Anticardiolipin Antibody Assay: a Methodological Analysis for a better Consensus in Routine Determinations

Despite the widely recognized practical importance of anticardiolipin (aCL) ELISA, the reliability of this test has been recently discussed. In order to investigate this area on European scale, we sent to 30 experienced centers a questionnaire focusing on the diagnostic procedures applied to patients with antiphospholipid syndrome (APS) and on the detailed protocols used to perform aCL. Anticardiolipin ELISA was found to be the most frequently performed test in patients with suspected APS, but significant difference was shown among the various protocols. The cross-laboratory multiple examination of ten serum samples evaluated independently by the 24 centers pointed out the difficulty in getting comparable results. Therefore a “consensus” protocol was derived from the aCL methods giving the best performance. The materials and reagents necessary to perform the “consensus” method, including, as putative standards, one IgG and one IgM monoclonal antibody (HCAL and EY2C9) were distributed to 19 Centers. The results of one IgG and one IgM aCL high positive sera measured in serial dilutions were compared. A progressive decrease in the variability of the values obtained for a given sample appeared evident when all the laboratories used the same standard, in their own in-house ELISA and even more in the “consensus” ELISA.

Our data show that aCL ELISA standardization is necessary in order to obtain comparable results in different laboratories.

Clinical characterization of antiphospholipid syndrome by detection of IgG antibodies against β2 -glycoprotein i domain 1 and domain 4/5: ratio of anti-domain 1 to anti-domain 4/5 as a useful new biomarker for antiphospholipid syndrome

OBJECTIVE

It has been suggested that only antibodies against domain 1 (D1) of β2 -glycoprotein I (β2 GPI) are pathogenic and diagnostic. The role of antibodies against other β2 GPI domains is still debated. This study was undertaken to evaluate the clinical relevance of domain specificity profiling of anti-β2 GPI IgG antibodies in antiphospholipid syndrome (APS) patients and in control groups of patients with systemic autoimmune rheumatic diseases and in asymptomatic antiphospholipid antibody (aPL) carriers.

METHODS

We evaluated 159 subjects with persistently positive, medium or high-titer anti-β2 GPI IgG, including 56 patients with thrombotic (obstetric or nonobstetric) primary APS, 31 women with obstetric primary APS, 42 aPL-positive patients with systemic autoimmune rheumatic diseases, and 30 asymptomatic aPL carriers. One hundred healthy donors were included. Anti-β2 GPI D1 and D4/5 IgG were tested on research enzyme-linked immunosorbent assays containing recombinant β2 GPI domains.

RESULTS

As compared to other groups, aPL carriers displayed higher frequency/titer of anti-D4/5 IgG. Unlike anti-D4/5, anti-D1 IgG antibodies were more frequent and at higher titer in triple than in single or double aPL-positive subjects. An anti-D1 to anti-D4/5 ratio of ≥1.5 was predictive of systemic autoimmunity (odds ratio 3.25 [95% confidence interval 1.45-7.49], P = 0.005). Neither anti-D1 nor anti-D4/5 antibodies were associated with APS clinical criteria.

CONCLUSION

Anti-D1 IgG is the preferential specificity not only in vascular and obstetric primary APS, but also in patients with systemic autoimmune rheumatic disease with no clinical features of APS. Conversely, aPL carriers do not have a polarized profile toward D1. Combined testing for anti-β2 GPI IgG with different domain specificity allows a more accurate aPL profiling, with polarization toward anti-D1 IgG as a possible fingerprint of systemic autoimmunity.

The prevalence and incidence of systemic lupus erythematosus in children and adults: a population-based study in a mountain community in northern Italy

OBJECTIVES

To estimate prevalence and incidence of systemic lupus erythematosus (SLE) in paediatric and adult populations in Italy.

METHODS

The study was carried out in Valtrompia, a valley in northern Italy, where a relatively close community lives, in 2009-2012. The only referral centre for SLE in the area is the Rheumatology Unit of the University Hospital of Brescia. The ascertainment of SLE cases was performed through the integration of three sources: 1) hospital database; 2) database of the Rheumatology laboratory; 3) database of general practitioners and general paediatricians practicing in the area. Each patient was evaluated by a rheumatologist for confirmation of SLE classification based on the presence of at least 4 criteria according to the American College of Rheumatology.

RESULTS

Forty-four SLE patients (39 females, 89%) were identified. The prevalence of SLE at 31st December 2012 was 39.2 (95% C.I. 28.5-52.6) cases per 100,000 individuals in all subjects, and 42.3 (30.5-57.2) and 15.3 (1.8-55.1) in adults and children, respectively. Nine new cases of SLE were diagnosed over the 4 years of the study period, with an annual incidence rate of 2.0 (0.9-3.8) per 100,000 individuals.

CONCLUSIONS

This is the first study estimating the prevalence and incidence of SLE in Italy in both adult and paediatric population. Prevalence and incidence rates in line with those reported in other Mediterranean European countries. The accurate assessment of the SLE frequency is supported by the choice of a well-defined area, the integration of multiple data sources and the revision of each case by a rheumatologist.

