Spectrum of autoantibodies other than anti-desmoglein in pemphigus patients

BACKGROUND

Pemphigus is a life-threatening autoimmune blistering disease mediated by autoantibodies against adhesion molecule of the skin. Its concurrence with systemic and organ-specific autoimmune disease was described in case reports.

OBJECTIVES

To evaluate the presence of a broad spectrum of organ-specific and non-organ-specific autoantibodies other than anti-desmoglein antibodies in pemphigus patients.

PATIENTS AND METHODS

Serum samples were obtained from 105 pemphigus foliaceus (PF) patients, 51 pemphigus vulgaris (PV) patients and 50 controls. Both indirect immunofluorescence assay and ELISA were used to assess the presence of autoantibodies related to connective tissue diseases, autoimmune hepatitis, vasculitis, rheumatoid arthritis, coeliac disease, diabetes and thyroiditis.

RESULTS

Significant difference was observed between the three groups for anti-thyroglobulin antibodies in the pemphigus foliaceus group (18% vs. 4%, P=0.03). A significantly higher occurrence of IgM anti-cardiolipin (P=0.03), IgG anti-reticulin (P=0.01) and IgG anti-gliadin antibodies (P=0.008) were observed in the PV group. Cases with more than four autoantibodies were frequently positives for both anti-desmoglein 1 and anti-desmoglein 3.

CONCLUSION

Autoantibodies other than anti-desmoglein antibodies are not rare in pemphigus patients. Clinical and serological follow-up of pemphigus patients with positive autoantibodies are needed to clarify their impact in disease evolution.

Enhanced reactivity to malondialdehyde-modified proteins by systemic lupus erythematosus autoantibodies

OBJECTIVE

Evaluation of the reactivity of autoantibodies of systemic lupus erythematosus (SLE) patients directed against malondialdehyde (MDA)-modified catalase, superoxide dismutase (SOD), and different Hep2 protein fractions (hydrophobic, hydrophilic, and nuclear).

METHOD

Thiol groups and MDA-protein adducts were first assessed among 65 SLE patients and 60 healthy controls. Then, the reactivities of SLE immunoglobulin (Ig)G autoantibodies towards MDA-modified and unmodified proteins were compared using a standard enzyme-linked immunosorbent assay (ELISA).

RESULTS

An increase in the levels of MDA-modified proteins and a decrease in the concentration of thiol groups among SLE patients (p < 0.05) were observed. IgG circulating autoantibodies in the sera of SLE patients exhibited a significant enhanced reactivity (p < 0.05) against catalase and SOD-modified proteins. The same data were observed in the different protein fractions extracted from cultured cells (p < 0.05).

CONCLUSION

These data reinforce the role of oxidative stress and especially lipid peroxidation products in the progression of SLE disease.

[Benzylthiouracil induced ANCA-positive vasculitis: study of three cases and review of the literature]

INTRODUCTION

Vasculitis with antineutrophilic cytoplasmic antibodies (ANCA) have been reported in patients treated with anti-thyroid drugs, especially propylthiouracil. Benzylthiouracil, which exhibits similar structural likeness with propylthiouracil, has been recently observed to be associated with Anca-positive vasculitis.

CASES REPORT

We present a study of three women with Grave's disease aged 21, 37 and 40 years, who were treated with benzylthiouracil. These patients developed vasculitis characterized by constitutional symptoms (two patients), joint pain (two patients), renal involvement (two patients), pulmonary hemorrhage (one patient) and multiple neuropathy (one patient). All patients presented p-ANCA with anti-MPO pattern. Discontinuation of benzylthiouracil and treatment with corticosteroids improved systemic involvement in all patients.

CONCLUSION

Much like other anti-thyroid drugs, benzylthiouracil can be associated with ANCA-positive vasculitis. Because of the gravity of this complication, clinical monitoring is recommended in patients taking benzylthiouracil. If vasculitis develops, the anti-thyroid drug should be discontinued and corticosteroid treatment, with immunosuppressors in some cases, is initiated.

Pancreatic autoantibodies in Tunisian children with newly diagnosed type 1 diabetes

We analyzed 86 children with newly diagnosed type 1 diabetes for antibodies to islet cells (ICA), glutamic acid decarboxylase (GADA), second-islet antigen (IA-2A), and insulin (IAA) in order to evaluate the prevalence of immune-mediated type 1 diabetes, as well as to recognize which autoantibody combination is more frequently associated with the disease. A positive result for one or more diabetes-related antibodies evaluated was found in 78 children (90.7%). With regard to single autoantibody testing, ICA were found to be positive in 49 patients (57%), GADA in 56 (65.1%), IA-2A in 37 (43%), and IAA in 43 (50%) patients. Combining the determination of at least two autoantibodies, GADA and/or IAA were better detectable than other antibody combination, being positive in 70 patients (81.4%). GADA and IA-2A represent also a useful screening combination; being positive in 65 patients (75.6%). Our data indicate that the vast majority of cases of type 1 diabetes in children may be considered as immune-mediated and that multiple autoantibody analysis improves identification of the disease.

