The kidney and intravascular coagulation in myelomatosis

Glomerular capillary aneurysms in light-chain nephropathy. An ultrastructural proposal of pathogenesis

The occurrence of glomerular capillary aneurysms in light-chain nephropathy and a morphologic pattern of development as determined by electron microscopy are described. Renal biopsies from 4 patients with nodular glomerulopathy were evaluated. Light-chain deposition in mesangium and capillary walls was associated with monocyte accumulation in capillaries. Loss of endothelial cell lining and disruption of mesangial anchoring points of basement membranes ensued, resulting in aneurysmal dilatation of the capillaries. The walls collapsed, and the aneurysms healed as a result of mesangial interposition, a process which, in combination with enlarging nodules, led to thickening and collapse of the walls and narrowing of the lumens. This study, in conjunction with review of photographs from previously published reports, indicates that glomerular aneurysms are a common feature of nodular light-chain glomerulopathy. It also emphasizes additional light-microscopic similarities between this glomerulopathy and nodular diabetic glomerulosclerosis.

Multiple myeloma with renal failure. A case for intensive treatment

A series of nine consecutive patients with multiple myeloma and renal failure is presented. All patients were treated with urinary alkalinisation with sodium bicarbonate and/or acetazolamide, diuresis with saline, mannitol and/or furosemide, pulse melphalan and prednisone and, where indicated, allopurinol and aluminium hydroxide. A substantial and sustained improvement in renal function has been achieved in all nine patients. Of five patients with a urea more than 25 mmol/L at presentation, the median survival to date is 64 weeks. Of these patients only one has died --not from renal failure but pneumonia, eighteen months after presentation. The others are alive and well. The results confirm the effectiveness of these measures in both improving renal function and prolonging survival, and suggest a more optimistic prognosis for patients with multiple myeloma and renal failure.

Cancer and the kidney: complications of neoplasms

Various renal complications occur during the course of neoplastic disease. The therapeutic and prognostic implications differ according to the reversibility of both the underlying malignancy and the superimposed complications in the kidney. Since the mechanisms of renal failure vary significantly in patients with different types of malignancy, it is essential to avoid generalizations about etiologic factors or likely outcomes of the disease processes. The pathophysiologic abnormalities should be determined in each patient, and the reversibility of both the neoplastic and problems assessed before therapeutic decisions are made. This often requires a team effort by the internist, oncologist, nephrologist, urologist and, most importantly, the patient.

Kappa light chain glomerulosclerosis in multiple myeloma

Kappa light chains were demonstrated by immunofluorescence microscopy in the renal basement membranes of 6 of 10 patients with multiple myeloma subjected to kidney biopsy. Nodular glomerulosclerosis was present in 2 of these patients, but the remainder showed only minor light microscopic abnormalities. Deposition of kappa light chains in renal basement membranes may be a frequent cause of kidney disease in multiple myeloma. This deposition may be detected with electron microscopy by the demonstration of granular dense transformation of basement membranes. Occasionally there is systemic vascular deposition of kappa light chains which may be difficult to distinguish from amyloid but lacks a fibrillar character. The tissue effects of light chains in multiple myeloma seem likely to be more extensive than their deposition in renal tubules. There appears to be a greater tendency for kappa light chains to accumulate in renal and systemic basement membranes, but the mechanisms governing this deposition are unknown.