Inhibiting insulin resistance mechanisms by DTS phytocompound: an experimental study on metabolic syndrome-prone adipocytes

The present study was designed to determine whether DTS a phytocompound endowed with antioxidant properties, could beneficially modulate nitric oxide (NO) production stimulated by lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-alpha) in adipocytes. Combined stimulation (CS-treatment) exerted by using 5 microg/ml of LPS together with 100 ng/ml of TNF-alpha significantly enhanced NO production in 3T3-L1 adipocytes. Preincubation of the adipocytes with DTS (10-30 mM) inhibited such phenomenon in a dose-dependent fashion. The production of NO was decreased by 52% at the concentration of 30mM of DTS. The decrease in NO production by DTS was associated also with a decrease in inducible nitric oxide synthase (iNOS) protein and iNOS mRNA expression. Nuclear factor-kappa B (NF-kappaB) was significantly enhanced by CS-treatment, while the pretreatment with 30 mM of DTS prevented the activity by 27%. IL-6 production in 3T3-L1 adipocytes was markedly increased by CS stimulus, and the enhanced secretion of IL-6 was suppressed in a dose-dependent manner by DTS. These results suggest that DTS regulates iNOS expression and NO production in adipocytes through the modulating activation of NF-kappaB and may have a potential clinical application within protocols designed for treating metabolic syndrome. (www.actabiomedica.it).

Effective properties of a sturgeon-based bioactive compound on stress-induced hippocampal degeneration and on in vitro neurogenesis

The aim of this study is to test the activity of a marine bioactive compound containing high-purity caviar-derived DNA, collagen elastin and protein extracts from sturgeon (LD-1227, Caviarlieri, Laboratoires Dom, Switzerland) to exert neuroprotective properties in an experimental setting while also being potential triggers of neurogenesis in a separate in vitro study. Supplementation with high-DHA mixture of LD-1227 was applied for 30 days to stress model rats. Both supplementations significantly mitigated the histological brain damage when analyzing hippocampal subregions and corticosterone level. However, LD-1227 was most significantly efficient in preventing SOD, Catalase and ascorbic acid decrease in brain tissue. Both supplementations stimulated neurogenesis in vitro and neuron markers in particular but og olygodendrocyte markers and glia increased only in LD-1227-enriched medium. Taken together, these data suggest that LD-1227 is able to significantly protect the brain structure redox system to higher degree than DHA. Moreover, from in vitro study it appears that marine bioactive compound, through it wide array of small unsaturated fatty acids, phospholipids and neurotransmitter precursors, is likely to influence neuronal and glial lineage to act differently from a DHA-rich mixture.

Beneficial effect of a sturgeon-based bioactive compound on gene expression of tumor necrosis factor-alpha, matrix metalloproteinases and type-10 collagen in human chondrocytes

In the present study, we examined the effect of a marine bioactive compound containing high-purity caviar-derived DNA, collagen elastin and protein extracts from sturgeon (LD-1227, Caviarlieri, Laboratoires Dom, Switzerland) on IL-1beta-induced activation and production of TNFalpha and MMP-13 in human osteo-arthritis (OA) chondrocytes and intracellular signaling factors. Human chondrocytes were derived from OA cartilage and stimulated with IL-1beta. Gene expression of TNFalpha, MMP-13, MMP-1 and Col10A1 was measured by quantitative RT-PCR. TNFalpha protein in culture medium was determined using cytokine-specific ELISA. Western immunoblotting was used to analyze the MMP-13 production in the culture medium and the activation of NF-kB. DNA binding activity of NF-kB p65 was determined using a highly sensitive and specific ELISA. MMP-13 activity in the culture medium was assayed by gelatine zymography. LD-1227 significantly decreased IL-1beta-stimulated gene expression and production of TNFalpha, MMP-1, MMP-13 and Col10A1 in human chondrocytes. The inhibitory effect of LD-1227 on the IL-1beta-induced expression of these genes was mediated at least in part via suppression of NF-kB p65. These data show that LD-1227 can inhibit IL-1beta-induced proliferation and inflammatory reactions via inhibited activation of the transcription factor NF-kB pathway in human chondrocytes derived from OA patients. These novel pharmacological actions of LD-1227 on IL-1beta-stimulated human OA chondrocytes provide suggestions that this marine biology compound may inhibit cartilage degradation by suppressing IL-1beta-mediated activation and the catabolic response in human chondrocytes.

Vitamin D and antiphospholipid syndrome

Vitamin D (vitD) has been shown to have multiple immunomodulatory properties. Hypovitaminosis D has been described in many systemic autoimmune diseases. Antiphospholipid syndrome (APS), an autoimmune disease characterized by immune-mediated thrombosis and pregnancy loss, is a peculiar model for studying vitD, since these patients do not usually have a full-blown autoimmune disease, nor do they have particular restrictions regarding sun exposure. We assessed 25-OH vitD levels in 115 APS and 128 normal healthy donors (NHD) with the LIAISON® chemiluminescent immunoassay by DiaSorin (Italy). Median values were lower in APS patients than in NHD, with the greatest difference occurring during summertime ( p < 0.01), suggesting that APS patients may be somehow prevented from vitD generation upon sun exposure. In our cohort, APS patients may have been instructed to use sunscreens in the presence of positive antinuclear antibodies (ANA). Comparing patients with positive and negative ANA, we found comparable vitD levels during the summer. By subdividing APS patients according to clinical features, thrombotic APS patients showed significantly lower levels than did pure obstetric APS patients ( p < 0.01). In conclusion, our study confirms previous reports of hypovitaminosis D in APS patients, making them more similar to patients with other systemic autoimmune diseases than NHD. Hypovitaminosis D may be part of the mosaic of factors that determine autoimmunity, rather than a consequence of chronic disease and its treatment. The observation that patients with thrombotic APS, an aggressive phenotype, may be more deficient than those with exclusive obstetric manifestations fits well with the beneficial effects of vitD on thrombosis described both in vitro and in vivo. Therefore, there may be a rationale to assess the efficacy of vitD supplementation in APS patients.

European registry of babies born to mothers with antiphospholipid syndrome

Objectives

This study aimed to describe the long-term outcome and immunological status of children born to mothers with antiphospholipid syndrome, to determine the factors responsible for childhood abnormalities, and to correlate the child's immunological profile with their mothers.

