Morphological changes in the kidney of fetuses with Down syndrome

Abstract

Background: A variety of renal and urological abnormalities have been reported in subjects with Down syndrome (DS). With increased longevity, it appears that a growing number of these subjects presents chronic renal failure. Definition of underlying cause of renal failure could lead to the prevention of progressive renal dysfunction in these patients. The aim of this study was to improve the understanding of the morphological changes that occur in the kidney of fetuses with DS.

Methods: To this end, 25 subjects were examined. Kidney sections were stained with H&E and digitally scanned. Subjects were subdivided into two groups: fetuses with DS (DS-fetuses, n = 11) with a gestational age ranging from 13 up to 21 weeks, and healthy fetuses (N-fetuses, n = 14) with a gestational age ranging from 9 up to 22 weeks.

Results: DS-fetuses showed slightly larger glomeruli as compared to N-fetuses. Moreover, glomeruli in DS-fetuses group were characterized by an enlarged Bowman’s space as compared to glomeruli in N-fetuses (p = 0.0028). Differences in the nephrogenic zone width were also observed; DS-fetuses showed a greater width of this zone as compared with N-fetuses.

Discussion: In conclusion, we found relevant morphological differences, which suggests delayed renal maturation. Furthermore, there was a significant increase in glomerular area and several glomeruli were morphologically abnormal. These harmful changes in the glomerular structure may result in a nephron deficit, which may be associated with development of renal diseases and hypertension later in life.

Conclusions: We hypothesize that the observed morphological anomalies could have significant implications for both the short- and long-term renal health of subjects with DS.