Myositis-specific autoantibodies in clinical practice: Improving the performance of the immunodot.

BACKGROUND/OBJECTIVES: Idiopathic inflammatory myopathies (IIM) diagnosis and sub-classification can be improved by detection of myositis specific antibodies (MSA) as a first step in diagnosis. However, when using semi-quantitative immunodots for MSA detection, clinical assay performance needs to be improved. METHODS: A retrospective study was done for the "myositis" and "synthetase" immunodots (SRP, NXP2, TIF1gamma, SAE1/2, Mi2, MDA5, Jo1, PL7, PL12, EJ, OJ, KS, ZO and HA) from D-Tek used for 270 patients who had tested positive for MSA in a tertiary laboratory hospital. RESULTS: Results from this analysis revealed: (i) none of the 60 healthy controls presented MSA; (ii) a low assay specificity among patients who tested positive for MSA, 128/270 (47%) were labeled IIM based on the manufacturer's recommended threshold; (iii) in non-IIM patients (53%), the MSA spectrum overlaps predominantly with other autoimmune diseases or idiopathic interstitial lung disease; and (iv) use of a clinical cut-off improves assay specificity for anti-SRP, anti-NXP2, anti-MDA5, anti-Jo1 and anti-PL7 Abs. CONCLUSION: Determining the clinical threshold of the semi-quantitative immunodot assay for MSA is effective for improving its capacity to discriminate IIM from non-IIM and, when IIM diagnosis is excluded, another autoimmune disease or an idiopathic interstitial lung disease should be considered in front of a positive MSA.

[Acyclovir-resistant perineal HSV infection revealing chronic lymphoid leukaemia]. / Herpès chronique périnéal résistant à l'aciclovir révélateur d'une leucémie lymphoïde chronique.

BACKGROUND: Chronic HSV infection is a cause of chronic perineal ulcerations. We report a case of a chronic and refractory HSV infection revealing chronic lymphoid leukaemia. PATIENTS AND METHODS: An 85-year-old woman with an 8-month history of chronic perineal ulcerations was referred to our dermatology department. She had no previous medical history of herpes infection. Skin biopsies ruled out carcinoma but were consistent with HSV infection. A local swab was positive for HSV2. Treatment with valaciclovir and intravenous acyclovir (ACV) at the recommended doses was ineffective. Laboratory tests revealed type-B chronic lymphoid leukaemia. Molecular biology studies confirmed the presence of ACV-resistant HSV via decreased thymidine kinase activity (stop codon: M183stop). Foscarnet was administered for a period of 3 weeks with almost complete healing of the ulcerations. Treatment was stopped prematurely due to acute renal insufficiency and the remaining lesions were treated using imiquimod cream. Valaciclovir was prescribed to prevent further episodes. The condition recurred a mere 11 months later. DISCUSSION: The prevalence of ACV-resistant HSV is 0.32 % in immunocompetent patients and 3.5 % in immunocompromised patients. Insufficient dosing regimens or prolonged treatment with TK inhibitors result in the local selection of pre-existing mutant HSV viruses. Foscarnet, a DNA polymerase inhibitor, is the treatment of choice in HSV-resistant infections. ACV-resistant HSV is less virulent and replicates less, with reactivations being mainly due to wild-type HSV latent in the neural ganglia. Valaciclovir can be used as a preventive treatment. To our knowledge, this is the first case of ACV-resistant HSV infection revealing chronic lymphoid leukaemia. CONCLUSION: Chronic perineal ulcerations can be the first manifestation of immunodeficiency seen for example with haematological diseases. In the event of clinical resistance of an HSV infection to recommended thymidine kinase inhibitor regimens, the use of foscarnet should be considered.

[Antidesmoglein antibodies in a patient with Hailey-Hailey disease]. / Détection d'anticorps antidesmogléines circulants chez un patient atteint de maladie de Hailey-Hailey.

