Islam Abdelkader
Alterations of the innate immune response is critical in the development of autoimmunity through self-antigens recognition, processing and presentation
to initiate an adaptive immune response towards self-antigens. Toll-Like Receptor 9 (TLR9) is an innate immune receptor expressed on
the endosomes of antigen presenting cells, and it recognizes microbial DNA. Hence, altered expression of TLR9 can be detrimental in recognizing
self-DNA, triggering autoimmune conditions such as Systemic Lupus Erythematosus (SLE) for which the positivity for ANA and anti dsDNA is a
hallmark for diagnosis. Although there is a growing interest in the research for using TLR9 agonists for immune stimulation against cancers, the
research interest is relatively slim regarding ameliorating autoimmune diseases and glomerulonephritis through targeting TLR9. Our aim was to
assess the association between SLE and Lupus Nephritis (LN) with TLR9 rs352140 gene polymorphism. The study was conducted on a group of
Egyptian individuals at Mansoura University Hospital, comprising 38 SLE patients without nephritis, 62 LN patients and 100 healthy individuals
as a control group.
Methodology and results: An informed consent was taken from the subjects before peripheral blood sample was taken. Genomic DNA extraction
was done followed by conventional PCR, and the PCR product was digested by Bstu1 restriction enzyme through the Restriction Fragment Length
Polymorphism (RFLP) technique. Out of the 3 genotypes, GA genotype was found to be uniquely associated with the risk for lupus nephritis despite
the lack of association with cutaneous and joint involvement. Conversely, there was no significant association between the polymorphism
with the risk for developing SLE.
Conclusion and recommendations: TLR9 gene polymorphism plays an important role in the pathogenesis of LN. Therefore, TLR9 gene expression
in kidney tissue is an attractive target for further comprehensive studies in kidney tissue in LN patients to assess its value as a target for
immune-modulatory therapy.