Methods

A prospective follow-up of a European multicentre cohort was conducted. The follow-up consisted of clinical examination, growth data, neurodevelopmental milestones and antiphospholipid antibodies (APL) screening. Children were examined at 3, 9, 24 months and 5 years.

Results

134 children were analysed (female sex in 65 cases, birth weight 3000±500 g, height 48±3 cm). Sixteen per cent had a preterm birth (<37 weeks; n=22), and 14% weighted less than 2500 g at birth (n=19). Neonatal complications were noted in 18 cases (13%), with five infections (4%). During the 5-year follow-up, no thrombosis or systemic lupus erythematosus (SLE) was noted. Four children displayed behavioural abnormalities, which consisted of autism, hyperactive behaviour, feeding disorder with language delay and axial hypotony with psychomotor delay. At birth lupus anticoagulant was present in four (4%), anticardiolipin antibodies (ACL) IgG in 18 (16%), anti-β₂ glycoprotein-I (anti-β2GPI) IgG/M in 16 (15%) and three (3%), respectively. ACL IgG and anti-β2GPI disappeared at 6 months in nine (17%) and nine (18%), whereas APL persisted in 10% of children. ACL and anti-β2GPI IgG were correlated with the same mother's antibodies before 6 months of age (p<0.05).

Conclusion

Despite the presence of APL in children, thrombosis or SLE were not observed. The presence of neurodevelopmental abnormalities seems to be more important in these children, and could justify long-term follow-up.

Multicentric evaluation of a second generation assay to detect antiviral citrullinated peptide antibodies: a collaborative study by the Forum Interdisciplinare per la Ricerca nelle Malattie Autoimmuni

Aims

A novel immunoenzymatic assay using viral citrullinated peptides derived from Epstein–Barr virus-encoded proteins (viral citrullinated peptide 2 (VCP2)) has been developed and evaluated by means of a multicentre collaborative study.

Methods

Three hundred nine sera from patients with established rheumatoid arthritis (RA), 36 with early arthritis, 12 with juvenile arthritis and 453 controls were tested for VCP2 and cyclic citrullinated peptide (CCP) antibodies.

Results

The VCP2 assay showed 78.3% sensitivity and 97.1% specificity. VCP2 and CCP had a high concordance rate in patients with RA (88%) and controls (97%). However, 36 RA sera were positive in the CCP assay but negative on VCP2, and two RA sera reacted only on VCP2.

Conclusions

The new VCP2 assay is endowed with high sensitivity and specificity. VCP2-positive RA sera are mostly but not completely contained in the CCP-positive population. Studies are in progress to establish whether the VCP2 assay can detect clinically distinct subsets of patients with RA.

Laboratory criteria of the obstetrical antiphospholipid syndrome. Data from a multicentric prospective European women cohort

A debate on updating the laboratory criteria of antiphospholipid syndrome (APS) was recently opened in view to lower the risk of over diagnosis of the syndrome. Based on data related to thrombotic APS, it proposes the exclusion of anticardiolipin antibodies (aCL) and anti-beta2-glycoprotein 1 (a-beta2-GPI) IgM detection. Here, we examine this possibility in a study which focuses on obstetrical APS (OAPS). We report new data on a prospective multicenter European cohort of 109 pregnant women having APS. Among them, 73 had purely obstetrical APS, not associated to autoimmune diseases or thrombosis. Isolated antibodies and isolated aCL positivity were present in 50/109 (46%) and in 34/109 (31%) of the women, respectively. An isolated a-beta2-GPI IgM was present in three women. These results suggest that aCL and a-beta2-GPI IgM cannot be dropped for the diagnosis and classification of OAPS. The low level of some antibodies associated with severe obstetrical complications raise the issue of keeping or not the same laboratory criteria for OAPS and for thrombotic APS and whether additional criteria after large prospective studies could further improve diagnosis.

Anti-DNA antibodies: a diagnostic and prognostic tool for systemic lupus erythematosus?

The clinical impact of anti-DNA antibodies lies on their diagnostic power for systemic lupus erythematosus (SLE), being a formal classification criterion. In spite of such a disease association, low-avidity anti-DNA antibodies might also be part of the natural autoantibody repertoire. Their switch to pathogenic high-avidity autoantibodies is the result of the autoimmune process leading to SLE.Anti-DNA antibodies were shown to play a role in SLE pathogenesis and particularly in kidney damage. Accordingly, antibody titres might fluctuate in relation to disease activity, but their prognostic value for flares is still debated.Several methods for anti-DNA detection were described and there is evidence that the assays identify different antibodies with different prognostic value. The results of a multicenter study on four different routine tests for anti-dsDNA antibody detection showed that: (i) Farr assay displays the best diagnostic specificity/sensitivity for SLE, followed by Crithidia luciliae method (CLIFT), (ii) the new generation of solid phase assay (EliA) shows an increased sensibility versus the classical enzyme linked immune assay (ELISA) but a decreased specificity. Antibody titre detected by EliA and Farr assay correlated with disease activity. These findings would suggest that more than one assay should be useful for SLE diagnosis and monitoring.

[Primary antiphospholipid syndrome evolving into systemic lupus erythematosus: may antinucleosome antibodies be predictive?]

OBJECTIVE

It was reported by several groups that patients diagnosed as primary antiphospholipid syndrome (PAPS) had developed a full-blown systemic lupus erythematosus (SLE) even after many years of follow-up. Little is known about clinical and/or serological factors that may help predict such evolution. Antinucleosome antibodies (anti-NCS) were described to appear in early stages of SLE, in particular before anti-dsDNA antibodies. The aim of the study is to evaluate the prevalence of anti-NCS in a large cohort of PAPS patients.

