Maria Helena B. Kiss

Antibodies against neural, nuclear, cytoskeletal, and streptococcal epitopes in children and adults with Tourette’s syndrome, Sydenham’s chorea, and autoimmune disorders

BACKGROUND Some cases of Tourettes syndrome (TS) are hypothesized to be caused by autoantibodies that develop in response to a preceding group A beta hemolytic streptococcal infection. METHODS To test this hypothesis, we looked for the presence ot total and IgG antibodies against neural, nuclear, cytoskeletal and streptococcal epitopes using indirect immunofluorescent assays and Western blot techniques in three patient groups: TS (n = 81), SC (n = 27), and a group of autoimmune disorders (n = 52) and in normal controls (n = 67). Subjects were ranked after titrations of autoantibodies from 0 to 227 according to their level of immunoreactivity. RESULTS TS patients had a significantly higher mean rank for total antineural and antinuclear antibodies, as well as antistreptolysin O titers. However, among children and adolescents, only the total antinuclear antibodies were increased in TS patients compared to age matched controls. Compared to SC patients, TS patients had a significantly lower mean rank for total and IgG class antineural antibodies, significantly lower IgG class anticytoskeletal antibodies, and a significantly higher rank for total antinuclear antibodies. Compared to a mixed group of autoimmune disorders, the TS patients had a significantly lower mean rank for total and IgG class antineural antibodies, total and IgG class antinuclear antibodies, IgG class anticytoskeletal antibodies, and a significantly higher rank for antistreptococcal antibodies. CONCLUSIONS TS patients had significantly higher levels of total antineural and antinuclear antibodies than did controls. Their relation to IgG class antineural and antinuclear antibodies, markers for prior streptococcal infection, and other clinical characteristics, especially chronological age, was equivocal.

Association of human leukocyte class II antigens with rheumatic fever or rheumatic heart disease in a Brazilian population.

BackgroundThe incidence of rheumatic heart disease is great in Brazil. We analyzed the distribution of human leukocyte (HLA) antigens in a Brazilian population sample with rheumatic fever or rheumatic heart disease, with the aim of better understanding the mechanisms involved. Methods and ResultsHLA class I (A, B, and C) and class II (DR and DQ) antigen distribution was studied in 40 patients with diagnosis of rheumatic fever or rheumatic heart disease and compared with a control group of 617 healthy individuals for class I typing, from which 118 were drawn for class II typing. A strong correlation between rheumatic fever and rheumatic heart disease and HLA-DRw53 (72.9% in the disease group versus 39%1 in the control group: p = 0.00061, relative risk, 4.2; etiologic fraction, 0.43) was found. We also found an increase in the frequency of HLA-DR7 (57.5% in the disease group versus 26.3% in control group: p=O0.00715; relative risk, 3.8; etiologic fraction, 0.56). HLA class I and HLA-DQ typing did not point to any association with these diseases. ConclusionsHLA-DR7 and HLA-DRw53 are markers for susceptibility to rheumatic fever and rheumatic heart disease in Brazil. These results could be explained by genetic differences resulting from racial or geographical diversity. (Circulation 1991;83:1995—1998)

T-Cell Reactivity against Streptococcal Antigens in the Periphery Mirrors Reactivity of Heart-Infiltrating T Lymphocytes in Rheumatic Heart Disease Patients

ABSTRACT T-cell molecular mimicry between streptococcal and heart proteins has been proposed as the triggering factor leading to autoimmunity in rheumatic heart disease (RHD). We searched for immunodominant T-cell M5 epitopes among RHD patients with defined clinical outcomes and compared the T-cell reactivities of peripheral blood and intralesional T cells from patients with severe RHD. The role of HLA class II molecules in the presentation of M5 peptides was also evaluated. We studied the T-cell reactivity against M5 peptides and heart proteins on peripheral blood mononuclear cells (PBMC) from 74 RHD patients grouped according to the severity of disease, along with intralesional and peripheral T-cell clones from RHD patients. Peptides encompassing residues 1 to 25, 81 to 103, 125 to 139, and 163 to 177 were more frequently recognized by PBMC from RHD patients than by those from controls. The M5 peptide encompassing residues 81 to 96 [M5(81–96) peptide] was most frequently recognized by PBMC from HLA-DR7+DR53+ patients with severe RHD, and 46.9% (15 of 32) and 43% (3 of 7) of heart-infiltrating and PBMC-derived peptide-reactive T-cell clones, respectively, recognized the M5(81–103) region. Heart proteins were recognized more frequently by PBMC from patients with severe RHD than by those from patients with mild RHD. The similar pattern of T-cell reactivity found with both peripheral blood and heart-infiltrating T cells is consistent with the migration of M-protein-sensitized T cells to the heart tissue. Conversely, the presence of heart-reactive T cells in the PBMC of patients with severe RHD also suggests a spillover of sensitized T cells from the heart lesion.

