Antinuclear antibodies positivity is not rare during multiple sclerosis and is associated with relapsing status and IgG oligoclonal bands positivity.

INTRODUCTION: As an immune-mediated disease of the central nervous system, multifaceted aspects of a humoral immune response are widely described during multiple sclerosis (MS). However, the prevalence of different auto-antibodies, such as antinuclear antibodies (ANA), during MS is very variable and their clinical relevance remains controversial. Our aim was to evaluate the prevalence and clinical correlations of ANA positivity in South Tunisian MS patients. MATERIAL AND METHODS: We performed ANA screening using indirect immunofluorescence (IIF) on HEp-2 cells (Biosystems®) in 82 MS patients. For ANA positive samples (titer ≥1/160), anti-ds-DNA detection (IIF on Crithidia luciliae (Biosystems®)) and extractable nuclear antigen typing (immunodot (Euroimmun®)) were performed. RESULTS: ANA were positive in 35/82 MS patients (42.7%). The titer was ≥1/320 in 16/35 patients. The antigenic specificity of ANA was identified in 7/35 patients. None of the patients had extra-neurological manifestations. No correlation was found between ANA and age, gender, MS course, disease duration, disability, annual relapse rate nor IgG index. ANA positivity was more frequent in patients with IgG oligoclonal bands (OCB) (47.1%) than in patients without IgG OCB (16,6%) (p=0.049). Regarding disease activity, ANA positivity was significantly more frequent in patients with relapse (52.6%) than in patients in remission (25.9%) (p=0.031). CONCLUSION: Our results showed that ANA positivity in MS disease is not rare. This positivity was not associated with clinical expression of any connective tissue disease. ANA occurrence in MS was associated with IgG OCB+ profile and relapsing status, probably reflecting an ongoing immune dysregulation.

Neuromyelitis optica spectrum disorders in South of Tunisia: A rare entity with low seroprevalence of anti-aquaporin 4 autoantibodies.

INTRODUCTION: Screening for anti-aquaporin 4 (anti-AQP4) antibodies, a specific marker of neuromyelitis optica spectrum disorders (NMOSD), is part of the immunological investigation performed in a context of central nervous system (CNS) inflammation with optic neuritis and/or myelitis. The aim of our study was to evaluate the prevalence and the diagnostic value of anti-AQP4 antibodies in Tunisian patients with such inflammatory neurological conditions. METHODS: During 3years, 170 consecutive serum samples of Tunisian patients with CNS inflammatory disorders and optico-spinal involvement were tested in our laboratory for anti-AQP4 antibodies using indirect immunofluorescence on transfected cells. RESULTS: The global seroprevalence of anti-AQP4 in our study was 4.1% (7 cases/170). The diagnosis of NMOSD was made for the 7 seropositive patients and for 2 seronegative patients, which leads to a seroprevalence of 77.7% in our NMOSD subgroup. The detection of anti-AQP4 allowed the diagnosis of NMOSD in 4 patients with incomplete clinical presentation and 5 patients with positive antinuclear antibodies. In one case, seropositivity was detected in a second sample, one year after an initial seronegativity. CONCLUSION: NMOSD seem to represent a rare etiology of optic neuritis and/or myelitis in Tunisian patients. Despite its low global seroprevalence in our study population, anti-AQP4 appears to be a very clinically relevant marker for NMOSD diagnosis. Repeating the screening in case of initial negativity could be interesting in clinical practice.

Phenotypic abnormalities of peripheral blood mononuclear cells in patients with Behçet's disease and association with HLA-B51 expression.

