An assessment of the clinical usefulness of plasma ribonuclease assays.

The usefulness of plasma ribonuclease assays was studied in (i) patients with possible protein deficiency, (ii) patients with myelomatosis, (iii) patients with carcinoma of the breast. In each group, the major factor associated with elevation of plasma ribonuclease was impairment of renal function. The assay was therefore of little value in the assessment of patients with myelomatosis or carcinoma of the breast. However, in the patients with possible protein deficiency and normal renal function, an elevation of plasma ribonuclease is, in general, associated with a decrease in serum albumin, transferrin and cholinesterase. Plasma ribonuclease may therefore be a useful parameter in the assessment of protein nutritional status.