Juvenile rheumatoid arthritis of the knee: evaluation with contrast-enhanced color Doppler ultrasound

Abstract.Background. Contrast-enhanced color Doppler ultrasonography is a non-radiation-bearing tool that can be of value for assessment of inflammatory and vascular synovial changes in juvenile rheumatoid arthritis (JRA). Objectives. To evaluate the effect of contrast-enhanced color Doppler ultrasound (US) in the evaluation of synovial changes in the knees of children with JRA. Materials and methods. Sagittal color Doppler sonograms of 31 knees in 22 patients with JRA and of 10 knees in 5 control subjects were obtained before (at baseline) and after (at peak contrast phase) intravenous injection of SHU 508. Images were assessed for overall mean pixel intensity within the synovial tissue and for peak enhancement ratios {[(mean pixel intensity values at maximum contrast enhancement–unenhanced mean pixel intensity values)/unenhanced mean pixel intensity values] × 100}. The joints were classified into three groups by clinical/laboratory criteria: group A (active disease in the knee), n = 9; group B (quiescent disease with serum chemistry levels of active disease), n = 12 and group C (remission disease), n = 10. Results. Mean color pixel intensity values were markedly increased by the use of US contrast agents in groups A (P = 0.004) and B (P = 0.0001), did not reach statistical significance in group C (P = 0.06) and remained essentially unchanged in the control group (P = 0.25). Enhancement ratios for the three groups of JRA patients were not different (P = 0.38) (mean ± SD, 720 % ± 402 for group A, 731 % ± 703 for group B and 314 % ± 263 for group C). Conclusion. Contrast-enhanced color Doppler imaging holds promise for the detection of active synovial inflammatory disease in subclinical cases of JRA, thereby allowing earlier treatment and improved clinical outcome.

Antiphospholipid antibodies and antiphospholipid syndrome in 57 children and adolescents with systemic lupus erythematosus

The presence of antiphospholipid (aPL) antibodies and antiphospholipid syndrome (APS) was researchedin 57 childrenand adolescentswith systemic lupus erythematosus(SLE). The frequencyof aPL antibodies was 75.4% (anticardiolipin70.2% and lupus anticoagulant29.1%). The positivity for these antibodies fluctuated during the course of the disease. No association was found between aPL antibodiesand clinical or laboratory manifestationsor the autoantibodiesstudied, nor with the activity or gravity of the SLE. APS was diagnosed in 14% of the cases (eight patients), on average three years after the diagnosis of SLE. Four patients had arterial thrombosis (stroke, three; transient ischaemic attack, one; amaurosis fugax, two; renal, one), one presented with deep vein thrombosis (DVT) and three had involvement of small calibre vessels (osteonecrosis, two; transverse myelitis, one). Recurrences were observed in three of the eight cases (37.5%), with a mean interval of 13 months between the events. The presence of APS was associated with haemolytic anaemia, leukopenia, thrombocytopenia, coagulation abnormalities, ischaemic cerebrovascularaccidents, amaurosis fugax, osteonecrosisand interstitial pneumonitis. A negative association was observed between APS and the presence of anti-Ro antibodies.

PDIA3, HSPA5 and vimentin, proteins identified by 2-DE in the valvular tissue, are the target antigens of peripheral and heart infiltrating T cells from chronic rheumatic heart disease patients.

Rheumatic fever (RF) is a post-infectious autoimmune disease due to sequel of group A streptococcus (GAS) pharyngitis. Rheumatic heart disease (RHD), the major manifestation of RF, is characterized by inflammation of heart valves and myocardium. Molecular mimicry between GAS antigens and host proteins has been shown at B and T cell level. However the identification of the autoantigens recognized by B and T cells within the inflammatory microenvironment of heart tissue in patients with RHD is still incompletely elucidated. In the present study, we used two-dimensional gel electrophoresis (2-DE) and mass spectrometry to identify valvular tissue proteins target of T cells from chronic RHD patients. We could identify three proteins recognized by heart infiltrating and peripheral T cells as protein disulfide isomerase ER-60 precursor (PDIA3), 78kD glucose-regulated protein precursor (HSPA5) and vimentin, with coverage of 45%, 43 and 34%, respectively. These proteins were recognized in a proliferation assay by peripheral and heart infiltrating T cells from RHD patients suggesting that they may be involved in the autoimmune reactions that leads to valve damage. We also observed that several other proteins isolated by 2-DE but not identified by mass spectrometry were also recognized by T cells. The identified cardiac proteins are likely relevant antigens involved in T cell-mediated autoimmune responses in RF/RHD that may contribute to the development of RHD.

