Serum Levels and Genetic Polymorphisms of Matrix Metalloproteinase-9 (MMP-9) in Patients with Scabies

Abstract

Background: Scabies is a contagious parasitic skin disease caused by Sarcoptes scabiei var. hominis, leading to severe itching, dermatitis, and skin lesions. The infection triggers host immune responses, activating T and B lymphocytes and inducing both cellular and humoral immunity, along with an allergic reaction. Matrix metalloproteinase-9 (MMP-9) is a zinc-dependent enzyme involved in extracellular matrix (ECM) remodeling and tissue degradation, playing a crucial role in inflammatory and immune-mediated skin disorders. This study investigates serum MMP-9 levels and genetic polymorphisms in patients with scabies to assess their potential role in disease susceptibility. Methods: A case-control study was conducted at Baquba Teaching Hospital, Dermatology Unit, Diyala Governorate, from December 4, 2022, to June 10, 2023. A total of 75 patients diagnosed with scabies and 75 age- and sex-matched healthy individuals were enrolled as controls. Serum MMP-9 levels were measured, and allele-specific primer polymerase chain reaction (ASP-PCR) was used to analyze MMP-9 gene polymorphisms at rs17576 and rs760670157. Results: MMP-9 levels were significantly elevated in scabies patients compared to the control group (p < 0.05). Genetic analysis revealed an increased frequency of the GG and TG genotypes, along with a higher prevalence of the G allele in scabies patients at the rs17576 locus, suggesting an association with disease susceptibility. Conversely, the TT genotype and T allele were less frequent in the scabies group. At the rs760670157 locus, the GA genotype and A allele were more prevalent in scabies patients, whereas the GG and AA genotypes and G allele were found at lower frequencies compared to controls. Conclusion: This study suggests that MMP-9 gene polymorphisms may be associated with susceptibility to scabies. The presence of TG and GG genotypes, as well as the G allele at rs17576, and the GA genotype and A allele at rs760670157, appear to be risk factors for scabies development. Further research is needed to explore the functional impact of these polymorphisms on MMP-9 expression and their role in scabies pathogenesis.