Biclonal Gammopathies in South Tunisia: Clinical and Biological Characteristics.

OBJECTIVE: Biclonal gammopathies (BGs) are rare situations characterized by the production of 2 monoclonal proteins. There are no available data on BGs in North Africa. We aimed to estimate the prevalence of BGs in our population and describe their clinical and laboratory features. METHODS: We conducted a 31-year retrospective study including patients with persistent double monoclonal bands based on the results of immunofixation/immunoelectrophoresis. RESULTS: A total of 35 patients with available clinical data (sex ratio, M/F = 1.53; mean age, 70 ±â€…10.87 years [range, 45-90 years]) were included. The main associated conditions were multiple myeloma (MM) (40%), BG of undetermined significance (BGUS) (34%), and lymphoproliferative diseases (23%). Only one-third of the patients had 2 monoclonal spikes on serum protein electrophoresis. The most common paraprotein combinations were immunoglobulin (Ig)G-IgG (25%) and IgG-IgA (23%) with different light chains in one-half of the cases. The mean follow-up was 25.6 months (median, 12 months). No BGUS evolved into a malignant disease. CONCLUSION: BGs are rare in clinical laboratory routine but must be accurately identified by the pathologist. Our cohort is characterized by a high prevalence of BGUS compared with MM.

Subglottic Masses Revealing Rosai-Dorfman Disease.

Rosai-Dorfman disease (RDD) is an uncommon lymphoproliferative disorder; RDD with oropharyngeal involvement is extremely rare, especially in adults. A 65-year-old woman with a complaint of progressive dyspnoea since 2016 presented with laryngeal involvement of RDD. A laryngoscopy examination revealed two solid, polypoid masses in the subglottic region, and a laryngeal biopsy concluded chronic inflammation without signs of malignancy. A second biopsy of axillary lymph nodes was performed, supporting the diagnosis of histiocytosis. The patient was treated with corticosteroids and then lost to follow-up. In 2019, she suffered from dyspnoea and a hoarse voice. Laryngoscopy examination showed a polypoid lesion causing airway obstruction at 70% and thickening of the lateral wall of the cavum. Physical examination found left axillary and submandibular adenopathy, and computed tomography revealed thickening of the supraglottic larynx narrowing the laryngeal pathway. Lymphadenectomy with immunohistochemical analysis revealed typical protein positive S-100 histiocytes and emperipolesis. The patient was treated with high doses of corticosteroids for six weeks then these were progressively decreased. The outcome was favourable; the laryngeal lesion disappeared after two weeks of treatment. LEARNING POINTS: Rosai-Dorfman disease is a rare cause of lymphadenopathy in adults. Extranodal presentation of the disease is possible mainly in the head and the neck region.The diagnosis is based on histological examination with the presence of histiocytes, which are S-100 positive, CD68 positive, and CD1a negative immunohistochemistry.The outcome is usually good in asymptomatic forms of the disease with no critical organ involved. The surgical resection is appropriate to the localised symptomatic form of the disease while corticosteroids are indicated in disseminated RDD as a first-line therapy.Inspired by our case, rare localisation of Rosai-Dorfman disease (RDD), led to clinical and therapeutic issues. That is why a review of the literature must be undertaken, to share experiences.

[A rare cause of AA amyloidosis: Hereditary epidermolysis bullosa]. / Une cause rare de l'amylose AA : les épidermolyses bulleuses héréditaires.

INTRODUCTION: Recessive dystrophic epidermolysis bullosa is a rare genetic condition characterized by fragile skin and mucous membrane, caused by mutations in the COL7A1 gene. AA amyloidosis is a rare complication of these genodermatosis. OBSERVATIONS: Two patients with recessive dystrophic epidermolysis bullosa, generalized severe in the first case and generalized intermediate in the second case, developed at the age of 38 and 28, respectively, nephrotic syndrome. The diagnosis of secondary renal amyloidosis was confirmed by renal biopsy in the first case and by minor salivary gland biopsy in the second case. Death occurred 2 months after diagnosis in both cases. CONCLUSION: Renal involvement is quite common in AA amyloidosis in patients with recessive dystrophic epidermolysis bullosa. Nephrotic syndrome and rapid decline in renal function renal are characteristic features. The prognosis is poor due to underlying conditions and the lack of an etiological treatment.

