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.

Understanding systemic lupus erythematosus physiopathology in the light of primary immunodeficiencies

INTRODUCTION

Associations between systemic lupus erythematosus (SLE) and primary immunodeficiencies (PIDs) were analyzed to gain insight into the physiopathology of SLE. Some PIDs have been consistently associated with SLE or lupus-like manifestations: (a) homozygous deficiencies of the early components of the classical complement pathway in the following decreasing order: in C1q, 93% of affected patients developed SLE; in C4, 75%; in C1r/s, 57%; and in C2, up to 25%; (b) female carriers of X-linked chronic granulomatous disease allele; and (c) IgA deficiency, present in around 5% of juvenile SLE.

DISCUSSION

In the first two groups, disturbances of cellular waste-disposal have been proposed as the main mechanisms of pathogenesis. On the other hand and very interestingly, there are PIDs systematically associated with several autoimmune manifestations in which SLE has not been described, such as autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), immunodysregulation polyendocrinopathy enteropathy X-linked (IPEX), and autoimmune lymphoproliferative syndrome (ALPS), suggesting that mechanisms considered as critical players for induction and maintenance of tolerance to autoantigens, such as (1) AIRE-mediated thymic negative selection of lymphocytes, (2) Foxp3+ regulatory T cell-mediated peripheral tolerance, and (3) deletion of auto-reactive lymphocytes by Fas-mediated apoptosis, could not be relevant in SLE physiopathology. The non-description of SLE and neither the most characteristic SLE clinical features among patients with agammaglobulinemia are also interesting observations, which reinforce the essential role of B lymphocytes and antibodies for SLE pathogenesis.

CONCLUSION

Therefore, monogenic PIDs represent unique and not fully explored human models for unraveling components of the conundrum represented by the physiopathology of SLE, a prototypical polygenic disease.

Rituximab in refractory autoimmune diseases: Brazilian experience with 29 patients (2002-2004)

OBJECTIVE

Rituximab, a monoclonal antibody against B-lymphocytes that express CD 20, is already available for the treatment of non-Hodgkin's lymphoma. Due to the increased relevance of B-cell regulation in the pathogenesis of autoimmune diseases, rituximab is being used in the treatment of patients whose condition is refractory to conventional therapy.

METHODS

We retrospectively evaluated the short-term efficacy and tolerance of rituximab in patients with various autoimmune diseases who were treated at the Hospital Israelita Albert Einstein in the city of Sao Paulo.

RESULTS

During the period 2002-2004, 29 patients with various autoimmune diseases were treated with rituximab 375 mg/m2 for 4 consecutive weeks, or two doses of 1 g 2 weeks apart. We observed remarkable short-term results in all cases, except for one patient with thrombocytopenic purpura. Of note, we describe the results in two patients with diseases not previously treated with rituximab (hypergammaglobulinemic purpura of Waldenstrom and eosinophilic fasciitis with hypergammaglobulinemia). Treatment was well tolerated, with no unexpected adverse events. We also observed a marked reduction in steroid dosage.

CONCLUSION

Rituximab seems to be safe and effective in the treatment of patients with a variety of autoimmune diseases that are refractory to other modalities of treatment.

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 researched in 57 children and adolescents with systemic lupus erythematosus (SLE). The frequency of aPL antibodies was 75.4% (anticardiolipin 70.2% and lupus anticoagulant 29.1%). The positivity for these antibodies fluctuated during the course of the disease. No association was found between aPL antibodies and clinical or laboratory manifestations or the autoantibodies studied, 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 cerebrovascular accidents, amaurosis fugax, osteonecrosis and interstitial pneumonitis. A negative association was observed between APS and the presence of anti-Ro antibodies.

T-cell reactivity against streptococcal antigens in the periphery mirrors reactivity of heart-infiltrating T lymphocytes in rheumatic heart disease patients

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.

Correlation between osteochondral changes depicted by magnetic resonance imaging and disease progression

PURPOSE

To determine the consequences of the chronic use of systemic corticosteroids in children with juvenile rheumatoid arthritis by means of evaluating osteochondral effects depicted by magnetic resonance imaging.

PATIENTS AND METHODS

We reviewed clinical and magnetic resonance imaging findings in 69 children (72 knees) with juvenile rheumatoid arthritis. Two groups were studied. Group I: 34 (49.3%) children had previous or current use of systemic corticotherapy (22 girls; 12 boys; mean age: 11.3 years; mean disease duration: 5.9 years; mean corticotherapy duration: 2.9 years; mean cumulative dose of previous corticosteroids: 5000 mg); Group II: 35 (50.7%) children had no previous use of corticosteroids (27 girls; 8 boys; mean age: 11.7 years; mean disease duration: 5.3 years). The groups were compared statistically.

RESULTS

In the group that had received corticotherapy (Group I), osteochondral abnormalities were significantly correlated to long-standing disease (>3.5 years; p<0.001). This correlation was not found in the group that had no previous history of corticotherapy (Group II). No correlations were established between median dose of corticosteroids and magnetic resonance imaging findings.

CONCLUSION

It is important to further investigate the long-term intra-articular effects of systemic corticotherapy to ensure that the side effects of the aggressive therapy will not be more harmful for the joints than the symptoms suffered over the natural course of the disease.

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

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] x 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.

