No Association of Eight TNFAIP3 Single Nucleotide Variants to Rheumatoid Arthritis in Native Mexicans

Rheumatoid arthritis (RA) is a chronic inflammatory disease of autoimmune origin associated with many genetic traits, including genes related to the control of inflammation. The A20 protein, encoded by the TNFAIP3 gene, is a negative regulator of NF-kB-mediated inflammation. Several single nucleotide variants (SNVs) of TNFAIP3 are associated with susceptibility to RA in different ethnic groups, but not in Chileans, the only Latin Americans studied thus far. Objective. To examine the association of eight TNFAIP3 SNVs, four of them not previously studied, with RA in Mexican patients. Materials . We studied 471 RA patients (ACR-EULAR 2010) and eight TNFAIP3 SNVs: including, rs10499194C/T, rs6920220G/A and rs2230926T/G, which are associated with RA in European and Asian patients, in addition to rs373421182G/C, rs139054966T/G, rs5029924C/T, rs59693083A/G and rs61593413T/A, not previously examined in RA. All SNVs were evaluated by means of an allelic discrimination assay and TaqMan probes. Results. The allelic and genotypic frequencies of all SNVs examined were similar between cases and controls, and none of them was associated with RA under the allelic, codominant, dominant, and recessive models was observed. Conclusion. Our data indicate that the TNFAIP3 SNVs evaluated herein are not risk factors for RA in Mexican subjects.

Clinical characteristics and genetic analysis of A20 haploinsufficiency

Purpose To evaluate the clinical and genetic characteristics of 3 children with Haploinsufficiency of A20 (HA20). Methods:The clinical and genetic testing data of 3 children with HA20 treated at Capital Institute of Pediatrics (CIP) between August 2016 and October 2019 were retrospectively analysed. Result Patient 1 presented with arthritis and inflammatory bowel disease, patient 2 presented with axial spinal arthritis and lupus-like syndrome, and patient 3 presented with recurrent oral ulcers, gastrointestinal ulcers, and perianal abscesses. Regarding laboratory tests, patients were found to have elevated white blood cell (WBC) count, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The CRP and ESR was reported to be high in all the patients. The WBC was reported to be high in patient 1 and 3. Patient 2 was positive for antinuclear antibodies, anti-Sjögren’s syndrome antigen A, dsDNA, rheumatoid factor and Coombs test. Genetic testing showed that all three patients had heterozygous mutation in TNFAIP3 gene. As for the treatment, patient 1 was treated with TNFα antagonist, patient 2 was treated with TNF α antagonist and sulfasalazine, and patient 3 was treated with corticosteroids and thalidomide. Patients 1 and 2 were followed for four and 3 months, respectively. There was an improvement in joint and gastrointestinal symptoms; inflammatory indices and rheumatoid factor (RF) were normal, and dsDNA and Coombs test became negative. Patient 3 was treated at another hospital and showed gradual improvement in oral ulcers and perianal abscesses. Conclusion HA20 is a single-gene auto-inflammatory disease caused by mutation in tumour necrosis factor (TNF)-α-induced protein 3 (TNFAIP3) gene. It may present as Behçet-like syndrome and resemble various other autoimmune diseases as well. Corticosteroids and immunosuppressive agents are effective treatments, and cytokine antagonists can be used in refractory cases. Whole-exome genetic testing should be proactively performed for children with early-age onset or Behçet-like syndrome to achieve early diagnosis and accurate treatment.

Central Role of Dendritic Cells in Pulmonary Arterial Hypertension in Human and Mice

The pathogenesis of idiopathic pulmonary arterial hypertension (IPAH) is not fully understood, but evidence is accumulating that immune dysfunction plays a significant role. We previously reported that 31-week-old Tnfaip3DNGR1-KO mice develop pulmonary hypertension (PH) symptoms. These mice harbor a targeted deletion of the TNFα-induced protein-3 (Tnfaip3) gene, encoding the NF-κB regulatory protein A20, specifically in type I conventional dendritic cells (cDC1s). Here, we studied the involvement of dendritic cells (DCs) in PH in more detail. We found various immune cells, including DCs, in the hearts of Tnfaip3DNGR1-KO mice, particularly in the right ventricle (RV). Secondly, in young Tnfaip3DNGR1-KO mice, innate immune activation through airway exposure to toll-like receptor ligands essentially did not result in elevated RV pressures, although we did observe significant RV hypertrophy. Thirdly, PH symptoms in Tnfaip3DNGR1-KO mice were not enhanced by concomitant mutation of bone morphogenetic protein receptor type 2 (Bmpr2), which is the most affected gene in PAH patients. Finally, in human IPAH lung tissue we found co-localization of DCs and CD8+ T cells, representing the main cell type activated by cDC1s. Taken together, these findings support a unique role of cDC1s in PAH pathogenesis, independent of general immune activation or a mutation in the Bmpr2 gene.

