Urinary protein excretion in children from families with Balkan nephropathy.

We studied the urinary excretion of total protein and five other proteins in urine samples from a total of 831 children and adolescents. The characteristics of the children were: (1.) they resided in areas where Balkan nephropathy (BEN) is endemic and also had family members suffering from BEN; (2.) they resided in areas where BEN is endemic, but the families had no members suffering from the disease; (3.) they lived in nonendemic settlements; (4.) they lived in the city of Nis. Urinary excretion of total protein (TP), albumin (ALB), alpha 2-macroglobulin (alpha 2m), transferrin (TF), IgG, and beta 2-microglobulin (beta 2m) were measured. This study showed that urinary excretion of beta 2m and albumin in children from endemic settlements and from families affected with Balkan nephropathy were not different from the control rural settlements. However, children residing in the city of Nis had significantly increased urinary beta 2m and albumin excretion, over 1.5 to 2.6 times the excretion in the other three groups, although excretion of either protein remained within accepted normal ranges in all groups. The increased excretion of beta 2m and albumin in children from the city of Nis could probably be related to the different growth conditions and/or the effect of toxic environmental factors. These data could serve as a reference base for future comparative studies of urinary protein excretion in children as well as in BEN populations.