Autoimmunity
Increased
neopterin concentrations are common in patients with autoimmune disorders,
e.g. rheumatoid arthritis and systemic lupus erythematosus. Neopterin
concentrations correlate with disease activity and indicate response to
therapy.
Serum
soluble markers of immune activation and disease activity in systemic lupus
erythematosus
Samsonov MY, et al.
Laboratory
of Clinical Immunology, Cardiology Research Center, Moscow, Russia
(Lupus
1995; 4: 29-32)
We
investigated a possible association between markers of immune activation
and disease activity in 52 patients with systemic lupus erythematosus
(SLE). Serum concentrations of neopterin, beta-2-microglobulin, 55 kD-type
soluble tumor necrosis factor receptor, soluble interleukin-2 receptor and
soluble CD8 were compared to the Index of European Consensus Lupus Activity
Measurement (ECLAM). All markers of immune activation, except sCD8,
significantly correlated with ECLAM. Stepwise multiple linear regression
analysis revealed erythrocyte sedimentation rate and neopterin to correlate
best with ECLAM (multiple correlation coefficient = 0.74, P < 0.001).
The study shows that serum neopterin concentrations are a useful
independent index for disease activity in SLE. The finding of enhanced
concentrations of various parameters of immune activation in patients
confirm a role of the T cell and macrophage activation in the pathogenesis
of SLE.
Correlation
between synovial neopterin and inflammatory activity in rheumatoid
arthritis
Krause A, et al.
Department of Medicine, University Hospital Marburg, West Germany
Ann Rheum Dis 1989; 48: 636-40
According to recent investigations neopterin (a pyrazinopyrimidine
derivative) is a biochemical marker that reflects the activity of the
proinflammatory immunocellular system of the synovial tissue in rheumatoid
arthritis (RA). Interferon gamma, derived from antigen activated T
lymphocytes, stimulates macrophages to synthesise and release neopterin
into the culture supernatant in vitro. To extend this in vitro model to a
clinical level a sensitive new radioimmunoassay technique was used to
measure neopterin concentrations in the synovial fluid (SF) of 17 patients
with active RA, nine with osteoarthritis, and six with acute gout, and in
that of 12 controls undergoing meniscectomy. The SF neopterin
concentrations were significantly higher in patients with RA than in the
other groups of patients, particularly the controls. Multivariant analysis
showed that SF neopterin concentrations correspond better with the systemic
inflammatory activity of RA than with the local disease activity of the
knee joints. Thus the study strengthens the hypothesis that neopterin
reflects the essential role of the activated immunocellular reaction in the
pathogenesis of RA.
Urinary
neopterin reflects clinical activity in patients with rheumatoid arthritis
Reibnegger G, et al.
Institute of Medical Chemistry and Biochemistry, University of
Innsbruck, Innsbruck, Austria
(Arthritis Rheum 1986; 29: 1063-70)
Neopterin is a marker for activation of cellular immunity. Urinary
neopterin levels were measured in 106 patients with rheumatoid arthritis
(RA) and in 45 patients with osteoarthritis. Levels were significantly
higher in RA patients than in osteoarthritis patients and were strongly
dependent on stage and activity of RA. Correlations with other laboratory
parameters were weak. Multivariate analysis demonstrated that urinary
neopterin levels reflected clinical activity better than did other
laboratory findings. Thus, urinary neopterin determination might be useful
in monitoring RA patients.