BACKGROUND: Hailey-Hailey disease (HHD) is a rare hereditary disease in which the genetic defect is characterized by mutation in the ATP2C1 gene coding for a transmembrane calcium pump. It is generally considered a non-immunologic acantholytic dermatosis in which direct and indirect immunofluorescence studies are negative, unlike in autoimmune pemphigus. PATIENTS AND METHODS: We describe a case of HHD associated with antidesmoglein antibodies in a 53-year-old woman. The clinical symptoms and histology were typical of HHD. Antidesmoglein antibody tests were positive on several occasions and a difference was found between the two types of Elisa test performed (positive with the MBL kit, negative with the Euroimmun kit). DISCUSSION: The positive result for desmoglein antibodies could be due to unmasking of antigens by the mechanism of acantholysis. The specificity of the main desmoglein Elisa tests also requires discussion.

[Antiphospholipid antibodies and the risk of thrombosis: a comparative survey between chronic immune thrombocytopenia and primary antiphospholipid syndrome]. / Profil des anticorps antiphospholipides et risque de thrombose : étude comparative entre thrombopénie immunologique chronique et syndrome des antiphospholipides primaire.

PURPOSE: The prevalence of antiphospholipid antibodies (APA) in patients with immune thrombocytopenic purpura (ITP) varies from 25 to 75% in the literature. The risk of thrombosis in this subgroup of patients is debated. In parallel, thrombocytopenia is present in 22 to 42% of patients with antiphospholipid syndrome (APS). PATIENTS AND METHODS: The main study objective was to compare the profile at diagnosis of lupus anticoagulant (LA), anticardiolipin antibody (ACL) and anti-ß(2)GP-I antibody between a cohort of 93 chronic ITP patients and a cohort of 27 primary APS patients. The secondary objectives were: to evaluate the risk of thrombosis in ITP patients depending on the presence of APA; to compare the profile of APA and to assess the occurrence of lupus in APS patients depending on the presence of thrombocytopenia. RESULTS: In ITP patients, the prevalence of APA was 25%; association of several different APA was less frequent than in APS patients; mean titles of ACL and anti-ß(2)GP-I antibodies were comparable between the two cohorts; two spontaneous venous thromboses occurred in ITP patients, with no particular profile of APA (median follow-up: 36 months). Thrombocytopenia was present in 26% of APS patients; it was always moderate and asymptomatic, and sometimes intermittent; no particular profile of APA was associated to thrombocytopenia; only one thrombocytopenic patient developed a systemic lupus and no particular profile of APA could be found associated (median follow-up: 48 months). CONCLUSION: ITP patients with APA have less frequently an association of different APA than APS patients do; their risk of thrombosis appears low.

Duodenal villous atrophy: a cause of chronic diarrhea after solid-organ transplantation.

Persistent diarrhea is commonly observed after solid organ transplantation (SOT). A few cases of mycophenolate mofetil (MMF)-induced duodenal villous atrophy (DVA) have been previously reported in kidney-transplant patients with chronic diarrhea. Herein, we report on the incidence and characteristics of DVA in SOT patients with chronic diarrhea. One hundred thirty-two SOT patients with chronic diarrhea underwent an oesophago-gastroduodenoscopy (OGD) and a duodenal biopsy after classical causes of diarrhea have been ruled out. DVA was diagnosed in 21 patients (15.9%). It was attributed to mycophenolic acid (MPA) therapy in 18 patients (85.7%) (MMF [n = 14] and enteric-coated mycophenolate sodium [n = 4]). MPA withdrawal or dose reduction resulted in diarrhea cessation. The incidence of DVA was significantly higher in patients with chronic diarrhea receiving MPA compared to those who did not (24.6% vs. 5.1%, p = 0.003). DVA was attributed to a Giardia lamblia parasitic infection in two patients (9.5%) and the remaining case was attributed to azathioprine. In these three patients, diarrhea ceased after metronidazole therapy or azathioprine dose reduction. In conclusion, DVA is a frequent cause of chronic diarrhea in SOT recipients. MPA therapy is the most frequent cause of DVA. An OGD should be proposed to all transplant recipients who present with persistent diarrhea.

Incidence of auto-immune pemphigus in the Midi-Pyrénées region in 2002-2006.

