Cardiac troponin and beta-type myosin heavy chain concentrations in patients with polymyositis or dermatomyositis.

Cardiac troponin T (cTnT), cardiac troponin I (cTnI), myosin heavy chains (MHC), myoglobin, creatine kinase (CK), and creatine kinase isoenzyme MB (CKMB), were measured in blood samples from 39 polymyositis (PM) or dermatomyositis (DM) patients without clinical evidence for cardiac involvement to evaluate their clinical usefulness in this patient population. MHC, myoglobin, and CKMB were frequently elevated and correlated with each other and with disease severity. Undetectable cTnI in all but one patient indicated that MHC was released from skeletal muscle, thereby providing the first laboratory evidence of frequent slow-twitch muscle fibre-necrosis in patients with PM or DM. CKMB was elevated in 51%, cTnT in 41%, and cTnI in only 2.5% of patients. cTnI did not correlate with other markers or with disease severity scores. The close correlations found between cTnT and skeletal muscle damage markers and the relationship between cTnT with disease severity without clinical evidence for myocardial damage suggest a release of cTnT from skeletal muscle. The relationship of cTnT with disease severity indicates a possible role of the marker for risk stratification. However, the prognostic values of cardiac troponins and other muscle damage markers in PM/DM patients remain to be compared in prospective outcome trials.

Anti-endothelial cell antibody, thrombomodulin, and von Willebrand factor in idiopathic inflammatory myopathies.

Sera from 19 patients with idiopathic inflammatory myopathy (IIM) were examined for the presence of anti-endothelial cell antibodies (AECA) by an immunoglobulin G-specific cellular enzyme-linked immunosorbent assay. The mean binding index of AECA was found to be 37.7% +/- 26.5% for the patients, compared with a mean of 7.2% +/- 2.7% for normal controls (P < 0.04). Levels of thrombomodulin, von Willebrand factor antigen, and serum creatine kinase were also shown to be augmented. Interestingly, positive correlations between AECA on the one hand and Raynaud's phenomenon and interstitial lung disease on the other were demonstrated. Given that the pathogenesis of IIM remains uncertain, these findings may be of importance.

Elevated serum levels of neopterin in adult patients with polymyositis/dermatomyositis.

We determined serum concentrations of neopterin, soluble tumour necrosis factor (55 kDa) receptor (sTNF-R) and soluble interleukin-2 receptor (sIL-2R) in plasma of 44 patients with polymyositis (PM)/dermatomyositis (DM), including 15 patients with primary PM, 13 patients with primary DM, and 16 patients with myositis and systemic sclerosis in overlap. Concentrations of neopterin, sTNF-R and sIL-2R were measured using commercially available immunoassays. Serum neopterin was increased in 35 of 44 PM/DM patients (80%), sTNF-R in 14 (32%) and sIL-2R in 18 (41%) patients, respectively. There were significant correlations between serum neopterin and sTNF-R, sIL-2R and erythrocyte sedimentation rate (all P < 0.001). Neopterin, as well as sTNF-R and sIL-2R, did not correlate with clinical (neuromuscular and activities of daily living scores) and laboratory (creatine kinase levels) manifestations of myositis. Increased serum levels of neopterin were associated with non-muscular manifestations of PM/DM. In conclusion, serum neopterin appears to be a useful laboratory marker for ongoing immune activation and global disease activity in PM/DM.

Serum concentrations of neopterin, soluble interleukin 2 receptor, and soluble tumor necrosis factor receptor in Wegener's granulomatosis.

OBJECTIVE: To investigate the possible relationship between serum levels of neopterin, soluble tumor necrosis factor-55 receptor (sTNF-55R), and soluble interleukin 2 receptor (sIL-2R) with disease activity in patients with Wegener's granulomatosis (WG). METHODS: Serum neopterin was measured by radioimmunoassay, sTNF-55R and sIL-2R were measured by ELISA in 26 patients with WG. RESULTS: Serum neopterin, sTNF-55R, and sIL-2R were significantly elevated in patients with generalized WG compared with healthy controls. Concentrations of the analytes correlated with disease activity indices in patients without infectious complications. The highest elevations of all 3 variables were observed in patients with intercurrent infections. CONCLUSION: The increased serum levels of neopterin, sTNF-55R, and sIL-2R suggest activation of cellular immunity in WG.

Antiendothelial cell antibodies: useful markers of systemic sclerosis.

