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.

Association of IGHM polymorphisms with susceptibility to type 1 diabetes.

Differentiation of B lymphocytes is accompanied by a regulated switch in the expression pattern and stability of surface and secretory immunoglobulins (Igs). Several lines of evidence show that autoimmune responses evolving in much autoimmune pathologies were associated with a high level of humoral Ig, but their pathogenic role remains elusive. The aim of this study was to test the hypothesis that variants at the immunoglobulin heavy-chain IGH locus are genetic determinants to T1D susceptibility. Here, we tested the genetic association of the variants of the immunoglobulin heavy-chain IGH locus as a genetic determinant to T1D susceptibility. A total of 255 subjects from 59 Tunisian families were genotyped for 15 SNPs mapping in 4 regions in IGH locus. We found that rs1950942, rs2180790, rs1808152, and rs1956596 of IGHM and rs2516751 variant located in the IGHA1/IGHG2 region were significantly associated with a risk for T1D p = 7E-3; p = 0.03; p = 0.02; p = 0.043; and p = 3.65E-5, respectively. The TATGG haplotype derived from LD across three SNPs from IGHM gene and two SNPs from IGHD gene was significantly over-transmitted from parents to affect offspring. Our results suggest that genetic variants at the IGH locus are associated with T1D susceptibility. These variations may predispose to IgG AutoAbs production against pancreatic antigens and AutoAbs multi-reactivity, leading to T1D development.

[Variations in immunological parameters after treatment of a manic episode]. / Variations immunologiques après traitement d'un épisode maniaque.

Bipolar disorder is a chronic and disabling mental illness affecting approximately 1-2% of the general population, characterized by the occurrence of manic episodes alone or alternating with depressive episodes. Bipolar disorder is associated with significant morbidity, mortality and personal suffering. The mechanisms underlying the onset and progression of bipolar disease are still poorly understood. Recently, immunological dysfunctions have been suggested in the pathogenesis of bipolar disorder, and many studies have focused on the interaction between bipolar disorder and immunity. Immunological changes have been widely studied during depressive episodes but less explored during manic episodes. The objective of our study was to explore changes in serum proteins and autoantibodies after treatment for a manic episode of bipolar I disorder. This study was carried out over a 30-month period from January 2017 to June 2019, in collaboration between the psychiatry department B of the Hédi Chaker CHU and the immunology department of the Habib Bourguiba CHU, in Sfax, Tunisia. It focused on a sample of 45 bipolar patients with manic relapse, naïve to psychotropic treatment, or discontinuing treatment for a period of at least three months and without a history of autoimmune disease. The study was conducted in two stages : on admission and after treatment. The mean plasma levels of IgG and complement C3 fraction were significantly higher in bipolar patients with relapsing mania. Studies of variation in immunoglobulins and complement fractions during relapses of bipolar disorder have all objected to variations in these serum proteins, but their results were inconsistent regarding the direction of variation and the fractions affected. After treatment, there was a statistically significant increase in the mean plasma levels of IgG and IgA and a decrease in the mean plasma level of the C4 fraction of complement. No significant variation in autoantibodies was noted after treatment. The mean plasma IgM level was significantly lower with sodium valproate. On atypical antipsychotic medication, the mean plasma level of fraction C3 was statistically lower, whereas on conventional antipsychotic medication it was statistically higher. This is in line with the data in the literature which support the immunomodulatory role of thymoregulators and antipsychotics. Serum proteins have been more sensitive than autoantibodies to the effect of psychotropic therapy during manic relapse.

Toll-like-Receptor Gene Polymorphisms in Tunisian Endemic Pemphigus Foliaceus.

