Confirmation of antiphospholipid antibody positivity: a year's results in a cohort of 113 patients

Objective: To evaluate the confirmation rate of antiphospholipid antibodies (aPL), to analyze their behaviour at confirmation time, and to study the clinical value of their confirmation. Methods: Blood samples from 380 subjects, enrolled in this study from June 1, 2007 to May 31, 2008, were tested for anti-cardiolipin (aCL) and anti-beta2glycoprotein (aβ2GPI) antibodies using an ELISA method and for Lupus anticoagulant (LA) using a series of clotting tests. The samples of the 113 subjects resulting positive at the first testing time were assayed again to confirm antiphospholipid positivity. Results: aPL positivity was confirmed in 67 out of the 113 subjects (59.3%). Medium-high antibody levels of all, except IgM aCL, aPL/ELISA had a significantly higher confirmation rate with respect to that in subjects with low levels. The confirmation rate in the category I antibody patients (multiple positivity) was higher than that in the category II antibody subjects (single positivity). LA positivity was confirmed only when it was associated to other aPL. The cut-off of 40 GPL produced a confirmation rate equal to that resulting from a 99th percentile cut-off. Confirmation of aPL positivity made it possible for us to confirm the diagnosis of antiphospholipid syndrome (APS) in 8 out of the 113 subjects originally resulting positive (7,1%). APS clinical features were vascular thrombosis in 4 of these and pregnancy morbidity in the other 4. Conclusions: Our data emphasize aPL positivity confirmation selectivity, and medium-high antibody levels and category I antibodies (multiple positivity) had the best confirmation rates

Clinical significance of fluoroscopic patterns specific for the mitotic spindle in patients with reumatic diseases

Objective: we proposed to determine the clinical significance of anti-NuMA and anti-HsEg5 antibodies in a group of patients affected with rheumatic diseases. Materials and methods: indirect immunofluorescence on HEp-2000 cells at serum dilution of 1:40 was used to examin 26 sera which had previously showed a "mitotic spindle" fluoroscopic pattern type during laboratory routine. Results: 21 sera (80,7%) were identified with NuMA and 5 (19,3%) with HsEg5 patterns alone or associated with other ANA patterns. However only patients with isolated positiveness and that is 15 with NuMA and 4 with HsEg5 stainings were included in this study. Of the NuMA positive patients 5 were affected with arthropathies associated to different forms of thyroiditis, 2 with seronegative arthritis, 2 with antiphospholipid syndrome, 1 with systemic lupus erythematosus (SLE), 1 with rheumatoid arthritis, 1 with sicca syndrome, 1 with undifferentiated connective tissue disease, 1 with Mycoplasma pneumaniae infection and 1 with retinal thrombosis. Of the HsEg5 positive patients 3 were affected with SLE and 1 with seronegative arthritis. Conclusions: NuMA does not prevail in any defined rheumatic disease, while HsEg5 staining were more frequent (75%) in patients affected with SLE all of whom showing high antibody titres

Complement activation in the plasma and placentas of women with different subsets of antiphospholipid syndrome

Problem: As antiphospholipid antibody\u2010positive women with adverse pregnancy outcomes have higher plasma complement activation product levels, and the placentas of women with antiphospholipid syndrome (APS) exhibit C4d complement component deposition, complement activation involvement has been hypothesized in APS pregnancy complications. Method of study: Plasma levels of C5a and C5b\u20109 complement components of 43 APS non\u2010pregnant patients and 17 pregnant APS women were measured using enzyme\u2010 linked immunosorbent assay. The results were compared with those of 16 healthy non\u2010pregnant women and eight healthy pregnant women, respectively. Placenta samples of five APS patients at high risk of pregnancy complications and of five healthy controls were subjected to immunoblotting analysis with specific antibodies to C5b\u20109 and CD46, CD55, CD59 complement regulators. Results: The mean plasma C5a and C5b\u20109 levels were significantly higher in the nonpregnant APS patients with previous thrombosis \ub1 pregnancy morbidity (P = .0001 and P = .0034, respectively) and in the pregnant APS women with adverse outcomes (P = .0093 for both). Similarly, C5b\u20109 amounts were significantly higher in the adverse pregnancy outcome placenta (P = .0115) than in those associated to a favorable outcome. The mean CD46, CD55 and CD59 amounts were, instead, lower, although not always significantly, in the placentas of all the high\u2010risk APS women with respect to the control placentas. Conclusion: Data analysis demonstrated that there was significant complement activation in the more severe subset of APS patients and in only the adverse pregnancy outcome APS women. Further studies will clarify whether the lower CD46, CD55, and CD59 expressions in the APS placentas are limited to only high\u2010risk APS patients

THE CROSSTALK BETWEEN THE COMPLEMENT SYSTEM AND THE COAGULATION CASCADE IN THE ANTIPHOSPHOLIPID SYNDROME. PRELIMINARY DATA FROM BASIC RESEARCH.

