Similar serum levels of IL-6 and its soluble receptors in patients with HCV-related arthritis and rheumatoid arthritis: a pilot study.

The high serum levels of Interleukin-6 (IL-6) and its soluble receptors (sIL-6r and sgp130), described in the course of Rheumatoid Arthritis (RA), have been linked to the enhanced activity of this cytokine in this disorder. In this study, the serum concentrations of IL-6 and its soluble receptors were determined in a group of patients with HCV-related arthritis (HCVrA), a condition resembling RA in several aspects, and then compared to those found in a sample of subjects affected by RA. Twenty-one patients with HCVrA, 24 patients with RA and 20 healthy subjects (control group) were examined. Different ELISA methods were used for determination of serum concentrations of IL-6, sIL-6r and sgp130. Increased IL-6 serum levels were found in 15 (71 %) of the patients with HCVrA and in 16 (62 %) of those with RA. Eight (38 %) of the patients with HCVrA and 11 (46%) of those with RA denoted high levels of sIL-6r, while sgp130 levels were elevated in 21 (76%) of the patients with HCVrA and in 16 (69%) of those with RA. A significant difference between the median values of sIL-6r and sgp130 levels in the two groups of patients versus controls was found. A mild correlation of these parameters with RF levels was detected in the RA group. Furthermore, in HCVrA patients the serum levels of IL-6, sIL-6r and sgp130 appeared unrelated to HCV viraemia and to levels of transaminases. The enhanced serum levels of IL-6 in HCVra patients indicate an increased synthesis and hyperactivity of this cytokine in HCVrA, and the substantial similarity of the behaviour of IL-6 and its serum receptors in the two groups of patients suggests common mechanisms with RA, in which the function of I L-6 is central.

Circulating levels of interferon-gamma in course of hepatitis C virus-related arthritis.

The aim was to weigh the serum concentrations of interferon gamma (IFN-gamma), a cytokine that enhances Th1-cell differentiation and suppresses collagen synthesis and angiogenesis, in two apparently distinct diseases, hepatitis C virus-related arthritis (HCVrA) and rheumatoid arthritis (RA), which share some overlapping immunological features. In this study, IFN-gamma serum levels were assayed by an ELISA method in 21 HCVrA patients and in 16 with RA. Very low IFN-gamma serum levels were found in five out of 21 patients with HCVrA and only in three out of 16 RA patients. Median value (range) resulted decrease in both HCVrA and RA groups, that is, 0.29 (0.04-1.49) versus 0.20 (0.05-1.18) IU/mL, P = 0.58. No correlation was evidenced with hepatic and arthritic involvements, nor between IFN-gamma serum levels and viral replication and moreover with the positivity of antinuclear antibody, rheumatoid factor, and anti-cyclic citrullinated peptides antibodies. These results show that IFN-gamma behavior appears similar in HCVrA and RA groups reinforcing the lack of significant differences between HCVrA and RA patients. Low circulating levels could be explained with the fact that IFN-gamma is not an isolate cytokine, but a piece of composite system regulated in a complex fashion, with many different factors contributing.

A new strategy for the early diagnosis of rheumatoid arthritis: a combined approach.

Rheumatoid arthritis [RA] is one of the most common and severe autoimmune rheumatic diseases, diagnosed primarily according to clinical manifestations and radiological reports. For many years, laboratory diagnosis of rheumatoid arthritis has relied on the detection of rheumatoid factor [RF], as established by the ACR criteria. A recent test to detect antibodies towards citrullinated peptides, called the anti-CCP assay, showed a similar sensitivity but a more elevated specificity than the RF test. Our intention was the recognition of an optimal diagnostic strategy that exhibits the highest sensitivity and specificity for RA detection. To this purpose, we examine the usefulness of autoantibodies in RA testing, evaluating the diagnostic performance of conventional and innovative assays for RF detection, and ELISA anti-CCP test, for anti-CCP antibodies detection, by a prospective study. Multiplex cytofluorimetric test appeared to be more sensitive and specific than nephelometric assay for RF detection. Hence, a novel combined approach, significantly increasing the diagnostic sensitivity for RA, was planned, employing the multiplex RF test in combination with the anti-CCP test.