INTRODUCTION: Auto-immune pemphigus is an organ-specific immune disorder due to pathogenic auto-antibodies. Both genetic and environmental factors have been associated with the occurrence of auto-immune pemphigus. Little is known about the epidemiology of auto-immune pemphigus in western Europe. OBJECTIVE: To evaluate the incidence of auto-immune pemphigus in south-western France (namely the Midi-Pyrénées region) in a 5-year period between 2002 and 2006. MATERIALS AND METHODS: We performed a retrospective study of the annual incidence of auto-immune pemphigus diagnosed in the Midi-Pyrénées region, between January 1, 2002, and December 31, 2006. Possible cases of pemphigus were initially selected using skin direct immunofluorescence (DIF) databases from all laboratories in the Midi-Pyrénées region. Systematic validation of all cases was performed by two of the authors (N.M., M.T.). To qualify as a case of auto-immune pemphigus, patients had to fulfil the following criteria: history of clinical signs of pemphigus as assessed by a dermatologist and a positive DIF. To be included in the study, validated cases of auto-immune pemphigus had to fulfil the following criteria: the date of first positive skin DIF between January 1, 2002, and December 31, 2006, and patient living in the Midi-Pyrénées region at the time of the first positive skin DIF. RESULTS: Between 2002 and 2006, 91 patients with positive DIF were identified. Fifty-four patients with positive DIF did not meet the validation criteria for the study. Thirty-seven cases were included in the analysis. The crude annual mean incidence of auto-immune pemphigus between 2002 and 2006 was 2.7 cases/10(6) inhabitants/year (95% CI: 1.87-3.69). The world-population-standardized annual mean incidence of auto-immune pemphigus was 1.55 (95% CI: 0.99-2.11). CONCLUSION: We report a 1.55/10(6) inhabitants/year world-population-standardized incidence of auto-immune pemphigus in the south-west of France. A nationwide epidemiological study of pemphigus should be performed in France.

[Wegener's granulomatosis with clinical manifestations of temporal arteritis]. / Une maladie de Wegener avec des signes d'artérite temporale.

A 51-year-old woman presented with crusting rhinitis, bilateral serous otitis, inflammatory arthralgias, fever, weight loss and signs of temporal arteritis. Temporal arteries were increased in size, painful, with inflammatory signs. There was microscopic hematuria and inflammatory parameters were increased. The renal function was normal. Anticytoplasmic neutrophils antibodies were detected (anti-PR3). Temporal artery biopsy did not show signs of giant cell arteritis. A diagnostic of Wegener's granulomatosis was established and steroid treatment allowed disappearance of clinical and biologic features.

[Anti PM-Scl antibodies. Study of prevalence and of meaning]. / Autoanticorps anti-PM-Scl. Etude de prévalence et de signification.

OBJECTIVE: The purpose of our study is to appreciate the prevalence of antibodies anti PM-Scl within the framework of antinuclear antibodies detection and to clarify clinical biological and evolutive features associated to these antibodies. METHODS: 9,747 consecutive antinuclear testing datas allowed us to evaluate anti PM-Scl antibodies frequency. A retrospective analysis of patients characteristics was performed to identify clinical, biological and evolutive signs associated with this antibody over a five years follow up period. RESULTS: Over the 9,747 samples tested for antinuclear antibodies detection, 3,493 (35.8%) are positive. An anti ENA activity is observed in 727 (7.5%) cases and anti PM-Scl in 6 (0.06%). These antibodies are described in systemic sclerosis, myositis or overlap syndromes. All theses diseases showed a low evolutivity over the five years of follow up. CONCLUSIONS: Low prevalence and possible association with an overlap autoimmune syndrome of quite good prognosis are reported with anti PM-Scl antibodies.

[Analysis of nine autoantibodies associated with systemic autoimmune diseases using the Luminex technology. Results of a multicenter study]. / Apport de la technologie Luminex pour la recherche simultanée de neuf autoanticorps associés aux connectivites. Résultats d'une étude multicentrique.

