Infrequent patterns in cerebrospinal fluid isofocusing test: Clinical significance and contribution of IgG index and Reiber diagram to their interpretation

Cerebrospinal fluid (CSF) isoelectrofocusing (IEF) is considered as the gold standard for detecting an intrathecal synthesis of IgG, which is a hallmark of multiple sclerosis (MS). This corresponds to the presence of CSF-restricted IgG oligoclonal bands (OCB) (typically type 2 pattern). Moreover, this technique can also detect a systemic immune reaction with passive transfer of IgG (type 3 and 4 patterns) for which the clinical relevance is less understood. The aim of our study was to determine the frequency and disease associations of IEF type 3 and 4 patterns and to investigate the potential usefulness of including quantitative data (IgG index and Reiber Diagram) in interpreting such IEF profiles. Among 544 patients who underwent CSF IEF (Hydragel CSF isofocusing kit, Sebia®, France) in our Laboratory during a six-year-period, those who presented type 3 or 4 patterns were selected. Clinical data and results of other immunological tests were analyzed for 27 patients followed in the Neurological Department. Frequencies of type 3 and type 4 patterns were relatively low (2.3 % and 3.4 % respectively). Among patients with type 3 pattern included in our study (n = 10), 5 were diagnosed with MS. For the 5 other patients, the diagnosis was a clinically isolated syndrome (CIS) (2 cases), a probable auto-immune encephalitis (2 cases) and a possible genetic neurodegenerative disease (1 case). MS patients had an IgG index >0.7 and fell into area 4 of Reiber diagram while non-MS patients had an IgG index <0.7 and fell into area 1, except the last case. Regarding type 4 pattern (n = 17), the diagnoses were as follows: MS (3), CIS (4), Neuromyelitis optica spectrum disorders with positive anti-AQP4 antibodies (3) and anti-NMDAR autoimmune encephalitis (1). The remaining cases had central nervous system impairment related to vascular, metabolic or tumoral etiologies (3) or peripheral nervous system impairment (3). In this group (type 4 pattern), IgG index was <0.7 in 15/17 cases. Interpretation using Reiber diagram showed an abnormal blood-brain barrier for 8/17 patients. Type 3 and 4 IEF patterns are infrequently observed in routine neurology practice. It is important for the diagnostic laboratory professional as well as for the neurologist to understand their clinical relevance. Our findings highlight the contribution of quantitative evaluation of CSF (IgG index, Reiber diagram) for the interpretation of such situations. Despite the small size of our study population, our results emphasize the importance of reporting the exact type of IEF pattern and not only the positivity or not of OCB.

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 ± 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.

Vitamin D deficiency in relation with the systemic and central inflammation during multiple sclerosis

Background

During the last decade, vitamin D (VitD) has become a topic of interest in immune regulation, especially in multiple sclerosis (MS) disease. Amongst the wide range of effects reported for this vitamin on the immune system, a regulatory role on cytokines production has been described. Our aim is to analyze the status of VitD and its correlation with the circulating inflammation and the intrathecal humoral response during MS.

Methods

We analyzed samples of 318 individuals: 108 MS patients and 210 controls. Determination of 25-(OH) VitD3 level in serum was made using electrochemiluminescence method. Circulating inflammatory cytokines (IL-6, IL-8, IL-10, TNF-a, IL12p70 and IL-1b) were investigated using Cytometer Bead Array Technology. The central humoral response was characterized using CSF isofocusing test and IgG Index calculation.

Results

As expected, mean value of VitD was significantly lower in MS group (26 nmol/L) than in control group (34.75 nmol/L) (p=0.002), with a severe deficiency in 67% of MS patients. Mean value of VitD was significantly lower in MS female patients. Regarding cytokines, mean value of TNFa was significantly higher in MS patients with oligoclonal bands of IgG in the CSF. IL6 was positively correlated with IgG level in serum of MS patients.

