Persistence on therapy is a major determinant of patient-, physician- and laboratory- reported outcomes in recent-onset rheumatoid arthritis patients.

OBJECTIVES: To evaluate impact of persistence on therapy on sustained major patient-, physician- and laboratory-reported outcomes (PROs, PHYROs and LAROs, respectively) in 112 recent-onset rheumatoid arthritis (RA) patients. METHODS: At each visit a rheumatologist interviewed patients regarding therapy, morning stiffness and fatigue, scored the 28-joint disease activity score and a visual analogue scale (VAS) and determined acute-phase-reactants. The patients completed the Hispanic version of the Rheumatoid Arthritis Disease Activity Index, the Medical Outcome Short Form 36 (SF-36), the Health Assessment Questionnaire (HAQ), a pain-VAS and an overall-disease activity-VAS. Persistence was defined by self-report through directed interview. Sustained major PROs, PHYROs and LAROs were defined according to cut-offs, when maintained for ≥6 months and until last follow-up. Descriptive statistics, Kaplan-Meier curves and Cox models were used. RESULTS: Total person-time of receiving therapy was of 375.5 patient-years. From February 2004 to June 2009, 36 (32.1%) patients were persistent. Baseline PROs/PHYROs/LAROs showed active disease and poor health status in both groups, but persistent patients (PP) had significantly lower HAQ (p=0.03) and overall-disease activity-VAS (p=0.01). More PP reached a sustained major SF-36-physical function-score (p=0.02). Persistence was the greatest independent risk factor for sustained major PROs (but absence of fatigue) and PHYROs, (p≤0.04). Time from baseline to major and sustained PROs (excluded absence of fatigue), PHYROs and C-reactive protein were shorter in PP (p≤0.04). CONCLUSIONS: Persistence was a strong predictor for major and sustained outcomes in early RA. Favourable outcomes appear earlier in persistent than in non-persistent patients.

Antiphospholipid antibodies and the antiphospholipid syndrome in systemic lupus erythematosus. A prospective analysis of 500 consecutive patients.

Five hundred consecutive patients with systemic lupus erythematosus (SLE) were entered into a prospective study of anticardiolipin antibodies (ACLA) in their 3 major immunoglobulin isotypes and followed thereafter with repeated testing for a mean period of nearly 8 months. Manifestations of SLE that were strongly associated with ACLA included venous thrombosis (particularly when recurrent), thrombocytopenia, hemolytic anemia, recurrent fetal loss, and leg ulcers. Other manifestations found to be associated with ACLA were arterial occlusions, transverse myelitis, and pulmonary hypertension. Conversely, we found no relationship between ACLA and migraine, convulsions, transient ischemic attacks, psychoses, or avascular necrosis of bone. No relationship was found between the presence of ACLA and that of anti-DNA antibodies studied in the same serum sample. Association with ACLA grew stronger and titers became higher in patients with several of the associated manifestations. Statistical analyses revealed the existence of a syndrome, the antiphospholipid syndrome, comprising 2 or more manifestations in conjunction with ACLA titers 5 standard deviations above the mean of normal control subjects, particularly if ACLA had been positive on at least 2 occasions. We propose that such criteria could be applied to the definition of the antiphospholipid syndrome. The presence and the titers of these antibodies related to disease activity and titer decreased by treatment, particularly when they were of the IgM isotype. Patients in whom a thrombotic episode occurred during the course of the study were observed to have a coincident decrease in ACLA titers, a finding that might indicate consumption of the antibody during the event. Treatment and the resulting inactivation of disease appear to have independent effects on ACLA titers. Physicians should therefore be cautious in prescribing high doses of corticosteroids or immunosuppressants to patients with SLE solely because they have high titers of ACLA.

Tween 20 detaches cardiolipin from ELISA plates and makes anticardiolipin antibodies undetectable regardless of the presence of beta 2-glycoprotein-I.

We investigated the effects of polyoxyethylene sorbitan monolaurate (Tween 20) in the detection of IgG anticardiolipin antibodies (aCL) by the CL-beta 2-glycoprotein-I and the standard aCL solid-phase immunoassays. We found that Tween 20 disengages cardiolipin from a variety of microtiter wells rendering aCL undetectable by both methods. Our results agree with a previous report but are discordant with others. We offer rationale that may explain some of the discrepancies. Based in our findings, we do not recommend the use of Tween 20 for the detection of aCL.