Pemphigus foliaceus (PF) is considered to be caused by the combined effects of susceptibility genes and environmental triggers. The polymorphisms of Toll-like receptors (TLRs) genes have been associated with the risk of various autoimmune diseases. The aim of this study was to evaluate the potential association of TLR2-3-4 and 7 gene polymorphisms with Tunisian PF. Fourteen polymorphisms were analyzed in 93 Tunisian PF patients compared to 193 matched healthy controls: rs5743703-rs5743709 and (GT)n repeat (TLR2); rs5743305, rs3775294, and rs3775291 (TLR3), rs4986790 and rs4986791 (TLR4); and rs3853839 (TLR7). Our results showed that the genetic factors varied depending on the epidemiological feature stratification. In fact, in the whole population, no association with the susceptibility to PF was found. The TLR2 GT repeat seems to be closely associated with PF risk in patients originated from the endemic localities (group 3); the GT18 allele and the heterozygous genotype GT18/GT19 seem to confer risk to endemic PF (P = 0.02; OR = 2.3 [1.1-4.9] and P = 0.0002, OR = 20 [2.5-171], respectively). In contrast, the GT23 repeat could be considered as protector allele (P = 0.02, OR = 0.2 [0.06-0.87]). Furthermore, medium GT alleles which induce high promoter activity were also significantly more frequent in patients versus short or long GT repeats (P = 0.0018 with OR = 3.26 [1.5-7]). On the other hand, the TLR3-rs574305 AA genotype and A allele were significantly more frequent in patients whose age of the onset was above 35 years (group 2) (P = 0.038, OR = 1.78 and P = 0.009, OR = 3.92, respectively). Besides, the TLR4>rs3775294 A allele was found to be protector only in patients with sporadic features (groups 2 and 4) (P = 0.03, OR = 0.57 [0.3-0.9] and P = 0.006, OR = 0.24 [0.08-0.74], respectively). No statistically significant difference was observed in the genotypic and allelic frequencies of TLR-4 and TLR-7 gene polymorphisms. The present data suggest that TLR2and TLR3 polymorphisms are significantly associated with increased susceptibility to PF in the Tunisian population.

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.

Involvement of the IL23/Th17 Pathway in the Pathogenesis of Tunisian Pemphigus Foliaceus.

Pemphigus foliaceus (PF) is a rare autoimmune skin disease caused by anti-Dsg1 pathogenic autoantibodies. It is considered as a Th2-mediated disease. Likewise, Th17 cells were recently described in the pathogenesis of the disease but their role is still unclear. We aimed to unravel the eventual implication of the IL23/Th17 pathway in the development of PF. A case-control study was conducted on 115 PF patients and 201 healthy controls using PCR-RFLP and AS-PCR methods. SNPs in IL23R, RORγt, IL17A, IL17F, IL17AR, TNFa, and STAT3 genes were genotyped. mRNA expression of IL23R and RORγt was evaluated using Q-PCR. The frequency of circulating Th17 cells was analyzed by flow cytometry. Genetic associations between IL23R>rs11209026, IL17A>rs3748067, IL17F>rs763780, and TNFa>rs1800629 and the susceptibility to PF were reported. Moreover, we revealed a significant increased frequency of circulating CD4+IL17+ cells as well as higher mRNA levels of RORγt and IL23R in PBMCs of patients. However, no significant increase of RORγt and IL23R mRNA expression was observed in lesional skin biopsies. In spite of the little size of specimens, our results provide converging arguments for the contribution of the IL23/Th17 pathway in the pathogenesis of PF.

Effect of cannabis and tobacco on emphysema in patients with spontaneous pneumothorax.

