Biological and Clinical Relevance of Anti-Prothrombin Antibodies

Anti-prothrombin (anti-PT) antibodies are recently identified antibodies directed toward a phospholipid-binding protein (prothrombin), which deserve attention for the reported clinical and pathogenic relevance in antiphospholipid syndrome and systemic lupus erythematosus (SLE). We have recently carried out a longitudinal study on the predictive value of anti-PT antibodies in SLE showing that they have a higher diagnostic accuracy for thrombosis than anti-beta(2)-GPI and anticardiolipin antibodies, and, along with LAC activity, are the best predictors of thromboembolic events in SLE patients.

An Analysis of Experimental Conditions Influencing the Anti-beta2-Glycoprotein I ELISA Assay Results

Five components of the anti-beta(2)-glycoprotein I (abeta(2)GPI) enzyme-linked immunosorbent assay (ELISA) (coating buffer, microplate brand, blocking buffer, dilution buffer, and conjugate) were analyzed to evaluate how they affect variability in test results. Thirty-two samples from patients with antiphospholipid syndrome (APS) positive for abeta(2)GPI IgG antibodies and three calibrators (a pool of abeta(2)GPI-positive patients, the monoclonal HCAL antibody, and a home-made calibrator) were tested. No differences with regard to the blocking step were noted. Differences were found between the neutral and basic coating buffer when HCAL was used. There were significant differences between Maxisorp and all the other brands of tested microplates. Differences were found between phosphate-buffered saline (PBS) and all the other dilution buffers examined, with exception of TRIS when HCAL or the home-made calibrator was used. There were differences between our routine conjugate and one of the other four conjugates tested when using two of the three calibrators. There were also significant differences between the routine and another conjugate analyzed when using the third calibrator. As variations in abeta(2)GPI ELISA conditions determine significant differences in the results, selecting the appropriate test variables is an important step toward abeta(2)GPI assay standardization.

Evaluation of Current Methods for the Measurement of Serum Anti Double-Stranded DNA Antibodies

Autoantibodies to double-stranded DNA (dsDNA) are, by definition, serological markers of systemic lupus erythematosus. However, the clinical value of anti-dsDNA antibodies largely depends on the assay principle and analytical variables of the methods used to quantitate and immunologically characterize them. In the present article, an overview of current methods for anti-dsDNA antibody detection is presented, together with a look at the future trends in technologies newly employed in this field.

Anti-prothrombin antibodies predict thrombosis in patients with systemic lupus erythematosus: a 15-year longitudinal study

OBJECTIVE

To evaluate the role of anti-prothrombin (anti-PT) antibodies in predicting thrombosis in patients with systemic lupus erythematosus (SLE).

METHODS

An inception cohort of 101 SLE patients (12 males, 89 females; mean age 30 +/- 8 years), was considered. Clinical and laboratory evaluations were regularly performed during a 15-year follow-up (median 108 months) with a special focus on thromboembolic events. Serum samples were collected at time of diagnosis and at least once a year thereafter. IgG and IgM anti-PT, anti-cardiolipin (aCL) and anti-beta(2)glycoprotein I (beta(2)GPI) antibodies were measured by enzyme-linked immunosorbent assay (ELISA); lupus anticoagulant (LAC) was assayed by the dilute Russell's viper venom time and activated partial thromboplastin time tests. The analytical specificity of anti-PT ELISA was investigated. The timing of thrombosis occurrence was calculated using the Kaplan-Meier method.

RESULTS

In the 15-year follow-up, thrombosis occurred in 14 out of the 101 patients: venous thrombosis in nine cases and arterial thrombosis in five. IgG and/or IgM anti-PT, anti-beta(2)GPI and aCL antibodies, and LAC activity were detected in ten, nine, seven, and nine cases, with sensitivity for thrombosis of 71.4%, 64.3%, 50% and 64.3%, respectively. Thrombosis-free survival was 90% at 5 years and 85.8% at 10 and 15 years, respectively. Thrombosis was predicted by anti-PT (P = 0.001), anti-beta(2)GPI antibodies (P = 0.002) and LAC activity (P = 0.001). Moreover, the risk of thrombosis progressively increased with the number of positive antiphospholipid antibody tests. The presence of four positive antibody tests was associated with a risk of thrombosis thirtyfold higher than in their absence.

CONCLUSIONS

This longitudinal study shows that IgG anti-PT antibodies are predictors of thrombosis in SLE patients.

Validation of a new immunoenzymatic method to detect antibodies to RNA polymerase III in systemic sclerosis

OBJECTIVE

To test the reliability of a new enzyme-linked immunosorbent assay (ELISA) to identify anti-RNA polymerase III (RNAP III) positive sera from Italian patients with Systemic Sclerosis (SSc) and other chronic inflammatory disorders.

METHODS

A comparison between the new ELISA for anti-RNAP III and the gold standard technique, immunoprecipitation (IP), was first performed on 106 SSc patients, 16 patients with other connective tissue diseases and 10 healthy subjects. A further ELISA evaluation was performed on 224 SSc patients, 120 subjects with other rheumatic or infectious diseases, and 81 healthy controls.

RESULTS

Plotting ELISA and IP data in a Receiver Operator Characteristic curve, the ELISA cut-off value providing the best specificity (99.1%) and sensibility (100%) was 28 U/ml (AUC=0.999; p<0.0001). Using this cut-off in the second analysis, anti-RNAP III positive results were found in 41 (18.3%) SSc patients, all negative for anticentromere or anti-topoisomerase I antibodies, while only 3 subjects tested positive among the 120 sera collected from other patients. All the healthy subjects were negative.

CONCLUSION

This new ELISA for anti-RNAP III is highly accurate when a proper cut-off value is employed and represents a valid substitute to IP in a clinical setting.

[Primary antiphospholipid syndrome and hyperhomocysteinemia: a study of a group of 29 patients]

OBJECTIVE

In order to investigate the potential role of hyperhomocysteinemia as an additional risk factor for thrombotic events, we studied its prevalence in patients with primary antiphospholipid syndrome (APS) and evaluated its association with different clinical features.