The antiphospholipid/cofactor syndromes: a primary variant with antibodies to beta 2-glycoprotein-I but no antibodies detectable in standard antiphospholipid assays.

BACKGROUND: Most systemic lupus erythematosus (SLE) patients with two or more clinical manifestations of the antiphospholipid syndrome (APS) and negative antiphospholipid antibodies (aPL) have antibodies to beta 2-glycoprotein-I (a beta 2 GP-I). Herein we describe a similar set of circumstances, but in patients without evidence of SLE. PATIENTS AND METHODS: We studied 6 patients with recurrent venous and/or arterial thromboses without aPL as detected by routine assays nor clinical or serological evidence of other autoimmune disease. Immunoglobin (Ig) G and IgM antibodies to bovine and human phospholipid-free beta 2 GP-I were studied by Western blot test and by enzyme-linked immunosorbent assay (ELISA) utilizing radiated and nonirradiated plates. We also tested antibodies to cardiolipin, phosphatidylserine, and phosphatidylethanolamine by ELISA. As controls, 54 normal sera were studied. RESULTS: All 6 patients had recurrent arterial and/or venous thromboses. Three also had thrombocytopenia, 1 had livedo reticularis, and 2 had valvular heart disease. None of the patients had aPL, but all had serum IgG reactivity against human and bovine beta 2 GP-I (P < 0.001 versus controls for both). Titers of anti-bovine beta 2 GP-I were higher when studied in irradiated plates but were also higher than normal in nonirradiated plates (P < 0.001). These antibodies did not recognize human or bovine beta 2 GP-I bound to cardiolipin in solid phase. We confirmed by Western blot that these autoantibodies recognize human beta 2 GP-I. We found no IgM a beta 2 GP-I. CONCLUSIONS: We describe a primary condition akin to the antiphospholipid syndrome with negative aPL, but with serum IgG antibodies to human and bovine beta 2 GP-I. These antibodies recognize beta 2 GP-I epitopes that are not accessible when beta 2 GP-I is bound to cardiolipin.

Decrease in serum antiphospholipid antibody levels upon development of nephrotic syndrome in patients with systemic lupus erythematosus: relationship to urinary loss of IgG and other factors.

PURPOSE: Having observed a decrease in antiphospholipid antibodies (aPL) upon the development of nephrotic syndrome, as well as a negative association between nephrotic syndrome and secondary antiphospholipid syndrome, in patients with systemic lupus erythematosus (SLE), we sought to determine if this could be due to urinary loss of aPL and/or other factors. SUBJECTS AND METHODS: IgG and IgM aPL as well as other autoantibodies were studied by enzyme-linked immunosorbent assay with cardiolipin as antigen in serum and urine from six patients with SLE who had elevated serum aPL levels and developed nephrotic syndrome (cases). For controls, we studied: (1) three SLE patients with nephrotic syndrome but low aPL levels; (2) three patients with non-SLE nephrotic syndrome; (3) three SLE patients with high-titer aPL but no proteinuria; and (4) 10 healthy volunteers. RESULTS: We found urinary IgG, but no IgM, aPL in all cases and in one control from Group 2. Serum IgG aPL had gradually decreased after the development of nephrotic syndrome and had become normal. IgM aPL had also decreased in the four patients who had elevated levels, having reached normal levels at the time of the study in two. There was an apparent correlation between serum and urine IgG aPL levels but not between urinary IgG aPL and total proteinuria. By Farr's method, we found no urinary anti-DNA despite high serum titers in three cases. The two cases and one of the controls in Group 1 who had serum antibodies to extractable antigens also had these antibodies in the urine. CONCLUSION: Urinary loss of IgG aPL during nephrotic syndrome does not completely explain the reduction in serum aPL, since IgM also decreases. There could also be decreased synthesis and/or increased catabolism of immunoglobulins.

Serum anti-beta2-glycoprotein-I and anticardiolipin antibodies during thrombosis in systemic lupus erythematosus patients.