PURPOSE: To compare imaging findings on thoracic computed tomography (CT) examination in patients with primary spontaneous pneumothorax (SP), depending on their tobacco and/or cannabis consumption. MATERIALS AND METHODS: A total of 83 patients who had thoracic CT for primary SP were prospectively included. There were 65 men and 18 women with a median age of 33 years (IQR: 27; 44 years). The patients were further categorized into three groups according to their smoking habits. Thirteen patients were non-smokers, 38 were tobacco only smokers and 32 were tobacco and cannabis smokers. CT examinations were retrospectively reviewed for the presence of blebs, centrilobular and paraseptal emphysema and lung nodules in each group for comparison. RESULTS: Emphysema was detected in 43/85 patients (51.8%), including 1/13 patients (7.7%) in the non-smoking group, 19/38 patients (50%) in the tobacco only group and 23/32 patients (71.9%) in the tobacco and cannabis smokers, with no difference between tobacco only and tobacco and cannabis smokers. No differences in type and location of emphysema was found between tobacco only and tobacco and cannabis smokers. Tobacco and cannabis smokers with emphysema were significantly younger than tobacco only smokers with emphysema (35 vs. 46 years, respectively) (P=0.009). CONCLUSION: The prevalence of emphysema visible on CT is not different between tobacco and tobacco/cannabis smokers, however, it occurs at a younger age in tobacco and cannabis smokers. This result suggests that cannabis, when added to tobacco, may lead to emphysema at a younger age.

[Bronchial carcinoid tumor and recurrent pneumothoraxes]. / Tumeur carcinoïde bronchique révélée par un pneumothorax récidivant.

Pneumothorax is a rare clinical manifestation of lung cancer. It can exceptionally reveal a bronchial carcinoid tumor. We present the case of a 27-year-old woman in whom recurrent pneumothoraxes were the clinical manifestation of a bronchial carcinoid tumor. The interest for chest computed tomography and bronchoscopy to identify etiology of secondary pneumothoraxes will be discussed.

Relevant genetic polymorphisms and kidney expression of Toll-like receptor (TLR)-5 and TLR-9 in lupus nephritis.

Toll-like receptor (TLR) genetic polymorphisms may modify their expression causing inflammatory disorders and influencing both susceptibility and severity of lupus erythematosus. We aim to determine whether TLR-5 and TLR-9 gene polymorphisms are implicated in the susceptibility to systemic lupus erythematosus (SLE) and lupus nephritis (LN) and to evaluate their expressions and distributions in renal LN patients' biopsies. The frequencies of two SNP in the TLR-9 gene and one in the TLR-5 gene was examined in 106 SLE patients (among them 37 LN patients) and in 200 matched controls by polymerase chain reaction-restriction fragment-length polymorphisms (PCR-RFLP) analysis. TLR-9 and TLR-5 expressions were assessed by reverse transcription (RT)-PCR and immunohistochemistry carried on LN renal biopsies compared to healthy renal tissue. A significant genotypic and allelic association was revealed between TLR-9-rs352140 and both SLE and LN (P < 0·05). The TLR-9 transcript level was significantly higher in LN biopsies compared to control (P < 0·05). This increase was observed histochemically in the tubulointerstitial compartment. TLR-9 was detectable in LN glomeruli patients but not in normal control glomeruli. No allelic nor genotype association was found with TLR-5-rs5744168 in SLE. but the T allele and the TT genotype were raised significantly in the LN group (P < 0·05). A significant increase in TLR-5 gene expression in LN biopsies, which contrasted with normal kidneys (P < 0·05), was confirmed by an intense and diffuse staining for TLR-5 only in LN tubules (P < 0·05). Our data show that TLR-5 and TLR-9 are susceptible genes to LN and that their expression is dysregulated in LN patients' kidneys, supporting a role of these mediators in the pathogenesis of LN.

CREM variant rs17583959 conferred susceptibility to T1D risk in the Tunisian families.