METHODS

IgG and IgM anti-NCS antibodies were detected using a home made assay with H1-stripped chromatin as antigen. Sera from 106 PAPS patients were tested; 52 of them were also tested during the follow-up, at least 2 years apart form the basal sample.

RESULTS

Medium-high titre anti-NCS were found in nearly half of the patients (49/106, 46%), more frequently in those presenting features of "lupus like disease". Most of patients displayed an unchanged pattern of anti-NCS over time. We describe three cases of PAPS patients that developed SLE after many years of follow-up; high titre and low titre anti-NCS were present in two and one of them respectively several years before evolving into SLE.

CONCLUSIONS

A significant proportion of PAPS patients displayed medium-high titre anti-NCS, suggesting that the autoimmune response against chromatin may be a relevant event not only in patients with SLE. Further studies are warranted to explore the predictive value of anti-NCS with respect to the evolution from PAPS to SLE.

Are the current attempts at standardization of antiphospholipid antibodies still useful? Emerging technologies signal a shift in direction

The pathogenic role of antiphospholipid antibodies (aPL) has been widely established over past years in several experimental models and clinical studies. Accordingly, the detection of aPL by immunoassays (anticardiolipin antibodies; anti-beta2 glycoprotein I antibodies) has become a routine practice in the clinical workup of patients with systemic autoimmune diseases. aPL are mostly assayed using commercial ELISA kits, whose performance has not been found to be sufficiently concordant among the different manufacturers. In the past years, collaborative groups have spent considerable effort to reach some form of standardization but this process is still ongoing. Such lack of standardization has recently become even more crucial, as manufacturers have had to face an increasing demand for fully automated tests for aPL, like those test systems that have been developed for other autoantibodies (e.g., antinuclear antibodies, anti-ENA antibodies). We therefore report our recent experience with two newly developed automated methods for anticardiolipin antibodies testing. In particular, we discuss the results obtained using routine samples, as we believe that these better reflect the "real-life" situation in which those automated methods will operate. We also mention other emerging technologies in the field of aPL detection.

[Radon exposition preliminary research in a Sicilian territory]

Radon toxicity on human body is well known from along (in 1988 radon has been classified as first type carcinogen, after only to tobacco's smoke, as cause of lung's cancer). Based on known scientific data, preliminary study has been conducted by the AA. It concerns radon exposition on inhabitants living in a Sicilian territory featured by previous seismic events: the territory and the town of Montevago. The project has been sponsored by ARPA Palermo. The territory of Montevago has been divided in several areas in order to assign detectors homogeneously, to begin the environmental sampling. In the period between May and October 2006, instruments has been calibrated and standardization of the procedure has been completed, in collaboration with Centro Studi Nucleare Enrico Fermi del Dipartimento di Ingegneria Nucleare del Politecnico di Milano. The values obtained result in European range.

Antiprothrombin antibodies: a comparative analysis of homemade and commercial methods. A collaborative study by the Forum Interdisciplinare per la Ricerca nelle Malattie Autoimmuni (FIRMA)

OBJECTIVE

Prothrombin (PT) is a target for antibodies with lupus anticoagulant (LA) activity, suggesting the possible application of anti-prothrombin antibody (aPT) assays in patients with antiphospholipid syndrome (APS). Different methods - both homemade and commercial - for the detection of aPT are available, but they seem to produce conflicting results. The purpose of this study was to compare the performance of different assays on a set of well-characterized serum samples.

PATIENTS AND METHODS

Sera were gathered from 4 FIRMA institutions, and distributed to 15 participating centres. Forty-five samples were from patients positive for LA and/or anticardiolipin antibodies (aCL) with or without APS, and 15 were from rheumatoid arthritis (RA) patients negative for antiphospholipid antibodies. The samples were evaluated for IgG and IgM antibodies using a homemade direct aPT assay (method 1), a homemade phosphatidylserine-dependent aPT assay (aPS/PT, method 2), and two different commercial kits (methods 3 and 4). In addition, a commercial kit for the detection of IgG-A-M aPT (method 5) was used.

RESULTS

Inter-laboratory results for the 5 methods were not always comparable when different methods were used. Good inter-assay concordance was found for IgG antibodies evaluated using methods 1, 3, and 4 (Cohen k > 0.4), while the IgM results were discordant between assays. In patients with thrombosis and pregnancy losses, method 5 performed better than the others.

CONCLUSION

While aPT and aPS/PT assays could be of interest from a clinical perspective, their routine performance cannot yet be recommended because of problems connected with the reproducibility and interpretation of the results.

Anticardiolipin and anti-beta2 glycoprotein I antibodies in infants born to mothers with antiphospholipid antibody-positive autoimmune disease: a follow-up study

Infants born from mothers with antiphospholipid antibody (aPL) -positive autoimmune disease were prospectively evaluated for anticardiolipin and anti-beta2 glycoprotein I antibodies (group 1) and for growth and neurological development. The results were compared with those obtained from two age-matched control groups (group 2 and 3). All infants were negative for anticardiolipin at 12 months of life, whereas 14 (63.6%), eight (33.3%), and 10 (55.5%) of infants from group 1, 2, and 3, respectively, were positive for anti-beta2 glycoprotein I. At follow-up, all infants had normal growth and neurological development. No thrombotic complication was observed. The negativity of anticardiolipin in all infants at 12 months suggests that anticardiolipin detection is the best assay to evaluate the disappearance of maternal aPL and to estimate the potential risk of thrombosis associated with these antibodies. The high rate of anti-beta2 glycoprotein I positivity in all three groups of infants may indicate that the synthesis of this antibody is stimulated by aspecific factors.

