Correlation between anti-Proteus antibodies and isolation rates of Proteus mirabilis in rheumatoid arthritis Iraqi patients


Abstract:Rheumatoid arthritis (RA) is a chronic inflammatory polyarthritic disease associatedwith remissions and exacerbations and characteristic genetic, clinical, pathological, andimmunological features. The present study was designed to examine the evidence linkingProteus mirabilis to RA in some Iraqi patients. The study was carried out on 70 Iraqi RApatients, during the period from March 2010 to March 2011. For purposes of comparison, 10of Systemic Lupus Erythematousus (SLE) patients and 10 of apparently healthy subjects wereinvolved as a control groups. After bacterial isolation and identification, Enzyme linkedImmuno sorbent Assay (ELISA) technique has been applied for estimation of antibacterialantibodies.Results of this study revealed that out of 70 urine samples of RA patients, E.coli waspresent in 12.9%, followed by P. mirabilis which present in 7.1%. Regarding SLE andhealthy control group, urine samples were negative from any bacterial strains except E. coli,which present in about 10% of each group. Frequency of Proteus mirabilis in RA group washighly significant when compared with that of other groups (p<0.01). All rheumatoid arthritispatients and control groups were tested by ELISA technique for detection of IgM, IgG andIgA antibodies specific to Proteus mirabilis. Results demonstrated that the levels of theseantibodies were elevated in the sera of RA patients with a high significant degree, incomparison with control groups (p<0.01). The same sera were tested for anti- E. coliantibodies and the results showed that there was no significant difference in the IgM and IgGantibodies level to E. coli in RA patients when compared with control groups (p>0.05).In conclusion, these findings suggested a possible association between infection withProteus mirabilis and rheumatoid arthritis. The elevated levels of Proteus mirabilis antibodieswithin RA sera could be helpful in the identification of those patients during early stages ofthe disease