Monocyte chemoattractant protein 1 is a prognostic marker in ANCA-associated small vessel vasculitis

BACKGROUND

The (anti neutrophil cytoplasmatic autoantibody ANCA), associated small vessel vasculitides (ASVV) are relapsing-remitting inflammatory disorders, involving various organs, such as the kidneys. (Monocyte chemoattractant protein 1 MCP-1) has been shown to be locally up regulated in glomerulonephritis and recent studies have pointed out MCP-1 as a promising marker of renal inflammation. Here we measure urinary cytokine levels in different phases of disease, exploring the possible prognostic value of MCP-1, together with (interleukin 6 IL-6), (interleukin 8 IL-8) and (immunoglobulin M IgM).

METHODS

MCP-1, IL-6 and IL-8 were measured using commercially available ELISA kits, whereas IgM in the urine was measured by an in-house ELISA.

RESULTS

The MCP-1 levels in urine were significantly higher in patients in stable phase of the disease, compared with healthy controls. Patients in stable phase, with subsequent adverse events; had significantly higher MCP-1 values than patients who did not. MCP-1 and IgM both tended to be higher in patients relapsing within three months, an observation, however, not reaching statistical significance. Urinary levels of IL-6 correlated with relapse tendency, and IL-8 was associated with disease outcome.

CONCLUSIONS

Patients with ASVV have raised cytokine levels in the urine compared to healthy controls, even during remission. Raised MCP-1 levels are associated with poor prognosis and possibly also with relapse tendency. The association with poor prognosis was stronger for U-MCP-1 than for conventional markers of disease like CRP, BVAS, and ANCA, as well as compared to candidate markers like U-IgM and U-IL-8. We thus consider U-MCP-1 to have promising potential as a prognostic marker in ASVV.

Urinary matrix metalloproteinases reflect renal damage in anti-neutrophil cytoplasm autoantibody-associated vasculitis

Renal expression of MMP-2, -9, and tissue inhibitor of MMP-1 (TIMP-1) correlates with histological disease activity in anti-neutrophil cytoplasm autoantibody (ANCA)-associated vasculitis (AAV). We studied whether urinary and plasma levels of MMP-2, -9, and TIMP-1 reflect renal expression of these proteins and renal disease-activity in AAV. Urine and plasma samples of patients with AAV who underwent a renal biopsy were collected (n = 32). Urinary activity of MMP-2 and -9 was measured by activity assays. Urinary and plasma levels of MMP-2, MMP-9, and TIMP-1 proteins were measured by ELISA. Healthy controls provided plasma and urine for comparison (n = 31). In patients, the relationship of urinary and plasma levels with renal expression of MMP-2 and MMP-9 and clinical and histological disease activity was studied. Renal MMP expression was compared between patients and controls (n = 8). Urinary MMP-2 and MMP-9 activity and urinary and plasma TIMP-1 levels were significantly higher in patients than in controls. In glomeruli of patients, both MMP-2 and MMP-9 expression reflected active glomerular inflammation. Urinary activity of MMP-2 and MMP-9 did not correlate with renal MMP expression or plasma levels. Urinary MMP activity correlated negatively with glomerular inflammation, but positively with fibrous crescents. Urinary MMP-2 and TIMP-1 levels showed a positive correlation with tubulointerstitial damage and a negative correlation with creatinine clearance. Urinary MMP-2, MMP-9, and TIMP-1 are elevated in AAV but do not reflect renal MMP expression and glomerular inflammation. However, urinary MMP-2 activity and TIMP-1 levels reflect tubulointerstitial damage and correlate negatively with creatinine clearance at biopsy.

Urinary eicosanoid and tyrosine derivative concentrations in patients with vasculitides

BACKGROUND

Vasculitides are classified on the basis of the type of cell involved, namely, eosinophilic vasculitides such as Churg-Strauss syndrome (CSS) and noneosinophilic vasculitides. However, knowledge on inflammatory mediators and oxidative tissue damage associated with vasculitides is insufficient.

OBJECTIVE

We measured the urinary concentrations of inflammatory mediators and tyrosine derivatives to assess biomarkers associated with the pathophysiology of vasculitides.

METHODS

Urine was collected from 9 patients with CSS during acute exacerbation and during clinical remission, 24 patients with rheumatoid arthritis in stable condition, and 8 patients with vasculitis diseases (VDs) during acute exacerbation. Leukotriene E 4 (LTE 4 ), 9alpha,11beta prostaglandin F 2 , and eosinophil-derived neurotoxin (EDN) concentrations were determined by enzyme immunoassay. 3-Bromotyrosine (BrY) and 3-chlorotyrosine (ClY) concentrations were determined by gas chromatography-mass spectrometry.

