Rheumatoid arthritis (RA) is an autoimmune disease with difficulty to diagnose. The association of natural resistance-associated macrophage protein-1 (NRAMP-1) gene polymorphisms with rheumatoid arthritis (RA) is the aim of this study.
Methods: Two hundred individuals who were divided into two groups: RA patients group (100 Patients with RA) and control group: (100 apparently healthy subjects). NRAMP1 polymorphisms were determined by the polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) method, including D543N.
Results: Rheumatoid arthritis patients demonstrated significant increase in C-reactive protein (CRP), Rheumatoid Factor Ab, Human cartilage oligomeric matrix protein (COMP) and Anti-Cyclic Citrullinated Peptide (anti-CCP) in comparison to normal. Clinical disease activity index (CDAI) and the radiological erosion score of joints in RA patients were 29.8 ± 5.3 and 60.03 ± 38.71 respectively. The G/G, G/A and A/A genotypes were 64, 33, and 3% respectively in RA patients and were 60, 25, and 15% respectively in controls with a significant difference between RA patients and controls. The CDAI and radiological erosion score of joints had the least values in NN followed by DN while DD patients had the highest levels. The patients with phenotype DD had a grade III of disease in 40 patients and grade IV in 21 patients while grade II found in three patients. However, in patients with phenotype DN, the grading of disease II, III and IV were found to be 10, 20 and 3 respectively. All patients with NN phenotype showed a grade II of disease. There was a significant difference in percentage between RA patients and controls as regard to G or A alleles distribution. The nodule associated with G/G genotype in 58.8% while bone erosion associated with G/G genotype in 65% of RA patients.
Conclusion: The present study showed that NRAMP1 1703G (543D) is a risk factor for the development of RA. The estimated NRAMP1 1703G haplotype is associated with susceptibility to RA. In RA patients with 1703A, development of rheumatoid nodule is absent.