The association between antiphospholipid antibodies (aPL) and thrombophilic state in antiphospholipid syndrome (APS) is well recognized, but the underlying pathophysiology remains incompletely elucidated. Several findings suggest the role of complement system (CS) in the pathogenesis of antiphospholipid syndrome (APS). The importance of CS in APS is understandable since complement-derived inflammatory mediators increase vascular permeability, activate platelets and promote release of cytokines from monocytesthat favor systemic inflammation and coagulation. It has been demonstrated in a mouse model of aPL-induced pregnancy loss that complement activation can amplify the fetal injury. CS activation has been also documented in patients with APS, but there are far fewer clinical data

Lupus anticoagulant identifies two distinct groups of patients with different antibody patterns

Background: Whether antibodies directed to β2-Glycoprotein I (aβ2GPI) are responsible for LA activity is not well defined. However, in the absence of such antibodies the molecule responsible for LA phenomenon is unknown. Objective: The aim of this study was the biochemical identification of the target antigen epitope of aPL responsible of LA activity in the absence of aβ2GPI antibodies together with the biological and clinical characteristics of these patients in comparison with classical triple positive patients. Patients/methods: A comparison of patients with LA without (LA+/aβ2GPI−) and those with (LA+/aβ2GPI+) associated aβ2GPI antibodies was performed. Size exclusion chromatography and analytical chromatography were used to identify the molecule with LA activity in patients LA+/aβ2GPI-. Results and conclusions: Analytical size-exclusion chromatography revealed a peak of 996Kd with LA activity perfectly overlapping that of IgM anti phosphatidylserine/prothrombin (aPS/PT) antibodies. Similarly, all the 25 LA+/aβ2GPI− patients were positive for aPS/PT antibodies. LA+/aβ2GPI− compared to 33 LA+/aβ2GPI+ patients turned out to be significantly older, with a lower rate of previous thromboembolic events and a weaker LA activity. Search for aPS/PT and aβ2GPI antibodies in patients with LA is useful to identify two subgroups of LA at different risk of thromboembolic event

Prevalence and clinical significance of cathepsin G antibodies in systemic sclerosis

Objectives: To evaluate the prevalence and clinical significance of cathepsin G antibodies in patients affected with systemic sclerosis (SSc, scleroderma). Methods: 115 patients affected by SSc, 55 (47,8%) with diffuse scleroderma (dSSc) and 60 (52,2%) with limited scleroderma (lSSc), were tested for cathepsin G antibodies by ELISA method. Moreover these sera were evaluated by indirect immunofluorescence (IIF) on ethanol and formalin fixed human neutrophils. Results: By means of the ELISA method 16 (13,9%) patients were found to be sera positive for anti-cathepsin G, 2 (12.5%) of which showed a perinuclear fluorescence pattern (P-ANCA) and 4 (25%) an atypical ANCA staining, while 10 (62,5%) were negative on IIF. The IIF on scleroderma sera revealed 5 (4,3%) P-ANCA and 18 (15,7%) atypical ANCA patterns. The anti-cathepsin G antibodies significantly prevailed in scleroderma sera (p=0.02) when their frequency was compared with that of healthy controls; while they were not significantly associated to any clinical or serological features of SSc patients. Conclusions: The anti-cathepsin G antibodies were significantly frequent in scleroderma sera; however, no clinical correlations were found. Thus, the significance of their presence in SSc still needs to be clarified

Digital ulcers in a cohort of 333 scleroderma patients

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Isolated congenital heart block in undifferentiated connective tissue disease and in primary Sjögren's syndrome: a clinical study of 81 pregnancies in 41 patients

Objective: To study the incidence and the features of congenital heart block (CHB) in patients with undifferentiated connective tissue disease (UCTD) and primary Sjögren's syndrome (pSS). Methods: We studied 81 pregnancies of 41 women attending the Outpatients' Clinic of the Rheumatology Unit of University Hospital of Padova from July 1989 to March 2004. Twenty five of these (61%) were affected with UCTD and 16 (39%) with pSS. Serologic inclusion criteria was anti-Ro/La positivity, assessed by counterimmunoelectrophoresis and ELISA. Results: CHB was found in 2 out of the 46 (4,3%) pregnancies followed by our Staff and in 2 out of the 35 (5,7%) included in the retrospective part of the study. In 3 cases CHB was a 3rd degree block, causing pregnancy termination in 2. The only 2nd degree block was identified in one patient at the 22nd week of gestation and treated with dexamethasone and plasma-exchange. All of the women were positive to 52 kd and 60 kd Ro autoantibodies. CHB mothers had higher titer antibodies to 52 kd Ro protein than did the mothers with healthy infants (P = 0,026). Electrocardiographic abnormalities at birth were found in 3 out of 29 asymptomatic infants. One presented sinus bradycardia, the second abnormalities of ventricular repolarization, both regressed spontaneously, while the third ventricular extrasystoles which continue even now at 5 months. Conclusion: These results showed that in UCTD and pSS there is a higher incidence of CHB than that reported in Systemic Lupus Erythematosus. Electrocardiographic screening in all infants born to mothers with anti-Ro/La antibodies would seem an important measure to identify those with irreversible heart conduction abnormalities

Corrigendum to: Comparative study of obstetric antiphospholipid syndrome (OAPS) and non-criteria obstetric APS (NC-OAPS): report of 1640 cases from EUROAPS registry

Rheumatology 2020;59:1306–1314. doi:https://doi.org/10.1093/rheumatology/kez419 In the original article, the affiliation of co-author Cecilia Beatrice Chighizola should have read: “Experimental Laboratory of Immunological and Rheumatologic Researches, Istituto Auxologico Italiano, IRCCS, Cusano Milanino, Milan, Italy”. These details have been corrected only in this corrigendum to preserve the published version of record