Antikeratin antibodies and antiperinuclear factor as diagnostic criteria for rheumatoid arthritis

Various auto-antibodies have been described in the serum of rheumatoid arthritis [RA] patients, such as rheumatoid factor [RF], Antiperinuclear factor [APF] and antikeratin antibodies [AKA]. The aim of this study was to evaluate the association of AKA with the activity and severity of RA. Also, to assess their diagnostic value in relation to RF and APF, as well as to determine whether measurements of these antibodies are useful to distinguish early RA from other inflammatory connective tissue disorders. One hundred and ten serum samples from connective tissue [CT] disorders patients who were diagnosed according to the American College of Rheumatology [ACR] criteria were enrolled in this study. They included 68 RA and 42 different rheumatic disorders. They were tested along with 30 serum samples from apparently healthy subjects. AKA and APF were detected with the indirect immunofluorescence [IIF] technique. RF was estimated with latex fixation test [LFT] and then titrated with Rose Waaler test [RW]. Detection of erythrocyte sedimentation rate [ESR] and C reactive protein [CRP] were used as disease activity parameters. Hands and wrists x-ray films were obtained from all RA patients for joint damage evaluation. A positive AKA test was found in 48.5% of RA patients and turned to be highly specific for RA cases [disease specificity 95.8%]. RF and APA were more sensitive than AKA in detection of RA [78% and 58.8% respectively] but less specific [83.3% and 90.2% respectively]. RF positivity [>1:128] was restricted to RA but occurred only in 39.6% of sero-positive RA cases. AKA fluorescence intensity grade 2 and 3 occurred only in RA patients and in 57.5% of AKA -positive RA cases. APF titer >1:20 was restricted to RA and occurred in 42.5% of APF-positive RA cases. No significant differences were found between RA positive and negative cases of AKA, APF or RF as regards the age or the disease duration. While significant differences were found when positive and negative cases of AKA and RF were compared as regards the ESR, CRP and radiographic changes. A significant positive correlation was found between the degree of positivity of AKA and RF titers. Moreover, a significant positive correlation was found between the degree of positivity of AKA levels and ESR and CRP levels, and also with the radiographic changes

Possible role of serum thrombomodulin as a mediator of endothelial cell damage in systemic sclerosis

The aim of this study was to find out the role of thrombomodulin as a mediator of damage to endothelial cells in systemic sclerosis patients. This study was carried out on 20 systemic sclerosis patients who used to attend the Outpatient Clinic of the Rheumatology and Rehabilitation Department of Ain Shams University Hospitals. All patients fulfilled the American College of Rheumatology criteria for diagnosis of systemic sclerosis. Ten age and sex matched healthy controls were also included. Determination of serum thrombomodulin [TM] level was done for both patients and controls using sCD141 thrombomodulin kit, which is a solid phase sandwich enzyme linked immunosorbant assay [ELISA]. Serum TM was higher in the patients group than in the control group with a highly significant difference [t=6.75, p<0.001]. There was also, a significant difference between the level of serum TM in patients with Raynaud's phenomenon, digital ulcers and interstitial pulmonary fibrosis as compared to those without these clinical manifestations [t=0.034, 0.013, 0.25 respectively, p<0.05]. There was a significant positive correlation between serum TM level and the duration of illness, Raynaud's phenomenon, digital ulcers and interstitial pulmonary fibrosis [r=0.69, 0.48, 0.58, 0.49 respectively, p<0.05]. Also, there was a significant positive correlation between serum TM level and ESR and serum urea [r=0.72, 0.61 respectively, p<0.05]. We can conclude that the serum level of TM was higher in our patients and this may reflect its pathogenetic role [through endothelial cell damage] in systemic sclerosis

Soluble urokinase plasminogen activator receptor in plasma and synovial fluid of rheumatoid arthritis and knee osteoarthritis

To determine the level of soluble urokinase plasminogen activator receptor [suPAR] in the plasma and synovial fluid of rheumatoid arthritis [RA] patients and osteoarthritis [OA] patients in comparison to normal healthy subjects, in order to find out its possible role in the pathogenesis of these diseases and to detect whether it can be used as a marker of disease activity and severity. Our study was conducted on 53 subjects. 23 rheumatoid arthritis [RA] patients, 20 patients having knee osteoarthritis [OA] and 10 healthy subjects served as the control group. suPAR level in plasma and synovial fluid of all subjects was measured by ELISA technique. The mean value of soluble urokinase plasminogen activator receptor [suPAR] in plasma and synovial fluid of RA patients was highly significantly increased in comparison to OA patients and healthy subject [p<0.001]. The mean value of plasma suPAR level was also higher in OA patients than healthy subjects but no significant difference was found between them [p>0.05]. While its value in the synovial fluid was significantly increased in OA patients than healthy subjects. Also, no significant difference was found between plasma and synovial fluid suPAR level in RA, and the control group [p>0.05]. While a highly significant difference in its level was found between them in OA patients. There was a significant positive correlation between plasma and synovial fluid level of suPAR and age, duration of disease and disease severity in RA patients. While no significant correlation was found in RA patients between both plasma and synovial fluid level of suPAR and sex, rheumatoid factor sero reactivity, tenderness, swelling [or any of the clinical data], ESR, disease activity index and type of drug received. Also no significant correlation was found between synovial fluid level of suPAR in OA patients and age, and disease severity. A significant positive correlation was found between plasma and synovial fluid level of suPAR in RA patients. The highly significant in crease in the level of suPAR in both plasma and synovial fluid of RA patients compared to other studied groups and the significant correlation between both plasma and synovial fluid suPAR level and disease severity may clarify its possible role in the pathogenesis of RA and may reflect the destructive and erosive nature of this disease. So suPAR appears to be a useful marker that reflects disease severity in RA patients. Also the significant increase in the synovial fluid suPAR level in OA patients in comparison to the control group suggest that alterations in the PA/PAR system also occur in OA and thus might contribute to the pathogenesis of this disease. Since there was no significant difference in the level of suPAR between plasma and synovial fluid, therefore we suggest measuring plasma suPAR only. Also no correlation was found between plasma and synovial fluid suPAR level and disease activity. This needs further extended studies to confirm this result, as it will determine the value of suPAR as a marker of disease activity