Conclusions

Our results support the association of VitD deficiency with MS, especially in female patients of our region. However, the vitamin level seems to not correlate with inflammatory cytokines nor with disability. Interestingly, TNFa and IL6 levels were correlated with the intrathecal synthesis of IgG and the circulating IgG level, respectively.

ICOS gene polymorphisms in systemic lupus erythematosus: A case-control study

The inducible T-cell costimulator (ICOS) may play an important role in adaptive immunity by regulating the interaction between T cells and antigen-presenting cells. Disruption of this molecule can lead to autoimmune diseases, in particular systemic lupus erythematosus (SLE). In this study, we aimed to explore the possible association between ICOS gene polymorphisms and SLE as well as their influence on disease susceptibility and clinical outcomes. A further objective was to assess the potential impact of these polymorphisms on RNA expression. A case-control study, including 151 patients with SLE, and 291 unrelated healthy controls (HC) matched in gender, and geographical origin, was performed to genotype two polymorphisms located in the ICOS gene: rs11889031 (-693 G/A) and rs10932029 (IVS1 + 173 T/C); using the polymerase chain reaction (PCR)-restriction fragment length polymorphism method. The different genotypes were validated by direct sequencing. The expression level of ICOS mRNA was assessed by quantitative PCR in peripheral blood mononuclear cells of SLE patients and HC. The results were analysed using Shesis and spss.20. Our results revealed a significant association between ICOS gene rs11889031 > CC genotype and SLE disease (codominant genetic model 1, (C/C vs. C/T), p = .001, odds ratio [OR] = 2.18 IC [1.36-3.49]); codominant genetic model 2, (C/C vs. T/T) p = .007, OR = 15.29 IC [1.97-118.5]); dominant genetic model, (C/C vs. C/T + T/T) p = .0001, OR = 2.44 IC [1.53-3.9]). Besides, there was a marginal association between rs11889031 > TT genotype and T allele with a protective role from SLE (recessive genetic model, p = .016, OR = 0.08 IC [0.01-0.63] and p = 7.6904E - 05, OR = 0.43 IC = [0.28-0.66], respectively). Moreover, statistical analysis indicated that the rs11889031 > CC genotype was linked with clinical and serological manifestations of SLE, including blood pressure, and anti-SSA antibodies production in SLE patients. However, the ICOS gene rs10932029 polymorphism was not associated with susceptibility to SLE. On the other side, we did not note any effect of the two selected polymorphisms on the level of ICOS mRNA gene expression. The study showed a significant predisposing association of the ICOS rs11889031 > CC genotype with SLE, in contrast to a protective effect of rs11889031 > TT genotype in Tunisian patients. Our results suggest that ICOS rs11889031 may act as a risk factor for SLE and could be used as a genetic susceptibility biomarker.

miRNA implication in the pathogenesis and the outcome of Tunisian endemic pemphigus foliaceous

Pemphigus foliaceous (PF) is a bullous autoimmune skin disease diagnosed through sera and skin analyses. PF severity is associated with maintained anti-Dsg1 sera levels and its prognosis is unpredictable. MicroRNA (miRNA), dynamic regulators of immune function, have been identified as potential biomarkers for some autoimmune diseases. This study aimed to assess the miRNA expression of miR-17-5p, miR-21-5p, miR-146a-5p, miR-155-5p and miR-338-3p using quantitative real-time PCR in peripheral blood mononuclear cells (PBMC) and lesional skin samples from untreated and treated PF patients (both remittent and chronic) over 3 months. Overall, miRNA expression was significantly higher in PBMC than in biopsy samples. Blood miR-21 expression was increased in untreated patients compared to controls and had a diagnostic value with an AUC of 0.78. After 6 weeks, it decreased significantly, similar to anti-Dsg1 antibodies and the PDAI score. In addition, a positive correlation was observed between cutaneous miR-21 expression and the disease activity score. Conversely, cutaneous expressions of miR-17, miR-146a and miR-155 were significantly higher in treated chronic patients compared to remittent ones. The cutaneous level of miR-155 positively correlated with pemphigus activity, making it a potential predictive marker for patients' clinical stratification with an AUC of 0.86.These findings suggest that blood miR-21 and cutaneous miR-155 can be used as supplemental markers for PF diagnosis and activity, respectively in addition to classical parameters.