The aim of this study was to investigate the subclasses and the immunophenotypic profile of peripheral mononuclear cells in patients with Behçet's disease (BD) and to assess associations between the expression of HLA-B51 antigen and that of other cell markers. Thirty healthy volunteer blood donors and forty patients with BD were enrolled into this study. Phenotyping was performed using two color flow cytometry. HLA-B51 typing was performed using the complement dependent microlymphocytotoxicity assay. Unlike controls, patients with BD presented a modified immunophenotypic profile of lymphocytes. Compared to those in the remission phase, patients with active BD showed an increased mean of MFI ratio of CD56 on CD16+CD56+ cells (32.47 ± 14.26 versus 23.87 ± 10.3; p = 0.032), increased absolute numbers of CD4(-)CD8(bright) and CD4(+)CD8(+) cells (657.1 ± 463.6 cells/µL versus 319.24 ± 116.4 cells/µL; p = 0.017 and 40.77 ± 36.41 cells/µL versus 10.77 ± 9.78 cells/µL; p < 0.0001, respectively) and an elevated mean of MFI ratio of CD19 on B cells (252.3 ± 56.7 versus 205.67 ± 32.3; p = 0.021). However, expression of HLA-B51 was not associated with any specific immunophenotypic profile. In conclusion, abnormal immunophenotypic profile of peripheral lymphocytes was found in patients with BD, especially in active phase, reflecting an immune dysregulation. Moreover, HLA-B51 expression was not found to be related to the expression of other cell markers.

HLA-G 14 bp insertion/deletion polymorphism and its association with sHLA-G levels in Behçet's disease Tunisian patients.

The purpose of this study was to investigate the HLA-G 3'UTR 14 bp polymorphism and sHLA-G levels in Tunisian patients with BD. The study included 119 patients with BD and 170 healthy blood donors (HD). HLA-G 14 bp polymorphism was genotyped by polymerase chain reaction. Serum levels of soluble HLA-G (sHLA-G) were measured using a commercial ELISA kit. A significant increased frequency of the -14 bp HLA-G allele was detected in patients with BD compared to HD (0.58 vs 0.49, p=0.023), and a significant increased frequency of HLA-G -14/-14 bp was observed in patients with BD compared to HD [0.37 vs 0.22, p=0.007, OR 2.04 (95% CI 1.21-3.42)]. The mean plasmatic concentration of sHLA-G levels were significantly increased in patients with active disease [231.63±286.4 U/mL] compared to those with inactive disease (103.14±77.8 U/mL, p=0.03) and HD (121.41±24.1 U/mL, p=0.04). Furthermore, our results showed that there is no association between HLA-G 14 bp polymorphism and sHLA-G plasma levels.

[Neonatal lupus and maternofetal transmission of anti-SSA/Ro and anti-SSB/La antibodies]. / Lupus néonatal et transmission materno-fœtale des anticorps anti-SSA/Ro et anti-SSB/La.

Neonatal lupus (NL) is a rare syndrome caused by placental transfer of maternal anti-SSA/Ro (60 and 52kDa) or anti-SSB/La antibodies. The aim of this study was to evaluate the clinical and biological profile of NL at the neonatal unit of Sfax, Tunisia, over a 10-year period. Six mother-NB pairs (two sets of twins and two sisters) had positive ANA by transplacental transmission during the study period. The ANA pattern was speckled and the NBs' sera titer was half that of their mothers'. Anti-SSA, anti-Ro52, and anti-SSB were found in 100%, 33%, and 50% of the mothers' sera, respectively. The transmission of anti-SSA was observed in four pregnancies out of six, anti-Ro52 in two pregnancies out of two, and anti-SSB in one pregnancy out of three. The patients' clinical records showed that two NBs had a congenital heart block: one with anti-SSA, whose mother had Sjögren syndrome, and another with anti-SSA, anti-SSB, anti-Ro52, and anti-mitochondrial antibodies (M2 type), whose mother had no diagnosis at the child's birth (cutaneous erythema and positive ANA with the same profile). Cutaneous signs (erythema, petechia) were described in three NBs out of six. The two sets of fraternal twins had cutaneous signs with the same ANA titer and profile (no anti-SSA transmission from their mother with lupus and anti-phospholipid syndrome). The two sisters' (two pregnancies 3 years apart) mother had Sjögren syndrome, one of them had heart block with positive anti-SSA, and the other was asymptomatic with anti-SSA and anti-Ro52. The same mother had a history of three pregnancies with two NBs who died of heart block.

Contribution of flow cytometry to acute leukemia classification in Tunisia.