Systemic lupus erythematosus in Europe at the change of the millennium: lessons from the "Euro-Lupus Project"

The "Euro-Lupus Cohort" is composed by 1000 patients with systemic lupus erythematosus (SLE) that have been followed prospectively since 1991. These patients have been gathered by a European consortium--the "Euro-Lupus Project Group". This consortium was originated as part of the network promoted by the "European Working Party on SLE", a working group created in 1990 in order to promote research in Europe on the different problems related to this disease. The "Euro-Lupus Cohort" provides an updated information on the SLE morbidity and mortality characteristics in the present decade as well as defines several clinical and immunological prognostic factors.

Minimal requirements for antiphospholipid antibodies ELISAs proposed by the European Forum on antiphospholipid antibodies

Antiphospholipid ELISAs are part of the Antiphospholipid Antibodies Syndrome classification criteria, having the same diagnostic value as lupus anticoagulant. However, sometimes their results appear scarcely meaningful especially when wide metanalyses studies are performed, probably because of their well-known inter-laboratory variability. The application of a common protocol was shown to improve the test reproducibility, but this observation did not have any influence on the routine performances. After discussion among experts at the European level, we identified four conditions named "minimal requirements" considered useful to decrease the inter-laboratory variability: (1) to run the samples in duplicate; (2) to determine the cut off level in each laboratory analysing at least 50 samples from normal subjects, possibly age- and sex-matched with the patient population usually attending the Centre; (3) to calculate the cut-off level in percentiles; (4) to use stable external control in the tests. A collaborative study involving 36 European centres proved that the use of monoclonal anti-beta2 glycoprotein I antibodies, HCAL (IgG) and EY2C9 (IgM) as standards, can help to reduce the inter-laboratory coefficient of variation both in anticardiolipin (aCL) and anti-beta2GPI (anti-beta2 glycoprotein I) ELISA. Therefore, we propose HCAL and EY2C9 as external controls, but other monoclonal or polyclonal preparations may be considered. During an interactive workshop held last May in Italy, 16 companies producing these tests agreed to consider the introduction of the "requirements" in their products. We suggest to adopt these "requirements" particularly in clinical studies, in order to compare more easily the literature data.

[Clinico-pathologic features of occupational allergic eczema]

The Authors study the fundamental role of individual predisposition in professional eczema. They remark the relation between medicine and dermatology and, particularly, the possible interference of immediate hypersensibility.

Lessons from the "Euro-Lupus Cohort"

The "Euro-Lupus Cohort" is composed by 1,000 patients with systemic lupus erythematosus (SLE) that have been followed prospectively since 1991. These patients have been gathered by a European consortium - the "Euro-Lupus Project Group". This consortium was originated as part of the network promoted by the "European Working Party on SLE", a working group created in 1990 in order to promote research in Europe on the different problems related to this disease. The "Euro-Lupus Cohort" provides an updated information on the SLE morbidity and mortality characteristics in the present decade as well as defines several clinical and immunological prognostic factors.

[Role of anti-prothrombin in antiphospholipid syndrome]

We studied 99 patients with systemic autoimmune disease (5 males, 94 women; mean age 37 year, range 16-72): 28 Primary Antiphospholipid Syndrome, 67 Systemic lupus Erythematosus, 1 Mixed Connective Tissue Disease, 2 Undifferentiated Connective Tissue Disease and 1 Discoid Lupus. Based on the observation that native PT shows conformational changes in presence of Ca++ ions and discloses new epitopes available for binding with phospholipids, we performed 3 different methods for the detection of aPT in presence and absence of Ca++, finding a different incidence of specific autoantibodies, associated with clinical features of APS (aPT in presence of Ca++) or non associated (aPT in absence of Ca++). The presence of aPT was significantly associated also with the presence of Lupus Anticoagulant (LAC). The detection of aPT (in presence of Ca++) significantly enhances diagnostic sensibility of APS allowing the identification of a subset of patients (6/99) with clinical features of APS, but with negative LAC, aCL and a beta2-GPI; in fact (limited to thrombotic episodes) the sensibility rises from 56.2% with one test (LAC) to 81.1% with the application of LAC, aCL, a(beta)2GPI and aPT.

Immunization of naive BALB/c mice with human beta2-glycoprotein I breaks tolerance to the murine molecule

OBJECTIVE

Immunization of naive mice with beta2-glycoprotein I (beta2GPI) leads to the generation of pathogenic anticardiolipin antibodies associated with clinical manifestations of the antiphospholipid syndrome (APS). The aim of this study was to determine whether immunization of naive mice with human beta2GPI, which shares homology with mouse beta2GPI molecules, breaks tolerance to murine beta2GPI and leads to the generation of anti-mouse beta2GPI.

METHODS

Twenty-four female BALB/c mice were immunized in the footpads with 10 microg of human beta2GPI. Twelve age- and sex-matched BALB/c mice were immunized in the same manner with Freund's complete adjuvant and served as controls. The reactivity of whole sera, polyclonal IgG, and affinity-purified anti-beta2GPI IgG antibodies against human, bovine, and mouse beta2GPI was evaluated by enzyme-linked immunosorbent assay.

RESULTS

High titers of anti-human beta2GPI IgG antibodies were detected 1 month after immunization. Progressively increasing titers against murine and bovine beta2GPI were recorded 1-4 months after injection.

CONCLUSION

Immunization of mice with human beta2GPI resulted in the generation of antibodies reacting with human, bovine, and murine beta2GPI. The loss of tolerance to mouse beta2GPI is attributable to the high interspecies homology of beta2GPI. These results may point to molecular mimicry as a possible cause of APS.