The presence of two light chain bands on immunofixation is associated with poor outcomes in newly diagnosed multiple myeloma patients

We aimed to describe the clinical and biological characteristics and the prognosis of patients presenting with an additional light chain (LC) band along with a complete monoclonal protein on immunofixation (IF).An 8-year descriptive study was conducted to assess all cases with confirmed monoclonal gammopathies (MG). We studied those with an entire M-protein with 2 bands of LC of the same isotype based on the results of IF. Data were collected from patients' files.Among 548 cases of MG, we found 32 cases (5.8%) with an additional LC band. We included 28 patients (5%) with a confirmed diagnosis of multiple myeloma (MM). The m/f ratio was 2.5 with a median age of 63 years [32-80 years]. All MM patients had anemia, 16 (57%) had renal failure, 14 (50%) had lytic lesions, 9 (32%) received hemodialysis, and 7 (25%) had hypercalcemia. The free-kappa-lambda ratio was abnormal in all cases: median = 0.07 [0.002-58.57]. The mean overall survival (OS) was 22 months ± 38.76.Fifteen MM patients (48%) received chemotherapy, and 7 (22%) autologous stem cell transplants (SCT). Patients who received SCT had an OS higher than those who received other treatments (p = 0.038). OS was low in patients with high β2microglobulin levels (rho = -0.791; p = 0.001), and abnormally low free-kappa-lambda ratio (rho = -0.852;p = 0.04).The presence of an additional LC band with a complete monoclonal protein seems to identify newly diagnosed MM patients with poor outcomes and frequent renal impairment.

Evaluation of X chromosome inactivation in endemic Tunisian pemphigus foliaceus

BACKGROUND

Almost 5% of the world's population develops an autoimmune disease (AID), it is considered the fourth leading cause of disability for women, who represent 78% of cases. The sex ratio when it comes to the most prevalent AID varies from 9:1 in systemic lupus erythematosus (SLE) to 13:1 in endemic Tunisian pemphigus foliaceus (PF).

METHODS

To test the potential involvement of skewed x-inactivation in the pathogenesis of Tunisian PF, we analyzed the methylation status of a highly polymorphic CAG repeat in the androgen receptor gene and evaluated the x chromosome inactivation (XCI) patterns in peripheral blood-leukocyte-derived DNA samples of female patients with PF (n = 98) compared to healthy control (HC) subjects (n = 150), as well as female patients with SLE (n = 98) were enrolled as a reference group.

RESULTS

XCI status was informative for 50 of the 98 PF patients (51%) and 70 of the 150 HC women (47%). Extremely skewed XCI patterns were more frequent in PF and SLEwomen than HC, but the difference was statistically significant only in women with SLE. No statistical difference was observed in XCI patterns between PF and SLE patients. PF phenotype-XCI correlation analysis revealed that (i) skewed XCI patterns may be involved in the disease's subtype and (ii) it was more pronounced in the endemic group than the sporadic one. Furthermore, preferential XCI showed an increase in heterozygote genotypes of PF's susceptibility polymorphisms in immunity-related X genes (FOXP3, AR, and TLR7) in PF patients compared to HC.

CONCLUSION

Our results suggest that skewed XCI could lead to hemizygosity of X-linked alleles that might unmask X-linked deleterious alleles.

