The delayed appearance of an antinuclear factor and the diagnosis of systemic lupus erythematosus in glomerulonephritis.

In 11 patients who presented with apparently idiopathic glomerular disease the antinuclear factor (ANF) was absent initially but was eventually detected during observation extending over 6 years. In 4 patients a diagnosis of systemic lupus erythematosus (SLE) has now been made and the disease treated. Of the remaining 7, 2 had conditions known to be associated with a positive ANF, and in 4, drug therapy induced the ANF. Clinical features, complement studies and measurement of anti-DNA antibody were of value in distinguishing those patients with SLE from the others.     

Tubular function in multiple myeloma

In 42 myeloma patients our results confirm the association of light chain proteinuria and renal damage, but suggest that while the amount of light chain excreted is an important factor, only some light chains are nephrotoxic. The excretion of the proximal tubular cell lysosomal enzyme N acetyl B D glucosaminidase was a sensitive index of tubular injury, while the presence of low molecular weight proteinuria (Retinol Binding Protein and Lysozyme) was shown to indicate tubular dysfunction in a kidney sufficiently damaged to produce an impaired GFR. Isolated defects of distal tubular function (acid load response and concentrating ability) were rare. Such changes were seen mainly as part of global renal impairment and were usually associated with such specific pathophysiological conditions as plasma hyperviscosity or tubular crystal deposition. Hypercalcemia had a specific effect on the concentrating ability independent of any impairment of renal acidification.     

Prognostic indicators in patients presenting with the nephrotic syndrome

Clinical data from 246 patients presenting with a nephrotic syndrome and biopsy-proven glomerular disorder were analyzed, using statistical survival techniques, to determine which of several variables (sex, age, plasma creatinine, diastolic blood pressure and 24-hour urinary protein loss) were associated with subsequent end-stage renal failure. The best prediction of outcome could be made at one year (N = 121); then plasma creatinine (P less than 0.001) and heavy proteinuria (P = 0.049) were the best determinants. For a given plasma creatinine level, heavy urinary protein was associated with a worse outcome. The incidence of end-stage renal failure was greatest three to four years from the date edema first developed. Plasma creatinine and urinary protein values, collected four-monthly throughout the study period, were analyzed as time-dependent covariates. A relationship was found between the prevailing risk of renal failure and earlier heavy proteinuria (P less than 0.001). Spontaneous complete remission of proteinuria was associated with a highly favorable outcome (P = 0.001) and normal, or impaired but stable, renal function.