Type 1 diabetes mellitus (T1D) is a chronic autoimmune disease caused by the destruction of insulin-producing pancreatic ß-cells by autoreactive T cells. Studies in animal models, such as the non-obese diabetic (NOD) mouse reveal that this disease is under the control of several genes that encode molecules implicated in regulation of transcription factors and in T cell activation. In order to underline the role of the genes involved in this regulation pathways, we investigated, using the Sequenom MassARRAY platform, 13 single-nucleotide polymorphisms (SNPs) belonging to CREM, IRF5, STAT4, and STAT5a/b genes in 59 T1D Tunisian families. In the current study, we identified an association with rs17583959 (allele G; Z score=2.27; p=0.02; Genotype GG: score=1.96; p=0.04) of CREM gene. In LD analysis a strong LD between the 3 CREM variants (Block 1) was detected; rs2384352 was in complete LD with rs1148247. When haplotypes were constructed between CREM polymorphisms (rs1148247, rs17583959, rs2384352), AGA haplotype (H2) was significantly over-transmitted from parents to affected offspring (Z score=2.988; P=0.002) and may confer a risk for T1D disease. Whereas, AAG haplotype (H5) (Z score=-2.000; p=0.045) was less transmitted than expected to affected children suggesting its protective effect against T1D pathology. No significant association in IRF5, STAT4, and STAT5a/b genes were observed. In conclusion, this study shows an eventually involvement of CREM gene in the development of T1D pathology in Tunisian families. These facts are consistent with a major role for transcription factor genes involved in the immune pathways in the control of autoimmunity. Further researches of association and functional analysis across populations are needed to confirm these findings.

Is there any relationship between polymorphism of Heat Shock Protein 70 genes and Pemphigus foliaceus?

The human Heat Shock Proteins (HSP70) family plays a key role in up-regulating stress responses. Some studies reported possible associations of single nucleotide polymorphisms in the HSP70 genes with some autoimmune diseases. However, whether HSP70 polymorphisms represent a risk factor for pemphigus foliaceus (PF) is still unkown. We analyzed by PCR-RFLP polymorphisms of HSP70 genes HSA1A, HSPA1B and HSPA1L in 80 Tunisian patients with PF, 160 matched healthy controls and 147 related healthy subjects. There were significant differences between PF patients and controls in the allelic (pc=5.91×10(-12), pc=1.14×10(-5) and pc=0.0089, respectively) and homozygous genotypic frequencies of HSPA1L>T, HSPA1A>C and HSPA1B>G (p=2.617×10(-12), p=1.017×10(-5) and p=0.0058, respectively). Haplotype analysis showed significant differences between PF patients and controls: the CCA, CGA, CCG and CGG haplotypes were significantly over-represented in controls whereas the TCG haplotype was significantly over-represented in patients. However, the significant LD found between the HSP70 and the HLA class II susceptibility alleles together with the multivariant regression analysis data between the two loci could argue against a direct role of the HSP70 polymorphism in the occurrence of PF.

Association of TCR/CD3, PTPN22, CD28 and ZAP70 gene polymorphisms with type 1 diabetes risk in Tunisian population: family based association study.

Type 1 diabetes (T1D) is caused by an immune-mediated destruction of the insulin-producing ß-cells. Several studies support the involvement of T cell activation molecules in the pathogenesis of T1D. In order to underline the role of the genes involved in this activation pathway, we investigated, using the Sequenom MassARRAY platform, 45 single-nucleotide polymorphisms (SNPs) belonging to TCR/CD3, CD28, ZAP70, and PTPN22 genes in 59 T1D Tunisian families. In the current study, we identified an association with rs706 (Z score=2.782; p=0.005) of TCRß gene. We also demonstrated that rs10918706 in the intron of the CD3z gene was associated with increased risk of T1D (Z score 2.137; p=0.032). In the same region, rs2949655 (Z score=2.101; p=0.035) and rs1214611 (Z score=4.036; p=0.00005) showed a genotype association with the risk of T1D. When haplotypes were constructed, GAA haplotype displayed significant association with T1D (Z score=2.135; p=0.032), while GGA haplotype (Z score=-1.988; p=0.046) was negatively associated with the disease. We also identified an association with rs3181096 (Z score=2.177; p=0.029), rs17695937 (Z score =2.111; p=0.034) and rs2488457 (Z score=2.219; p=0.026), respectively of CD28, ZAP70 and PTPN22 genes. In addition, our results suggest a significant effect on T1D susceptibility for AC (Z score=2.30; p=0.02) and CTGGC (Z score=2.309, p=0.02) haplotypes of ZAP70 and PTPN22 genes, respectively. While, the GTCT (Z score=-2.114, p=0.034) and CTAGG (Z score=-2.121, p=0.033) haplotypes of CD28 and PTPN22 genes, may confer protection against T1D. These findings confirm the role of PTPN22 and CD28 involved in the T cell activation pathway in the development of T1D in Tunisian families. Interestingly, ZAP70 and TCRß/CD3z seem to contribute to the susceptibility to the disease in our population. However, this finding has to be confirmed in further studies.