Th17 and Th1 cells in systemic lupus erythematosus with focus on lupus nephritis

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by T cells imbalance. Indeed, a correlation between levels of Th17 cells and disease activity has been reported. Our work aimed to study the functional association of subpopulations of Th cells and SLE with (lupus nephritis, LN) or without (lupus erythematosus, LE) renal involvement in Tunisian patients through the detection of intracellular cytokines and surface marker expression. The IL23R and RORC mRNA expression levels were evaluated. The level of Th17 and Th1 cells was higher in LE and LN patients compared to healthy controls (HC) (p = 0.007 and p = 0.018, respectively), while Th1/17 cells were increased only in LN patients compared to HC (p = 0.011). However, no significant difference was described in the mRNA expression levels of RORC and IL-23R between SLE and HC. Our findings suggest that the Th1/Th17 differentiation mechanisms are altered in SLE and that this imbalance should have an important influence on the development and severity of the disease.

Antinuclear antibodies in children: clinical signification and diagnosis utility

BACKGROUND

Antinuclear antibodies (ANA) test is used to screen adults as well as children for connective tissue diseases (CTD) and autoimmune hepatitis. However, interpretation of ANA positivity can be delicate.

AIM

to determine clinical significance and diagnosis utility of ANA positivity in children.

METHODS

Patients from a general pediatric department with ANA positive results were included (follow-up period of 2 years). ANA screening was performed by indirect immunofluorescence (IIF) on HEp-2 cells substrate (BioSystems®). In case of ANA positivity (cut-off: 1:80), the specificity was determined by IIF on Crithidia luciliea substrate (BioSystems®) and immunodot (Euroimmun®).

RESULTS

Among 102 ANA tests, 55 (53,9%) were positive. We recorded the data of 38 patients (age average: 9,5 years - sex ratio: 0.72). The most frequent signs were join pain (55,3%). ANA titer varied between 1:80 (39,5% of cases) and 1:1280 (2,6% of cases). Typing was negative in 89,5% of cases. The majority (42,1%) of children with positive ANA test had musculoskeletal diseases. The others (57,9%) had systemic lupus erythematosus(n=2),  overlap syndrome(n=1), rheumatoid purpura(n=2), idiopathic thrombocytopenic purpura(n=1), coeliac disease(n=1) or non-autoimmune diseases/no confirmed diagnosis(n=15).

CONCLUSIONS

ANA prevalence in children was relatively high. When the pretest probability is low, the positive predictive value for CTD or autoimmune hepatitis is low. However, depending on the clinical context, ANA detection can represent a supplement diagnostic tool for these diseases and/or can lead to a clinico-biological monitoring.

Role of innate immune receptors TLR4 and TLR2 polymorphisms in systemic lupus erythematosus susceptibility

AIM

Through their recognition of various bacterial cell wall components, TLR2 and TLR4 participate in the innate response and modulate the activation of adaptive immunity. Therefore, the genetic background of these receptors might play a crucial role in autoimmune diseases such as systemic lupus erythematosus (SLE). In this study, we investigated the possible association between polymorphisms within TLR2 and TLR4 genes with SLE susceptibility.

MATERIAL AND METHODS

A total of 100 SLE patients and 200 unrelated healthy controls of the Tunisian population were enrolled in the study.TLR4rs4986790, TLR4rs4986791, and TLR2rs5743708 genotyping were performed using a polymerase chain reaction-restriction fragment length polymorphism method. The number of guanine-thymine (GT) repeat microsatellite in the intron 2 of TLR2 gene was analyzed by sequencing.

RESULTS

We reported a lack of allelic and genotypic association between SNPs of TLR4 and TLR2 genes and SLE pathogenesis. No correlation was found with any SLE features. However, SLE susceptibility was associated with the GT repeat microsatellite polymorphism in the human TLR2 gene. Further subclassification of alleles into three subclasses revealed a significant association between the long-sized repeats ((GT) >23) and SLE.

CONCLUSION

Though the results showed the absence of genetic association of TLR4 and TLR2 SNPs with the risk of developing SLE, we have identified a protective association between the microsatellite polymorphism in intron 2 of the TLR2 gene and SLE. Functionally, these (GT)n repeats may confer modifying effects or susceptibility to certain inflammatory conditions.