Plasma Saturated and Monounsaturated Fatty Acids in Behçet's Disease.

BACKGROUND: Fatty Acid (FA) composition of serum has been associated with many markers of inflammation. In this study, we tried to examine plasma Saturated Fatty Acid (SFA) and Monounsaturated Fatty Acid (MUFA) composition in Behçet's Disease (BD) patients. The associations between the circulating FA levels and some markers of inflammation have also been investigated. METHODS: This study is a cross-sectional one. In fact, a total of 101 BD patients and healthy controls group of 99 subjects are enrolled. Gas Chromatograph equipped with a Capillary Split/Splitless Injector and flame ionization detector was used to analyze the plasma SFA and MUFA compositions. The high sensitivity C-Reactive Protein (hsCRP) and fibrinogen levels were measured using standard techniques. RESULTS: BD patients had significantly higher proportions of Mystiric Acid (MA), Palmitic Acid (PAM), Palmitoleic Acid (POA) and Stearoyl-CoA Desaturase (SCD)-16, compared to controls.The results revealed that patients with severe involvements had high levels of POA and total MUFA associated with higher SCD-16 activity compared to those with minor ones. The receiver operator characteristic curve analysis revealed that POA could well discriminate BD patients with severe clinical manifestations. In the bivariate analysis, hsCRP was found to be positively correlated with total SAFA and POA elongase activity index but negatively correlated with SCD-18 activity index. The STA, POA, elongase and SCD-16 activity index are correlated with fibrinogen. On the other hand, the multivariate analysis showed that POA remained associated with higher levels of hsCRP. CONCLUSION: Unfavourable plasma SFA and MUFA profile were reported in BD patients. POA, which is associated with higher plasma hsCRP level, may play a role in the pathogenesis of BD.

HLA Class III: A susceptibility region to systemic lupus erythematosus in Tunisian population.

BACKGROUND AND OBJECTIVES: Short tandem repeats (STR) are usually used as informative polymorphic markers for genetic mapping and for disease susceptibility analysis. The involvement of these microsatellite markers localized in the MHC region was reported in many auto-immune diseases. In this study we analyzed for the first time eight polymorphisms of microsatellite loci at the HLA region: D6S291, D6S273, TNFa, b and c, MICA, D6S265 and D6S276, in Tunisian systemic lupus erythematosus (SLE) patients. MATERIALS AND METHODS: We performed a case control study in which the microsatellite loci were amplified using specific primers labeled with NED, VIC, PET or 6-FAM and analyzed using GeneScan software 3.7. For the statistical analysis, we used SPSS software and we performed a sub-haplotype scoring test using the haplo.stats software developed in the R language. RESULTS: We found that two mean associated regions existed; the most statistically significant encompassed the 3 TNF markers (p = 0.0003, OR = 19.34); the latter covered the DR region. In fact, when scoring haplotypes in 3 marker- sliding windows, the p value increased as we moved away from the TNF region and decreased again when we approached the DRB1 locus. We also established for the first time the negative association between alleles of D6S291 and SLE. The majority of clinical and serological correlations were noted with TNF alleles. CONCLUSION: Our results confirm the association between TNF and DRB1 polymorphisms and SLE. The association between alleles of D6S291 and SLE needs however to be verified by the analysis of other markers beyond this region.

Association of hyperhomocysteinemia with genetic variants in key enzymes of homocysteine metabolism and methotrexate toxicity in rheumatoid arthritis patients.

OBJECTIVES: The study investigated the association between plasma homocysteine, folate and vitamin B12 with 5,10 methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), thymidylate synthase (TYMS 2R â†’ 3R) and methionine synthase (MTR A2756G) polymorphisms and methotrexate (MTX) treatment and toxicity in Tunisian Rheumatoid arthritis (RA) patients. METHODS: A total of 185 patients with RA were included. Homocysteine (Hcy) was assessed by fluorescence polarization immunoassay, and folate and vitamin B12 were measured by chemiluminescence immunoassays. The genetic polymorphisms were analyzed by PCR or PCR-RFLP. Hyperhomocysteinemia (HHC) was considered for Hcy > 15 µmol/L. RESULTS: MTHFR C677T polymorphism was associated with HHC in RA patients (multi-adjusted OR, 95% CI 2.18, [1.07-4.57]; p = 0.031). No association was detected with the remaining polymorphisms. Plasma Hcy, folate, and vitamin B12 did not differ according to each polymorphism, or with MTX treatment or toxicity. However, HHC was more prevalent in patients with than those without MTX toxicity (32.7 vs. 16.7%; p = 0.035). CONCLUSIONS: The MTHFR 677TT genotype is an independent risk factor for HHC in Tunisians RA patients. HHC could be a useful marker of MTX toxicity in RA patients.