Observational study of quality of life in patients with headache, receiving homeopathic treatment

This study describes the results obtained from a prospective observational research of homeopathic treatment for patients suffering from headache (migraine with- and without aura and tension-type headache). Fifty-three patients were asked to complete the SF-36 questionnaire at the beginning of the treatment and after 4-6 months. The homeopathic medicine and potency were not pre-defined, but were adapted to each single patient according to individualised homeopathic prescription. Most patients (73.6%) completed the study. There was heterogeneity in the answers (patients in very poor health as well as those with only slight disorders). Analysis of the data according to the concept of 'intention-to-treat' showed that after therapy, the mean and median scores of all life quality dimensions rose. More than 60% of the cases experienced an improvement in pain and the limitations caused by pain, as well as in limitations in social activities and health in general. All the differences between pre/post post treatment were statistically highly significant, with the strongest results in the 'bodily pain' and 'vitality' parameters (P < 0.0001).

Anticardiolipin antibody assay: a methodological analysis for a better consensus in routine determinations--a cooperative project of the European Antiphospholipid Forum

Despite the widely recognized practical importance of anticardiolipin (aCL) ELISA, the reliability of this test has been recently discussed. In order to investigate this area on European scale, we sent to 30 experienced centers a questionnaire focusing on the diagnostic procedures applied to patients with antiphospholipid syndrome (APS) and on the detailed protocols used to perform aCL. Anticardiolipin ELISA was found to be the most frequently performed test in patients with suspected APS, but significant difference was shown among the various protocols. The cross-laboratory multiple examination of ten serum samples evaluated independently by the 24 centers pointed out the difficulty in getting comparable results. Therefore a "consensus" protocol was derived from the aCL methods giving the best performance. The materials and reagents necessary to perform the "consensus" method, including, as putative standards, one IgG and one IgM monoclonal antibody (HCAL and EY2C9) were distributed to 19 Centers. The results of one IgG and one IgM aCL high positive sera measured in serial dilutions were compared. A progressive decrease in the variability of the values obtained for a given sample appeared evident when all the laboratories used the same standard, in their own in-house ELISA and even more in the "consensus" ELISA. Our data show that aCL ELISA standardization is necessary in order to obtain comparable results in different laboratories.

Urine volume: stone risk factor and preventive measure

BACKGROUND

A high fluid intake is the oldest existing treatment for kidney stones, and, up until a few decades ago, it was the only preventive measure at the physician's disposal for stone recurrences.

METHODS

Using the data available in literature and partly unpublished personal research, we examine the role of urine volume as a stone risk factor, its impact on calcium crystallization mechanisms and its real importance as a means of prevention.

RESULTS

To sum up, the most important findings are: (1) a low urine volume must be considered as a real risk factor, both as regards the onset of renal calculi and stone relapses; (2) an increase in urine volume induced by a high water intake produces favourable effects on the crystallization of calcium oxalate and does not reduce the activity of natural inhibitors; (3) a sufficiently high intake of water and probably other fluids such as coffee, tea, beer and wine has a preventive effect on nephrolithiasis and its recurrence, and (4) the role of fruit juice is still to be defined.

CONCLUSIONS

A high intake of fluids, especially water, is still the most powerful and certainly the most economical means of prevention of nephrolithiasis, and it is often not used to advantage by stone formers.

HLA class II alleles associations of anticardiolipin and anti-beta2GPI antibodies in a large series of European patients with systemic lupus erythematosus

The objective of this study was to determine the HLA class II associations of the anticardiolipin (aCL) and anti-beta2GPI (abeta2GPI) antibodies in a large series of European patients with systemic lupus erythematosus (SLE). A cohort of 577 European SLE patients was enrolled. aCL and abeta2GPI were measured by ELISA methods. Molecular typing of HLA-DRB1, DRB3, DRB4, DRB5, DQA1 and DQB1 loci was performed by the polymerase chain reaction-sequence specific oligonucleotide probes (PCR-SSOP) method. aCL of IgG, IgM and IgA isotypes were detected in 22.8%, 14% and 13.9% of patients, respectively. IgG and IgM abeta2GPI were detected in 20% of patients. aCL showed positive association with HLA DRB1*04, DRB1*0402, DRB1*0403, DRB1*07, DRB3*0301, DQA1*0201, DQA1*0301, DQB1*0302, and negative association with DQA1*0501, DRB3*0202. abeta2GPI showed positive association with DRB1*0402, DRB1*0403, DQB1*0302. DRB1*0402 carried the highest relative risk for the presence of both aCL (RR=8. 1) and abeta2GPI (RR=4.6). Our results confirm the already described associations of aCL with HLA DR4 and DR7, but also demonstrate that, among the alleles at the DRB1*04 locus, the *0402 was most represented both in aCL and in abeta2GPI positive patients. In addition, HLA class II associations of abeta2GPI are for the first time extensively examined in a large cohort of European SLE patients.

Anticardiolipin and anti-beta2GPI antibodies in a large series of European patients with systemic lupus erythematosus. Prevalence and clinical associations. European Concerted Action on the Immunogenetics of SLE

OBJECTIVE

To test the prevalences and the clinical associations of anticardiolipin (aCL) and anti-beta2GPI (abeta2GPI) antibodies in a large series of European patients with systemic lupus erythematosus (SLE).