Annexin A1 and its receptor gene polymorphisms in systemic lupus erythematosus in the Tunisian population

BACKGROUND

An association between ANXA1, FPR1 and FPR2 gene polymorphisms and the patho-physiology of many human diseases was suggested by numerous studies.

OBJECTIVE

Our study aimed to evaluate association between common polymorphisms in the 9q21.13 and 19q13.41 and susceptibility to systemic lupus erythematosus (SLE) in the Tunisian population.

MATERIALS

We performed a case-control study on 107 Tunisian SLE patients and 122 healthy controls to explore 9 polymorphisms of the three studied genes: rs2811226 and rs3739959 (ANXA1), rs5030880, rs1042229, rs1461765570, rs17849971, rs867228 (FPR1), rs17694990 and rs11666254 (FPR2).

RESULTS

Four polymorphisms were found to be linked with SLE susceptibility: rs3739959-ANXA1 > G and GG (p = 0.021, OR = 1.73 and p = 0.014, OR = 2.06 respectively), rs867228-FPR1 > TT (p = 0.014, OR = 4.59), rs11666254-FPR2 > GG (p = 0.019, OR = 8.34) and rs17694990-FPR2 > T (p = 0.05, OR = 1.506). In homogenous groups of SLE patients depending on clinical manifestations and serological results, previous associations were confirmed with a panoply of manifestations of lupus including lupus nephritis, malar rash, mouth ulceration and hypocomplementia.

CONCLUSION

Our study showed an association between ANXA1 > rs3739959, FPR1 > rs867228, FPR2 > rs11666254, FPR2 > rs17694990 and SLE susceptibility. Our results also showed a strong association between the two ANXA1 studied SNPs and LN which allowed us to suggest these two SNPs as biomarkers of LN development in SLE. Further research is needed to understand by which mechanism the gene variants affect susceptibility to SLE. Key Points • Lupus erythematosus is an autoimmune disease in which a panoply of factors are implicated • Annexin A1 interaction with its receptors are suggested as a target in therapy of a panoply of human disease in particular cancers • The present results highlighted the implication of Annexin A1 and its receptors gene polymorphisms in the physiopathology of lupus, in particular in the involvement of renal and cutaneous lesions.

Autoantibodies against Desmoglein 1 and 3 in South Tunisian pemphigus

BACKGROUND

Desmoglein (Dsg) 1 and 3 are the 2 major autoantigens in pemphigus foliaceus (PF) and pemphigus vulgaris (PV).

AIM

We aimed to determine anti-Dsg1 and 3 Abs'usefulness in the diagnosis of pemphigus and to assess the correlation of these antibodies (Abs) with clinical phenotype and disease activity in south Tunisian patients.

METHODS

We retrospectively analyzed 131 samples from 82 patients (52 with PF and 30 with PV) during follow-up. Anti-Dsg1 and 3 Abs were measured by ELISA. Consecutive anti-Dsg1 and 3 Abs were correlated with disease activity. Receiver operating characteristics (ROC) curve were calculated to determine anti-Dsg1 and 3 Abs'cut-offs with optimal sensitivity and specificity for disease activity.

RESULTS

Anti-Dsg1 and 3 levels were associated to in PF and PV patients respectively (p<0,001). Anti-Dsg1 and 3 Ab were associated with skin (95%) and mucosal (60%) lesions, respectively. A significant decrease of anti-Dsg1 Abs was observed in patients with PF in clinical remission (36 ± 62 U/mL; (p=0,04). No correlation was found between anti-Dsg3 Abs and the course of mucosal lesions in PV (p=0,3). During follow-up, anti-Dsg1 Abs correlated with relapses (177 ±60 U/mL ; p=0,04). The 161,5 U/mL cut-off for anti-Dsg1 Abs provided 100% specificity and 86,4% sensitivity in PF disease activity. The 30,7U/mL cut-off for anti-Dsg3 provided 89,5% sensitivity and 100% specificity in PV.