Human leukocyte antigens-DRB1*03 is associated with systemic lupus erythematosus and anti-SSB production in South Tunisia.

INTRODUCTION: Systemic lupus erythematosus (SLE) is an autoimmune disease with various presentations. This variation is due to the interaction of hormonal, environmental, and genetic factors. Associations between human leukocyte antigens and SLE have long been recognized in different ethnic populations and have been suggested to represent the most important association. OBJECTIVES: The objectives of this paper were to determine susceptibility and protection human leukocyte antigens (HLA) Class II markers for SLE and to highlight, for the first time, associations between HLA alleles and clinical and serological features in South Tunisia. METHODS: We conducted a case-control study on 75 SLE patients and 123 healthy controls. The HLA Class II DRB1/DQB1 of all patients and controls was genotyped using polymerase chain reaction-sequence specific primer technique. Statistical analysis was performed using SPSS software. RESULTS: HLA-DRB1*03 was the principal Class II allele associated with the genetic susceptibility to SLE (pc = 0.02; OR = 2.57; CI = [1.39-4.75]; this allele was also associated with anti-SSB production (P = 0.016; OR = 4.00; CI = [1.24-12.96]). HLA-DRB1*01 was significantly more expressed in SLE patients with neurologic disorders (P = 0.013; OR = 20.25; CI = [1.87-219.21]). No allele was found to be protective against SLE in our study group. CONCLUSION: Our results show that in South Tunisia SLE is associated with HLA-DRB1*03 and that some clinical features of SLE may be influenced by specific DRB1 and DQB1 alleles.

Measurement of absolute copy number variation of Glutathione S-Transferase M1 gene by digital droplet PCR and association analysis in Tunisian Rheumatoid Arthritis population.

BACKGROUND: The investigation of copy number variations (CNVs) analysis of candidate genes is currently an important research area in modulating human diseases. We aimed to quantify CNVs in glutathione S-transferase M1 (GSTM1) gene and determine its genetic contribution in Tunisian rheumatoid arthritis (RA) and its subsets through an innovative technique for quantification. METHODS: A total of 165 RA cases and 102 healthy controls were included in the study. Using a recently powerful approach of digital droplet PCR (ddPCR), we quantified GSTM1 gene to determine the presence of no, one, or multiple copy number (CN) at high levels of sensitivity and specificity. Odds ratio and Fisher exact test were performed to estimate the association risk for GSTM1CNVs in RA. RESULTS: Copy number identified by ddPCR was 0, 1, and 2 copies per diploid genome. A high frequency of '0' copy was revealed with 54% in RA patients. The deletion ('0' copy) of GSTM1 was found to be a significant risk factor for anti-cyclic citrullinated peptide (anti-CCP) positive RA (OR=4.16, CI95% =[1.17-14.7]). In addition, a lack of association was found when comparing between the CNVs of RA patients and those of controls. CONCLUSION: This study highlights the powerful accuracy of ddPCR for the quantification of CNVs and suggests that the variation in the CN of GSTM1 is associated with anti-CCP positivity in RA. However, it does not indicate a specific role in the susceptibility to the disease in our Tunisian sample.

Beyond Human Leukocyte Antigen Class I Antigens: Hereditary Hemochromatosis Gene Mutations in Recurrent Aphthous Oral Ulcers and Behçet Disease in the South of Tunisia.

