-CL/beta2-GPI and anti-PS/PT may cooperate to promote platelet activation, which may contribute to the risk of cerebral infarction in patients with SLE.

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.

Acquired activated protein C resistance is associated with the co-existence of anti-prothrombin antibodies and lupus anticoagulant activity in patients with systemic lupus erythematosus.

Summary. Venous thromboembolism (VTE) is one of the common manifestations in the anti‐phospholipid (aPL) syndrome. We examined the levels of IgG antibodies (Abs) to β2‐glycoprotein I (β2‐GP I) and prothrombin, lupus anticoagulant (LA) activity, activated protein C resistance (APC‐R), and factor V Leiden in 96 patients with systemic lupus erythematosus (SLE); 19 with VTE and 77 without VTE. Acquired APC‐R, which was not found in any patient with the factor V Leiden mutation, was present in 33 (34·4%) out of the 96 patients with SLE. The presence of acquired APC‐R was a strong risk factor for VTE. The SLE patients were divided into four groups according to the results of enzyme‐linked immunosorbent assay (ELISA) and LA activity for each aPL Abs: ELISA+, LA+; ELISA+, LA–; ELISA–, LA+; and ELISA–, LA–. A significant association was observed between APC‐R and the co‐existence of anti‐β2‐GP I Abs and LA activity or of anti‐prothrombin Abs and LA activity. There was no association between APC‐R and the presence of anti‐β2‐GP I Abs, anti‐prothrombin Abs, or LA activity alone. However, when multivariate logistical regression analysis was performed, it was clear that only the co‐existence of anti‐prothrombin and LA activity was a significant risk factor for APC‐R. These findings indicate that the co‐existence of anti‐prothrombin Abs and LA activity may be an important factor in the pathogenesis of acquired APC‐R in patients with SLE.

Phenotypical heterogeneity of CD4 + CD8 + double-positive chronic T lymphoid leukemia

Chronic T lymphoid leukemias are defined as leukemias of post-thymic T cells. The CD4+CD8+ double-positive (DP) phenotype is seen in a few cases. Since DP generally occurs in thymic T cells, whether the DP T leukemia cells represent thymic or peripheral T cells has been a matter of controversy. To address this issue, we studied phenotypical features in eight cases of DP T cell leukemia. Thymic DP T cells and peripheral CD8+ T cells have CD8 of αβ subunit, while CD8αα is induced in CD4+ T cells on activation with IL-4. We found that two patients with DP T large granular lymphocyte leukemia (LGLL) showed dim expression of CD8αα, identical to the phenotype on IL-4-activated DP-T cells. The leukemic cells of these patients expressed IL-4 mRNA and produced high levels of IL-4. These findings suggest that they may be derived from peripheral CD4+ T cells. Three patients with adult T cell leukemia/lymphoma (ATLL) showed CD8αα, suggestive of an activated peripheral T cell origin. One case expressed CD8αα dim and IL-4 mRNA, while the other two cases expressed no IL-4 mRNA and showed CD8αα bright phenotype, features not found in normal T cell populations. Three patients with T-prolymphocytic leukemia (T-PLL) expressed CD8αα. The DP phenotype is relatively common in T-PLL, and CD4+CD8αβ+ is characteristic of thymic T cells. The DP T-PLL cells did not express TdT,CD1 or recombination activating gene-1 (RAG-1), which is down-regulated at the late stage of thymic T cell development. On the basis of these findings, we propose a late thymic origin for DP T-PLL. The phenotype of DP T cells differed for each entity and appeared to correlate with minor normal DP T cell population.

Arteriosclerosis obliterans associated with anti-cardiolipin antibody / β2-glycoprotein I antibodies as a strong risk factor for ischaemic heart disease in patients with systemic lupus erythematosus

OBJECTIVE The main objective of this study was to clarify the role of aPLs in the pathogenesis of arteriosclerosis obliterans (ASO), ischaemic heart disease (IHD) and cerebral vascular disorder (CVD) in patients with SLE. METHODS We evaluated 155 patients with SLE by using objective tests for diagnosing ASO, IHD and CVD and laboratory tests including ELISA for aCL/beta2-glycoprotein I antibodies (aCL/beta2-GPI) and anti-phosphatidylserine/prothrombin antibodies (anti-PS/PT). RESULTS Twenty-five (16.1%) of the 155 SLE patients were diagnosed with ASO. Both aCL/beta2-GPI and anti-PS/PT levels were significantly higher in SLE patients with ASO (mean +/- S.E., 104.3 +/- 38.8 U/ml for aCL/beta2-GPI, P < 0.01; 72.6 +/- 48.9 U/ml for anti-PS/PT, P < 0.05) than in SLE patients without ASO (22.8 +/- 9.9 U/ml for aCL/beta2-GPI; 18.3 +/- 4.4 U/ml for anti-PS/PT). Multivariate logistic analysis including aCL/beta2-GPI, anti-PS/PT and traditional risk factors (hypercholesterolaemia, hypertension and diabetes mellitus) confirmed that the presence of aCL/beta2-GPI was the most significant risk factor for ASO in SLE patients [odds ratio (OR) 3.45; 95% CI 1.40, 8.56; P < 0.01]. Furthermore, the prevalence of ASO was associated strongly with IHD (OR 11.8; 95% CI 3.45, 40.1; P < 0.0001) but not CVD (OR 1.84; 95% CI 0.65, 5.21; P = 0.25). CONCLUSIONS The presence of aCL/beta2-GPI contributes to the risk of development of ASO, which may represent an important mechanism for the pathogenesis of IHD in patients with SLE.