METHODS

We enrolled 29 patients without any current evidence of underlying connective tissue disorder and fulfilling the Sapporo preliminary classification criteria for APS.

RESULTS

Ten (34,4%) patients showed mild hyperhomocysteinemia (18,34 micromol/L +/- 2,04 DS). Nine had history of cerebrovascular disease, isolated (3 cases) or more often (6 cases) in association with other APS features. All patients, but one, showed multiple ischemic cerebral lesions. Seven of the 10 patients with hyperhomocysteinemia had multiple antiphospholipid antibody positivity and presented more frequently (6 cases) multi-site vascular involvement.

CONCLUSIONS

The frequency of hyperhomocysteinemia in patients with primary APS is not negligible and appears to be associated with cerebral microangiopathic disease, multiple antiphospholipid antibody positivity and the simultaneous involvement of different vascular districts. For this reason and because hyperhomocysteinemia can be easily corrected with safe and relatively inexpensive therapeutic interventions, we advocate the measurement of homocysteinemia in every patient affected by APS and possibly in subjects with positive antiphospholipid antibody without a history of thrombosis.

[Antinuclear, anti-dsDNA and anti-ENA antibodies in patients affected with rheumatoid arthritis or ankylosing spondylitis during treatment with infliximab]

OBJECTIVE

We evaluated the induction and clinical significance of ANA, anti-dsDNA and anti-ENA during infliximab therapy in patients with Rheumatoid Arthritis (RA) or Ankylosing Spondylitis (AS).

METHODS

We tested sera from 30 RA and 30 AS patients before and during treatment with infliximab. ANA and antidsDNA were determined by indirect immunofluorescence and anti-ENA by an "in house" counterimmunoelectrophoresis. Statistical analysis was performed by X2 and McNemar's tests and U-test of Mann-Whitney.

RESULTS

Eight of the 30 RA patients and 1 of the 30 AS patients were positive for ANA before treatment with infliximab. Eighteen of the 22 (81.8%) negative patients with RA and 11 of the 29 (37.9%) negative patients with AS became positive for ANA during infliximab treatment. No ANA positive patients became negative during the therapy. The difference between ANA before and after treatment resulted significant in both RA and AS patients (p=0.001). The frequency of anti-dsDNA and anti-ENA did not change significantly from baseline, in both RA and AS patients. Acquired ANA positivity was not associated with clinical signs of lupus syndrome and was not correlated with adverse events. The mean values of ESR and CRP in RA patients who became positive for ANA were significantly decreased (p=0.01 and p=0.02 respectively).

CONCLUSIONS

Infliximab treatment induced a significant increase in the frequency of ANA in RA and AS patients. The significance of ANA development in these diseases is at present unknown. The significant decrease of ESR and CRP in RA patients who became positive for ANA after treatment should be investigated in a larger number of patients.

The Diagnosis of the Antiphospholipid Syndrome

The concurrence of antiphospholipid (aPL) antibodies and thrombosis or pregnancy loss defines the 'antiphospholipid syndrome' (APS). The Sydney update of the classification criteria for definite APS diagnosis introduced numerous ameliorations to the previous preliminary consensus statement. Clinical criteria are now better defined as vascular thrombosis must be diagnosed on the basis of objective criteria. Moreover,additional risk factors for thrombosis or pregnancy loss must be taken into account before the diagnosis is made and should be described in detail in scientific reports. As far as laboratory criteria are concerned,the lack of standardization and the misinterpretation of results remain major problems often leading to overdiagnosis. A single positive test result out of the possible assays determining aPL antibodies (Lupus Anticoagulant, LAC, anticardiolipin, aCL and anti. beta2-Glycoprotein I, beta2-GPI, antibodies) is still sufficient,according to the Sydney criteria, to justify a diagnosis of APS. Nevertheless single test positivity may result in overdiagnosis or identification of low risk patients and use of all three tests seems more reasonable. Multiple positivity or (better) triple positivity in our experience allows for the identification of high risk patients for possible recurrence. In the near future, coagulation tests discriminating between a beta2-GPI and anti-prothrombin LAC may be useful in identifying high risk patients.

Unstabilized DNA breaks in lymphocytes of patients with systemic sclerosis

The clastogenic effects on DNA, proven by the presence of micronuclei (MN), and the protective cellular mechanisms normally used to stabilize DNA breaks were investigated in patients with systemic sclerosis (SSc). The frequency of micronucleated cells found in cultures of peripheral lymphocytes in patients was significantly higher than in the control group. The patient group with anti-centromere antibodies showed a significantly higher frequency of micronucleated cells than that observed in the patients with anti-topoisomerase I antibodies (4.22% versus 2.34%, p < 0.001). Moreover, we attempted to characterize MN for the presence or absence of DNA fragments with free 3'-OH ends by digoxigenin-dUTP (DIG-dUTP) using terminal deoxynucleotidil transferase. It was found that the frequency of MN containing DNA fragments with 3'-OH free ends (unstable fragments) increased in SSc patients compared to that observed in the control group. Moreover, this increase was significantly higher in lymphocytes of the patients with anti-centromere antibodies than in those with anti-topoisomerase I antibodies (35% versus 20.08%, p < 0.001). Our results indicate that in SSc patients there is an interference in the protective cellular mechanisms, normally stabilizing DNA breaks.