CONCLUSIONS

High anti-Dsg3 Abs values are not always associated with PV disease activity. Anti-Dsg1 Abs showed a closer relationship with skin activity in PS and should be therefore taken into account in management of pemphigus patients.

[Variations in immunological parameters after treatment of a manic episode]

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.

RNA receptors, TLR3 and TLR7, are potentially associated with SLE clinical features

The influence of intracellular Toll-like-receptors (TLR), recognized as nucleic acid sensors, in the immunopathogenesis of systemic lupus erythematosus (SLE) is increasingly explored. Yet, the results of both functional and genetic studies remain conflictual. We evaluated the association between TLR3 and TLR7 genes selected variants and SLE and investigated the possible relationship with clinical and serological parameters. Then, we studied the genetic expression of these receptors, and if the TLR7 gene evades X chromosome inactivation (XCI). Our study covers 106 cases and 200 controls, genotyped using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. TLR3 and TLR7 expression level was assessed by qPCR carried, respectively, on renal tissues and PBMC, and methylation status was evaluated by methylation-specific PCR. Results were statistically analysed using Shesis software, χ² , and Mann-Whitney test. Significant associations with SLE susceptibility were found for the TLR3 rs3775291, rs5743305 and rs3775294 polymorphisms. Further subgroup analysis, TLR3 rs3775291 and rs3775294 polymorphisms were significantly associated with lupus nephritis (LN) and even correlate with the presence of auto-antibodies binding RNA molecules. SLE and LN were more common in men with rs3853839-G variant within TLR7 gene versus those carrying the C allele. Moreover, the role of the G allele in the TLR7 expression up-regulation was confirmed. However, gene expression analysis showed no significant differences in TLR3 and TLR7 mRNA levels between LN patient biopsies and healthy tissues (p > .05). When comparing patients and controls, no statistical difference was observed in XCI pattern. Otherwise, notable associations were raised between TLR3 and TLR7 gene variants and clinical and serological lupus features pointing towards the role of genetic background in the physiopathogenesis of the disease.

Vitamin D status and CYP27B1-1260 promoter polymorphism in Tunisian patients with systemic lupus erythematosus

Aim

An association between serum vitamin D (Vit D) levels and systemic lupus erythematosus (SLE) has been reported by several studies that suggested the involvement of genetically determined characteristics of enzymes of vitamin D metabolism. Our study aimed to evaluate the relationship between 25 hydroxyvitamin D (25[OH]D) level, the most representative metabolite of VitD status, and polymorphism of the cytochrome P450, CYP27B1 gene, which influence vitamin D metabolism, and serum levels, in SLE Tunisian patients.

Material and Methods

A cross‐sectional study has been conducted in SLE patients (supplemented and not supplemented patients), matched to healthy controls by age and gender. The 25[OH]D serum level was measured by chemiluminescence assay and CYP27B1‐1260 genetic polymorphism was carried out using PCR‐RFLP methods. Statistical analysis was made using Shesis and SPSS.20 Software.

Results

Controls and Vit D not supplemented patients’ groups presented the highest percentage of hypovitaminosis D. A significant difference in the mean level of circulating 25[OH]D between Vit D supplemented SLE patients and controls was observed (23.91 ng/ml and 7.18 ng/ml, respectively p = 3.4 10⁵). Our results showed a correlation of high 25[OH]D level with complement component 3 levels and prednisolone drug. Moreover, the analysis of CYP27B1‐1260 polymorphism in SLE patients and controls revealed a nonsignificant allelic or genotypic association.

Conclusion

Despite the sunny climate, the high prevalence of Vit D deficiency is common in Tunisia. This hypovitaminosis D feature may affect the Vit D levels in our SLE patients but a direct association with the disease or with the genetically determined features remains unclear. More studies are needed to establish thresholds and susceptibility genes according to the characteristics of each population.

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.

