POS1290 CYTOKINE BIOMARKERS IN COMMON LOW BACK PAIN

Background:

Common low back pain (LBP) is a common health problem affecting 50 to 80% of working age adults. It is one of the common and costly health problems in Tunisia. Actually, the role of the immune response and inflammatory cytokines in the pathogenesis of chronic pain has been of growing interest.

Objectives:

The aim of this study was to assess whether pro and anti-inflammatory cytokines could be detected in serum in patients with LBP compared with healthy subjects and whether they could be related to pain severity and to clinical findings.

Methods:

It was a an analytical cross-sectional study including 50 patients with at least three months of LBP, in the department of rheumatology, orthopedics and immunology at the Military Hospital of Tunis between January 1st and March 31, 2020. All patients had a standardized clinical assessment.

Levels of serum cytokines IL-6, IL-8, IL-1β and TNF- α, were measured using the chimiluminescence technique. Serum concentration of IL-10 was assayed by the enzyme-linked immunosorbent assay technique (ELISA). The normal levels of cytokines were determined in 50 healthy controls.

Results:

The mean age of the patients was 41.9 ± 8.4 years and the sex ratio was 4.5. LBP duration was 66.4 months. The mean lumbar visual analog scale (VAS) was 4.5 ± 1.9, and the root VAS was 2.6 ± 2.5. Neuropathic pain was found in 26% of patients. The average BMI was 27 ± 3.7 kg/m2. Only serum level of IL-8 was significantly higher in subjects with LBP compared to healthy controls (p <10-3). IL-1β was indetectable in both patients and controls. Positive correlations were found between IL-8 levels and anxiety/functional scores (r = 0.3; p = 0.02/ r = 0.3; p = 0.04). IL-6 was positively correlated with BMI, and negatively correlated with the Schober test. No correlations were found between serum levels of IL-6, IL-8, IL-10, TNF-α and pain intensity (VAS), neuropathic pain (DN4), fibromyalgia (FIRST), depression (HAD) and various radiological data.

Conclusion:

Interleukin-8 is a biomarker of common low back pain and correlate with anxiety and functional disability. These results suggest that IL-8 may be a therapeutic target to reduce chronic back pain and reduce the social and profession impact.

Disclosure of Interests:

None declared

High levels of proinflammatory cytokines IL-6, IL-8, TNF-Α, IL-23, and IFN- in Tunisian patients with type 1 autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic hepatitis of unknown etiology and several cytokines have been implicated in its pathogenesis and onset. Our objective was to determine the profile of pro and anti-inflammatory cytokines, including IL-1β, IL-6, IL-8, IL-23, IFN-, TNF-α, IL-10 in autoimmune hepatitis and their association with HLA gene polymorphisms. Serum cytokine levels were determined in 50 autoimmune hepatitis patients and one hundred fifty controls using chemiluminescence and ELISA techniques and HLA genotyping performed by PCR SSP. The levels of IL-6 (12 pg/mL vs. 5.5 pg/mL, p = 0.017), IL-8 (24.1 pg/mL vs. 7.8 pg/mL, p = 0.006), and TNF-α (61.1 pg/mL vs. <4.00 pg/mL, p = 0.002) were significantly higher in AIH patients in pretreatment phase compared to levels after remission and in controls. HLA*DRB15 was significantly associated with higher levels of IL-8. IL-6, IL-8, and TNF-α may be biomarkers of AIH activity. HLA gene expression may play a role in higher cytokine production and could allow an earlier diagnosis and better management of the disease.

Association of STAT4, TGFβ1, SH2B3 and PTPN22 polymorphisms with autoimmune hepatitis

The physiopathology of autoimmune hepatitis (AIH) is complex and still not fully elucidated. The genes localized outside the histocompatibility complex involved in regulation and signal transduction of the immune system SH2B3, TGFβ1, STAT4 and PTPN22 could be associated to the susceptibility and hepatocyte lysis mechanism of this lethal autoimmune disorder.

PATIENTS AND METHODS

We investigated four polymorphic sites in SH2B3 (rs3184504), TGFβ1 (rs1800471), STAT4 (rs7574865) and PTPN22 (rs2476601) in 45 AIH patients and 150 healthy controls from Tunisia using real-time PCR.

RESULTS

Significant associations were found for SH2B3 T allele (OR = 1.861; p = 0.015, pc = 0.366) and PTPN22 A allele (OR = 7.070; p = 0.026; pc = 1.00) and AIH with opposite homozygous being protective against the disease (CC genotype with OR = 0.420, p = 0.025; GG genotype with OR = 0.136, p = 0.025, respectively). No statistically significant associations were found for the TGFβ1 and STAT4 polymorphisms with AIH susceptibility.

CONCLUSION

Our work enlarges information on non-HLA genes that are associated with AIH by focusing in a region of the world that was poorly molecularly characterized for this disease.

Association of TNF-α-308 Polymorphism with Susceptibility to Autoimmune Hepatitis in Tunisians

Autoimmune hepatitis (AIH) is a chronic hepatitis of unknown etiology and several proinflammatory cytokines are implicated in its pathogenesis. The association of TNF-α gene polymorphism with AIH onset is not fully elucidated especially in the Tunisian population. The aim of this study was to determine the association of TNF-α (-308 G > A) polymorphism with AIH susceptibility and with TNF-α expression or clinical manifestations of AIH. A total of 50 AIH patients and 150 controls were included. Evaluation of TNF-α polymorphism was performed by ARMS PCR method. A significantly higher frequence of the AA genotype was found in AIH patients compared to controls (34 vs. 8%, p = 0.00002, OR 5.88). The frequency of the A-allele was significantly higher in patients with AIH compared to controls (55 vs. 37.3%, p = 0.002, OR 2.05). The G-allele was significantly more frequent in healthy controls compared to AIH patients [43 vs. 61.3%, p = 0.001, OR 0.47 (0.3-0.75)]. There was a positive correlation between the A/A genotype and a higher serum expression of TNF-α. The TNF*A allele confer susceptibility to AIH in the Tunisian patients and is associated with increased production of TNF-α. Anti-TNF antibodies could be an alternative to the use of corticotherapy and may avoid the exacerbated immune response in AIH.

Cytotoxic T lymphocyte antigen-4 gene polymorphisms and susceptibility to type 1 autoimmune hepatitis in the Tunisian population

Genetic factors and gene polymorphisms leading to the onset of autoimmune response in autoimmune hepatitis (AIH) are still not full elucidated. Since the CTLA-4 molecule is a key modulator of the lymphocytes responses we hypothezied that deficiencies or mutations in the gene encoding CTLA4 protein may be involved in AIH susceptibility and trigger the autoimmune response. We investigated 3 distinct polymorphic sites (+49A > G, CT60 G > A and -318C > T) of the CTLA4 gene in 50 AIH patients and 100 healthy controls using the KASP genotyping technology. A significant positive association with AIH susceptibility was found for the GG genotype in +49 position of the CTLA4 gene which was significantly higher in AIH patients compared to controls (28% vs 9%, p = 0.003, OR = 3.93 [1.56-9.88]). The CTLA4 A/A genotype in position CT60 was more significantly frequent in controls comparing to AIH patients and could be considered as a protective genotype for the tunisian patients. CTLA4 genotyping in position -318 did not show any statistically significant difference in genotype or allele distribution. The CTLA4 gene polymorphism in position +49 is associated to AIH susceptibility in the Tunisian population. Mutation in the CTLA4 gene may lead to a modification of the CTLA4 protein structure that could have functional relevance in AIH pathogenesis and onset.