Urine IgM excretion predicts outcome in ANCA-associated renal vasculitis

Abstract

The occurrence of an increased amount of IgM in urine at presentation is a strong marker of poor prognosis for patients with ANCA-associated renal vasculitis.

Outcomes from studies of antineutrophil cytoplasm antibody associated vasculitis: a systematic review by the European League Against Rheumatism systemic vasculitis task force

“…59 In two separate studies, the 1-year (83% vs 85%, p = not significant and 87% vs 97%, p<0.01) and 5-year (45% vs 76%, p = 0.02 and 63% vs 91.5%, p<0.01) survival of MPA was lower than WG 45 46. The survival advantage of WG may be lost following the onset of end stage renal disease 60…”

The value of IgG-uria in predicting renal failure in idiopathic glomerular diseases. A long-term follow-up study

“…However, an increased urinary excretion of larger proteins, like IgG, imply a worse kidney outcome [7,8,20].…”

“…It has been observed that patients with increased glomerular filtration of high molecular weight plasma proteins like IgG, IgM, have a greater risk of progressing to end-stage renal disease (ESRD) than patients with pure albuminuria [6][7][8]. However, the predictive value of increased urine IgG excretion was evaluated mostly in short term studies of patients with nephrotic syndrome [9][10][11].…”

Urinary Biomarkers in Glomerulonephritis

“…In ASVV, urinary levels of IgM was found to be a better independent predictor of renal survival than serum creatinine at diagnosis and, in addition to age, it was an important predictor for patient survival. Patients with low urinary IgM excretion maintained their kidney function despite a high degree of albuminuria, and patients with high urine IgM excretion were more likely to develop ESRD [Bakoush O, Segelmark M et al 2006]. The authors of this study recommend routine measurement of urine IgM concentrations at diagnosis in patients with ANCAassociated small vessel vasculitis, as a relatively cheap, non-invasive and early prognostic marker.…”