[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.

Causes and outcome of hospitalisations in Tunisian patients with systemic lupus erythematosus.

OBJECTIVE: To describe the most common reasons of admission of Tunisian patients with systemic lupus erythematosus (SLE) and the outcomes of these hospitalisations. METHOD: The charts of patients with SLE who were hospitalised at our Department of Internal Medicine during a 2-year period from January 2011 to December 2012 were retrospectively reviewed, and the demographic characteristics, clinical and laboratory features, as well as all comorbidities, were collected. RESULTS: There were 128 episodes of hospitalisation of 87 patients with SLE. 25 patients (28.7%) were admitted twice or more. The median length of stay for all admissions was 11 days (2-76). The total number of days of hospitalisation was 1896 days, which represent 10.7% of the total number of days of hospitalisation in our department. The most common overall reason for hospitalisation was active SLE (55 events, 43%). In 29 patients, SLE was newly diagnosed during hospitalisation. Other causes of hospitalisation included assessment of the disease, infections (9.4%) and associated autoimmune disease (6.25%). Adverse drug reaction (3.1%) and thromboembolic events (1.25%) were uncommon causes of hospitalisations. There was a significant difference in length of stay between patients admitted with SLE flare and those admitted for non-SLE flare reasons (p<0.01). Four hospitalisations (3%) resulted in death. The principal cause of death was active SLE. CONCLUSIONS: Hospitalisation of patients with SLE is common in our department. Our study of this North African SLE population confirms the findings of previous studies suggesting that active SLE and infection remain the most common causes of hospitalisation of patients with SLE.

[Flexible endoscope in thoracic surgery: CITES or cVATS?]. / L'endoscope souple en chirurgie thoracique, quel abord: CITES ou cVATS?

Early pain and persistent parietal disorders remains a major unresolved problem in thoracic surgery. Thoracotomy and the use of multiple ports in most Video Assisted Thoracic Surgery (VATS) procedures are the major cause of this persistent pain. For the last decade, a few publications describing the use of either single incision VATS and cervical thoracic approaches have been reported without significant results in comparison with current used techniques. Intercostals compression during surgery and early after by intercostals chest tube placement, are probably the major cause of postoperative pain. Flexible endoscope is currently used in several surgeries and will take more and more importance in our daily use in thoracic surgery. Instrument flexibility allows its use through minimally invasive approaches and offers a very interesting intra-thoracic navigation. We describe here the first use in France of a flexible endoscope in thoracic surgery through a single cervical incision to perform simultaneous exploration and biopsies of the mediastinum and right pleura using the original approach of Cervical Incision Thoracic Endoscopic Surgery (CITES).

Cytokine gene polymorphisms in Tunisian endemic pemphigus foliaceus: a possible role of il-4 variants.

