Kidney biopsies can be used for estimations of glomerular number and volume: a pig study

摘要

In this study, we wanted to evaluate the use of kidney biopsies for estimation of N(glom) and V(glom) in both healthy and chronically diseased kidneys. Danish Landrace pigs with mean weight of 29 kg (range: 25–35 kg) were either subjected to unilateral ureteral obstruction (UUO) or non-obstruction (healthy). N(glom) and V(glom) was estimated by design-based methods using biopsies, N(glom)biopsy and V(glom)biopsy. From each kidney, six biopsies were withdrawn at six topographically different sites. All estimates were done following stereological principles and reference methods estimated number with the physical fractionator, N(glom)PF, and volume with test point system, V(glom)TPS. N(glom)PF was $1.30 pm 0.28 times 10^6 $ for UUO kidneys and $1.59 pm 0.28 times 10^6 $ for healthy kidneys. N(glom)biopsy was $1.18 pm 0.28 times 10^6 $ (p > 0.05) for UUO and $1.33 pm 0.24 times 10^6 $ (p = 0.04) for healthy kidneys. When UUO and healthy kidneys were grouped, N(glom)PF was $1.46 pm 0.31 times 10^6 $ , and N(glom)biopsy was $1.28 pm 0.25 times 10^6 $ (p > 0.05). V(glom)TPS was 1,079 ± 126 mm3 for UUO and 1,707 ± 263 mm3 for healthy kidneys. V(glom)biopsy was 1,048 ± 291 mm3 for UUO (p > 0.05) and 1,373 ± 393 mm3 for healthy kidneys (p > 0.05). When UUO and healthy kidneys were grouped, V(glom)TPS was 1,180 ± 229 mm3 and V(glom)biopsy 1,129 ± 334 mm3 (p > 0.05). Biopsy sites were tested for any systematic differences between site- and mean values, and no significant difference was found (p > 0.05). This study showed that biopsies can be used for estimating N(glom) and V(glom) by design-based methods, but more precise determination of biopsy volume is needed.