Use of a new silica clotting time for diagnosing lupus anticoagulant in patients who meet the clinical criteria for antiphospholipid syndrome

The silica clotting time (SCT) is a phospholipid-dependent coagulation assay used for the laboratory diagnosis of lupus anticoagulant (LA) antibodies. The sensitivity and specificity of a new commercial SCT for identifying LA in patients who meet the clinical criteria for antiphospholipid syndrome (APS), and its association with thrombotic events were evaluated here. Forty-five patients who met the clinical criteria for APS according to the Sapporo International Consensus Statement were examined. Sixty-nine patients who did not meet the clinical criteria for APS, and 20 blood donors were used as controls. Plasma samples from the patients and controls were tested for LA using a new commercial SCT with low and high synthetic phospholipid concentrations. The results were compared with those obtained by diluted Russell's viper venom time (dRVVT) and activated partial thromboplastin time (APTT). SCT's sensitivity for identifying LA in patients who met the clinical criteria of APS was higher compared to APTT and dRVVT (53.3% vs. 31.1% and 31.1%), and the specificities of these assays were 96.6%, 100%, and 98.9%, respectively. When dRVVT was combined with SCT, and dRVVT was combined with APTT their sensitivities were 57.7% and 48.8%, and their specificities were 96.6% and 98.9%, respectively. A stepwise logistic regression analysis indicated that the combination of dRVVT with SCT was associated with total thrombotic events (odds ratio (OR)=11.5, 95% confidence interval (CI)=1.25-106.3, P=0.031) as well as with venous thrombosis (OR=4.09, 95% CI=1.16-14.43, P=0.028). According to our results, SCT is the most sensitive assay for identifying LA in patients who meet the clinical criteria for APS. Moreover, the highest sensitivity was reached with a combination of SCT and dRVVT. The method's association with total thrombotic events and venous thrombosis was in fact significant.

[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.

CONCLUSIONS

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.

[Sensibility and specificity for pregnancy morbidity of anti-β2-glycoprotein I antibodies in antiphospholipid syndrome]

OBJECTIVE

This study aimed to evaluate the sensitivity and specificity of the anti-&beta;2-glycoprotein I (GPI) antibodies for pregnancy morbidity in the antiphosoplipid syndrome (APS).

METHODS

335 women were recruited and on the basis of their clinical features were subdivided into 2 groups homogenous for number and age. The first (study) group contained the women whose pregnancy complications satisfied the classification criteria for APS. The second (control) group was made up of women with pregnancy complications not included in the classification criteria for APS. Anti-&beta;2-GPI, anticardiolipin antibodies (aCL) and lupus anticoagulants (LA) were determined in all of these women.

RESULTS

The only antiphospholipid antibodies occurring with a significant frequency (p=0,00) in the women with pregnancy criteria for APS were the IgG anti-&beta;2-GPI and the IgG aCL present respectively in 23,92% and in 27,60% of the women. Its association was found to be significant (p=0,000). The distribution of the different levels of positivity of the IgG and IgM anti-&beta;2-GPI in the patients of the study and control groups was not significantly different. The highest sensitivity for pregnancy complications was that of the IgG aCL and of the IgG anti-&beta;2-GPI whose difference was not statistically significant. The comparison of the specificity of the IgG and IgM anti-&beta;2-GPI with that of the IgG and IGM aCL was not statistically significant.

CONCLUSIONS

The importance of determining the IgG anti-&beta;2-GPI as part of routine laboratory testing of women with pregnancy complications typical of APS was confirmed. Together with IgG aCL these antibodies have proved to be the most sensitive and specific markers of pregnancy complications in APS.

Pregnancy, cytokines, and disease activity in systemic lupus erythematosus

OBJECTIVE

To evaluate levels of selected cytokines and soluble receptors involved in the humoral immune response during pregnancy in systemic lupus erythematosus (SLE) patients.

METHODS

Seventeen consecutive SLE patients and 8 matched healthy controls were prospectively studied during pregnancy. Sera were obtained within the last 3 months prior to pregnancy; at 9, 17, and 29 weeks of pregnancy; and at 1 month after delivery. Serum levels of interleukin-10 (IL-10), interleukin-6 (IL-6), and soluble tumor necrosis factor receptors p55 (sTNFR I) and p75 (sTNFR II) were evaluated. SLE activity was measured by the European Consensus Lupus Activity Measurement score modified for pregnancy.

RESULTS

IL-10 serum levels were found to be higher (P <0.0001) in patients than in controls before conception, and still higher (P <0.0001) in SLE patients during gestation, without intertrimester changes. In SLE patients, IL-6 serum levels did not increase in the third trimester of pregnancy, as was observed in controls (P=0.011). No significant differences between SLE patients and controls were found in either sTNFR I or II levels or profiles before and during pregnancy. IL-10 and sTNFR I levels were significantly higher during pregnancy and postpartum in SLE patients with active disease (P=0.03 and P=0.01, respectively).

CONCLUSION

The levels of some cytokines involved in the humoral immune response seem to be modified in the peripheral circulation of pregnant SLE patients. The most relevant modifications are the lower than expected increase of IL-6 in the third trimester of gestation and persistently high levels of IL-10 during pregnancy.

Prevalence and clinical correlations of antibodies against six beta2-glycoprotein-I-related peptides in the antiphospholipid syndrome

Two-hundred ninety five patients with the antiphospholipid syndrome (APS) were studied for the presence of antibodies against six anti-beta2GPI-related peptides Abs. The prevalence of a wide spectrum of clinical and laboratory parameters of APS was evaluated in all patients, and correlated with the presence of each anti-beta2GPI peptide antibody. The rates of the various antipeptides Abs ranged from 18.0 to 63.7%. Altogether, 87.1% of the patients had antibody reactivity against at least one of the six beta2GPI-related peptides. A high degree of simultaneous reactivity against several beta2GPI-peptides was found. Positive and negative correlations were found between several antipeptides Abs and the rates of thrombosis and fetal loss. Our results point to a heterogeneous activity of antiphospholipid Abs in APS patients, directed, often concurrently, against various epitopes of the beta2GPI molecule. Evaluation of APS patients for the presence of specific antipeptides Abs may be of a value in predicting the risk for future thrombotic and obstetrical complication, as well as for specific therapeutic purposes.

Features associated with epilepsy in the antiphospholipid syndrome

OBJECTIVE

To assess the frequency of epilepsy in primary and secondary antiphospholipid syndrome (APS); to analyze the clinical and laboratory features characterizing those with epilepsy in a cohort of 538 patients with APS; and to find associated features that would suggest risk factors for epilepsy in APS.

METHODS

We analyzed the clinical features of patients with APS who had epilepsy and compared them to the clinical features of non-epileptic APS patients.

