Recent Research on Rapidly Progressive Glomerulonephritis 2006.6.28

Recent Research on Rapidly Progressive Glomerulonephritis 2006.6.28

The positive test for anti-glomerular basement membrane (GBM) antibodies is an important diagnostic tool for rapidly progressive glomerulonephritis (RPGN); at the same time, neutrophil cytoplasmic antibody positivity can also be detected in these patients, who are then referred to as ANCA-positive, or double-antibody-positive. Some people classify double-antibody-positive cases as RPGN type IV. GBM-related diseases generally include: ① RPGN type I; ② Goodpasture syndrome; ③ ANCA-positive. According to statistics from Beijing Medical University over the past six years, among 41 cases of GBM antibody-related diseases, 9 were double-antibody-positive (ANCA-positive).

Among these three related kidney diseases, RPGN is pathologically classified as crescentic nephritis, with IgG and C3 deposition on the GBM and positive anti-GBM antibodies. Goodpasture’s disease is crescentic nephritis combined with pulmonary hemorrhage and positive anti-GBM antibodies. ANCA-positive cases are classified as type III.

Where exactly is the antigenic determinant of anti-glomerular basement membrane (GBM) antibodies located? By using three indicators—monoclonal antibodies M3 and M5, and enzyme-labeled affinity chromatography to purify autoantibodies—as probes to identify the antigenic determinant on the GBM, it was determined that the main antigenic determinant lies in the non-collagenous region of type IV collagen α3.

What is rapidly progressive nephritis? It refers to acute nephritis that develops into renal failure within weeks or months. The prognosis is very poor, also known as “crescentic nephritis” or “extracapillary nephritis.” It can be primary or secondary. The cause of primary cases remains unknown, while secondary cases can be seen in lupus, allergic purpura, infectious endocarditis, etc.