PURPOSE: Antibodies to beta2-glycoprotein-I are more strongly associated with clinical antiphospholipid syndrome than are anticardiolipin antibodies. We previously found a decrease in anticardiolipin antibodies at the time of thrombosis in 6 patients with systemic lupus erythematosus (SLE). We therefore sought to determine the prevalence and levels of antibodies to beta2-glycoprotein-I and to cardiolipin before, during, and after thrombosis in patients with SLE, and to compare them with patients who did not have thrombosis. METHODS: We studied 24 patients with SLE who had at least one episode of thrombosis and 102 patients with SLE without thrombosis. Serum anticardiolipin antibodies were measured by conventional enzyme-linked immunosorbent assay (ELISA) using newborn calf serum as the blocking agent. Serum anti-beta2-glycoprotein-I antibodies were measured by ELISA on nonirradiated plates, using purified human beta2-glycoprotein-I without phospholipid. RESULTS: All patients with thrombosis had anti-beta2-glycoprotein-I antibodies, compared with only 17% of controls (P <0.0001). We observed a significant decrease in serum anti-beta2-glycoprotein-I levels at the time of thrombosis, as compared with previous and subsequent samples. The prevalence and levels of IgG and IgM anticardiolipin antibodies were similar in patients with and without thrombosis. A decrease in IgG or IgM anticardiolipin titers occurred during thrombosis in 6 patients. Anticoagulant, corticosteroid, and immunosuppressive treatments did not appear to affect anti-beta2-glycoprotein-I levels at the time of thrombosis. CONCLUSION: Anti-beta2-glycoprotein-I antibodies are strongly associated with thrombosis in patients with SLE. The decrease of anti-beta2-glycoprotein-I levels at the time of thrombosis may indicate a pathogenic role. This antibody may also be a marker of predisposition for thrombosis in these patients.

Preliminary classification criteria for the antiphospholipid syndrome within systemic lupus erythematosus.

Ten percent of 667 consecutive systemic lupus erythematosus (SLE) patients were considered to have definite antiphospholipid syndrome (aPLS) because they had two or more antiphospholipid (aPL)-related clinical manifestations and aPL titers more than 5 SD above the mean of normal controls. Another 14% had either one aPL-related manifestation but high titers of the antibody or two manifestations and low aPL titers (probable aPLS). One fourth of the patients had no manifestations but high titers, one manifestation and low titers, or two or more manifestations and negative aPL titers ("doubtful" aPLS); the other half were considered negative for aPLS. In patients with high-titer aPL, the number of aPL-related manifestations was influenced by disease duration and number of pregnancies, indicating potential mobility of category with time or with risk of recurrent pregnancy loss. Patients with two or more manifestations but variable aPL levels differed in immunosuppressive treatment and in the number of times they had been tested, indicating potential mobility of category with lower treatment and/or further aPL testing. Patients with definite aPLS had increased risk of cutaneous vasculitis, peripheral neuropathy, seizures, psychosis, transient ischemic attacks, and leukopenia. In 11 of 52 SLE patients with definite aPLS the initial manifestation was related to aPL, and in 16 it concurred with an unrelated one. Only two patients fulfilled criteria for aPLS before having other evidence of SLE. The authors conclude that aPLS occurring within SLE is part of the disease rather than an associated condition and propose the use of definite and probable classification categories. These criteria, with appropriate follow-up and clinical and serological exclusion clauses for potential primary conditions, could also be applied to primary aPLS.

Antiphospholipid antibodies in patients with idiopathic autoimmune haemolytic anemia.

Isolated cases of anti-phospholipid antibody (aPL)-associated idiopathic autoimmune haemolytic anemia (IAHA) have been recently described. To assess the significances of this association, we studied by ELISA the presence of aPL in sera from 18 patients with IAHA and 14 patients with non-autoimmune haemolysis (NON-AH). Four IAHA cases and none of the NON-AH controls showed IgM anticardiolipin antibodies (aCL) that crossreacted extensively with zwitterionic as well as with other anionic phospholipids. IgG aCL were detected in 6 patients with IAHA and in 1 patient with NON-AH; there was little cross-reactivity with other phospholipids. Our results suggest that antiphospholipid antibodies are present in a substantial number of patients with IAHA. This humoral response does not seem to be secondary to the haemolysis proper. The potential pathogenic significance of this finding is discussed.