RESULTS

Of 538 APS patients, 46 (8.6%) had epilepsy. Epilepsy was more prevalent among APS secondary to systemic lupus erythematosus (SLE) compared to primary APS (13.7% vs 6%; p < 0.05). The patients with epilepsy had a higher prevalence of central nervous system (CNS) manifestations including focal ischemic events (strokes or transient ischemic events, 54.3% vs 24.6%; p < 0.0001) and amaurosis fugax (15.2% vs 4.9%; p < 0.05). APS patients with epilepsy had a higher frequency of valvular pathology (30.4% vs 14.6%; p < 0.01), thrombocytopenia (43.5% vs 25%; p < 0.05), and livedo reticularis (26.1% vs 11.5%; p < 0.01). The multivariate logistic regression analysis found CNS thromboembolic events as the most significant factor associated with epilepsy, with an odds ratio (OR) of 4.05 (95% confidence interval, CI: 2.05-8), followed by SLE (OR 1.4, 95% CI 1.2-4.7), and valvular vegetations (OR 2.87, 95% CI 1-8.27).

CONCLUSION

Epilepsy is common in APS and most of the risk seems to be linked to vascular disease as manifested by extensive CNS involvement, valvulopathy, and livedo reticularis and to the presence of SLE. These factors, however, explain only part of the increased occurrence of epilepsy in APS and other causes such as direct immune interaction in the brain should be investigated.

[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.

Sensitivity and specificity for primary Sjögren's syndrome of IgA and IgG anti-alpha-fodrin antibodies detected by ELISA

OBJECTIVE

To investigate the sensitivity and specificity of anti-alpha-fodrin antibodies in patients with primary Sjögren's syndrome (pSS).

METHODS

IgA and IgG anti-alpha-fodrin antibodies were measured in the sera of 80 patients with pSS, 60 blood donors matched for age and sex, 50 patients with systemic lupus erythematosus (SLE), 30 with rheumatoid arthritis (RA), 20 with systemic sclerosis (SSc), and 10 with polymyositis or dermatomyositis (PM/DM) by an ELISA method employing recombinant human alpha-fodrin as antigen.

RESULTS

The sensitivity of IgA and IgG anti-alpha-fodrin antibodies for pSS was 32.50% and 21.25%, respectively. When the prevalence of these antibodies in patients with SLE, RA, SSc, and PM/DM was evaluated, we observed specificity of these antibodies of 68.18% and 79.09%, respectively. The sensitivity and specificity for pSS of the combined determination of IgA and IgG anti-alpha-fodrin antibodies were 40% and 58.18%, respectively.

CONCLUSION

The prevalences of IgA and IgG anti-alpha-fodrin antibodies in our patients with pSS and other chronic autoimmune diseases have induced us to doubt their use as diagnostic markers of pSS.

[Clinical significance of fluoroscopic patterns specific for the mitotic spindle in patients with rheumatic diseases]

OBJECTIVE

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 examine 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 positivity 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 pneumoniae 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.

Autoantibodies to proteinase 3 and myeloperoxidase in systemic sclerosis

OBJECTIVE

We evaluated the prevalence and clinical significance of proteinase 3 (PR3-) and myeloperoxidase (MPO-) antineutrophil cytoplasmic antibodies (ANCA) in 115 patients with systemic sclerosis (SSc, scleroderma).

METHODS

Sera were assayed by 2 independent centers, which used indirect immunofluorescence (IIF) and direct ELISA as screening tests. Inhibition-ELISA for PR3- and MPO-ANCA and PR3 capture-ELISA experiments were also performed. The clinical features of the ANCA positive were compared with those of the ANCA negative scleroderma patients.

RESULTS

The IIF test revealed 5 P-ANCA positive sera (4.34%). Surprisingly, by ELISA 2 of these were PR3-ANCA positive, one was MPO-ANCA positive, and 2 were both PR3- and MPO-ANCA positive. In addition, 3 IIF negative sera were ELISA positive, 2 for PR3- and one for MPO-ANCA. ELISA results were confirmed by fluid phase inhibition experiments. Only 2 out of the 6 PR3-direct ELISA positive sera were positive by PR3-capture ELISA at low titers. Neither PR3- nor MPO-ANCA were significantly associated to any clinical feature of patients with SSc.

CONCLUSION

As well as the previously described MPO-ANCA, even PR3-ANCA may be detected in some sera from patients with SSc. The IIF pattern and the negative results obtained with PR3-capture ELISA suggest that different epitopes from those recognized by vasculitis sera might be involved with PR3-ANCA in SSc, and show the importance of combining IIF and ELISA tests for ANCA detection.

Some patients with antiphospholipid syndrome express hitherto undescribed antibodies to cardiolipin-binding proteins

Contrary to infective anticardiolipin (aCL) antibodies, autoimmune aCL antibodies react with phospholipids (PL) mainly via binding to the plasma glycoprotein cofactor beta2-Glycoprotein I (beta2GPI). While there is a well-documented link between the risk of thrombosis and the presence of beta2GPI-dependent anticardiolipin antibodies, the pathological impact of other antiphospholipid antibodies is less clear. By means of cardiolipin affinity-chromatography, we isolated and identified 3 CL-binding proteins, complement component C4, complement factor H and a kallikrein-sensitive glycoprotein, and tested for the presence of autoantibodies against these proteins in patients with antiphospholipid syndrome (APS), systemic lupus erythematosus (SLE) and other autoimmune diseases. High titers of autoantibodies to C4 as compared to age- and sex-matched healthy controls were present in 3 of 26 patients with APS, and weak titers were found in 2 of 26 patients with SLE and in none of 26 patients with other autoimmune diseases. Autoantibodies to complement factor H were found in 4 APS, 3 SLE and none of the other autoimmune patients. Autoantibodies to kallikrein-sensitive glycoprotein were detected in 6 APS patients, 1 SLE patient, and 1 patient with another autoimmune disease. A close relationship between these antibodies was found, suggesting their origin from a common macromolecular complex. However, no relationship with anti-beta2GPI antibodies was found, with the three patients with higher levels of autoantibodies having a low titer of anti-beta2GPI antibodies. In conclusion, some patients with APS harbor circulating antibodies to other CL-binding proteins which might be useful to further characterize these patients.