METHODS

574 SLE patients from 7 European countries were tested for aCL and abeta2GPI by ELISA methods.

RESULTS

aCL of IgG, IgM, and IgA isotypes were detected in 22.8%, 14%, and 13.9% of the patients, respectively. IgG and IgM abeta2GPI were detected in 20% of the patients. The presence of aCL was highly associated with the presence of abeta2GPI. Medium-high titer IgG aCL and abeta2GPI were associated with thrombosis, with similar sensitivity, specificity, and positive predictive value. When present at medium-high titer, IgG aCL were associated with thrombocytopenia, IgM aCL with hemolytic anemia, and cerebrovascular accidents. IgA aCL with livedo reticularis and Raynaud's phenomenon.

CONCLUSIONS

aCL, when present at medium-high titer, are as important as abeta2GPI, as a risk factor for thrombosis. Medium-high titer aCL, but not abeta2GPI, are associated with other clinical features of the antiphospholipid syndrome.

Essential arterial hypertension and stone disease

BACKGROUND

Cross-sectional studies have shown that nephrolithiasis is more frequently found in hypertensive patients than in normotensive subjects, but the pathogenic link between hypertension and stone disease is still not clear.

METHODS

Between 1984 and 1991, we studied the baseline stone risk profile, including supersaturation of lithogenic salts, in 132 patients with stable essential hypertension (diastolic blood pressure of more than 95 mm Hg) without stone disease and 135 normotensive subjects (diastolic blood pressure less than 85 mm Hg) without stone disease who were matched for age and sex (controls). Subsequently, both controls and hypertensives were followed up for at least five years to check on the eventual formation of kidney stones.

RESULTS

Baseline urine levels in hypertensive males were different from that of normotensive males with regards to calcium (263 vs. 199 mg/day), magnesium (100 vs. 85 mg/day), uric acid (707 vs. 586 mg/day), and oxalate (34.8 vs. 26.5 mg/day). Moreover, the urine of hypertensive males was more supersaturated for calcium oxalate (8.9 vs. 6.1) and calcium phosphate (1.39 vs. 0.74). Baseline urine levels in hypertensive females were different from that of normotensive females with regards to calcium (212 vs. 154 mg/day), phosphorus (696 vs. 614 mg/day), and oxalate (26.2 vs. 21.7 mg/day), and the urine of hypertensive females was more supersaturated for calcium oxalate (7.1 vs. 4.8). These urinary alterations were only partially dependent on the greater body mass index in hypertensive patients. During the follow-up, 19 out of 132 hypertensive patients and 4 out of 135 normotensive patients had stone episodes (14.3 vs. 2.9%, chi-square 11.07, P = 0.001; odds ratio 5.5, 95% CI, 1.82 to 16.66). Of the 19 stone-former hypertensive patients, 12 formed calcium calculi, 5 formed uric acid calculi, and 2 formed nondetermined calculi. Of the urinary factors for lithogenous risk, those with the greatest predictive value were supersaturation of calcium oxalate for calcium calculi and uric acid supersaturation for uric acid calculi.

CONCLUSIONS

A significant percentage of hypertensive subjects has a greater risk of renal stone formation, especially when hypertension is associated with excessive body weight. Higher oxaluria and calciuria as well as supersaturation of calcium oxalate and uric acid appear to be the most important factors. Excessive weight and consumption of salt and animal proteins may also play an important role.

Relationship between supersaturation and calcium oxalate crystallization in normals and idiopathic calcium oxalate stone formers

BACKGROUND

In an earlier study on recurrent CaOx stone formers with no detectable abnormalities, we found that the urine of these subjects had a lower tolerance to oxalate load than controls and that the removal of urinary macromolecules with a molecular weight greater than 10,000 D improved their tolerance to oxalate.

METHODS

The effects on CaOx crystallization of reduced urinary supersaturation of calcium oxalate (CaOx), induced by night water load, were studied in 12 normal males and in 15 male OxCa stone formers who were free from urinary metabolic abnormalities. The effect of the macromolecules, purified and retrieved from the natural and diluted urine, were analyzed in a metastable solution of CaOx.

RESULTS

The water load caused an increase in urine volume (from 307 +/- 111 to 572 +/- 322 ml/8 hr, P = 0.014 in normal subjects, and from 266 +/- 92 to 518 +/- 208 ml/8 hr, P = 0.001 in the stone formers) and a concomitant reduction of the relative CaOx supersaturation (from 8.7 +/- 2.5 to 5.1 +/- 2.5 ml/8 hr, P = 0.001 in normal subjects, and from 10.4 +/- 3.5 to 5.0 +/- 2.7 ml/8 hr, P = 0.001 in the stone formers). The decrease in CaOx supersaturation was accompanied by an increase of the permissible increment in oxalate, both in normal subjects (from 43.8 +/- 10.1 to 67.2 +/- 30. 3 mg/liter, P = 0.018) and in the stone formers (from 25.7 +/- 9.4 to 43.7 +/- 17.1 mg/liter, P = 0.0001), without any significant variations of the upper limit of metastability for CaOx (from 21.6 +/- 5.3 to 20.5 +/- 4.2 mg/liter in normal subjects, and from 18.7 +/- 4.5 to 17.1 +/- 3.7 mg/liter in the stone formers). The inhibitory effect of urinary macromolecules with molecular weight greater than 10,000 Daltons did not undergo any change when the latter were recovered from concentrated or diluted urine, either in normal subjects or in the stone formers.

CONCLUSIONS

Reduced CaOx supersaturation by means of water load has a protective effect with regards to CaOx crystallization in subjects who do not present any of the common urinary stone risk factors.

