Anti-glomerular basement membrane (anti-GBM)

A test for the differential diagnosis of rapidly progressive glomerulonephritis and pulmonary bleeding

Antibodies to the glomerular basement membrane are directed against type IV collagen. Type IV collagen can be found in the kidneys, lungs, lens, brain, and testicle. In addition, type IV collagen is the main component of the basement membranes of the alveoli and glomerulus of the kidney. Antibodies to the type IV collagen site react with the basement membranes of the alveoli and renal glomeruli, which causes a specific clinical picture of Goodpasture syndrome, combining glomerulonephritis and hemorrhagic alveolitis. Kidney damage usually prevails in the clinical picture, which allows us to characterize the limited form of Goodpasture syndrome, manifested by the development of rapidly progressive glomerulonephritis without lung damage.

Antibodies to the basement membrane are directly involved in the pathogenesis of kidney damage in this disease. In an experiment, their management of a laboratory animal leads to the development of extracapillary glomerulonephritis. The content of antibodies in serum correlates with the clinical activity of this disease, and deposits of immunoglobulins along the glomerular basement membrane can be detected by examining a kidney biopsy.

High titers of antibodies to the basement membrane may persist at the stage of clinical remission and gradually decrease after a few months. Kidney transplantation can be recommended only in seronegative patients, since while maintaining significant titers of antibodies to the basement membrane, there is a high risk of recurrence of the disease in the transplant. Early examination of patients with Goodpasture syndrome is extremely important for the prognosis of patients with this disease, as only the prescription of specific therapy will preserve renal function, and often, prevent the death of the patient.

In patients with rapidly progressive glomerulonephritis or unexplained acute kidney failure, it is advisable to prescribe a test to detect antibodies to the glomerular basement membrane in conjunction with the detection of antineutrophil cytoplasmic antibodies (ANCA), antibodies to proteinase 3, and antibodies to myeloperoxidase.