Polymorphism in the genes of TH2 cytokines and/or theirs receptors can influence serum cytokine levels in and the switch to the pathologic IgG4 auto-antibodies. In order to underline the role of these genes in the aethiopathogenesis of Pemphigus Foliaceus, we conduct a familial and a case control studies including 80 Tunisian patients, 147 related subjects and 160 matched healthy controls. We investigated, by PCR-RFLP technique, seven nucleotide polymorphisms: rs2243250 in promoter region of IL4 gene, rs47877948, rs3024530 and rs30246223 in the IL4R gene, rs1881457and rs205412 SNPs in IL13 gene and rs535036 in IL13RA2 gene. After Bonferroni adjustment, T allele and the TT genotype of IL4-590 were significantly increased in the PF patients group compared to healthy controls. This association was confirmed by the family study. Interestingly, the serum IL-4 levels were significantly increased in patients with the TT genotype compared to CT or CC genotypes. Interestingly, the IL4/IL13:T-A-C haplotype exhibited a significant effect on PF susceptibility. In addition, a significant gene-gene interaction between the IL4/IL4R (TACA) significantly increases in PF patients as compared to controls. These findings assess the role of the IL4/IL4R axis in the aethiopathogenesis of Tunisian endemic PF by the induction of a high transcriptional activity which could enhance the T-cell balance and inducing immunoglobulin isotype switching.

Polymorphisms of HLA microsatellite marker in Tunisian pemphigus foliaceus.

Pemphigus foliaceus (PF) is an autoimmune blistering skin disease that partly results from genetic factors, especially from human leucocyte antigen (HLA) class II genes. Several data have reported the involvement of microsatellite (STR) markers across different regions of the HLA in many auto-immune diseases. To test the hypothesis of the existence of a major HLA haplotype predisposing to PF, we analyzed six polymorphisms of microsatellite loci at 6p21.3-21.4 spanning HLA: D6S291, D6S273, TNFa, MICA, D6S265 and D6S276 in 81 PF patients compared to 123 healthy individuals recruited from the south of Tunisia. In this study, after Bonferroni's correction, 3 STR alleles from the TNFa locus were associated with the disease: the allele TNFa(∗)2 (p(c) = 4.2×10(-6)) and, at a lower level, the TNFa(∗)5 (p(c) = 0.014) as susceptibility alleles and TNFa(∗)6 (p(c) = 0.014) as protective ones. Furthermore, the expression of the TNFa(∗)2/TNFa(∗)5 genotype seem to confer susceptibility to PF (p = 0.00001, OR = 11.25). Interestingly, no significant LD was found between TNFa2/TNFa5 alleles and DRB1(∗)03/DRB1(∗)04 alleles. However, the multivariant regression analysis indicates that both the HLA class II and the TNFa alleles remained significant (p < 0.001). Although, these findings rejected our hypothesis on the existence of HLA susceptibility haplotype, they assessed the role of TNFa loci. Accordingly, TNFa seem to contribute to the aethiopathogenesis of Tunisian endemic PF may be by the induction of a high TNFα production which is known to enhance the autoimmune cascade of the disease.

Biomarkers of oxidative stress in epidermis of Tunisian pemphigus foliaceus patients.

BACKGROUND: Reactive oxygen species play a key role in the development of many dermatological disorders. OBJECTIVE: The purpose of this study is to examine the lipid peroxidation, protein oxidation and antioxidative profile in Tunisian pemphigus foliaceus (PF) patients. METHODS: Malondialdehyde (MDA), conjugated dienes (CD), protein thiol levels, catalase (CAT) and superoxide dismutase (SOD) activities were evaluated in skin biopsies of 13 patients compared to biopsies of 7 healthy controls. RESULTS: Oxidative stress was confirmed in these three types of patient biopsies as compared to controls. Thus, MDA, CD levels and catalase CAT and SOD activities were significantly increased in lesional, perilesional and normal biopsies of PF patients than in those of control subjects. Protein oxidative was confirmed by lower levels of protein thiols in lesional, perilesional and normal biopsies than in control's biopsies. Otherwise, in patients, a significant rise of these biomarkers was observed in lesional and perilesional biopsies compared with normal biopsies. CONCLUSION: This study shows that oxidative stress could be involved in the pathogenesis of PF by the spread of skin lesions and/or by the increase in auto-antibodies' reactivity.