High prevalence of thrombocytopenia in SLE patients with a high level of anticardiolipin antibodies combined with lupus anticoagulant

The relationship between thrombocytopenia and the level of anticardiolipin antibodies (aCL) and/or the existence of lupus anticoagulant (LA) ware studied in 146 patients with systemic lupus erythematosus (SLE). These patients were divided into six groups: A, those LA positive with a high level of aCL (>10 U/ml) (10 cases); B, those LA positive with a low level of aCL (3–10 U/ml) (15 cases); C, those LA positive but aCL negative (<3 U/ml) (12 cases); D, LA negatives with a high level of aCL (12 cases); E, LA negatives with a low level of aCL (16 cases); and F, aCL and LA double negatives (81 cases). The prevalence of thrombocytopenia (platelet count ≦ 100 × 109/L) was by far the highest in group A (9/10 cases, 90.0%, P < 0.005, Fishers exact probability test) as compared with group B (4/15 cases, 26.7%), group C (4/12 cases, 33.3%), group D (1/12 cases, 8.3%), group E (4/16 cases, 25.5%), and group F (9/81 cases, 11.1%).

A potential biomarker for fatigue: Oxidative stress and anti-oxidative activity

We sought to determine whether oxidative stress and anti-oxidative activity could act as biomarkers that discriminate patients with chronic fatigue syndrome (CFS) from healthy volunteers at acute and sub-acute fatigue and resting conditions. We calculated the oxidative stress index (OSI) from reactive oxygen metabolites-derived compounds (d-ROMs) and the biological antioxidant potential (BAP). We determined changes in d-ROMs, BAP, and OSI in acute and sub-acute fatigue in two healthy groups, and compared their values at rest between patients with CFS (diagnosed by Fukuda 1994 criteria) and another group of healthy controls. Following acute fatigue in healthy controls, d-ROMs and OSI increased, and BAP decreased. Although d-ROMs and OSI were significantly higher after sub-acute fatigue, BAP did not decrease. Resting condition yielded higher d-ROMs, higher OSI, and lower BAP in patients with CFS than in healthy volunteers, but lower d-ROMs and OSI when compared with sub-acute controls. BAP values did not significantly differ between patients with CFS and controls in the sub-acute condition. However, values were significantly higher than in the resting condition for controls. Thus, measured of oxidative stress (d-ROMS) and anti-oxidative activity (BAP) might be useful for discriminating acute, sub-acute, and resting fatigue in healthy people from patients with CFS, or for evaluating fatigue levels in healthy people.

Anti-phospholipid antibodies contribute to arteriosclerosis in patients with systemic lupus erythematosus through induction of tissue factor expression and cytokine production from peripheral blood mononuclear cells

INTRODUCTION In systemic lupus erythematosus (SLE) patients, the prevalence of arteriosclerosis obliterans (ASO) is high despite a lack of common risk factors for ASO. The main objective of this study was to investigate a possible direct role of anti-phospholipid antibodies (aPLs), which are frequently detected in SLE patients, in the pathogenesis of ASO. MATERIALS AND METHODS We examined tissue factor (TF) expression on the monocyte surface by flow cytometric analysis in 89 SLE patients with or without ASO and/or aPLs and studied the in vitro effect of purified IgG fractions from plasma of SLE patients or normal healthy volunteers (aPLs(+) IgG, n=8; aPLs(-) IgG, n=6; Normal IgG, n=6) on the expression of TF and production of TNF-α and IL-1β in healthy peripheral blood mononuclear cells (PBMCs) or isolated monocytes. RESULTS We confirmed that high expression of monocyte TF was strongly associated with the prevalence of ASO and the presence of aPLs. Treatments of PBMCs with aPLs(-) IgG or normal IgG did not significantly increase expression of TF, TNF-α, and IL-1β messenger RNA (mRNA) and the production of TNF-α and IL-1β. However, stimulation of PBMCs with aPLs(+) IgG caused significant increase in expression of TF, TNF-α, and IL-1β mRNA. Moreover, aPLs(+) IgG stimulated PBMCs and significantly enhanced the production of TNF-α and IL-1β. CONCLUSION These results suggest that IgG-aPLs cause persistently high TF expression and inflammatory cytokine production by interacting with peripheral blood monocytes and lymphocytes, which may be an important mechanism in the pathogenesis of ASO peculiar to SLE patients.

Acquired activated protein C resistance is associated with IgG antibodies to protein S in patients with systemic lupus erythematosus

The objective of this study was to clarify the roles of anti-phospholipid antibodies (aPLs) in the pathogenesis of acquired activated protein C resistance (APC-R) in patients with systemic lupus erythematosus (SLE). We examined several aPLs levels (lupus anticoagulant, anti-cardiolipin antibodies, anti-beta2-glycoprotein I antibodies, anti-protein C antibodies, and anti-protein S antibodies), the APC-R test, and the factor V Leiden test in 85 SLE patients. Acquired APC-R, which was not found in any patient with the factor V Leiden mutation, was present in 26 (30.6%) of 85 patients, and confirmed that acquired APC-R was a significant risk factor for thromboembolic complications [odd ratio (OR), 3.36; 95% confidence interval (CI), 1.24-9.11]. Multivariate logistic analysis revealed that both LA and anti-PS strongly associated with the presence of APC-R, and that the correlation between anti-PS and APC-R was much stronger (OR, 46.7; 95%CI, 6.99-311) than that between LA and APC-R (OR, 11.3; 95%CI, 2.26-57.0). Furthermore, the mean value of APC sensitivity ratios was significantly lower in SLE patients with anti-PS (mean +/- SD, 1.68 +/- 0.37, p < 0.0001) than in those without anti-PS (2.23 +/- 0.40). These results suggest that acquired APC-R is most strongly attributable to functional interference of the APC pathway by anti-PS, which contribute to risk of thromboembolic complications.