Gammapathies monoclonales en Tunisie : analyse épidémiologique, immunochimique et étiologique d'une série de 288 cas

From July 1992 to December 2000, 288 cases of monoclonal gammapathy (MG) were collected at the university hospital of Sfax. The middle age of the patients at the time of the diagnosis was 62 years and 7 months with extremes to 18 months and 99 years and median to 64 years. One hundred and eighty-two patients were men and 106 women. Among the 270 observations for which aetiology has been established, 73 were classified MG of undetermined significance (MGUS), 160 myeloma (or plasmocytoma) and 37 other malignant MG (Waldenstrom's macroglobulinemia: 13, lymphoma: 9, alpha heavy chains disease: 6, primary amyloidosis: 5, chronic lymphocytic leukaemia: 4). Rheumatological affections (19.2%), infections and renal failure (10% each), haematological and autoimmune diseases (9.6% each) were pathologies most often associated with MGUS. Agarose gel electrophoresis did not show a monoclonal peak in 16% of the cases. In the 242 patients with a peak on electrophoresis, the peak was in the beta zone in 22% of cases and in the gamma zone in 78% of cases. The IgG isotype represents more than the half of the cases of our set (51.7%). IgG is even more predominant in the MGUS group (65.8%). The IgA isotype counts for 20.8% of the cases in our set and the free light chains (kappa or lambda) for 13.6% of the cases whereas the IgM represents 8.7% only of the 288 cases of our set which involves three cases of IgD myeloma and six cases of biclonal gammapathy.

[Autoantibodies in systemic lupus erythematosus: spectrum and clinical associations]

We have analysed the clinical features and autoantibody profile of 84 tunisian patients with newly diagnosed systemic lupus erythematosus (SLE). Antinuclear antibodies (ANA) were detected by an immunofluorescence method, anti-dsDNA and anti-cardiolipin (aCL) antibodies by ELISA, antinucleosome and anti-extractible nuclear antigens (or anti-ENA: anti-Sm, anti-RNP, anti-SSA and anti-SSB) by immunodot. The mean age of the patients was 29,9 years and the sex-ratio F/M was 6. The most common initial features were haematological (80%), rheumatological (78%) and cutaneous (75%) disorders. 59% of the patients had glomerular nephropathy. ANA were detected in 97.6%, antinucleosome in 78.6%, anti-dsDNA in 75%, anti-histones in 44%, anti-Sm in 36.9%, anti-RNP in 32.1%, anti-SSA in 54.8% and anti-SSB in 14.3% of patients. IgG and IgM aCL were detected in 45 and 40% of the patients respectively. The significant clinical associations were those of nephropathy and disease activity with anti-dsDNA and antinucleosome antibodies. Our results confirm the clinical polymorphism of SLE, the high frequency of antinucleosome antibodies at time of diagnosis and the predominance of anti-SSA among anti-ENA antibodies.

Clinical significance of antinucleosome antibodies in Tunisian systemic lupus erythematosus patients

The aim of this study was to investigate the clinical significance of antinucleosome antibodies in Tunisian systemic lupus erythematosus (SLE) patients. IgG antinucleosome antibodies were detected by a qualitative enzyme immunoassay (immunodot) in the sera of SLE patients at onset of disease. The patients were divided into two groups according to the result of the antinucleosome antibodies test: positive (group A) and negative (group B). The two groups were also evaluated for clinical and biological parameters. Of 84 patients with SLE, 66 (78.6%) had antinucleosome antibodies. Among 21 patients negative for anti-double-stranded DNA (anti-dsDNA), 5 (23.8%) were antinucleosome positive. The most common initial features were haematological disorders (80.1%) and arthritis or arthralgias (79.8%). Renal disorders, observed in 59.5% of SLE patients, were more common in group A compared to group B (65 vs 38%) (p=0.04). The European Consensus Lupus Activity Measurement (ECLAM) mean score was higher in group A (6.42) than in group B (4.44) (p=0.002). Antinucleosome antibodies were positive in nearly one-fourth of SLE patients negative for anti-dsDNA. We found a correlation between antinucleosome antibodies, nephritis and SLE disease activity. Therefore, the determination of circulating antinucleosome antibodies could be a useful parameter for early diagnosis and follow-up of SLE patients.