Objective To investigate the diagnostic value of gluocose-6-phosphate isomerase (G6PI) detected by an enzy-me linked immunosorbent assay (ELISA) in patients with rheumatoid arthritis (RA). Methods The G6PI was detected by ELISA in serum samples from 106 patients with RA, 53 non-RA controls with various rheumatic diseases, and healthy individuals. The level of rheumatoid factor (RF), anti-CCP antibodies and AKA were also assessed in RA patients. The correlation analysis beween G6PI and anti-CCP, IgM-RF. G6PI, anti-CCP, IgM-RF and AKA were carried out between patients with erosion and with non-erosion diseases . Results ① G6PI serum level of patients with RA was (1.61 ±1.20) μg/ml, and was (0.11 ±0.17) in patients with other rheumatic diseases, and (0.06±0.07) μg/ml in healthy individuals. There was statistical significant difference between RA patients and patients with other rheumatic diseases (P<0.05). Receiver operator curve analysis (ROC) showed an opitium cut off level for C6PI at 0.225 μl/ml. The sensitivity of G6PI was 0.868, the specificity was 0.853 in RA. C6PI was associated with RF, but was not associated with anti -CCP. C6PI ws not associated with disease activity index by Spearman' s correlation analysis. The association between above parameters with bone erosion was not detected, however. Conclusion C6PI is abnormally increased in some RA so it may be a new diagnostic marker for RA. G6PI has a reasonable sensitivity (86.8%) and with high specificity(85.3%) to RA and it is valuable for RA diagnosis. C6PI is associated with RF, but not completely overlaps. C6PI is not associated with diseases activity. No association is found between G6PI and bone erosions.

BACKGROUNDPulmonary hypertension (PH) is a common complication of chronic obstructive pulmonary disease (COPD). Although alveolar hypoxia is considered as a main cause of PH in COPD, structural and functional changes of pulmonary circulation are apparent at the initial stage of COPD. We hypothesized that an inflammatory response and oxidative stress might contribute to the formation of PH in COPD.

METHODSWe measured the levels of interleukin-6 (IL-6) and 8-iso-prostaglandin (8-iso-PSG) in exhaled breath condensate (EBC) and serum in 40 patients with COPD only or in 45 patients with COPD combined with PH. Pulmonary arterial systolic pressure (PASP) was assessed by Doppler echocardiography and defined as PH when the value of systolic pressure was greater than 40 mmHg.

RESULTSCompared with the COPD only group, the level of IL-6 in EBC was significantly increased in all 45 patients with COPD combined with PH ((8.27±2.14) ng/L vs. (4.95±1.19) ng/L, P < 0.01). The level of IL-6 in serum was also elevated in patients with COPD combined with PH compared with the COPD only group ((72.8±21.6) ng/L vs. (43.58±13.38) ng/L, P < 0.01). Similarly, we also observed a significant increase in the level of 8-iso-PSG in both EBC and serum in the COPD with PH group, compared with the COPD only group (EBC: (9.00±2.49) ng/L vs. (5.96±2.31) ng/L, P < 0.01 and serum: (41.87±9.75) ng/L vs. (27.79±11.09) ng/L, P < 0.01). Additionally, the value of PASP in the PH group was confirmed to be positively correlated with the increase in the levels of IL-6 and 8-iso-PSG in both EBC and serum (r = 0.477-0.589, P < 0.05).

CONCLUSIONThe increase in the levels of IL-6 and 8-iso-PSG in EBC and serum correlates with the pathogenesis of PH in COPD.

Aged ; Breath Tests ; Female ; Humans ; Hypertension, Pulmonary ; blood ; metabolism ; Interleukin-6 ; blood ; metabolism ; Male ; Middle Aged ; Prostaglandins A ; blood ; metabolism ; Pulmonary Disease, Chronic Obstructive ; blood ; metabolism