Identification of four subpopulations of IgG anticardiolipin antibodies in patients with primary antiphospholipid syndrome on the basis of their requirement for beta 2-glycoprotein-I and their unmasking by heat.

Heat-treatment of normal human serum (NHS) results in positive seroconversion of IgG anticardiolipin antibodies (aCL) that do not depend on beta 2-glycoprotein-I (beta 2GP-I) for their detection in vitro as do some IgG aCL from patients with primary antiphospholipid syndrome (PAPS). Other IgC aCL from PAPS depend on beta 2GP-I for phospholipid binding. Here, we studied heat-unmasked aCL from 22 PAPS sera and from eight normal individuals. IgG aCL were detected in standard (using new born calf serum [NBCS] that contains beta 2GP-I as blocking agent and to dilute samples) and in a modified ELISA (using beta 2GP-I-free-bovine serum albumin instead of NBCS). Overt and heat-unmasked IgC aCL were purified from CL micelles alone or mixed with purified beta 2GP-I. NHS had no overt IgG aCL. In contrast, aCL titers increased almost ten-fold after heat-inactivation of NHS, a result which was equally detectable in both assay conditions. As expected, PAPS patients had one population of overt beta 2GP-I-dependent IgG aCL. After heat-treatment of all PAPS sera, we detected IgG aCL in both standard and modified aCL ELISA with an approximately three-fold increase in IgG aCL titers when tested in the standard assay. Two PAPS patients also had a second population of beta 2GP-I-independent overt IgG aCL. Purified IgG from these PAPS sera retained both reactivities.(ABSTRACT TRUNCATED AT 250 WORDS)

Some patients with primary antiphospholipid syndrome have increased circulating CD5+ B cells that correlate with levels of IgM antiphospholipid antibodies.

Antibodies against bromelain-treated erythrocytes occurring in normal mice are germline gene-encoded IgM natural autoantibodies that are secreted by CD5+ B cells, and react primarily with phosphatidylcholine (PTC), but may crossreact with cardiolipin (aCL). Some of the IgM antiphospholipid antibodies (aPL) present in patients with the recently described primary antiphospholipid syndrome (PAPS) also react with PTC and could thus be natural autoantibodies akin to those found in mice. Patients with PAPS (n = 20) were found to have increased total B cells, as well as CD5 + B cells, in their peripheral blood, but normal total lymphocytes, as well as CD4 and CD8 T lymphocytes, compared to normal controls. The 6 PAPS patients with increased CD5+ B cells were found to have increased levels of IgM aPL, including aPTC. In them we also found a correlation between the number of CD5+ B cells and the levels of IgM aCL. Our findings suggest that within the family of aPLs present in patients with PAPS there may be some that could be IgM natural autoantibodies secreted by CD5+ B cells.

[Prevalence of antinuclear antibodies in primary biliary cirrhosis, with negative antimitochondrial antibodies]. / Prevalencia de anticuerpos antinucleares en cirrosis biliar primaria, con anticuerpos antimitocondriales negativos.

Recently it has been described in the literature a subpopulation of PBC patients with negative AMA that might represent patients with ANA positive autoimmune cholangitis. We review 25 cases of PBC (23 females) with AMA negative. Our aim was to determine the frequency of ANA(+) in this group. We studied serum transaminases, total bilirubin, AMA and ANA by indirect immunofluorescence considering positive dilutions of 1:40. All patients had elevated alkaline phosphatase (641 +/- 389 U/l). Total bilirubin was below 2.5 in 59%. Thirteen patients had esophageal varices. The histologic stage was I-II in eleven and III-IV in 14 cases. Fourteen patients (56%) has ANA(+) (dilution 1:40), 44% had lower dilutions. We confirm the presence of a subpopulation of PBC AMA negative, ANA positive patients and the observations of different and diverse immune alterations in PBC patients.

Antinuclear antibodies: a marker associated with steroid dependence in patients with ulcerative colitis.