BACKGROUND: Systemic sclerosis (SS) encompasses a wide spectrum of clinical presentations. Antiendothelial cell antibodies (AECA) in patients with primary Raynaud's phenomenon (PRP), limited SS (lSSc), or diffuse SS (dSSc) may help to determine the long-term prognosis of the disease. METHODS: Twenty-seven normal controls, 13 patients with PRP, 36 with lSSc, and 31 with dSSc were included in the study. Sera were examined for the presence of AECA, using a cellular enzyme-linked immunosorbent assay (ELISA). Angiotensin-converting enzyme (ACE) activity, plasma von Willebrand factor antigen (vWfAg), and thrombomodulin (Tm) concentrations were also evaluated. The medical records of 50 of the lSSc and dSSc patients were reviewed and the organ system involvement noted. RESULTS: Antiendothelial cell antibodies were present in 3 patients with PRP, 16 patients with lSSc, and 26 patients with dSSc. These autoantibodies were mainly of the IgG isotype. There was no difference in ACE activity between patients and controls. In contrast, vWfAg and Tm concentrations were higher in patients with PRP relative to controls, and higher in patients with lSSc compared with those with PRP. The presence of AECA was associated with digital scars and ulcers (P < 0.004 and P < 0.003, respectively), severe RP (P < 0.01), grade 3 tortuosity of vessels (P < 0.0004), and lung involvement (P < 0.02). CONCLUSION: The significant trend for AECA to increase with disease severity across the three groups of patients studies suggests that the AECA test can identify subsets of SSc with differing prognoses.

Serum soluble markers of immune activation and disease activity in systemic lupus erythematosus.

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.

Serum-soluble receptors for tumor necrosis factor-alpha and interleukin-2, and neopterin in acute rheumatic fever.

Immune activation may play an important role in the pathogenesis of acute rheumatic fever (ARF). The objective of the present study was to investigate serum concentrations of various markers of immune activation in ARF patients. Sera of 32 patients with ARF were investigated, 20 of them in follow-up. Radioimmunoassay was used to quantify neopterin and ELISA for the measurement of 55-kDa-type soluble tumor necrosis factor receptor (sTNF-R) and soluble interleukin-2 receptor (sIL2-R). Markers of immune activation were found to be raised in 48% (sTNF-R), 28% (sIL2-R), and 78% (neopterin) of patients at the onset of ARF. There were significant correlations between the concentrations of neopterin and sTNF-R (rs = 0.60, P < 0.001) or sIL2-R (rs = 0.35, P < 0.05). Higher neopterin concentrations were found in patients with combined aortic and mitral insufficiency than in patients with mitral valve lesions alone (U = 2.67, P < 0.05) or without valve lesion (U = 2.36, P < 0.05). Increased concentrations of neopterin, sTNF-R, and sIL2-R demonstrate activation of the cellular immune system in patients with ARF. Higher serum neopterin concentrations are associated with development of combined aortic and mitral insufficiency during the first episode of ARF.

Stimulated cellular immune system in patients with congestive heart failure.

In this cross-sectional study, we analysed serum concentrations of soluble markers of cellular immune activation, namely, interferon-gamma, neopterin (a product of activated macrophages), soluble interleukin-2 receptor, and soluble CD8, in 25 patients with congestive heart failure. Ten (40%) patients showed increased concentrations (i.e. above the reference ranges of healthy controls) of neopterin, 14 (56%) showed increased soluble interleukin-2 receptor, and 6 (24%) showed increased soluble CD8. Endogenous interferon-gamma was detectable in 10 patients (40%). In addition, we found significant correlations between neopterin and interferon-gamma (rs = 0.417, p < 0.05), and between neopterin and soluble CD8 concentrations (rs = 0.430, p < 0.05). All patients with increased soluble CD8 also had increased soluble interleukin-2 receptor. However, no significant correlations of soluble interleukin-2 receptor with soluble CD8 or any of the other quantities were observed. Increased concentrations of soluble interleukin-2 receptors, soluble CD8 and neopterin indicate that cellular immunity is stimulated in patients with congestive heart failure. Activated CD8-positive T-lymphocytes may represent the source of increased soluble CD8. Endogenous interferon-gamma, which is derived from activated T-cells, may induce neopterin release by monocytes/macrophages.

Patterns of serological markers for cellular immune activation in patients with dilated cardiomyopathy and chronic myocarditis.

We determined serum concentrations of neopterin and beta 2-microglobulin, soluble markers of cellular immune activation, in 27 patients with either dilated cardiomyopathy (DCM) or chronic myocarditis. Neopterin and beta 2-microglobulin concentrations were respectively increased in 2 and 5 of 11 patients with DCM and in 11 and 9 of 16 patients with chronic myocarditis. A higher cardiac functional class (according to the New York Heart Association) was associated with greater neopterin and beta 2-microglobulin concentrations. During follow-up of patients, both neopterin and beta 2-microglobulin concentrations in serum correlated with the course of disease. Additionally, correlations were significant between left ventricular functional tests (end-diastolic volume, end-systolic volume, and ejection fraction) and neopterin and beta 2-microglobulin concentrations. We conclude that measurement of neopterin and beta 2-microglobulin are useful to monitor disease development in patients with myocardial inflammation.