Posttransplant recurrent FSGS: molecular insights and future directions

Oxidative stress and hemodynamic maladjustment in chronic renal disease: a therapeutic implication

Hemodynamic maladjustment with predominant constriction at the efferent arteriole has been encountered in a variety of clinical settings of glomerulonephropathy. In essence, it induces not only intraglomerular hypertension but also exaggeratedly reduces the peritubular capillary flow, which supplies the tubulointerstitial compartment. The hemodynamic maladjustment is believed to reflect a glomerular endothelial cell dysfunction. In this regard, oxidative stress and antioxidant defect are likely responsible for the glomerular endothelial dysfunction. Improvement in renal function was accomplished following the correction of oxidant and antioxidant imbalance with antioxidant therapy and vasodilators. Following such therapy, there was a correction in hemodynamic maladjustment with a decline in intraglomerular hydrostatic pressure and an increase in renal perfusion with a subsequent increase in renal functions namely creatinine clearance, glomerular filtration rate and a decline in FEMg.

Pathogenesis of focal glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is the histologic expression of diverse processes affecting the renal glomeruli and occurring in primary and secondary forms. A number of pathogenic factors have been identified in primary FSGS, and multiple etiologies have been defined as contributing factors for the development of secondary FSGS. There is a complex interplay between etiologic and pathogenic factors, progression factors and intervention in the phenotypic expression of FSGS. Key components include genetic predisposition, environmental influences and the impact on phenotype of pharmacologic intervention. The phenotypic spectrum for FSGS ranges from mild proteinuria and slow progression to a devastating clinical syndrome characterized by heavy proteinuria and rapid loss of renal function over a period of months. While the pathogenesis is unknown, much is known about factors which are involved in the development and progression of both primary and secondary FSGS. The ultimate goal of understanding pathogenesis is to provide specific nontoxic therapy for those patients who have a definable form of FSGS. While this goal is not yet in sight, many types of intervention, not addressed in the current chapter, can influence the course of various diseases presenting as FSGS. Until specific therapy can be fashioned, it is necessary for the clinician caring for these patients to appreciate the complex interaction of pathogenetic factors involved in the development and pregression of FSGS, as a rationale for providing intervention to prevent development of the disease and to slow its course.