BACKGROUND: The autoimmune phenomena and the autoantibody profile have acquired great importance in ulcerative colitis (UC). Few studies have explored antinuclear antibodies (ANAs) prevalence, but not its association with steroid dependence. We hypothesized that ANAs could be a factor associated to steroid dependence. METHODS: Ninety-seven consecutive patients with UC were included. ANA titers and staining patterns were determined by indirect immunofluorescence. Gender, age, follow-up time, C-reactive protein (CRP), disease extent, Mayo Score Activity Index, extraintestinal manifestations, and steroid dependence were analyzed in univariate and multivariate models. RESULTS: Ninety-seven patients were included and 49 (50.5%) were females; mean age was 41.7 +/- 22.2 years. Positivity for ANAs was encountered in 52 (53.5%) patients, and none for anti-dsDNA. The prevalence of ANAs was higher in steroid-dependent than in nonsteroid-dependent patients (77.8% versus 48.1%, P = 0.020; odds ratio [OR] = 3.8, 95% confidence interval [CI] 1.1-12.5), and in those with uveitis (100% versus 51.1%; P = 0.040) or pyoderma gangrenosum (100% versus 51.6%; P = 0.078). No association was observed with gender, age, CRP, disease extent, and Mayo Score Activity Index. The multiple regression analysis model showed an association between steroid dependence and ANAs (P = 0.033, OR = 3.9, 95% CI 1.4-14.9). CONCLUSIONS: ANAs are associated with steroid dependence in UC patients. Further studies are required to determine the role of ANAs as serological markers for prediction of steroid dependence in order to perform early therapeutic interventions with biological agents.

Anti-citrullinated peptide antibodies in lupus patients with or without deforming arthropathy.

The objective was to study the association of antibodies against cyclic citrullinated peptides (anti-CCP) in patients with lupus articular damage. We studied 34 systemic lupus erythematosus patients (30 women) with (n = 14) or without (n = 20) deforming arthropathy. Anti-DNA and arthritis were mandatory inclusion criteria for both groups. As controls, 34 patients with rheumatoid arthritis and nine patients with rheumatoid arthritis and systemic lupus erythematosus (rhupus) were included. Anti-CCP and rheumatoid factor were determined by ELISA and nephelometry respectively. All patients had recent x-ray films of the hands that were evaluated according to Sharp's method. Systemic lupus erythematosus patients had a mean 6.50 +/- 0.86 (SD, range 5-8) American College of Rheumatology (ACR) criteria, rheumatoid arthritis patients met 5.38 +/- 0.60 (range 4-6) ACR criteria for rheumatoid arthritis and rhupus patients had 5.78 +/- 0.44 (range 5-6) criteria for rheumatoid arthritis and 5.11 +/- 0.78 (range 4-6) for systemic lupus erythematosus. Systemic lupus erythematosus patients, with or without deforming arthropathy, had normal serum anti-CCP concentrations. In contrast, rheumatoid arthritis and rhupus patients had 30- and 23-fold higher than normal amounts of anti-CCP (p < 0.001, both comparisons). Rheumatoid arthritis (97%) and rhupus (100%) patients were more frequently positive for anti-CCP than SLE patients with (7%) or without (5%) deforming arthropathy (p < 0.001, both comparisons). Patients with lupus deforming arthropathy were more frequently positive for rheumatoid factor (65%) than patients with non-deforming arthritis (15%) (p = 0.005). Patients with lupus deforming arthropathy had similar frequency of erosions and mean Sharp's score than rhupus patients. Anti-CCP antibodies do not associate with lupus arthropathy, whether deforming, non-deforming or erosive.

Diminished expression of complement regulatory proteins (CD55 and CD59) in lymphocytes from systemic lupus erythematosus patients with lymphopenia.