Correction for age of anticardiolipin antibodies cut-off points

Immunoglobulin (Ig) isotypes G, M, and A of anticardiolipin antibodies (aCL) are considered markers of antiphospholipid syndrome (APS). They were determined by ELISA in sera of 100 healthy children aged between 6 months and 16 yrs (mean 5.4 yrs +/-3.4 SD) and 100 healthy elderly subjects aged between 65 and 103 yrs (mean 84.2 yrs +/-8.1 SD). The frequency with which they were detected was compared to that in sera of 100 healthy adults aged between 21 and 47 yrs (mean 25.8 yrs +/-5.2 SD) in order to evaluate if adult aCL cut-off levels were fit for pediatric and elderly populations. The cut-off points were calculated adding 2.5 SD to the mean values and, in the adult group, the results were 11.6 GPL, 7.5 MPL, and 23.9 APL for IgG, IgM, and IgA, respectively. In the children, IgG aCL were positive in 26 cases (26%), IgM and IgA aCL in 1 case (1%) respectively. Statistical comparison of these results to those of adults showed a higher significant frequency for children IgG aCL (P = 0.0001) with the major contribution by children aged between 6 months and 5 yrs, and a lower significant frequency for children IgA aCL (P = 0.041). In elderly subjects IgG aCL were positive in 12 cases (12%), IgM aCL in 4 (4%), and IgA aCL in 37 (37%). In a comparison of these values to those of adults, only elderly IgA aCL frequency was significantly higher (P = 0.0001) with the major contribution by the oldest subgroup. In order to avoid false positive results for IgG aCL in children and for IgA aCL in elderly, as well as false negative results for IgA aCL in children, we introduced three new cut-off points: (1) 27.7 GPL for IgG aCL in children; (2) 13.8 APL for IgA aCL in children; and (3) 51.1 APL for IgA aCL in elderly subjects. These data suggest that a correction for age of aCL cut-off levels should be considered to raise specificity and sensitivity for APS in pediatric as well as in elderly populations.

Outcome of fifty-five newborns of antiphospholipid antibody-positive mothers treated with calcium heparin during pregnancy

OBJECTIVE

The outcome of 55 infants born to 53 antiphospholipid antibody (aPL)-positive mothers treated during pregnancy with calcium heparin is described.

METHODS

The clinical state of the children was evaluated immediately after delivery by a clinical examination, and a neonatological check-up was performed no later than 24 hours after birth. Neonates with problems were transferred to the neonatal intensive care unit. After their discharge from hospital the clinical state of the babies was followed by means of interviews with the pediatricians and mothers for a period varying between 1.33 and 5.66 years (mean 2.51 +/- 0.92 SD).

RESULTS

The newborns comprised 30 females and 25 males, including 2 sets of twins, delivered between the 25th and 40th weeks of gestation (mean 36.69 +/- 2.91 SD). They had a mean birth weight of 2.828 g +/- 706.50 SD (range 800-4.000) and a mean Apgar score at 5 minutes of 9.60 +/- 0.68 SD (range 7-10). Soon after delivery, 12 children (21.81%) were admitted to the neonatal intensive care unit for periods varying between 2 and 120 days (mean 30.33 +/- 33.40 SD), after which the clinical course was normal. All of these neonates suffered from complications exclusively due to prematurity. Malformations and signs of thrombosis or other aPL-related disorders were not observed in any of the newborns. During the follow-up, none of the diseases suffered by the 55 children differed from those of the normal pediatric population; in particular, aPL-related manifestations were never observed.

CONCLUSION

These data indicate the absence of aPL-related problems in the offspring of aPL-positive mothers treated during pregnancy with calcium heparin.

A prospective study of fifty-three consecutive calcium heparin treated pregnancies in patients with antiphospholipid antibody-related fetal loss

OBJECTIVE

In this study the efficacy and safety of calcium heparin administered alone for the prevention of fetal loss related to antiphospholipid antibodies (aPL) were evaluated.

METHODS

Fifty-three consecutively ascertained pregnancies were followed in 53 patients who had a history of at least 2 consecutive miscarriages during the first trimester and/or 1 fetal death during the second or third trimesters. In addition, all patients had at least 2 positive aPL tests more than 8 weeks apart before pregnancy, or a positive aPL test at the beginning of pregnancy. They were treated with calcium heparin alone, self-administered subcutaneously 3 times daily at dosages varying between 15,000 and 37,500 units. Treatment was started soon after a sonogram demonstrated a live embryo and was continued throughout pregnancy until the end of puerperium.

RESULTS

All pregnancies terminated favourably between the 25th and 40th weeks (mean +/- SD: 36.69 +/- 2.91) with planned caesarean section in 27 cases and vaginal delivery in 26. Delivery was brought forward due to maternal and/or fetal complications in 18 cases (33.96%). Calcium heparin was associated with intravenous immunoglobulin therapy in 2 patients with fetal problems unresponsive to anticoagulant treatment alone. The newborns, 30 females and 25 males, had a mean birth weight of 2,828.3 g +/- 706.5 and a mean Apgar score at 5 minutes of 9.60 +/- 0.68. No malformations were observed. Thirty of the 37 examined placentas (81.08%) showed signs of thrombotic events. Only minor side effects of calcium heparin were observed during treatment.

CONCLUSION

Our study suggests that calcium heparin administered alone using the dosages and timing described here is effective in achieving the delivery of viable infants, and that it is well tolerated.

[Relationship between late ventricular potentials and ventricular arrhythmias in patients in chronic dialysis treatment]

BACKGROUND

Arrhythmias are frequent pathology in patients with chronic hemodialysis. We evaluated whether a relatively new technique, signal averaging, could be useful in predicting the development of complex arrhythmias in these patients.

