Glomerular malondialdehyde levels in patients with focal and segmental glomerulosclerosis and minimal change disease.

Minimal change disease (MCD) and focal and segmental glomerulosclerosis (FSGS) are often studied together, because both present with heavy proteinuria and the nephrotic syndrome. The precise distinction between MCD and FSGS is sometimes difficult because of inadequate number of glomeruli for definite diagnosis. Some evidence suggests that markers of lipid peroxidation, such as malondialdehyde (MDA) is an index of free radical mediated injury and may be involved in the pathogenesis of FSGS. In this study, we assessed the immunoreactivity of MDA, the end product of lipid peroxidation in glomeruli of patients with idiopathic FSGS, MCD as well as normal controls (NC). Our results showed that the immunostaining level of MDA was significantly higher in patients with FSGS (mean = 1.5) than in either patients with MCD (mean = 0.16) or normal controls (mean = 0.11) with P value < 0.001. Glomerular MDA level correlated well with the degree of glomerulosclerosis in patients with idiopathic FSGS. Our data demonstrates that the glomerular level of MDA is higher in idiopathic FSGS than MCD. We suggest that MDA immunostaining can be helpful in differentiating between FSGS and MCD in problematic cases and when we do not have enough glomeruli for definite and correct diagnosis.