OBJECTIVE: The aim of this work was to establish human leukocyte antigen (HLA) class I and hereditary hemochromatosis gene (HFE) mutation associations with recurrent aphthous oral ulcers (RAOU) and Behçet disease (BD) in a cohort of Southern Tunisian patients. SUBJECTS AND METHODS: A total of 232 patients with RAOU and 123 healthy controls (HCs) were enrolled in this study. The patients were divided into 2 groups based on the presence (BD+: n = 62) or absence of BD (BD-, n = 170). In the BD+ group, 28 patients had severe manifestations of BD. In the BD- group, RAOU was isolated in 81 patients, associated with mucocutaneous manifestations in 58 and with joint symptoms in 25. Complement-dependent microlymphocytotoxicity assay and polymerase chain reaction-restriction fragment length polymorphism were used to study HLA class I polymorphism and HFE mutations, respectively. RESULTS: HLA-B51 was positively associated with BD, particularly in those with severe manifestations. No association was detected with HLA class I polymorphism among the BD group. Based on stratification to clinical manifestations, the isolated RAOU was negatively associated with HLA-A1 with a difference close to significance (12 [14.81%] vs. 32 [26.02%] in HCs; p = 0.06). Furthermore, patients with mucocutaneous features had a higher frequency of HLA-B51 (14, 24.14%) than patients without mucocutaneous involvement (11, 11.37%). Considering HFE mutations, patients with isolated RAOU had a higher frequency of H63D when compared with other subgroups, especially after limiting the comparison to 27 patients of at least 5 years of follow-up. CONCLUSION: This study showed that, unlike BD, RAOU were not associated with HLA-B51. Moreover, we suggest that H63D mutation was positively associated with isolated RAOU.

Association study of human leukocyte antigen-DRB1 alleles with rheumatoid arthritis in south Tunisian patients.

The aim of this study is to explore relationship between HLA-DRB1 alleles and the susceptibility and clinical features of rheumatoid arthritis (RA) in the south Tunisian population. We studied 142 RA patients and 123 controls matched for age, sex, and ethnicity. HLA-DRB1 genotyping and HLA-DRB1*04 subtypes were performed using polymerase chain reaction/sequence-specific primers. Association was assessed based on the χ (2) test and odds ratio with 95% confidence interval. For multiple comparisons, p value was corrected (p (c)) with Bonferroni test. Two alleles, HLA-DRB1*04 (p=0.045, p(c)=NS) and HLA-DRB1*10 (p=0.021, p(c)=NS), were found to have increased frequencies in RA patients compared to controls. In contrast HLA-DRB1*08 allele was found to have a decreased frequency in patients compared to controls (p=0.044, p(c)=NS). Molecular subtyping of the most prevalent allele (DRB1*04) revealed increased frequencies of HLA-DRB1*04:05 in patients compared to controls (p=0.013, p(c)=NS) whereas HLA-DRB1*04:02 showed a protective effect (p=0.005, p(c)=0.04). Moreover, stratified analyses indicated statistically significant associations between HLA-DRB1*04 allele and anti-cyclic peptides antibodies positivity (ACPA(+)) and rheumatoid factor positivity (RF(+); p(c)=0.03, for both subgroups), HLA-DRBI*10 and ACPA(+) and the presence of another autoimmune disease (p(c)=0.05 and p(c)=0.007, respectively), and HLA-DRB1*04:05 and RF(+) and erosion (p(c)=0.005 and p(c)=0.049; respectively). A significant decrease in the frequency of the DRB1*04:02 allele was observed in patients with ACPA(+) and RF(+) subgroups (p(c)=0.04 and p(c)=0.02, respectively). Our results showed that there was a trend of positive association of HLA-DRB1*04 and HLA-DRB1*10 with RA as such and significant associations with the disease severity in the south Tunisian population.

Association and frequency of HLA-A, B and HLA-DR genes in south Tunisian patients with spondyloarthritis (SpA).

