Investigation of the crystallisation inhibitory properties of albumin isolated from the urine of Black and White South Africans

Abstract

Stone incidence in South African blacks is extremely rare. The hypothesis to be tested is whether this apparent immunity can be attributed to the presence of more potent inhibitors of calcium oxalate (CaOx) crystallisation in urine from blacks compared to those occurring in the urine of white subjects. Urinary proteins have been shown to be inhibitors. This study investigated the crystallisation inhibitory properties of albumin isolated from the urine of healthy black (BA) and healthy white (WA) South Africans as well as those of human serum albumin (HSA). Albumin was selected because previous studies on other population groups had revealed that the protein inhibits CaOx aggregation. This observation is significant because crystal aggregation is considered to be more important for stone formation than crystal nucleation or growth.