METHODS

Thirty-three patients, 18 male and 15 female, subjected to thrice weekly chronic hemodialytic treatment with various dialysis techniques, were studied. Exclusion criteria were the presence of antiarrhythmic and inotropic treatment. The following examinations were carried out in all patients: a Holter dynamic electrocardiography for a duration of 24 hours, begun on the day of dialysis, high resolution ECG pre- and post-dialysis to find out if there were any ventricular late potential (VLP). Four hundred beats were examined in order to obtain a background noise of less than 0.7 microV and a better definition of the signal. The following parameters were considered significant for the presence of VLP: a) filtered QRS duration > 120 msec; b) the root mean square of the signal expressed in the terminal portion of QRS (RMS) < 25 microV) high frequency low amplitude signals duration (HFLA) > 40 msec. A positive value in two of these parameters was considered indicative of the presence of VLP. In addition various pre and post-dialysis indices of dialytic efficiency and a mono and two-dimensional echocardiogram with pulsed and color Doppler were carried out. Of the 33 patients studied, ten were excluded because they presented too high a background noise at the high resolution ECG. Of the remaining 23 patients, 13 (56%) presented VLP and nine of these (69%) presented complex arrhythmias. Of the ten patients without VLP, 5 (50%) presented complex arrhythmias. The incidence of arrhythmias was highest during the last two hours of dialysis and in the two hours following it. The patients were then divided into two groups (A and B) according to the ejection fraction (EF) found at the echocardiogram. Group A was composed of 17 patients of whom 8 (47%) presented complex arrhythmias; group B (EF < 45%) was composed of the remaining six patients, who all presented complex arrhythmias. In group A nine patients (53%) out of 17 had LVP, in group B four out of six (66%) had it. All the patients except one presented an increase in the thickness of the ventricular wall and alterations of Doppler transmitral filling rate. Left ventricular hypertrophy was diagnosed in 22 out of the 23 patients. Four patients also had chronic ischaemic heart disease; of these three had LVP. There was no correlation between the presence of LVP and the hemodialytic indices and between the latter and complex arrhythmias.

CONCLUSIONS

Our study showed that arrhythmias are more frequent in patients with LVP before dialysis than in those without. The difference was statistically significant (p < 0.006); the incidence of arrhythmias was higher in patients with FE < 45% (p < 0.001). The majority of patients (95%) had left ventricular hypertrophy; only four (17%) had ischaemic heart disease too. It is highly probable that the presence of LVP in our patients can be attributed to hypertension and subsequent left ventricular hypertrophy. As patients with LVP at the end of dialysis had a greater incidence of arrhythmias than those without LVP, we suggest that this method could be useful as a first screening in dialysed patients.

Autoantibodies to phospholipid-binding plasma proteins in patients with thrombosis and phospholipid-reactive antibodies

Anti-phospholipid (aPL) antibodies are defined as antibodies detected in systems employing phospholipids (PL). This general definition is misleading as it comprises a large group of autoimmune phospholipid-reactive antibodies that are directed against specific phospholipid-binding plasma proteins, such as beta 2-glycoprotein I (beta 2GPI) and prothrombin. Definition of phospholipid-reacting antibodies according to the plasma protein against which they are directed appears more appropriate and could be useful in understanding clinical events and pathogenic mechanisms. Using ELISA systems we have studied the presence of antibodies directed against specific phospholipid-binding proteins in a series of 22 patients with thrombosis and phospholipid-reactive antibodies of the IgG isotype. High levels of anti-beta 2 GPI IgG were detected in all 22 patients. Normal values were calculated on the basis of OD values at 405 nm (OD405) obtained for 22 age- and sex-matched healthy subjects (cut off value = 0.401). Levels of anti-beta 2 GPI antibodies were linearly correlated with those of cardiolipin-reactive (aCL) antibodies. Eleven out of 22 patients (50%) had values of anti-prothrombin antibodies exceeding the cut-off value of 0.250. No relationship was found between the levels of anti-beta 2GPI and anti-prothrombin antibodies. Tests for antibodies against two natural inhibitors of blood coagulation, protein C and protein S, revealed elevated levels of anti-protein C IgG and anti-protein S IgG in 4 and 12 patients, respectively. A highly significant correlation between anti-protein C IgG and anti-protein S IgG values as well as between antibody titers against the two studied natural coagulation inhibitors and anti-prothrombin IgG was found. When comparing patients positive for aCL and presence or absence of a previous thrombotic episode (aCL+/T+ vs aCL+/T-), the positivity of anti-beta 2GPI IgG was found to be statistically associated with thrombosis. Conversely, among patients with previous thromboembolism with or without aCL (aCL+/T+ vs aCL-/T+ vs aCL-/T+) the positivity of anti-beta 2GPI IgG was strictly associated with the positivity of aCL, thus identifying the aPL antibody syndrome. These data demonstrate that anti-beta 2GPI antibodies are a marker of "autoimmune" thrombosis. Anti-prothrombin antibodies are not a marker of thrombosis and are closely associated with antibodies to protein C and protein S.

Trends in immunoglobulin G anticardiolipin antibodies in ten successful heparin-treated pregnancies

The pregnancies of ten women, all with histories of at least two spontaneous abortions of unknown cause, were followed. All patients were positive for immunoglobulin (Ig) G anticardiolipin antibodies (aCL) and one also for IgM aCL, while none had lupus anticoagulant activity. During pregnancy, the patients were treated with calcium heparin in doses varying between 15,000 and 30,000 IU daily. IgG aCL were assayed on average at the 9th, 17th, 24th and 29th weeks of pregnancy and at the moment of delivery. Mean values of IgG aCL levels during the 10 pregnancies steadily fell as the pregnancies progressed, and this decrease was significant (r = 0.985, P = 0.002). All pregnancies terminated favourably, although delivery was brought forward in eight patients and six of the nine placentas examined showed signs of thrombotic events. We assume that a steady fall in IgG aCL levels during pregnancy may be considered as indicative of a favourable outcome.

Anti beta 2-glycoprotein I antibodies in a patient with catastrophic antiphospholipid syndrome

Autoimmune antiphospholipid antibodies are a hallmark of patients with antiphospholipid syndrome, and require a protein cofactor, beta 2-glycoprotein I, to bind anionic phospholipids. In these same patients, moreover, IgG directly binding beta 2-glycoprotein I are described. We found high plasma titres of both IgM and IgG anti beta 2-glycoprotein I antibodies in a patient with catastrophic antiphospholipid syndrome. After passing plasma through a Sephacryl S-300 column, an identical distribution pattern between anti beta 2- glycoprotein I and anticardiolipin antibodies was observed. Moreover, when IgG immunocomplexes were isolated from a high molecular fraction, IgM anti- beta 2-glycoprotein I and anticardiolipin antibodies were detected. Thus IgG, IgM ad IgG-IgM complexes of anti-beta 2-glycoprotein I antibodies are present at the same time in a patient with antiphospholipid syndrome.

