AB0345 Th9 CELLS AND THEIR ASSOCIATED CYTOKINES: THE PROBABLE PLAYERS IN SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) AND TYPE 1 DIABETES MELLITUS (T1DM)
Authors: N. Mohannad, M. Moaaz, R. Mohamed Shehata
Journal: Annals of the Rheumatic Diseases (2021)

Background: SLE is an autoimmune disease (AID) of unknown origin. Several factors can contribute to immune dysfunction in SLE. Interleukin 9 (IL9) is a newly emerging T cell-derived factor preferentially expressed by CD4+T cells: T helper 9 (Th9) IL9 targets different cell lineages, and can contribute to the development of allergic &amp; AIDs Whether abnormal expression and secretion of IL9 are present in SLE patients (pts) still unidentified. It is also unclear whether IL9 exerts main proinflammatory or anti-inflammatory activities in SLE. T1DM is characterized by inflammation of the pancreatic islets of Langerhans. Insulitis progresses over time and β cells become destroyed then clinical DM is established. T1DM is regarded as a T cell-driven AID Objectives: Evaluation of the expression of CD4+ IL9+ T cells &amp; the level of IL9 in SLE pts compared to both healthy subjects &amp; pts with another AID: T1DM.Also, to evaluate the correlation of these expressions with clinical features, laboratory parameters and SLE activity Methods: The study included: Group I 25 SLE pts fulfilling SLICC classification criteria divided into 2 subgroups (gps) according to SLE disease activity index (SLEDAI) IA: 20 pts with mild to moderate activity (&lt;12) IB:5 pts with severe activity (&gt;12) recruited from rheumatology clinic or internal medicine ward (Rheumatology unit), Main University Hospital, Alexandria. Group II 15 healthy individuals as a first control gp. Group III 15 pts with T1DM fulfilling the American Diabetes Association criteria as a second control gp. All pts were subjected to history taking, clinical examination,laboratory investigations: CBC,LFT,KFT,ESR,CRP,ANA,Anti-dsDNA,Th9 cell expression detection by flowcytometry and serum IL9 by ELISA Results: There was no statistical difference between all gps as regards age &amp; sex but a significant increased ESR in SLE compared to controls &amp; T1DM p&lt; 0.001 p=0.001 Th9 expression was highly increased in SLE pts, range 0.13-4.54% &amp; mean ±SD=1.50 ± 1.47% than both control gps. In healthy controls Th9 ranged between 0.0-1.29% with mean 0.37 ±0.52%, while in T1DM pts ranged between 0.03 to 2.13% with mean of 0.67 ± 0.59%. A high significant difference was found between SLE pts and controls p=0.001, an insignificant rise was seen in SLE pts compared to T1DM pts p=0.157. A high significant increase in Th9 was found in severe SLE: mean of 3.74 ±1.15% than in pts with mild to moderate SLE: mean 0.94±0.88% p=&lt;0.001 IL9 level was highly increased in SLE pts: mean of 42.83± 23.98 pg/ml than both control gps. In healthy controls the mean was 8.54±13.27, while in T1DM with mean of 29.17±16.09 pg/ml. A high significant difference was found between SLE pts and normal controls p&lt;0.001 but an insignificant rise with T1DM p=0.294. A high significant increase in IL9 in pts with severe ds compared to mild to moderate pts p&lt;0.001.A significant direct correlation between Th9 &amp; IL9 and SLEDAI/105 A significant direct correlation between damage index and Th9 p=0.040 but not IL9 p=0.053 In SLE no significant relation between Th9 or IL9 &amp; clinical manifestations or disease duration. A direct correlations between Th9 &amp; ESR p=0.046 and CRP p=0.025,a significant correlation between IL9 and CRP p=0.033, no correlations between Th9&amp;IL9 level and anti-dsDNA p=0.593&amp; 0.4 Significant direct correlation between Th9 and IL9 in T1DM pts, still no correlation with glycemic profile. IL9 levels were significantly increased in SLE with elevated CRP p=0.033 &amp; the % of Th9 cells were increased with elevated ESR and CRP p=0.025, 0.046 Conclusion: In SLE pts; IL9 level and Th9 cells expression were significantly elevated compared to healthy controls. IL9 levels and the percentages of Th9 directly correlated with the SLE disease activity. IL9 levels also were significantly increased in T1DM pts compared to controls,but they were less expressed than in SLE. This suggests an important role of IL9 in the pathogenesis AIDs as SLE References: [1]Tahernia L et al. Cytokines in SLE: their role in pathogenesis of disease and possible therapeutic opportunities. Rheum Res 2017 Disclosure of Interests: None declared