Antiglobulins and glomerulonephritis. Classification of patients by the reactivity of their sera and renal tissue with aggregated and native human IgG.

Renal biopsies and sera from 41 consecutive patients were studied to determine if antiglobulins were found more frequently in patients with severely diseased glomeruli. Patients were classified into three groups: A, 12 patients with normal renal function and minimal histological evidence of glomerular disease; B, 18 patients with normal renal function but distinctly abnormal biopsies (16 cases) or proteinuria greater than 16 g/24 h (2 cases); and C, 11 patients with both decreased function and abnormal histology. Positive latex fixation tests for rheumatoid factor were found in none of group A, four (22%) of group B, and five (45%) of group C patients. Sera heated 56 degrees C for 30 min contained precipitins reactive with heat-aggregated IgG in none of seven group A, five of ten (50%) group B, and four of ten (40%) group C patients. The quantity of 135I-labeled patient globulin which bound to immunoadsorbents coated with Cohn fraction II in competition with an equal quantity of 131I-labeled globulin from pooled plasma of normal donors was also measured. Patient globulins bound in significantly greater quantity (greater than or equal 2 SD) than the control in none of the group A, 7 of 18 (39%) group B, and 7 of 11 (64%) group C patients. Renal biopsies from 18 patients were also studied for the ability to fix fluorescein-conjugated heat-aggregated and native human IgG. None of nine tissue specimens from group A or B patients fixed either fluorescein-conjugated protein whereas tissue from eight of nine group C patients showed glomerular localization of one or both reagents. Severity of disease as judged by renal function and glomerular histology correlated with the presence of tissue-fixed and serum antiglobulins. Thus, detection of antiglobulins in glomeruli and sera of patients with glomerulonephritis may indicate a relatively poor prognosis and raises the possibility that antiglobulins may be implicated in some way in the pathophysiology of human glomerulonephritis.