Anticardiolipin antibodies and antiphospholipid syndrome in chronic discoid lupus erythematosus

Anticardiolipin antibodies (aCL) of immunoglobulin (Ig) G and M classes were determined in 28 patients affected with chronic discoid lupus erythematosus (CDLE), comparing their prevalence and levels to those in 60 healthy subjects matched for age and sex. A high and significant frequency of IgG (67.8%) and IgM (50.0%) aCL together with prevalence of high antibody levels was found in CDLE patients, while healthy controls had IgG and IgM aCL in 1.6% and 3.3% of cases respectively. Clinical features in keeping with the diagnosis of antiphospholipid syndrome were found in one patient (3.5%), which, as the first manifestation of the syndrome, showed a pulmonary thromboembolism which appeared some days after prolonged exposure to the sun. These results provide additional data on autoimmune phenomena in CDLE and suggest that aCL test should be considered as useful aids in immunological diagnosis of CDLE.

Fibrinolytic pattern in recurrent spontaneous abortions: no relationship between hypofibrinolysis and anti-phospholipid antibodies

Patients with antiphospholipid antibodies may suffer from thrombotic events and recurrent spontaneous abortions. A defective fibrinolytic potential has been described in women with recurrent fetal losses. We investigated the prevalence of anticardiolipin antibodies and of various fibrinolytic abnormalities in 64 females with a history of at least two abortions of unknown origin. Anticardiolipin antibodies were present in the serum of 31 patients (48.4%). The overall prevalence of fibrinolytic disorders was 67.2% (43 cases) and resulted significantly higher than that of aCL positivity (P = 0.03). In most of cases the impaired fibrinolytic potential after venous occlusion test was due to increased PAI-1 levels; only in a few instances a defective fibrinolytic response was due to reduced t-PA release, a combined defect or an intrinsic fibrinolytic deficiency. After division of patients in two groups on the basis of the aCL presence, the distribution of different fibrinolytic defects was similar in aCL positive and negative women, suggesting the lack of correlation between hypofibrinolysis and aCL antibodies. Plasminogen abnormalities resulted compatible with congenital hypoplasminogenemia in two aCL negative women, whereas in four aCL positive patients they were suggestive for acquired dysplasminogenemia. Our results indicate that patients with recurrent spontaneous abortions may present fibrinolytic disorders, which occur independently and more often than aCL positivity. An accurate investigation of the fibrinolytic potential, and, namely, of PAI-1 levels, should be included in the study of females suffering from repeated fetal losses.

Antiphospholipid antibody syndrome associated with ovarian cancer. A new paraneoplastic syndrome?

We describe a 41-year-old woman, in whom antiphospholipid antibody syndrome (APS) occurred at presentation, before the detection of an ovarian endometrial adenocarcinoma. This syndrome was characterized by widespread and worsening thromboembolism and it did not respond to conventional anticoagulant treatment. The paraneoplastic nature of this APS was strongly suggested by the disappearance of both thromboembolism and antiphospholipid antibodies only after surgical removal of the cancer.

Cerebrovascular and neurological disorders associated with antiphospholipid antibodies in CSF and serum

Paired serum and cerebrospinal fluid (CSF) samples from 70 patients with inflammatory and non-inflammatory neurological diseases, as well as 10 sera from patients with primary antiphospholipid syndrome (PAS), six of which presented with cerebrovascular ischemic syndromes, were studied for the presence of anticardiolipin antibodies (ACA) of the G and M classes. PAS sera and some selected paired CSF and serum specimens, were also analyzed for the presence of anti-phosphatidylserine (PS) and anti-phosphatidylethanolamine (PE) antibodies. High levels of IgG and IgM ACA were synthesized intrathecally only in patients with neurosyphilis. Patients with other infectious or inflammatory neurological diseases very rarely showed detectable levels of ACA in serum and/or CSF. ACA were found not only in patients with untreated PAS but also in the serum of 3/7 patients with migraine, thus confirming a relationship between ACA and vascular disorders. The search for PS and PE antibodies disclosed that in PAS patients the serum titers of these antibodies mirrored ACA IgG and IgM titers, while they were never found in the CSF.

Antiphospholipid antibodies (aPL) in systemic lupus erythematosus. Are they specific tools for the diagnosis of aPL syndrome?

OBJECTIVE

Antiphospholipid antibody (aPL) specificity for aPL-related events was evaluated in systemic lupus erythematosus (SLE).

METHODS

A study was carried out on 105 patients affected with SLE comparing the prevalence of lupus anticoagulant (LA) and IgG and IgM anticardiolipin antibodies (aCL) between patients with and without features of antiphospholipid syndrome (APS). Antiphospholipid antibody profile was subsequently evaluated in the aPL positive patients with and without aPL-related events, thus excluding the patients with complications of APS possibly due to factors other than aPL.

RESULTS

LA showed a strong association with thrombosis and livedo reticularis, and IgG aCL with thrombosis and neurological disorders, while no clinical features were associated with IgM aCL. A considerable number of aPL positive patients with no aPL-related manifestations was also observed, suggesting the low specificity of aPL assays (54.4%). When studying the 60 aPL positive patients, LA was specific (91.3%) for the diagnosis of aPL-related thrombosis, whereas aCL were not specific, although IgG aCL mean levels were higher in patients with arterial thrombosis than in those without APS features.

CONCLUSIONS

LA but not aCL positivity is a specific tool for the diagnosis of thrombotic complications due to aPL in SLE.

A catastrophic antiphospholipid syndrome: the importance of high levels of warfarin anticoagulation

We report the clinical observation of a 23-year-old woman affected by the so-called 'catastrophic antiphospholipid syndrome'. Within a 3-month period she suffered a number of thrombotic events and haemolytic anaemia with thrombocytopenia and had high levels of immunoglobulins G and M and anticardiolipin antibodies associated with lupus anticoagulant activity. The severity of the clinical and laboratory changes is described and diagnostic and therapeutic difficulties are discussed. The apparent control of thrombotic events only with high levels of warfarin anticoagulation is stressed.

