Microalbuminuria as an early marker of renal involvement in Behcet's disease: it is associated with neurological involvement and duration of the disease.

BACKGROUND: Despite its nature as a systemic vasculitis, renal involvement is known to occur infrequently in Behçet's Disease (BD). OBJECTIVES: Our aim was to investigate proteinuria, microhematuria and microalbuminuria in 24-h urine and evaluate subclinical or symptomatic renal involvement in BD patients. METHODS: Two hundred and eleven patients who fulfilled the International Behçet's Disease criteria were included in the study. After urine analysis, five of 12 patients who were found to have proteinuria underwent renal biopsy, while 199 patients without proteinuria were investigated for microalbuminuria (MA). RESULTS: A total of 34 (16.1%) patients were found to have renal involvement including 22 (11.1%) with MA and 12 with proteinuria (5.6%). Renal biopsies resulted as focal glomerulosclerosis in three, membranous glomerulosclerosis in one and secondary amyloidosis in two patients. Neurological involvement was found to be significantly more prevalent in patients with MA (P < 0.01). Neurological involvement and duration of disease (> or = 10 years) was found to increase the risk for MA by 21.75-fold and 5.03-fold, respectively. Though age over 40 years, thrombophlebitis, HLA B51 haplotype and ophthalmological involvement were not found to be significantly associated with MA; these parameters increased the risk for MA. CONCLUSIONS: Renal involvement may be more prevalent in BD than it has been recognized; it usually presents with asymptomatic microhematuria, proteinuria and/or microalbuminuria; therefore clinicians must check 24-h urine for the presence of proteinuria, microhematuria and microalbuminuria; especially in patients who are aged over 40 years, have a longer duration of the disease and multisystem involvement.