Alpha-1-microglobulin: Prognostic value in chronic kidney disease

Abstract

Objectives: α1-microglobulin (α1M) is a tubular protein used for detecting acute lesions of proximal tubules. This study evaluated the use of urine α1M excretion as a marker of chronic kidney disease (CKD) progression and life survival.

Design and methods: In all 163 patients were recruited (90 men), mean age 61.6±16.4 years. Urinary α1M was evaluated using an immunonephelometric assay. Patients were divided into 2 groups according to urinary α1M excretion (cut-off value: 32.85mg/24h).

Results: End stage renal disease-free survival was 94.2% at 5 years for patients with lower α1M. For patients in the highest percentile, renal function survival was 72.7% (P=.011). Life survival was 94.4% for patients with α1M in the lower percentiles. For patients in the upper percentile, live survival was 54.2% (P=.001). The Cox regression analysis showed an independent association of CKD progression with high α1M excretion (P=.043).

Conclusions: α1M urinary excretion was associated with faster CKD progression and higher mortality. Further studies are needed to determine whether the association between α1M urinary excretion and excess mortality risk represents a causal link.

Keywords: Alfa-1-microglobulina; Alpha-1-microglobulin; Chronic kidney disease; Enfermedad renal crónica; Mortalidad; Mortality; Prognosis; Pronóstico.