The aim of this study is to investigate the association of HLA-A, B and HLA-DR gene expression and to assess an association of additional HLA antigens besides HLA-B27 in south Tunisian patients with spondyloarthritis (SpA). Eighty-five patients diagnosed with ankylosing spondylitis (AS, n=68) and reactive arthrithis (ReA, n=17) were selected and compared with 100 healthy controls (HC). HLA class I antigens were typed serologically using microlymphocytotoxicity technique. HLA-DRB1* alleles were studied by polymerase chain reaction amplification with sequence-specific primers. The significance of differences between patients and controls was tested by chi-square analysis. We found significantly increased frequencies of HLA-A3 (30.6%; pC=0.04; OR=2.95), HLA-B27 (62.35%; pC=4.10(-17), OR=53.55), and HLA-DRB1*15 (17.2%; pC=0.026; RR=2.58) alleles in SpA patients compared to HC. The most frequent and strongest association was observed for HLA-B27 in AS (pC=6.6 ×10(-16), OR=52.23). When AS and ReA patients were analysed separately, HLA-DRB1*15 and HLA-A3 were increased only in AS (pC=0.01, OR=2.99 and pC=0.03, OR=3.14, respectively). In ReA patients, HLA-DRB1*04 (p=0.033, pC=NS, OR=2.89) was found to be the most common allele. By analysing the HLA-B27-negative subgroup, HLA-A3 and HLA-DRB1*15 expression was found to be dependent on the presence of HLA-B27. HLA-B27 expression was higher in male (45/53; 85%) as compared to female (8/53; 15%) patients (p=0.03). Apart from HLA-B27, HLA-A3 and HLA-DRB1*15 are the MHC class I and II alleles found most frequent in Tunisian patients with AS, whereas HLA-DRB1*04 was found most frequent in ReA patients. HLA-B27 is more frequent in male than in female patients.

Analysis of skewed X-chromosome inactivation in females with rheumatoid arthritis and autoimmune thyroid diseases.

INTRODUCTION: The majority of autoimmune diseases such as rheumatoid arthritis (RA) and autoimmune thyroid diseases (AITDs) are characterized by a striking female predominance superimposed on a predisposing genetic background. The role of extremely skewed X-chromosome inactivation (XCI) has been questioned in the pathogenesis of several autoimmune diseases. METHODS: We examined XCI profiles of females affected with RA (n = 106), AITDs (n = 145) and age-matched healthy women (n = 257). XCI analysis was performed by enzymatic digestion of DNA with a methylation sensitive enzyme (HpaII) followed by PCR of a polymorphic CAG repeat in the androgen receptor (AR) gene. The XCI pattern was classified as skewed when 80% or more of the cells preferentially inactivated the same X-chromosome. RESULTS: Skewed XCI was observed in 26 of the 76 informative RA patients (34.2%), 26 of the 100 informative AITDs patients (26%), and 19 of the 170 informative controls (11.2%) (P < 0.0001; P = 0.0015, respectively). More importantly, extremely skewed XCI, defined as > 90% inactivation of one allele, was present in 17 RA patients (22.4%), 14 AITDs patients (14.0%), and in only seven controls (4.1%, P < 0.0001; P = 0.0034, respectively). Stratifying RA patients according to laboratory profiles (rheumatoid factor and anti-citrullinated protein antibodies), clinical manifestations (erosive disease and nodules) and the presence of others autoimmune diseases did not reveal any statistical significance (P > 0.05). CONCLUSIONS: These results suggest a possible role for XCI mosaicism in the pathogenesis of RA and AITDs and may in part explain the female preponderance of these diseases.

Clinical and diagnostic value of ribosomal P autoantibodies in systemic lupus erythematosus.

OBJECTIVE: To analyse prospectively the diagnostic sensitivity and specificity as well as the clinical relevance of ribosomal P (anti-P) autoantibodies in a large cohort of SLE patients. METHODS: The anti-P autoantibodies were evaluated in the serum of 200 Tunisian SLE patients at disease onset and 130 various control subjects by a sensitive immunodot assay. A complete laboratory evaluation and clinical examination were performed in each SLE patient. During the follow-up, the patients were regularly monitored for clinical parameters. Global SLE activity was measured by the ECLAM. RESULTS: The sensitivity and specificity of anti-P testing for SLE were 23.5 and 98.4%, respectively. The anti-P-positive samples 14/47 (29.8%), 27/47 (57.4%) and 5/47 (10.6%) were negative for anti-dsDNA, anti-Sm or both antibodies, respectively. The anti-P-positive patients showed more active disease activity and a much higher prevalence of arthritis. An association between IgG aCLs and anti-P antibodies was also found. However, anti-P antibodies were not associated with neuropsychiatric manifestations or lupus nephritis. CONCLUSION: This study does not seem to confirm the described association of anti-P antibodies with neuropsychiatric manifestations of SLE. However, it supports the anti-P antibody association with arthritis and disease activity as well as the presence of aCL. Based on our study and other related studies, we propose that, akin to anti-Sm and anti-dsDNA, anti-P antibodies detected by one agreed method may be considered for inclusion as a criterion for the classification of SLE.