CD55 and CD59 are glycophosphatidylinositol-anchored proteins with complement inhibitory properties. Lymphopenia in systemic lupus erythematosus (SLE) has been associated with autoantibodies targeting nuclear antigens. The aim of this study was to evaluate the surface density of CD55 and CD59 in T and B lymphocytes from patients with SLE and lymphopenia and its possible correlation with the presence of common SLE autoantibodies. Flow cytometric analyses were performed on CD55 and CD59 stained CD3+ and CD19+ cells from 40 SLE patients, 30 with lymphopenia and 10 without it, and 25 healthy controls. Autoantibodies were detected in the sera by enzyme linked immunosorbent assay. The mean fluorescence intensity of CD55 and CD59 in T and B cells was significantly diminished in SLE patients with lymphopenia when compared with healthy subjects. Interestingly, the opposite was found in T and B cells from non-lymphopenic SLE patients. Although there was no correlation between CD55 and CD59 surface density and the presence of any specificity of the autoantibodies tested, higher titres of anti-dsDNA, anti-SM and anti-ribosomal p antibodies were significantly associated with lymphopenia. The deficiency of CD55 and CD59 expression may play a role in the pathophysiology of lymphopenia, most likely by increasing the susceptibility of cells to complement mediated cytolysis.

Heterogeneity of antibodies to beta2-glycoprotein 1 from patients with systemic lupus erythematosus.

We studied antibodies to beta2-glycoprotein 1 (anti-beta2GP1) from 72 patients with systemic lupus erythematosus (SLE) with or without antiphospholipid syndrome (APS) or with or without anticardiolipin antibodies (aCL). Fifteen patients had APS and positive antiphospholipid antibodies [clinical APS(+)/aPL(+)], 12 patients had APS, negative serum IgG and IgM aCL, antiphosphatidylethanolamine, anti-phosphatidylserine and no lupus anticoagulant [clinical APS(+)/ aPL(-)]. A third group included 16 patients without APS but high aCL levels [clinical APS(-)/ aPL(+)]. In a fourth group we studied 29 patients without clinical manifestations of APS or aCL [clinical APS(-)/aPL(-)]. One hundred anticardiolipin and VDRL-negative normal sera were studied as controls. IgG antibodies to cardiolipin proper in a bovine beta2GP-free system, to human beta2GP1 immobilized on cardiolipin or to human beta2GP1 alone were detected in all sera by ELISA using irradiated and nonirradiated plates from two manufacturers. Sera from APS(+)/aPL(+) patients showed IgG binding to CL, CL + beta2GP1 and beta2GP1 in irradiated and nonirradiated plates. APS(+)/ aPL(-) sera had more significant IgG binding to beta2GP1 than normal controls when studied in both irradiated or nonirradiated plates (P = 0.001). This binding was inhibited by solid-phase cardiolipin in a dose-dependent manner. Sera from the APS(-)/aPL(+) subgroup had comparable IgG activity in both the CL and CL + beta2GP1 assays, while no anti-beta2GP1 activity was detected in these sera. Sera from the clinical APS(-)/aPL(-) patients were negative in the three ELISA systems. Antibodies to human beta2GP1 from SLE patients recognize various epitopes. Those from APS(+)/ aPL(+) patients appear to react with an epitope boosted by cardiolipin in addition to another one present in the native protein. In contrast, anti-beta2GP1 from patients with APS(+)/aPL(-) are blocked by cardiolipin, suggesting that their epitope is the phospholipid-binding site.

Hemolytic anemia related to an IgM autoantibody to phosphatidylcholine that binds in vitro to stored and to bromelain-treated human erythrocytes.

Both normal and autoimmune mice have IgM natural autoantibodies to bromelain-treated erythrocytes in which phosphatidylcholine (PTC) becomes exposed. At one stage this antibody may participate in the genesis of autoimmune hemolytic anemia in the NZB mouse. We have recently studied a patient with hemolytic anemia who had persistently high serum titers of IgM anticardiolipin antibodies (aCL) that were also demonstrated in a hemolysate of his erythrocytes obtained at the time of the anemia. We affinity-purified the antibody and sought its binding to normal human bromelain-treated erythrocytes (BrE) because of the IgM isotype of the antibody, since cardiolipin is not a constituent of the erythrocyte wall, and because the anionic phospholipids, with which aCL are known to cross-react, are not located at the outer leaflet of the erythrocyte membrane. We found binding of the antibody to HBrE in their hemolysates and by flow cytometry. We also demonstrated that the aCL cross-reacted extensively with PTC, as well as with other anionic or zwitterionic phospholipids. The purified IgM antibody lysed BrE in the presence of complement and also bound to in vitro-aged erythrocytes. Because this patient had no other evidence of systemic lupus erythematosus or any other autoimmune condition, his disease may represent a variant of the recently described primary antiphospholipid syndrome.