UNLABELLED: Luminex technology allows simultaneous detection of several analytes in a single well. Applications have been recently developed for the detection of autoantibodies. PURPOSE: To evaluate the performances and convenience of the Fidis analytical system (BioMedical Diagnostics, Marnes-la-Vallee, France) for the detection of nine autoantibodies associated with connective diseases: SS-A, SS-B, Sm, RNP, Scl-70, Jo-1, CENP-B, P ribosomal and double stranded DNA antibodies. MATERIALS AND METHODS: Three hospital laboratories analysed 366 samples taken from their serum banks and corresponding to the main systemic autoimmune diseases. Control samples included 120 sera from blood donors and 42 sera from patients with dysglobulinemia. RESULTS: In each laboratory, handling of this new analytical system was easy. Results are readily obtained: nine autoantibodies are quantitated in fourty-four sera in less than two hours. A clear-cut discrimination between negative and positive results was observed, due to very low backgrounds. Intra-assay and inter-assay variations were low: coefficients of variation were under 10% in 80 and 64% of the cases, respectively. Results obtained with Fidis correlated satisfactorily with those obtained with the numerous routine techniques used in each laboratory. The overall concordance exceeded 93%. CONCLUSION: Fidis is a reliable and time-saving analytical system for the detection of autoantibodies associated with systemic autoimmune diseases.

[Anti-Ku antibodies. Study of prévalence and of clinical meaning]. / Auto-immunité anti-Ku. Etude de prévalence et de signification clinique.

PURPOSE: Auto-immunity against Ku nuclear antigens is rare and clinical meaning remains badly estimated. Our study is for purposes: to appreciate the prévalence of antibodies anti-Ku within the framework of the search for antinuclear antibodies and to clarify clinical and biological relations associated to this auto-immunity. METHODS: A retrospective study of a series of 10,000 searches for antinuclear antibodies studies the prévalence of the auto-immunity anti-Ku and a retrospective analysis of the data found at the patients bearers of an anti-Ku identifies clinical and biological signs associated with this antibody. RESULTS: Prévalence anti-Ku is low (1/3493 case of antinuclear antibodies) and association is possible with in a myositic process through variable auto-immune contexts (overlap syndrome) of relative good preview. CONCLUSION: Auto-immunity anti-Ku is so characterized with its weak prévalence, a possible observation during different auto-immune diseases with an obvious frequency of the overlap syndrome often concerning a process myositic. Finally a weak évolutivité seems to characterize the auto-immune diseases of the patients with anti-Ku antibodies.

Characterization of the three immunoglobulin G subclasses of macaques.

Southern blot experiments with genomic DNA samples of rhesus monkeys and crab-eating macaques and human C gamma-specific probes indicated that the two macaque species studied here possessed three C gamma genes per haploid genome. By amplifying the cDNA from macaque-mouse hybridomas, the coding sequences of two different rhesus monkey immunoglobulin (Ig)G subclasses, IgG1rh (Cgamma1rh) and IgG2rh (Cgamma2rh), and one crab-eating macaque IgG subclass IgG1mafa (Cgamma1mafa), were characterized. None of the 16 rhesus monkey-mouse hybridomas studied here secreted IgG of the third subclass IgG3rh (Cgamma3rh). The Cgamma3rh gene was partly characterized at the genomic level. The cDNA of the Cgamma3rh gene was amplified from mRNA of rhesus monkey peripheral blood mononuclear cells (PBMC). The results are analysed in terms of phylogenesis of the C gamma genes. The cDNA sequences coding for the Cmu and the Ckappa domains of rhesus monkey Ig were established and compared to their human and non-human primate counterparts.

Antibodies against macaque monoclonal immunoglobulin G in rheumatoid arthritis.

The presence of rheumatoid factors (RF) in the serum of rheumatoid arthritis (RA) patients is commonly evidenced by agglutination tests: the Waaler-Rose assay, based on the use of human red blood cells (RBCs) coated with rabbit anti-RBC antibodies, and the latex test, which uses latex particles coated with denatured human immunoglobulin G (IgG). The aim of the present study was to characterize the RF able to agglutinate human RBCs coated with macaque antihuman RBC IgG antibodies secreted from macaque-mouse heterohybridomas (two from rhesus monkey and one from crab-eating macaque). Human RBCs coated with macaque monoclonal antibodies (MacMoAbs) were used for agglutination tests and these were carried out in parallel with standard tests (Waaler-Rose and latex agglutination tests) on sera from 82 RA patients, 86 patients with other forms of inflammatory chronic arthritis and 47 healthy human subjects. MacMoAb-coated RBCs identified RF in the sera of 66% patients with RA. By contrast, the frequency of positive sera in other inflammatory diseases was 5% and all 47 healthy controls were negative. Antimacaque IgG antibodies were found to be more specific for RF than standard tests, in the sera of patients with RA.