Renal Vein Thrombosis and Nephrotic Syndrome

To the Editor.— We must take exception to the statements by Luft et al (234:1158, 1975) accepting renal vein thrombosis as a "well-recognized cause of nephrotic syndrome" and as a cause of a pathologic picture similar to "membranous glomerulonephropathy." Although thrombosis is not uncommonly associated with nephrotic syndrome, this temporal relationship should not be interpreted as indicating a causal relationship. More than likely, this relationship indicates that factors intrinsic to the pathobiology of the nephrotic syndrome are associated with increased thrombotic phenomena. There is no evidence available to support the view that renal vein thrombosis has ever preceded the development of membranous glomerulopathy in any of the case reports cited to support the contention that renal vein thrombosis is a cause of the nephrotic syndrome.