Antibodies to phospholipid-free beta 2-glycoprotein-I in patients with primary antiphospholipid syndrome.

OBJECTIVE: To investigate serum anti-beta 2-glycoprotein-I antibodies (a beta 2 GP-I) in patients with primary antiphospholipid syndrome (APS). METHODS: We studied a beta 2 GP-I by Western blot, dot blot, and ELISA in the sera of 15 patients with primary APS with high titers of immunoglobulin G (IgG) and/or immunoglobulin M (IgM) anticardiolipin antibodies (aCL) at the time of study and compared findings with the sera of 13 aCL positive patients with syphilis and 76 healthy controls. Sera were also inhibited with cardiolipin micelles and tested for aCL and a beta 2 GP-I activities. RESULTS: Twelve patients with primary APS but no syphilis patient or control subject had IgG to phospholipid-free beta 2 GP-I (p < 0.0001) for both comparisons). The aCL activity was inhibited with cardiolipin micelles but this treatment had less effect on a beta 2 GP-I activity. We found no IgM a beta 2 GP-I in any serum. Nine of 14 patients had had lupus anticoagulant activity; 8 of these had a beta 2 GP-I. CONCLUSION: Patients with primary APS frequently have IgG a beta 2 GP-I that appear to differ from aCL. If aCL present in patients with primary APS actually react with a phospholipid induced neoepitope on beta 2 GP-I, as recently proposed, patients with primary APS have autoantibodies against 2 epitopes on beta 2 GP-I. Lack of a beta 2 GP-I in patients with syphilis might also contribute to protection from developing the APS.

Clinical manifestations of the antiphospholipid syndrome in patients with systemic lupus erythematosus associate more strongly with anti-beta 2-glycoprotein-I than with antiphospholipid antibodies.

OBJECTIVE: To investigate antibodies to phospholipid-free beta 2-glycoprotein-I (a beta 2 GP-I) in the serum of patients with systemic lupus erythematosus (SLE). METHODS: We studied alpha beta 2 GP-I by Western blot, dot blot, and ELISA in 94 patients with SLE. Twenty-one had antiphospholipid syndrome (APS) by clinical and serological criteria, 33 had neither of these features, 18 had the clinical criteria for APS but no serum antiphospholipid antibodies (aPL). and 22 had positive aPL but no related clinical manifestations. As controls, we also studied 76 normal sera. Sera were also inhibited with cardiolipin micelles and tested for anticardiolipin antibodies (aCL) or a beta GP-I activities. RESULTS: Thirty-five of 39 patients with SLE with clinical manifestations of APS has serum a beta 2 GP-I, while only 2 of 55 patients with SLE without such clinical manifestations had them (p = 0.000000001). Sixteen patients with SLE with clinical APS but aPL negative were a beta GP-I positive. All 35 patients with SLE who were a beta 2 GP-I positive had vascular manifestations, but these antibodies were present in only 4 of 55 patients with SLE without vascular manifestations (p = 0.00000001). No patient having either aPL or a beta 2 GP-I had clinical manifestations of APS, whereas all 19 patients positive for both antibodies had clinical APS. The a beta 2 GP-I positive, aPL negative patients with SLE had clinical APS more frequently (16/18) than did a beta GP-I negative, aPL positive patients with SLE (2/24) (p = 0.000000001). The association of clinical manifestations of APS with a beta 2 GP-I was stronger than with aPL. Inhibition studies also indicate that aPL and a beta 2 GP-I are 2 different antigen/antibody systems. CONCLUSIONS: Our findings indicate that the so called APS associates strongly with antibodies recognizing phospholipid-free beta 2 GP-I. There are patients' sera that also recognize cardiolipin and/or its cofactor beta 2 GP-I, the latter perhaps by reacting with a neoepitope on this protein that appears after its interaction with cardiolipin. These would be the previously considered (beta 2 GP-I dependent) aCL.