Affiliations: Department of Biochemistry, Genetic Engineering and
Biotechnology Research Division, National Research Center, Dokki, Giza,
Egypt | Department of Orthopedic and Rheumatology, Faculty of
Medicine, Alazhar University, Naser City, Cairo, Egypt
Note: [] Corresponding author: Associate Prof. Dr. Menha Swellam,
Biochemistry Department, Genetic Engineering and Biotechnology Research
Division, National Research Center, Tahrir Street, Dokki, Giza, 12622, Egypt.
Tel.: +20 23335451; Fax: +20 23370931; E-mail: [email protected], [email protected]
Abstract: Objectives: Genes encoding for cytokines have been associated with
susceptibility for joint osteoarthritis (OA) and interleukin (IL)-1 gene is
supposed to be involved in the cartilage destruction process. In this regard,
interleukin-1 receptor antagonist (IL-1RA) competing with IL-1 for binding to
its receptor may act as an inhibitor of cartilage breakdown. We assessed the
association of primary knee OA with IL-1RA region as a putative factor of
susceptibility to knee OA in Egyptian patients. Design and methods: Eighty patients with primary knee OA and 40 aged-matched healthy controls were
included into the study. DNA samples were used to study genotypes of IL-1RN
gene by polymerase chain reaction (PCR) in both groups. Results: An increased frequency of the IL-1RN*1 and IL-1RN*2 alleles was found in OA
patients relative to controls (60.5% vs. 39.5%, P=0.039, 85.4%
vs. 14.6%, P=0.002, respectively) however, only the carriage rate of
IL-1RN*2 allele was found to be significant when OA patients were compared to
the controls. Significant higher frequencies of IL-1RN*1/*2 and IL-1RN*2/*2
genotypes in OA patients were observed as compared with controls. Both visual
analogue scale (VAS) {and radiographic score revealed} significant correlation
with both the allelic frequency and the carriage rate of IL-1RN*2 allele.
Moreover, absolute frequency of IL-1RN*1/*2 genotype OA patients revealed
severe VAS and high radiographic score. Conclusion: These results suggest that IL-1RN*2 allele represent a significant factor influencing the
severity and course of knee OA; thereby supporting the potential role of IL-1
in the pathogenesis of this disease.