The intrathecal polyspecific antiviral immune response (MRZ reaction): A potential cerebrospinal fluid marker for multiple sclerosis diagnosis

We tested the performance of MRZ-reaction, an intrathecal humoral immune response against-Measles (M), Rubella (R) and Varicella Zoster (Z) viruses, in multiple sclerosis (MS) diagnosis. The MRZ-reaction was significantly more positive in MS than in non-MS group with a specificity of 91.9%. In MS group, the RZ-profile was the most prevalent and the R-specific antibody-index was correlated to the number of oligoclonal bands (OCB) in CSF. Interestingly, the MRZ-reaction was detected in 53% of OCB-negative-MS patients. The MRZ-reaction seems to be a relevant CSF diagnostic marker of MS disease. The likely relation between its positivity and the vaccination status deserves to be investigated.

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.

Genetic association and phenotypic correlation of TLR4 but not NOD2 variants with Tunisian inflammatory bowel disease

OBJECTIVE

The common association between NOD2/CARD15 and TLR4 gene variants with inflammatory bowel disease (IBD) has not been replicated in all studies. We studied the polymorphism of these two genes in Tunisian patients with IBD.

METHODS

Polymorphisms of NOD2 (R702W, G908R and L1007fs) and TLR4 (Asp299Gly and Thr399Ile) genes were analyzed in 106 patients with IBD (68 with ulcerative colitis [UC], 38 with Crohn's disease [CD]) and 160 healthy controls using polymerase chain reaction-restriction fragment length polymorphism. Genotypes and phenotypes were correlated.

RESULTS

The mutated allele of TLR4-Thr399Ile was strongly associated with IBD (9.4% in IBD, 7.4% in UC and 13.2% in CD vs 2.5% in controls; P = 0.0004, 0.014 and 0.00006, respectively). Heterozygous genotypes were significantly more frequent in patients with IBD (17.0%), UC (14.7%) and CD (21.1%) than in controls (5.0%) (P = 0.0012, 0.012 and 0.001, respectively). Interestingly, the wild genotype was found to be protective (odds ratio 0.24). The mutated allele of TLR4-Asp299Gly was more frequent in controls (6.8%) than in patients with IBD (2.9%). A phenotypic correlation of Asp299Gly-AG genotype with arthritis in UC patients was detected (P = 0.003). Regarding the NOD2 gene, the common variations studied were not polymorphic and there was no genetic association with IBD.

CONCLUSION

The TLR4-Thr399Ile variant was strongly associated with susceptibility to IBD, whereas TLR4-Asp299Gly seems to play a role in the clinical expression of UC. The rarity and non-association of NOD2 mutations with IBD may reveal a genetic characteristic of the population in our region.

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.

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.

Paranasal sinus osteomas: Diagnosis and treatment

INTRODUCTION

Osteoma is the most common benign tumor of the nose and paranasal sinuses. It is a slow-growing bony tumor, often asymptomatic, occurring mainly in frontal and ethmoid sinuses. Theories regarding the origin of osteomas are still discussed. The aims of the study were to describe diagnosis circumstances in our series and to set out our respective indications for open and endoscopic approaches in the treatment of nasosinusal osteomas.

PATIENTS AND METHODS

A retrospective study was conducted on the files of all the patients treated for a paranasal sinus osteoma in our department between 1990 and 2013. Diagnosis circumstances and kind of treatment were collected and analyzed.

RESULTS

The files of 45 patients (mean age: 49.2; sex-ratio: 1.19) could be collected. The most common symptom was headache found in all patients. The most common location was the frontal sinus (30 cases). Thirty-nine open procedures were performed. Four osteomas were removed under endoscopic assistance. In one case, a combined approach has been used. Overall complication rate was 11.1%. Symptoms improved in all patients. Two recurrences were observed.

DISCUSSION

Surgical indications in paranasal sinus osteomas are theorically well codified. However, approaches remain controversial. In our experience, the preferred approach was the open one. Endoscopic techniques, when indicated, are more challenging and need sophisticated instrumentation and a long learning curve.