Early phenotypic activation of circulating helper memory T cells in scleroderma: correlation with disease activity

OBJECTIVES

The differential expression of several accessory/activation molecules (CD26, CD29, CD45RA, CD25, MLR4, HLA-DR) on peripheral blood CD4+ and CD8+ T lymphocytes in patients with scleroderma was compared with that in controls and patients with other connective systemic diseases to look for evidence of the involvement of T cells in the disease process of scleroderma.

METHODS

The two colour expression of surface molecules by circulating T cells was analysed with a panel of monoclonal antibodies and flow cytometry in 17 patients with scleroderma, 10 patients with systemic lupus erythematosus, and five patients with rheumatoid arthritis, and the results compared with those for 10 normal controls. The two colour T CD4+ phenotype was further compared between patients with active and quiescent disease in these patients with scleroderma. The coexpression of surface molecules by CD4+ T cells was also analysed by three colour flow cytometry in eight patients with scleroderma.

RESULTS

Patients with scleroderma showed increased CD4+CD26+ and CD4+CD25+ percentages and absolute numbers and decreased CD8+CD29+ percentages compared with controls. Moreover, a significant correlation between the higher CD4+CD26+ T cell percentage and absolute cell numbers with disease activity was observed. Most of the CD4+ peripheral blood T cells from patients with scleroderma showed the CD26+CD45RA- phenotype by three colour flow cytometry analysis.

CONCLUSIONS

The distinctive pattern of early helper memory T cell activation in these patients with rapidly evolving scleroderma supports the role of a T cell mediated mechanism in the progression of scleroderma.

Antiphospholipid syndrome in a child with trisomy 21: the relationship between anticardiolipin G antibodies and the von Willebrand factor

A young child with trisomy 21 developed severe multiple arterial thromboses in a three-phase clinical course which proved fatal. The episodes were characterized by high levels of both IgG anticardiolipin antibodies and the von Willebrand factor. The data suggest that there is a relationship between these two elements and the clinical events which followed.

Antiphospholipid antibodies in mixed connective tissue disease

We studied the prevalence and clinical significance of antiphospholipid antibodies (ab) in 28 patients affected with well-defined mixed connective tissue disease (MCTD). Forty-two patients affected with systemic lupus erythematosus (SLE) and 60 healthy subjects were also evaluated, as controls. In MCTD the prevalence of anticardiolipin (aCL) ab was: IgG high level 17.8% (p less than 0.01 versus healthy controls), IgG low level 7.1% and IgM high level 7.1%. No patients had low level of aCL IgM, lupus anticoagulant or false positive VDRL. The aCL profile was similar to that found in SLE patients, but in SLE all prevalences were higher than in MCTD. Furthermore, in MCTD patients the aCL ab were correlated with thrombocytopenia but not with recurrent thrombosis and/or abortions.

Japanese diagnostic criteria for mixed connective tissue disease in Caucasian patients

Preliminary Japanese diagnostic criteria for the classification of mixed connective tissue disease (MCTD) were tested in a group of 32 Caucasian patients with this disease. Many clinical and laboratory similarities were found between Caucasian and Japanese patients. However, polyarthritis was more frequent in the Caucasians, while finger and hand swelling, DLCO reduction and muscle involvement were more frequent in the Japanese. In Caucasians the sensitivity of this criteria set was 87%, very similar to that found in the Japanese group (88%), and the specificity was 94%, higher than that of Japanese (87%). The difference resulted from the higher specificity of anti-nRNP antibody positivity in the Caucasian patients, probably due to the use of counterimmunoelectrophoresis in the detection of this antibody. The Japanese criteria seem more useful than others because they allow the use of techniques other than passive hemagglutination in detecting the anti-nRNP antibody. In our experience, such criteria also contribute to a better definition of MCTD in Caucasian patients.

Hepatitis C virus infection in hemodialyzed patients detected by first and second generation assays

A prospective study of liver disease has been conducted among patients entering our Dialysis Unit between 1987 and 1990. On entry, 7 patients had a history of blood transfusions but none had clinical or biochemical features of liver disease. During follow-up, 13 further patients were transfused; 1 case developed acute resolving hepatitis B and another acute non-A, non-B hepatitis progressing to chronicity. Eleven other cases showed transient or fluctuating ALT abnormalities. On entry, anti-HCV was negative by both 1st and 2nd generation ELISA assays (Ortho-Diagnostic Systems) in all cases. During follow-up, a positive reaction was detected in 17 cases: 4 patients were positive by both assays and 13 only by 2nd generation test (p less than 0.01). HCV was implicated in 66% of cases with liver disease of the non-A, non-B type and in 50% of transfused as compared to 23% of nontransfused cases (p = n.s.). These findings suggest that HCV could play a major etiological role in liver disease of hemodialysis patients and that anti-C100 reactivity is more affected by immunosuppression associated with chronic uremia.

[Study of the arrhythmia in patients with chronic uremia in periodic hemodialysis with Holter dynamic electrocardiography]

For the purpose of evaluating cause, frequency, type and seriousness of arrhythmias in dialysis patients, 14 chronic uremics, 8 on bicarbonate-dialysis, 6 on acetate-dialysis underwent a basal ECG, echocardiography and a Holter dynamic electrocardiography (ECGD) for a duration of 96 hours. Before and after dialysis PAO, body weight, serum electrolytes and arterial pH were controlled. In 11 patients (78%) supraventricular and ventricular arrhythmias were discovered of equal frequency and seriousness both in the inter and intra dialytic phase, even if more frequent in ventricular hypertrophic patients (IVSn) the complex ventricular arrhythmias (Lown greater than 2). The seriousness and frequency of ventricular and supraventricular arrhythmias in the dialytic phase did not seem to depend either on the type of tampon or on the presence or absence of cardiopathies while in the inter-dialytic phase the seriousness of ventricular arrhythmias seems to depend upon the presence of cardiopathies. The Authors conclude that the pathogenesis of arrhythmias in uremic patients on dialysis is multifactorial and that their elevated incidence makes the use of a Holter in these patients recommendable.