Circulating immune complexes following food: delayed clearance in idiopathic glomerulonephritis.

Following a meal containing a variety of animal and vegetable proteins circulating immune complexes (CIC) have been found in sera from eight normal subjects. Levels of CIC rose to significantly higher levels in ten patients with idiopathic immune complex glomerulonephritis and return to fasting levels was significantly delayed. The type of CIC detected bore no relation to those in renal biopsy material. The CIC which accumulated in GN were small (MW similar to or approximately 350,000), and plasma exchange did not influence the extent or duration of CIC rise following the meal. An immunological defect manifested by impaired clearance of frequently encountered antigens may exist in subjects who develop GN. The CIC detected in the serum of these patients may be markers of this state and cannot be assumed to be the pathogenic agents in the disease.