The R620W polymorphism of the protein tyrosine phosphatase 22 gene in autoimmune thyroid diseases and rheumatoid arthritis in the Tunisian population.

BACKGROUND: Protein tyrosine phosphatase (PTPN22) is involved in the negative regulation of T-cell responsiveness. The association of a coding variant of the PTPN22 gene (R620W) with a number of autoimmune diseases has been described. AIM: The present study investigated whether PTPN22 gene polymorphism was also involved in the genetic predisposition to autoimmune thyroid diseases (AITDs) and rheumatoid arthritis (RA) in a Tunisian case control study. SUBJECTS AND METHODS: DNA samples from 150 patients affected with RA, 204 patients affected with AITDs and 236 healthy controls were genotyped for PTPN22 R620W polymorphism (1858C/T). Genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: No significant differences in T allele frequency (2.3% in RA patients and 1% in AITDs patients vs 2.6% in controls; p=0.85 and p=0.08, respectively) and in genotype frequencies were detected between RA patients and controls (p=0.15) and between AITDs patients (p=0.11). Stratifying patients affected with AITDs according to their phenotype (Graves' disease and Hashimoto's thyroiditis) and RA patients according to the presence of rheumatoid factor (RF) and antibodies against cyclic citrullinated peptides (ACPA) did not show any significant association with PTPN22 R620W allele (p>0.05). CONCLUSION: Our data suggest that the PTPN22 C1858T single nucleotide polymorphism has no or minor effect on RA and AITDs susceptibility in the Tunisian population.

Clinical and immunological manifestations of systemic lupus erythematosus: study on 146 south Tunisian patients.

The objective of this study was to determine the main clinical and laboratory features as well as the morbidity and mortality of systemic lupus erythematosus (SLE) in a population of patients predominantly from the south of Tunisia. A retrospective review of a well documented population of 146 patients with SLE was undertaken. All patients fulfilled four or more criteria defined by the American College of Rheumatology. The mean age at presentation was 29.2 years (range 6-55) and the mean duration of follow-up was 62 months (range 0.25-374). Musculoskeletal (84.2%) and mucocutaneous (75.3%) were the most frequent clinical manifestations. Antinuclear antibodies were detected in 97.3%, anti-DNA antibodies in 69.2% and anti-Sm in 39.2% of the patients. Anti-cardiolipin antibodies and lupus anticoagulant were ob-served respectively in 71.6% and 37.8% of the patients. The five-year survival rate in our series was 92%. Renal involvement and thrombocytopenia were associated with poor prognosis (p< 0.05). The clinical and immunological characteristics of our SLE patients are largely comparable to most major studies. Main differences included prominent major organ damage and high pre-valence of anti-Sm and anti-cardiolipin antibodies.

[Mortality and prognostic factors in 146 patients with systemic lupus erythematosus in southern Tunisia]. / Mortalité et facteurs de mauvais pronostic au cours du lupus érythémateux systémique dans une série de 146 cas du Sud tunisien.

OBJECTIVES: The objective of this study was to analyze the survival rate, causes of death, and prognostic factors in patients with systemic lupus erythematosus (SLE), mainly from southern Tunisia. METHODS: This retrospective study examined the records of 146 Tunisian patients with SLE, all meeting at least 4 of the American College of Rheumatology criteria for this diagnosis. RESULTS: The mean age at presentation of these patients (126 women and 20 men) was 29.2 years (range: 6-55), and the mean duration of follow up 62 months (range: 3 days-374 months). Eleven patients (7.5%) died during follow-up. The 5- and 10-year survival rates in this cohort were both 92.1%. The most frequent causes of death were infections and disease activity, each accounting for 4 deaths. Logistic regression showed that nephrotic syndrome was an independent prognostic factor for death (p=0.032, OR=5.64). CONCLUSIONS: Our results confirmed the improvement in recent years of survival rates among SLE patients. Infections and disease activity remain the most common causes of death. Nephrotic syndrome is independent risk factor for mortality.