THE NUTCRACKER PHENOMENON IN COMBINATION WITH IGA NEPHROPATHY

The ''nutcracker'' phenomenon results from compression of the left ren al vein between the superior mesenteric artery and the aorta. The main features of this phenomenon are non-glomerular haematuria on urinalys is and stenosis of the left renal vein with dilatation of the vein dis tal to the stenosis. The characteristics of two patients with the ''nu tcracker'' phenomenon complicated by immunoglobulin A nephropathy were compared with those of 10 patients showing only the ''nutcracker'' ph enomenon. Patients with the ''nutcracker'' phenomenon complicated by i mmunoglobulin A nephropathy showed aggravation of haematuria after upp er respiratory infections, urinary red cell morphology indicating haem aturia of glomerular origin, elevation of serum IgA, persistence of pr oteinuria, and granular casts in the urine. The coexistence of immunog lobulin A nephropathy was suspected when these characteristics were ob served in patients with the ''nutcracker'' phenomenon. In such cases, a renal biopsy is needed for a final diagnosis.