Clinical characteristics and genetic analysis of 3 A20 Haploinsufficiency patients

Backguound To evaluate the clinical and genetic characteristics of 3 children with HA20. Methods The clinical and genetic testing data of 3 children with HA20 treated at CIP between August 2016 and October 2019 were retrospectively analysed. Results Patient 1 presented with arthritis and inflammatory bowel disease, patient 2 presented with axial spinal arthritis and lupus-like syndrome, and patient 3 presented with recurrent oral ulcers, gastrointestinal ulcers, and perianal abscesses. For laboratory examination, In patient 1, the WBC,CRP and AESR showed high. In patient 2, the WBC was normal, but CRP and AESR showed high. In patient 3, the WBC, CRP, and AESR showed high. Patient 2 was positive for antinuclear antibodies, anti-Sjögren’s syndrome antigen A, dsDNA, rheumatoid factor and Coombs test. Genetic testing showed that the 3 patients were heterozygous for mutations in the TNFAIP3 gene. For treatment, patient 1 used TNFα antagonist and thalidomide, patient 2 used TNFαantagonist and sulfasalazine, and patient 3 used hormones and thalidomide. Patients 1 and 2 were followed up for 4 and 3 months, respectively. There was improvement in joint and gastrointestinal symptoms, inflammatory indices and RF were normal, dsDNA and Coombs test became negative. Patient 3 was treated at an outside hospital and showed gradual improvement in oral ulcers and perianal abscesses. Conclusion HA20 is a single-gene auto-inflammatory disease caused by mutation in the TNFAIP3 gene. It presents clinically as a Behçet-like syndrome and can present as various other autoimmune diseases as well. Hormones and immunosuppressive agents are effective treatments, and cytokine antagonists can be used in refractory cases. Whole-exome genetic testing should be proactively performed for children with an early age of onset or Behçet-like presentation to achieve early diagnosis and accurate treatment.

POLYMORPHISM OF THE TNFAIP3 GENE (T380G) AND EXPRESSION OF TNFAIP3 IN PATIENTS WITH BRONCHIAL ASTHMA

The single nucleotide polymorphism (T380G) and the degree of expression of the TNFAIP3 gene encoding the ubiquitin-modifying factor A 20, providing an inhibitory effect on the intensity of the immune response of TLR4-mediated signals, were studied. Materials and methods. 84 patients with bronchial asthma of varying severity (14 patients with mild, 49 with moderate and 21 with severe) and 52 practically healthy controls were examined. The determination of single nucleotide polymorphism of the TNFAIP3 (T380G) gene was carried out by the method of allelic discrimination using real-time polymerase chain reaction. Expression of the TNFAIP3 gene was determined by the concentration to DNA relative to the level of expression of the reference GAPDH gene also by real-time PCR. Results. In the study of the TNFAIP3 gene polymorphic marker (T380G), the level of homozygosity for the dominant trait (TT) was 88.1% in patients with asthma, and 88.1% in healthy donors, for the recessive (GG) trait, 3.6% and 4, respectively. 8% (p <0,05), the degree of heterozygosity (TG) was 8.3% and 7.1% in the control group (p <0.05), ), which does not allow at this stage to consider the participation of this single nucleotide polymorphism in the genesis of asthma proven. Expression of the TNFAIP3 gene in both groups ranged from 0 to 5 units, including in patients of group 1 with mild asthma, the expression level of this gene was 2.36 (1.89; 2.94) units. and did not significantly differ from the value of this indicator in the control group (p> 0,05). In group 2 of patients with persistent asthma of moderate severity, the expression of the TNFAIP3 gene was 1.08 (0.87; 1.38) units, which is significantly lower than in patients of the control group (p 0,05). Conclusion. Low expression of the TNFAIP3 gene, leading to inadequate production of factor A 20, observed in severe asthma, can lead to a decrease in the function of the epithelial barrier to classical (ET) and potential ligands that activate type 4 toll-like receptors, followed by activation of intracellular NF-κB and the synthesis of proinflammatory cytokines that play a decisive role in the formation of chronic inflammation in asthma. This work was supported by the RFBR grant No. 19-315-90116.

Analysis of the Clinical and Genetic Characteristics of 3 Cases of A20 Haploinsufficiency

Background To evaluate the clinical and genetic characteristics of 3 children with HA20. Methods The clinical and genetic testing data of 3 children with HA20 treated at CIP between August 2016 and October 2019 were retrospectively analysed. Results Patient 1 presented with arthritis and inflammatory bowel disease, patient 2 presented with axial spinal arthritis and lupus-like syndrome, and patient 3 presented with recurrent oral ulcers, gastrointestinal ulcers, and perianal abscesses. For laboratory examination, In patient 1, the WBC,CRP and AESR showed high. In patient 2, the WBC was normal, but CRP and AESR showed high. In patient 3, the WBC, CRP, and AESR showed high. Patient 2 was positive for antinuclear antibodies, anti-Sjögren’s syndrome antigen A, dsDNA, rheumatoid factor and Coombs test. Genetic testing showed that the 3 patients were heterozygous for mutations in the TNFAIP3 gene. For treatment, patient 1 used TNFα antagonist and thalidomide, patient 2 used TNFαantagonist and sulfasalazine, and patient 3 used hormones and thalidomide. Patients 1 and 2 were followed up for 4 and 3 months, respectively. There was improvement in joint and gastrointestinal symptoms, inflammatory indices and RF were normal, dsDNA and Coombs test became negative. Patient 3 was treated at an outside hospital and showed gradual improvement in oral ulcers and perianal abscesses. Conclusion HA20 is a single-gene auto-inflammatory disease caused by mutation in the TNFAIP3 gene. It presents clinically as a Behçet-like syndrome and can present as various other autoimmune diseases as well. Hormones and immunosuppressive agents are effective treatments, and cytokine antagonists can be used in refractory cases. Whole-exome genetic testing should be proactively performed for children with an early age of onset or Behçet-like presentation to achieve early diagnosis and accurate treatment.