Adrenomedullin (am)‎ and rheumatoid arthritis

الملخص EN

Objective : the study was undertaken to measure the plasma and synovial concentration of AM and to investigate whether AM level is related to biochemical and / or clinical indicators of disease activity in RA.

Methodology : Twenty five adult RA patients and twenty age and sex matched healthy volunteers as a control group, were studied.

A full medical history and clinical examination were done.

Disease activity for the RA patients was assessed using the modified Disease Activity Score.

Synovial fluid (SF) was aspirated from the knee joint of 9 RA patients and 5 subjects undergoing knee arthroscopy for repair of traumatic anterior cruciate ligament injury.

Measurement of plasma and synovial fluid AM concentration was done with radio-immunoassay (RIA).

Results : RA patients had significantly (p < 0.001) elevated mean plasma AM concentration (16.

26 ± 2.98 pmoles / liter) as compared to healthy controls (2.55 ± 0.42 pmoles / liter).

Plasma AM levels were about 6–fold higher than those detected in controls.

Furthermore, the synovial fluid AM concentration was significantly (p < 0.001) higher in RA patients (5.64 ± 7.39 pmoles / liter) than in control subjects (0.85 ± 1.97 pmoles / liter), showing a 6.5–fold increase than normal values.

In fact both plasma and synovial fluid AM concentrations correlated positively with disease activity score, number of swollen and tender joints in the RA group (p < 0.005).

Also, there was a positive correlation between plasma AM and SF AM levels in both RA patients and controls.

Conclusion : Although the exact significance of elevation of adrenomedullin concentration in RA is not clear, these results suggest that the observed elevation of adrenomedullin in RA patients may be part of a compensatory mechanism to offset further development of inflammatory arthritis.

Our results also suggest the possibility that interventions aimed at controlling the balance of adrenomedullin and other vasoconstrictive peptides as endothelin-1 might prove fruitful in preventing sinusitis in RA patients.

However, further studies will be necessary to clarify the physiological significance of adrenomedullin in RA.