The precision of immunological characterization of leukemias was improved by a certain number of technical innovations, particularly hybridoma production and standardization, resulting in monoclonal antibodies and definition of recognised cellular antigens (designated by CD: Cluster of Differentiation). The aim of this work was to determine the immunophenotyping profile of patients with leukemia, by means of a flow cytometric method: 66 blood samples coming from leukemic persons in the Sahel region were studied by flow cytometry, using about thirty monoclonal antibodies all marked with a fluorochrome, in one or two colour systems to assess their distribution according to type (lymphoid B or T / myeloid) and age, and to search for possible co-expressions of markers of different lineages. The marked preponderance of childhood B-ALL in our series is, at least partly, attributable to the age distribution of the Tunisian population. In agreement with studies from other countries, the majority of AML cases occurred among adults. A high proportion of AML cases in our series co-expressed markers of other lineages. Overall, accurate classification of acute leukemias was possible from a simple peripheral blood sample in 62 of 66 cases (93.9%).

[Prevalence and diagnostic value of antinuclear antibodies without identified antigenic target: a retrospective study of 90 patients]. / Prévalence et valeur diagnostique des anticorps antinucléaires de spécificité antigénique indéterminée : étude rétrospective à propos d'une série de 90 patients.

PURPOSE: The objective of this study was to determine the clinical relevance and the diagnostic significance of positive antinuclear antibodies (ANA) without identified antigenic target by the usual characterization technique. PATIENTS AND METHODS: Retrospective study conducted in the Laboratory of Immunology of Habib Bourguiba Hospital (Sfax, Tunisia) during 18 months. The inclusion criteria were the presence of an ANA titer greater or equal to 1/320 with negative characterization result. ANA screening was performed by indirect immunofluorescence (IIF) on Hep2 cells. Each positive serum was tested by IIF on Crithidia luciliae (anti-native DNA) and by immunodot (anti-nucleosome, anti-histone, anti-Sm, anti-RNP, anti-SSA, anti-SSB, anti-Scl 70, anti-PM-Scl, anti-Jo1, anti-PCNA and anti-ribosomal protein). Sera of systemic lupus erythematosus (SLE), myositis, and scleroderma patients were tested for anti-Ku, anti-PL7, anti-PL12 and anti-Ro-52 using dot myositis. RESULTS: Sera of 90 patients were studied: 18 men and 72 women (average age: 44 years). Drug-induced ANA was found in eight patients. The most frequent clinical symptoms were joint (56.7%), cutaneous (54.4%) and constitutional symptoms (45.6%). The diagnosis of an autoimmune disease was suspected in 49 patients (54.5%) and confirmed in 30 (33.3%) including 20 cases of connective tissue disease: myositis (n=6), scleroderma (n=5), Sjögren's syndrome (n=3), SLE (n=4), rheumatoid arthritis (n=6) and antiphospholipid syndrome (n=4). Other autoimmune diseases were less frequent. The anti-Ku antibody was detected in the majority of patients with connective tissue disease. The diagnosis of non-autoimmune diseases was established in 25.5% of patients. Eighteen patients (20%) had no diagnosis orientation. CONCLUSION: Our study demonstrated the diagnostic value of the presence of ANA even in the absence of known antigenic target, confirmed the role of the IIF as "gold standard" test for ANA screening, and suggested the usefulness of the addition of Ku antigen in the immunodot classic profile.

Calciphylaxis in a chronic hemodialysis patient with protein S deficiency.

Vascular calcifications are common in uremic patients whereas calciphylaxis is rare. We report the case of a 45-year-old woman on chronic hemodialysis since 1977. She had a subtotal parathyroidectomy in 1985, aortic and mitral valve replacement in 1986, and has been treated since then with nicoumalone. In June 1991, she presented with repeated, painful cutaneous necrosis suggesting panniculitis. A skin biopsy showed lobular panniculitis and evidence of calciphylaxis. There was an obvious biological hyperparathyroidism. Protein C functional level was in the normal range whereas protein S functional level was low, i.e. 42%. The patient underwent cervical surgery to remove two parathyroid glands, and daily hemodialysis sessions. Despite this treatment, cutaneous necrosis progressed with superinfection. A few weeks later, the patient died from a septic shock after a myocardic infarction. Necropsy was not performed.