The anti-beta2-glycoprotein I activity in human anti-phospholipid syndrome sera is due to monoreactive low-affinity autoantibodies directed to epitopes located on native beta2-glycoprotein I and preserved during species' evolution

To characterize the reactivity pattern of Abs directed to beta2-glycoprotein I (anti-beta2GPI) in patients with anti-phospholipid syndrome, we have purified anti-beta2GPI Abs by affinity chromatography using the IgG fractions from sera of five different anti-phospholipid syndrome patients. Affinity-purified anti-beta2GPI were shown to be representative of Abs found in human sera because their activity could be virtually abolished from the IgG preparations after repeated absorptions on immobilized human beta2GPI column. Our results show that affinity-purified anti-beta2GPI: 1) do react with beta2GPI in the absence of any phospholipid, as demonstrated by the lack of phosphorus contaminant in the employed reagents, as well as by their comparable binding activity before and after extensive delipidation procedure; 2) can recognize beta2GPI regardless of its origin from different animal species; 3) are able to bind soluble beta2GPI with a mean Kd value of 4.65 x 10(-6) M (range 3, 4-7, 2 x 10(-6) M); 4) significantly enhance their binding avidity when beta2GPI is linked to a solid support; and 5) appear to be mainly monoreactive autoantibodies. In conclusion, we have shown that human polyclonal anti-beta2GPI are low affinity, mainly monoreactive autoantibodies directed to an epitope located on native beta2GPI, preserved along the species evolution.

The anti-beta2-glycoprotein I activity in human anti-phospholipid syndrome sera is due to monoreactive low-affinity autoantibodies directed to epitopes located on native beta2-glycoprotein I and preserved during species' evolution

To characterize the reactivity pattern of Abs directed to beta2-glycoprotein I (anti-beta2GPI) in patients with anti-phospholipid syndrome, we have purified anti-beta2GPI Abs by affinity chromatography using the IgG fractions from sera of five different anti-phospholipid syndrome patients. Affinity-purified anti-beta2GPI were shown to be representative of Abs found in human sera because their activity could be virtually abolished from the IgG preparations after repeated absorptions on immobilized human beta2GPI column. Our results show that affinity-purified anti-beta2GPI: 1) do react with beta2GPI in the absence of any phospholipid, as demonstrated by the lack of phosphorus contaminant in the employed reagents, as well as by their comparable binding activity before and after extensive delipidation procedure; 2) can recognize beta2GPI regardless of its origin from different animal species; 3) are able to bind soluble beta2GPI with a mean Kd value of 4.65 x 10(-6) M (range 3, 4-7, 2 x 10(-6) M); 4) significantly enhance their binding avidity when beta2GPI is linked to a solid support; and 5) appear to be mainly monoreactive autoantibodies. In conclusion, we have shown that human polyclonal anti-beta2GPI are low affinity, mainly monoreactive autoantibodies directed to an epitope located on native beta2GPI, preserved along the species evolution.

[Effects of prolonged work on "deep-sea" fishermen: influence of blood cortisol, prolactinemia and urinary catecholamines]

Effects of persistent overwork on the deep-sea fishermen: influence on serum cortisol and prolactin, and on urinary catecholamine levels. Variations in serum prolactin and cortisol levels and in urinary catecholamines levels were studied in fishermen exposed to a persistent overwork period of deep-sea fishing. Results indicate that prolactin was rapidly modified. In fact, the serum prolactin levels already increased on the first day and maximum levels were observed on the fifth day. On the contrary, the physiological rise and fall in the serum levels of cortisol were scarcely influenced on the first day while on the fifth day increased in the morning and fell in the evening in a very significant manner. No significant variation in urinary catecholamine levels was observed at the end of fifth day. These results suggest that, unlike for prolactin, the effects of stress on serum levels of cortisol are complex and, under our conditions, could be due, at least in part, to the duration of the stress and to the functional moment of pituitary-adrenal axis.

Anti-beta 2-glycoprotein I antibodies: a marker of antiphospholipid syndrome?

Anticardiolipin (aCL) and anti-beta 2-glycoprotein I(anti beta 2GPI) antibodies have been shown in animal models as not cross-reacting antibody populations. This observation prompted us to prove if anti-beta 2GPI exist in human sera by using a reliable method and then to investigate if these are independent from aCl antibodies. We have developed a new ELISA for the detection of anti-beta 2GPI antibodies employing the coating of the protein in carbonate buffer to irradiated microtitre plates and the filtration of serum samples, that makes irrelevant the binding to the uncoated wells. IgG F(ab)2 fragments from IgG positive sera were shown bind beta 2GPI, providing that the binding was a specific antibody binding, mediated by the antigen binding site of the antibody molecule: moreover the antibodies were not able to differentiate native and delipidated beta 2GPI coated plates, making a possible role of a phospholipid contaminant unlikely. On the other hand, the phosphorus content of native as well as delipitated beta 2GPI was undetectable. IgG, but not IgM, anti-beta 2GPI antibodies were classically inhibited by the addition of soluble beta 2GPI, while cardiolipin liposomes appear to modify the reaction in a completely different way, possibly by the described interaction between cardiolipin and beta 2GPI.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunization with anticardiolipin cofactor (beta-2-glycoprotein I) induces experimental antiphospholipid syndrome in naive mice

Beta-2-GPI is a 50 kDa glycoprotein which is known to be a serum co-factor, with a role in determining the binding of pathogenic anticardiolipin antibodies to phospholipids. Immunization of naive mice with beta-2-GPI resulted in elevated levels of antibodies directed against negatively charged phospholipids (cardiolipin, phosphotidylserine, phosphatidylinositol). The presence of increased titres of antiphospholipid antibodies in the sera of the mice was later followed by prolonged activated partial thromboplastin time (APTT), thrombocytopenia, and when the mice were mated, by a high percentage of fetal resorptions in the uterus. These data point to the ability of beta-2-GPI to induce pathogenic anti-cardiolipin antibodies following active immunization.