Inter- and intrareader variability in the interpretation of two radiographic classification systems for juvenile rheumatoid arthritis

ObjectiveTo evaluate the inter- and intrareader variability for interpretation of a modified Larsens radiographic classification system for juvenile rheumatoid arthritis (JRA) focused on osteochondral lesions and a conventional Larsens classification system, compared to a reference MR scoring system of corresponding images.Materials and methodsSeventy-five radiographs of 60 children with JRA, performed within a short interval of time from the MR examinations, were independently evaluated by three experienced radiologists, three diagnostic imaging residents and three rheumatologists, in two separate sessions, according to the two different classification methods, blinded to the corresponding MR images.ResultsThe inter- and intrareader concordance rates between the two radiographic classification systems and the MR-related radiographs were respectively poor and poor/moderate. The interobserver range of weighted kappa values for the conventional and the modified Larsens system respectively was 0.25–0.37 vs 0.19–0.39 for radiologists, 0.25–0.37 vs 0.18–0.30 for residents and 0.19–0.51 vs 0.17–0.29 for rheumatologists. The intrareader rate ranged from 0.17–0.55 for radiologists, 0.2–0.56 for residents, and 0.14–0.59 for rheumatologists.ConclusionAlthough the proposal of a new radiographic classification system for JRA focused on osteochondral abnormalities sounds promising, the low inter- and intrareader concordance rates with an MR-related radiographic system makes the clinical applicability of such a radiographic system less suitable.

Antinucleosome antibodies in patients with juvenile systemic lupus erythematosus.

Our objective was to evaluate the frequency of antinucleosome antibodies (anti-Ncs) in juvenile systemic lupus erythematosus (JSLE) comparing it to that observed for anti-DNA and to correlate the presence of these antibodies with clinical manifestations and disease activity. Anti-Ncs and anti-DNA were detected by ELISA in 74 patients with JSLE and 64 normal controls. Clinical records were reviewed. Disease activity was assessed by SLEDAI score. Anti-Ncs and anti-DNA showed sensitivity of 52.7% and 54% and specificity of 98.4% and 95.3%, respectively. Disagreement between the two assays was found in 25.7% of the cases: isolated positive Anti-Ncs in nine cases (12.2%) and isolated positive anti-DNA in 10 cases (13.5%). Agreement was found in 74.3%: both positive antibodies in 30 cases and both negative in 25. The presence of anti-Ncs was significantly associated with malar erythema, hemolytic anemia, anti-DNA and low complement levels, but not with renal manifestations. The presence of anti-Ncs was associated with a higher SLEDAI median (P < 0.001) and its titers correlated with the SLEDAI score (r = 0.504; P < 0.001). The frequency, sensitivity and specificity values were similar between anti-Ncs and anti-DNA antibodies in patients with JSLE. Nevertheless, the discordance of 25.7% between the two assays suggests that both antibodies may have a complementary diagnostic role. The association and correlation between anti-Ncs and several disease activity parameters demonstrated its usufulness in the follow-up of these patients.

Macrophage activation syndrome associated with systemic juvenile idiopathic arthritis

OBJECTIVE To describe the characteristics of macrophage activation syndrome associated with juvenile idiopathic arthritis. DESCRIPTION This is a retrospective study involving 462 patients with juvenile idiopathic arthritis. Seven (1.5%) of those patients suffered from systemic onset juvenile idiopathic arthritis and developed macrophage activation syndrome. The median age of the juvenile idiopathic arthritis onset was 3 years and 10 months and the median duration of juvenile idiopathic arthritis before macrophage activation syndrome was 8 years and 4 months. All of them presented with fever, jaundice, hepatosplenomegaly, bleeding, pancytopenia, abnormal liver function tests and abnormal coagulation profile. Three cases presented associated infections and one patient developed macrophage activation syndrome two weeks after the administration of sulfasalazine. Three patients died and the macrophage hemophagocytosis was present in five. The treatment of macrophage activation syndrome included pulse therapy with methylprednisolone in all of them, cyclosporine A in three, plasma exchange in two and intravenous immunoglobulin in two. COMMENTS Macrophage activation syndrome is a complication of the systemic onset juvenile idiopathic arthritis with a high morbidity and mortality rate.

The role of apoptosis proteins and complement components in the etiopathogenesis of systemic lupus erythematosus

Systemic lupus erythematosus is a prototypical autoimmune disease characterized by the deregulation of T and B cells, tissue infiltration by mononuclear cells, tissue damage and the production of autoantibodies. There is a consensus that accelerated apoptosis of circulating lymphocytes and/or impaired clearance of apoptotic bodies may increase the amount of nuclear antigens presented to T lymphocytes. This process is accompanied by autoimmune responses that can lead to the development of lupus. The dysfunction of apoptosis may be a direct consequence of alterations in proteins/genes such as Fas, Bcl-2 and C1q. Increased expression of Fas antigen could intensify the exposure of hidden antigens. The overexpression of Bcl-2 protein might inhibit the removal of auto-reactive cells, and the lack of C1q could impair the clearance of self-antigens. The complete knowledge of the role of apoptosis components in the etiopathogenesis of lupus could lead to the development of new therapies targeting the apoptotic threshold, which could result in a more specific and effective disease response compared to global immunosuppression. This review summarizes the role of each component of the apoptotic process in the pathogenesis of lupus.