The Brazilian version of the Childhood Health Assessment Questionnaire (CHAQ) and the Child Health Questionnaire (CHQ)

We report the cross-cultural adaptation and validation into Brazilian-Portuguese of the parent's version of two health related quality of life instruments. The Childhood Health Assessment Questionnaire (CHAQ) is a disease specific health instrument that measures functional ability in daily living activities in children with juvenile idiopathic arthritis (JIA). The Child Health Questionnaire (CHQ) is a generic health instrument designed to capture the physical and psychosocial well-being of children regardless the underlying disease. The Brazilian CHAQ was revalidated, while the CHQ has been derived from the Portuguese version. A total of 471 subjects were enrolled: 157 patients with JIA (27% systemic onset, 38% polyarticular onset, 9% extended oligoarticular subtype, and 26% persistent oligoarticular subtype) and 314 healthy children. The CHAQ discriminated clinically healthy subjects from JIA patients, with the systemic, polyarticular and extended oligoarticular subtypes having a higher degree of disability, pain, and lower overall well-being scores when compared to their healthy peers. Also the CHQ discriminated clinically healthy subjects from JIA patients, with the systemic onset, polyarticular onset and extended oligoarticular subtypes having a lower physical and psychosocial well-being score when compared to their healthy peers. In conclusion the Brazilian versions of the CHAQ-CHQ are reliable and valid tools for the combined physical and psychosocial assessment of children with JIA.

The psychiatric symptoms of rheumatic fever

OBJECTIVE

This study examined the frequency and age at onset of psychiatric disorders among children with rheumatic fever, Sydenham's chorea, or both and a comparison group.

METHOD

Twenty children with rheumatic fever, 22 with Sydenham's chorea, and 20 comparison children were assessed by means of a semistructured interview and rating scales for tic disorders and obsessive-compulsive disorder.

RESULTS

Obsessive-compulsive symptoms were more frequent in both the Sydenham's chorea and rheumatic fever groups than in the comparison group. The Sydenham's chorea group had a higher frequency of major depressive disorder, tic disorders, and attention deficit hyperactivity disorder (ADHD) than both the comparison and rheumatic fever groups. ADHD symptoms were associated with a higher risk of developing Sydenham's chorea.

CONCLUSIONS

Both the rheumatic fever and Sydenham's chorea groups were associated with a higher risk of developing neuropsychiatric disorders than the comparison group. ADHD appears to be a risk factor for Sydenham's chorea in children with rheumatic fever.

Obsessive-compulsive and related symptoms in children and adolescents with rheumatic fever with and without chorea: a prospective 6-month study

OBJECTIVE

The incidence and course of neuropsychiatric symptoms were determined in pediatric patients with rheumatic fever.

METHOD

The Leyton Obsessional Inventory and National Institute of Mental Health Global Obsessive-Compulsive Scale were used to evaluate children and adolescents who had rheumatic fever with Sydenham's chorea (N=30) or without chorea (N=20). They were assessed three times over 6 months from the onset of rheumatic fever. Psychiatric diagnoses were also determined.

RESULTS

Obsessive-compulsive symptoms abruptly appeared and peaked during the 2 months after the onset of rheumatic fever in 21 patients with chorea (70.0%) and were absent in all patients without chorea. Obsessive-compulsive disorder (OCD) was diagnosed in five patients with chorea (16.7%).

CONCLUSIONS

The association between Sydenham's chorea and OCD supports suggestions that similar mechanisms involving the basal ganglia underlie both disorders. Obsessive-compulsive symptoms occurred at the beginning of rheumatic fever, so early psychopathological assessments are essential.

Skeletal muscle pathology in systemic sclerosis

OBJECTIVE

Systemic sclerosis (SSc) is characterized by abnormal deposition of collagen in the skin and by visceral involvement. Muscle weakness is a relatively frequent complication of SSc, although severity varies. We studied muscle pathology in patients with SSc with progressive muscle involvement.

METHODS

We performed histochemical and immunohistochemical investigations to detect neural cell adhesion molecule (NCAM).

RESULTS

Five of the 6 cases of SSc expressed NCAM in atrophic angulated fibers (some fibers stained heavily with oxidative enzymes).

CONCLUSION

Neurogenic involvement in SSc is more frequent than reported.

[Clinical, laboratorial, and therapeutic aspects of 46 children with Henoch-Schönlein purpura]

Forty-six children with Henoch-Schönlein purpura were studied.Their clinical manifestations included palpable purpura in 100%, subcutaneous edema in 30%, arthritis/arthralgia in 78%, gastrointestinal involvement in 56% and renal abnormalities in 30%. Serum IgA was elevated in 12%, ASLO titers in 27% and microscopic hematuria and proteinuria were detected in 30% of the children, including two with nephrotic syndrome. Treatment with non-steroidal antiinflammatory drugs or corticosteroid was indicated in 43% of the children. Recurrence of the disease was observed in 22% and the prognosis seems to be related to severity of renal involvement.

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

BACKGROUND

The 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 RESULTS

HLA 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% 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 = 0.00715; relative risk, 3.8; etiologic fraction, 0.56). HLA class I and HLA-DQ typing did not point to any association with these diseases.

CONCLUSIONS

HLA-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.

Ureteral necrosis in dermatomyositis

We describe a child with dermatomyositis and calcified necrosis in the middle third of both ureters. Histopathological examination showed vasculitis associated with ureteral necrosis and calcification. These findings together with a similar previous report in the literature have prompted us to correlate dermatomyositis in childhood with ureteral necrosis and to anticipate specifically a lesion in the middle third of the ureter because of the relative lack of blood flow in that segment.