RESULTS

The urinary LTE 4 , EDN, BrY, and ClY concentrations were significantly higher in the patients with CSS during acute exacerbation than in healthy control subjects and, except for urinary ClY concentration, significantly decreased during clinical remission. The urinary EDN and BrY concentrations were significantly higher in patients with CSS during acute exacerbation than in patients with VD during acute exacerbation. Only urinary LTE 4 concentration was significantly different between the patients with rheumatoid arthritis in stable condition and the patients with VD during acute exacerbation.

CONCLUSION

Oxidative tissue damage caused by eosinophil peroxidase is a pathophysiological characteristic of eosinophil-associated diseases such as CSS. Urinary LTE 4 concentration may reflect a pathophysiological event involved in eosinophilic and noneosinophilic vasculitides. Cysteinyl-leukotriene pathways are potential therapeutic targets for small-vessel vasculitides.

Urinary monocyte chemoattractant protein-1 (MCP-1) is a marker of active renal vasculitis

BACKGROUND

Macrophage infiltration and cytokine production are important in the pathogenesis of crescentic glomerulonephritis in anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis. The aim of this study was to investigate whether urinary levels of chemokines, monocyte chemoattractant protein-1 (MCP-1) and fractalkine, were useful tools for non-invasive assessment of renal vasculitis.

METHODS

In a prospective study, concentrations of chemokines were measured in urine and serum samples using specific enzyme-linked immunosorbent assays, and related to the patients' clinical status. Renal expression of MCP-1 was studied by immunohistochemical staining of renal biopsies.

RESULTS

Urinary levels of MCP-1 were significantly higher in patients with active (P<0.01) or persistent (P<0.05) renal vasculitis, in comparison with healthy volunteers, control patients, patients with inactive vasculitis and patients with extra-renal disease only. There were no differences in serum concentrations of MCP-1 between these groups. Reduction in urinary MCP-1 levels following treatment preceded the improvement of renal function by a median of 2 weeks. In one patient, rising urinary levels of MCP-1, despite immunosuppressive therapy, was associated with progression to severe renal failure. There were no differences in urinary fractalkine levels between the different groups of patients and controls. Immunohistology of renal biopsies from patients with crescentic glomerulonephritis showed increased staining for MCP-1 in glomerular and interstitial cells. Urinary MCP-1 levels correlated with glomerular, but not tubulointerstitial, macrophage infiltration (P<0.05).

CONCLUSIONS

This study shows that measurement of urinary MCP-1, but not fractalkine, is a useful non-invasive technique for the assessment of renal involvement and monitoring the response to therapy in ANCA-associated vasculitis.

Metabonomic assessment of vasculitis in rats

The vasculitides are a heterogeneous group of lesions characterized by inflammation and necrosis of the vascular wall and have proven to be a disconcerting dilemma in the development of several classes of therapeutics. Metabonomics is an emerging technology having great potential for rapid noninvasive assessment of toxicity in vivo and providing identification of peripheral surrogate markers of toxicity. Metabonomic evaluation of CI-1018, a selective type 4 phosphodiesterase inhibitor associated with vasculitis in rats, was undertaken. Two experiments were performed in which CI-1018 was administered for up to 4 d to groups of male Wistar rats at doses up to 3000 mg/kg. Urine was collected from all animals pretest and daily for metabonomic analysis. Eleven of 38 CI-1018-treated animals were found to have vascular injury of varying severity at doses = or > 750 mg/kg. Principal component analysis produced a clear pattern separation among 8 of 11 animals with lesions and 36 of 37 animals without lesions in samples collected on d 3 or 4. These data demonstrate that the metabonomics approach has significant potential for developing a noninvasive method for identifying vasculitis in rats. It remains to be seen if urinary analyte patterns identified in this study are reproducible and whether a biomarker pattern for vasculitis can be established.

Urinary neopterin in idiopathic retinal vasculitis

AIMS

To determine whether urinary neopterin:creatinine (UNC) ratios relate to disease activity in idiopathic retinal vasculitis (RV).

METHODS

18 patients with RV were prospectively recruited into a year long longitudinal study. Patients collected first morning urine samples on a weekly basis and on the same day completed a diary which documented their subjective view of RV activity and any concurrent infection. They were examined in clinic on a 6-8 weekly basis and an objective assessment was made of RV disease activity. 14 healthy controls collected urine samples in the same way.

RESULTS

UNC ratios were significantly higher in patients than in controls (p=0.004, Mann-Whitney U test). UNC ratios were significantly higher when, according to their diaries, the patients had a subjective flare up of RV (p=0.001, Mann-Whitney U test). Subjective increased RV activity occurred more often when the patients had a concurrent infection (p<0.0001, chi(2) test). There was no significant difference in the UNC ratio between objective clinical relapse and non-relapse of RV. There was moderate agreement between the clinical assessment and patients' subjective impression of RV activity (kappa=0.48).

CONCLUSIONS

Higher neopterin levels reflect cell mediated disease that occurs in RV, but UNC ratios are not recommended as a means of monitoring clinical disease activity in RV.